From 7f70abd4ba35c36ce71021c1cc3d82c4ff566c3c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Felix=20Bu=CC=88nemann?= <buenemann@louis.info>
Date: Fri, 22 Apr 2016 19:45:53 +0200
Subject: [PATCH 01/34] Use advanced WebP Encoding API

This switch is required to enable encoder configuration.
---
 libvips/foreign/vips2webp.c | 184 +++++++++++++++++++-----------------
 1 file changed, 95 insertions(+), 89 deletions(-)

diff --git a/libvips/foreign/vips2webp.c b/libvips/foreign/vips2webp.c
index 52108cc8..b5b91a16 100644
--- a/libvips/foreign/vips2webp.c
+++ b/libvips/foreign/vips2webp.c
@@ -53,77 +53,102 @@
 
 #include "webp.h"
 
-typedef size_t (*webp_encoder)( const uint8_t *rgb, 
-	int width, int height, int stride, 
-	float quality_factor, uint8_t **output );
+typedef int (*webp_import)( WebPPicture *picture,
+	const uint8_t *rgb, int stride );
 
-typedef size_t (*webp_encoder_lossless)( const uint8_t *rgb, 
-	int width, int height, int stride, uint8_t **output );
+static int
+write_webp( WebPPicture *pic, VipsImage *in,
+	int Q, gboolean lossless )
+{
+	VipsImage *memory;
+	WebPConfig config;
+	webp_import import;
+
+	if ( !WebPConfigPreset(&config, WEBP_PRESET_DEFAULT, Q) ) {
+		vips_error( "vips2webp",
+			"%s", _( "config version error" ) );
+		return( -1 );
+	}
+
+	config.lossless = lossless;
+
+	if( !WebPValidateConfig(&config) ) {
+		vips_error( "vips2webp",
+			"%s", _( "invalid configuration" ) );
+		return( -1 );
+	}
+
+	if( !(memory = vips_image_copy_memory( in )) )
+		return( -1 );
+
+	pic->use_argb = lossless;
+	pic->width = memory->Xsize;
+	pic->height = memory->Ysize;
+
+	if( in->Bands == 4 )
+		import = WebPPictureImportRGBA;
+	else
+		import = WebPPictureImportRGB;
+
+	if( !import( pic, VIPS_IMAGE_ADDR( memory, 0, 0 ),
+		VIPS_IMAGE_SIZEOF_LINE( memory ) ) ) {
+		VIPS_UNREF( memory );
+		vips_error( "vips2webp",
+			"%s", _( "picture memory error" ) );
+		return( -1 );
+	}
+
+	if( !WebPEncode( &config, pic ) ) {
+		VIPS_UNREF( memory );
+		vips_error( "vips2webp",
+			"%s", _( "unable to encode" ) );
+		return( -1 );
+	}
+
+	VIPS_UNREF( memory );
+
+	return( 0 );
+}
 
 int
 vips__webp_write_file( VipsImage *in, const char *filename, 
 	int Q, gboolean lossless )
 {
-	VipsImage *memory;
-	size_t len;
-	uint8_t *buffer;
+	WebPPicture pic;
+	WebPMemoryWriter writer;
 	FILE *fp;
 
-	if( !(memory = vips_image_copy_memory( in )) )
+	if( !WebPPictureInit( &pic ) ) {
+		vips_error( "vips2webp",
+			"%s", _( "picture version error" ) );
 		return( -1 );
-
-	if( lossless ) {
-		webp_encoder_lossless encoder;
-
-		if( in->Bands == 4 )
-			encoder = WebPEncodeLosslessRGBA;
-		else
-			encoder = WebPEncodeLosslessRGB;
-
-		if( !(len = encoder( VIPS_IMAGE_ADDR( memory, 0, 0 ), 
-			memory->Xsize, memory->Ysize, 
-			VIPS_IMAGE_SIZEOF_LINE( memory ),
-			&buffer )) ) {
-			VIPS_UNREF( memory ); 
-			vips_error( "vips2webp", 
-				"%s", _( "unable to encode" ) ); 
-			return( -1 );
-		}
-	}
-	else {
-		webp_encoder encoder;
-
-		if( in->Bands == 4 )
-			encoder = WebPEncodeRGBA;
-		else
-			encoder = WebPEncodeRGB;
-
-		if( !(len = encoder( VIPS_IMAGE_ADDR( memory, 0, 0 ), 
-			memory->Xsize, memory->Ysize, 
-			VIPS_IMAGE_SIZEOF_LINE( memory ),
-			Q, &buffer )) ) {
-			VIPS_UNREF( memory ); 
-			vips_error( "vips2webp", 
-				"%s", _( "unable to encode" ) ); 
-			return( -1 );
-		}
 	}
 
-	VIPS_UNREF( memory ); 
+	WebPMemoryWriterInit( &writer );
+	pic.writer = WebPMemoryWrite;
+	pic.custom_ptr = &writer;
+
+	if( write_webp( &pic, in, Q, lossless ) ) {
+		WebPPictureFree( &pic );
+		WebPMemoryWriterClear( &writer );
+		return -1;
+	}
+
+	WebPPictureFree( &pic );
 
 	if( !(fp = vips__file_open_write( filename, FALSE )) ) {
-		free( buffer );
+		WebPMemoryWriterClear( &writer );
 		return( -1 );
 	}
 
-	if( vips__file_write( buffer, len, 1, fp ) ) {
+	if( vips__file_write( writer.mem, writer.size, 1, fp ) ) {
 		fclose( fp );
-		free( buffer );
+		WebPMemoryWriterClear( &writer );
 		return( -1 );
 	}
 
 	fclose( fp );
-	free( buffer );
+	WebPMemoryWriterClear( &writer );
 
 	return( 0 );
 }
@@ -132,49 +157,30 @@ int
 vips__webp_write_buffer( VipsImage *in, void **obuf, size_t *olen, 
 	int Q, gboolean lossless )
 {
-	VipsImage *memory;
+	WebPPicture pic;
+	WebPMemoryWriter writer;
+	FILE *fp;
 
-	if( !(memory = vips_image_copy_memory( in )) )
+	if( !WebPPictureInit( &pic ) ) {
+		vips_error( "vips2webp", 
+			"%s", _( "picture version error" ) );
 		return( -1 );
-
-	if( lossless ) {
-		webp_encoder_lossless encoder;
-
-		if( in->Bands == 4 )
-			encoder = WebPEncodeLosslessRGBA;
-		else
-			encoder = WebPEncodeLosslessRGB;
-
-		if( !(*olen = encoder( VIPS_IMAGE_ADDR( memory, 0, 0 ), 
-			memory->Xsize, memory->Ysize, 
-			VIPS_IMAGE_SIZEOF_LINE( memory ),
-			(uint8_t **) obuf )) ) {
-			VIPS_UNREF( memory ); 
-			vips_error( "vips2webp", 
-				"%s", _( "unable to encode" ) ); 
-			return( -1 );
-		}
-	}
-	else {
-		webp_encoder encoder;
-
-		if( in->Bands == 4 )
-			encoder = WebPEncodeRGBA;
-		else
-			encoder = WebPEncodeRGB;
-
-		if( !(*olen = encoder( VIPS_IMAGE_ADDR( memory, 0, 0 ), 
-			memory->Xsize, memory->Ysize, 
-			VIPS_IMAGE_SIZEOF_LINE( memory ),
-			Q, (uint8_t **) obuf )) ) {
-			VIPS_UNREF( memory ); 
-			vips_error( "vips2webp", 
-				"%s", _( "unable to encode" ) ); 
-			return( -1 );
-		}
 	}
 
-	VIPS_UNREF( memory );
+	WebPMemoryWriterInit( &writer );
+	pic.writer = WebPMemoryWrite;
+	pic.custom_ptr = &writer;
+
+	if( write_webp( &pic, in, Q, lossless ) ) {
+		WebPPictureFree( &pic );
+		WebPMemoryWriterClear( &writer );
+		return -1;
+	}
+
+	WebPPictureFree( &pic );
+
+	*obuf = writer.mem;
+	*olen = writer.size;
 
 	return( 0 );
 }

From f834ea39f6e9f35cf051352beba824529953c2ff Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Felix=20Bu=CC=88nemann?= <buenemann@louis.info>
Date: Fri, 22 Apr 2016 19:54:19 +0200
Subject: [PATCH 02/34] Add lossy compression "preset" option to webpsave

This allows to tune the lossy webp encoder for certain types of images.
---
 libvips/foreign/foreign.c        |  4 ++++
 libvips/foreign/vips2webp.c      | 38 +++++++++++++++++++++++++++-----
 libvips/foreign/webp.h           |  4 ++--
 libvips/foreign/webpsave.c       | 18 ++++++++++++---
 libvips/include/vips/enumtypes.h |  2 ++
 libvips/include/vips/foreign.h   | 23 +++++++++++++++++++
 libvips/iofuncs/enumtypes.c      | 22 ++++++++++++++++++
 7 files changed, 100 insertions(+), 11 deletions(-)

diff --git a/libvips/foreign/foreign.c b/libvips/foreign/foreign.c
index dd60b94b..a304ce08 100644
--- a/libvips/foreign/foreign.c
+++ b/libvips/foreign/foreign.c
@@ -2458,6 +2458,8 @@ vips_webpload_buffer( void *buf, size_t len, VipsImage **out, ... )
  * Optional arguments:
  *
  * @Q: quality factor
+ * @lossless: enables lossless compression
+ * @preset: #VipsForeignWebpPreset choose lossy compression preset
  *
  * See also: vips_webpload(), vips_image_write_to_file().
  *
@@ -2486,6 +2488,8 @@ vips_webpsave( VipsImage *in, const char *filename, ... )
  * Optional arguments:
  *
  * @Q: JPEG quality factor
+ * @lossless: enables lossless compression
+ * @preset: #VipsForeignWebpPreset choose lossy compression preset
  *
  * See also: vips_webpsave().
  *
diff --git a/libvips/foreign/vips2webp.c b/libvips/foreign/vips2webp.c
index b5b91a16..6c7cab42 100644
--- a/libvips/foreign/vips2webp.c
+++ b/libvips/foreign/vips2webp.c
@@ -56,15 +56,41 @@
 typedef int (*webp_import)( WebPPicture *picture,
 	const uint8_t *rgb, int stride );
 
+static WebPPreset
+get_preset( VipsForeignWebpPreset preset )
+{
+	switch( preset ) {
+	case VIPS_FOREIGN_WEBP_PRESET_DEFAULT:
+		return( WEBP_PRESET_DEFAULT );
+	case VIPS_FOREIGN_WEBP_PRESET_PICTURE:
+		return( WEBP_PRESET_PICTURE );
+	case VIPS_FOREIGN_WEBP_PRESET_PHOTO:
+		return( WEBP_PRESET_PHOTO );
+	case VIPS_FOREIGN_WEBP_PRESET_DRAWING:
+		return( WEBP_PRESET_DRAWING );
+	case VIPS_FOREIGN_WEBP_PRESET_ICON:
+		return( WEBP_PRESET_ICON );
+	case VIPS_FOREIGN_WEBP_PRESET_TEXT:
+		return( WEBP_PRESET_TEXT );
+
+	default:
+		g_assert_not_reached();
+	}
+
+	/* Keep -Wall happy.
+	 */
+	return( -1 );
+}
+
 static int
 write_webp( WebPPicture *pic, VipsImage *in,
-	int Q, gboolean lossless )
+	int Q, gboolean lossless, VipsForeignWebpPreset preset )
 {
 	VipsImage *memory;
 	WebPConfig config;
 	webp_import import;
 
-	if ( !WebPConfigPreset(&config, WEBP_PRESET_DEFAULT, Q) ) {
+	if ( !WebPConfigPreset(&config, get_preset( preset ), Q) ) {
 		vips_error( "vips2webp",
 			"%s", _( "config version error" ) );
 		return( -1 );
@@ -112,7 +138,7 @@ write_webp( WebPPicture *pic, VipsImage *in,
 
 int
 vips__webp_write_file( VipsImage *in, const char *filename, 
-	int Q, gboolean lossless )
+	int Q, gboolean lossless, VipsForeignWebpPreset preset )
 {
 	WebPPicture pic;
 	WebPMemoryWriter writer;
@@ -128,7 +154,7 @@ vips__webp_write_file( VipsImage *in, const char *filename,
 	pic.writer = WebPMemoryWrite;
 	pic.custom_ptr = &writer;
 
-	if( write_webp( &pic, in, Q, lossless ) ) {
+	if( write_webp( &pic, in, Q, lossless, preset ) ) {
 		WebPPictureFree( &pic );
 		WebPMemoryWriterClear( &writer );
 		return -1;
@@ -155,7 +181,7 @@ vips__webp_write_file( VipsImage *in, const char *filename,
 
 int
 vips__webp_write_buffer( VipsImage *in, void **obuf, size_t *olen, 
-	int Q, gboolean lossless )
+	int Q, gboolean lossless, VipsForeignWebpPreset preset )
 {
 	WebPPicture pic;
 	WebPMemoryWriter writer;
@@ -171,7 +197,7 @@ vips__webp_write_buffer( VipsImage *in, void **obuf, size_t *olen,
 	pic.writer = WebPMemoryWrite;
 	pic.custom_ptr = &writer;
 
-	if( write_webp( &pic, in, Q, lossless ) ) {
+	if( write_webp( &pic, in, Q, lossless, preset ) ) {
 		WebPPictureFree( &pic );
 		WebPMemoryWriterClear( &writer );
 		return -1;
diff --git a/libvips/foreign/webp.h b/libvips/foreign/webp.h
index 83e8653b..e1698239 100644
--- a/libvips/foreign/webp.h
+++ b/libvips/foreign/webp.h
@@ -49,9 +49,9 @@ int vips__webp_read_buffer( const void *buf, size_t len,
 	VipsImage *out, int shrink ); 
 
 int vips__webp_write_file( VipsImage *out, const char *filename, 
-	int Q, gboolean lossless );
+	int Q, gboolean lossless, VipsForeignWebpPreset preset );
 int vips__webp_write_buffer( VipsImage *out, void **buf, size_t *len, 
-	int Q, gboolean lossless );
+	int Q, gboolean lossless, VipsForeignWebpPreset preset );
 
 #ifdef __cplusplus
 }
diff --git a/libvips/foreign/webpsave.c b/libvips/foreign/webpsave.c
index b507785a..2b411d21 100644
--- a/libvips/foreign/webpsave.c
+++ b/libvips/foreign/webpsave.c
@@ -60,6 +60,10 @@ typedef struct _VipsForeignSaveWebp {
 	 */
 	gboolean lossless;
 
+	/* Lossy compression preset.
+	 */
+	VipsForeignWebpPreset preset;
+
 } VipsForeignSaveWebp;
 
 typedef VipsForeignSaveClass VipsForeignSaveWebpClass;
@@ -109,6 +113,14 @@ vips_foreign_save_webp_class_init( VipsForeignSaveWebpClass *class )
 		G_STRUCT_OFFSET( VipsForeignSaveWebp, lossless ),
 		FALSE ); 
 
+	VIPS_ARG_ENUM( class, "preset", 12,
+		_( "preset" ),
+		_( "Preset for lossy compression" ),
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsForeignSaveWebp, preset ),
+		VIPS_TYPE_FOREIGN_WEBP_PRESET,
+		VIPS_FOREIGN_WEBP_PRESET_DEFAULT );
+
 }
 
 static void
@@ -143,7 +155,7 @@ vips_foreign_save_webp_file_build( VipsObject *object )
 		return( -1 );
 
 	if( vips__webp_write_file( save->ready, file->filename, 
-		webp->Q, webp->lossless ) )
+		webp->Q, webp->lossless, webp->preset ) )
 		return( -1 );
 
 	return( 0 );
@@ -205,7 +217,7 @@ vips_foreign_save_webp_buffer_build( VipsObject *object )
 		return( -1 );
 
 	if( vips__webp_write_buffer( save->ready, &obuf, &olen, 
-		webp->Q, webp->lossless ) )
+		webp->Q, webp->lossless, webp->preset ) )
 		return( -1 );
 
 	blob = vips_blob_new( (VipsCallbackFn) vips_free, obuf, olen );
@@ -266,7 +278,7 @@ vips_foreign_save_webp_mime_build( VipsObject *object )
 		return( -1 );
 
 	if( vips__webp_write_buffer( save->ready, &obuf, &olen, 
-		webp->Q, webp->lossless ) )
+		webp->Q, webp->lossless, webp->preset ) )
 		return( -1 );
 
 	printf( "Content-length: %zu\r\n", olen );
diff --git a/libvips/include/vips/enumtypes.h b/libvips/include/vips/enumtypes.h
index 8fdc127a..f1b132fc 100644
--- a/libvips/include/vips/enumtypes.h
+++ b/libvips/include/vips/enumtypes.h
@@ -14,6 +14,8 @@ GType vips_foreign_flags_get_type (void) G_GNUC_CONST;
 #define VIPS_TYPE_FOREIGN_FLAGS (vips_foreign_flags_get_type())
 GType vips_saveable_get_type (void) G_GNUC_CONST;
 #define VIPS_TYPE_SAVEABLE (vips_saveable_get_type())
+GType vips_foreign_webp_preset_get_type (void) G_GNUC_CONST;
+#define VIPS_TYPE_FOREIGN_WEBP_PRESET (vips_foreign_webp_preset_get_type())
 GType vips_foreign_tiff_compression_get_type (void) G_GNUC_CONST;
 #define VIPS_TYPE_FOREIGN_TIFF_COMPRESSION (vips_foreign_tiff_compression_get_type())
 GType vips_foreign_tiff_predictor_get_type (void) G_GNUC_CONST;
diff --git a/libvips/include/vips/foreign.h b/libvips/include/vips/foreign.h
index 36328f43..a3a9af8e 100644
--- a/libvips/include/vips/foreign.h
+++ b/libvips/include/vips/foreign.h
@@ -338,6 +338,29 @@ int vips_jpegsave_buffer( VipsImage *in, void **buf, size_t *len, ... )
 int vips_jpegsave_mime( VipsImage *in, ... )
 	__attribute__((sentinel));
 
+/**
+ * VipsForeignWebpPreset:
+ * @VIPS_FOREIGN_WEBP_PRESET_DEFAULT: default preset
+ * @VIPS_FOREIGN_WEBP_PRESET_PICTURE: digital picture, like portrait,
+ * inner shot
+ * @VIPS_FOREIGN_WEBP_PRESET_PHOTO: outdoor photograph, with natural lighting
+ * @VIPS_FOREIGN_WEBP_PRESET_DRAWING: hand or line drawing, with high-contrast
+ * details
+ * @VIPS_FOREIGN_WEBP_PRESET_ICON: small-sized colorful images
+ * @VIPS_FOREIGN_WEBP_PRESET_TEXT: text-like
+ *
+ * Tune lossy encoder settings for different image types.
+ */
+typedef enum {
+	VIPS_FOREIGN_WEBP_PRESET_DEFAULT,
+	VIPS_FOREIGN_WEBP_PRESET_PICTURE,
+	VIPS_FOREIGN_WEBP_PRESET_PHOTO,
+	VIPS_FOREIGN_WEBP_PRESET_DRAWING,
+	VIPS_FOREIGN_WEBP_PRESET_ICON,
+	VIPS_FOREIGN_WEBP_PRESET_TEXT,
+	VIPS_FOREIGN_WEBP_PRESET_LAST
+} VipsForeignWebpPreset;
+
 int vips_webpload( const char *filename, VipsImage **out, ... )
 	__attribute__((sentinel));
 int vips_webpload_buffer( void *buf, size_t len, VipsImage **out, ... )
diff --git a/libvips/iofuncs/enumtypes.c b/libvips/iofuncs/enumtypes.c
index 4fb8062f..93f4564e 100644
--- a/libvips/iofuncs/enumtypes.c
+++ b/libvips/iofuncs/enumtypes.c
@@ -70,6 +70,28 @@ vips_saveable_get_type( void )
 	return( etype );
 }
 GType
+vips_foreign_webp_preset_get_type( void )
+{
+	static GType etype = 0;
+
+	if( etype == 0 ) {
+		static const GEnumValue values[] = {
+			{VIPS_FOREIGN_WEBP_PRESET_DEFAULT, "VIPS_FOREIGN_WEBP_PRESET_DEFAULT", "default"},
+			{VIPS_FOREIGN_WEBP_PRESET_PICTURE, "VIPS_FOREIGN_WEBP_PRESET_PICTURE", "picture"},
+			{VIPS_FOREIGN_WEBP_PRESET_PHOTO, "VIPS_FOREIGN_WEBP_PRESET_PHOTO", "photo"},
+			{VIPS_FOREIGN_WEBP_PRESET_DRAWING, "VIPS_FOREIGN_WEBP_PRESET_DRAWING", "drawing"},
+			{VIPS_FOREIGN_WEBP_PRESET_ICON, "VIPS_FOREIGN_WEBP_PRESET_ICON", "icon"},
+			{VIPS_FOREIGN_WEBP_PRESET_TEXT, "VIPS_FOREIGN_WEBP_PRESET_TEXT", "text"},
+			{VIPS_FOREIGN_WEBP_PRESET_LAST, "VIPS_FOREIGN_WEBP_PRESET_LAST", "last"},
+			{0, NULL, NULL}
+		};
+		
+		etype = g_enum_register_static( "VipsForeignWebpPreset", values );
+	}
+
+	return( etype );
+}
+GType
 vips_foreign_tiff_compression_get_type( void )
 {
 	static GType etype = 0;

From 58a2616f77e69870f2f2969c97bc1e2cb9886187 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Felix=20Bu=CC=88nemann?= <buenemann@louis.info>
Date: Sat, 23 Apr 2016 01:20:41 +0200
Subject: [PATCH 03/34] New webpsave option smart_subsample

This enables a high quality RGB to YUV converter in libwebp which
greatly improves the quality of fine details by reducing color bleeding
caused by the 4:2:0 chroma subsampling. This is slower and causes
slightly larger files. See WebPPictureSmartARGBToYUVA in libwebp.
---
 libvips/foreign/foreign.c   |  2 ++
 libvips/foreign/vips2webp.c | 20 ++++++++++++++------
 libvips/foreign/webp.h      |  6 ++++--
 libvips/foreign/webpsave.c  | 20 +++++++++++++++++---
 4 files changed, 37 insertions(+), 11 deletions(-)

diff --git a/libvips/foreign/foreign.c b/libvips/foreign/foreign.c
index a304ce08..c97c2d10 100644
--- a/libvips/foreign/foreign.c
+++ b/libvips/foreign/foreign.c
@@ -2460,6 +2460,7 @@ vips_webpload_buffer( void *buf, size_t len, VipsImage **out, ... )
  * @Q: quality factor
  * @lossless: enables lossless compression
  * @preset: #VipsForeignWebpPreset choose lossy compression preset
+ * @smart_subsample: enables high quality chroma subsampling
  *
  * See also: vips_webpload(), vips_image_write_to_file().
  *
@@ -2490,6 +2491,7 @@ vips_webpsave( VipsImage *in, const char *filename, ... )
  * @Q: JPEG quality factor
  * @lossless: enables lossless compression
  * @preset: #VipsForeignWebpPreset choose lossy compression preset
+ * @smart_subsample: enables high quality chroma subsampling
  *
  * See also: vips_webpsave().
  *
diff --git a/libvips/foreign/vips2webp.c b/libvips/foreign/vips2webp.c
index 6c7cab42..c0505f67 100644
--- a/libvips/foreign/vips2webp.c
+++ b/libvips/foreign/vips2webp.c
@@ -84,7 +84,8 @@ get_preset( VipsForeignWebpPreset preset )
 
 static int
 write_webp( WebPPicture *pic, VipsImage *in,
-	int Q, gboolean lossless, VipsForeignWebpPreset preset )
+	int Q, gboolean lossless, VipsForeignWebpPreset preset,
+	gboolean smart_subsample )
 {
 	VipsImage *memory;
 	WebPConfig config;
@@ -97,6 +98,8 @@ write_webp( WebPPicture *pic, VipsImage *in,
 	}
 
 	config.lossless = lossless;
+	if( smart_subsample )
+		config.preprocessing |= 4;
 
 	if( !WebPValidateConfig(&config) ) {
 		vips_error( "vips2webp",
@@ -107,7 +110,10 @@ write_webp( WebPPicture *pic, VipsImage *in,
 	if( !(memory = vips_image_copy_memory( in )) )
 		return( -1 );
 
-	pic->use_argb = lossless;
+	/* Smart subsampling requires use_argb because
+	 * it is applied during RGB to YUV conversion.
+	 */
+	pic->use_argb = lossless || smart_subsample;
 	pic->width = memory->Xsize;
 	pic->height = memory->Ysize;
 
@@ -138,7 +144,8 @@ write_webp( WebPPicture *pic, VipsImage *in,
 
 int
 vips__webp_write_file( VipsImage *in, const char *filename, 
-	int Q, gboolean lossless, VipsForeignWebpPreset preset )
+	int Q, gboolean lossless, VipsForeignWebpPreset preset,
+	gboolean smart_subsample )
 {
 	WebPPicture pic;
 	WebPMemoryWriter writer;
@@ -154,7 +161,7 @@ vips__webp_write_file( VipsImage *in, const char *filename,
 	pic.writer = WebPMemoryWrite;
 	pic.custom_ptr = &writer;
 
-	if( write_webp( &pic, in, Q, lossless, preset ) ) {
+	if( write_webp( &pic, in, Q, lossless, preset, smart_subsample ) ) {
 		WebPPictureFree( &pic );
 		WebPMemoryWriterClear( &writer );
 		return -1;
@@ -181,7 +188,8 @@ vips__webp_write_file( VipsImage *in, const char *filename,
 
 int
 vips__webp_write_buffer( VipsImage *in, void **obuf, size_t *olen, 
-	int Q, gboolean lossless, VipsForeignWebpPreset preset )
+	int Q, gboolean lossless, VipsForeignWebpPreset preset,
+	gboolean smart_subsample )
 {
 	WebPPicture pic;
 	WebPMemoryWriter writer;
@@ -197,7 +205,7 @@ vips__webp_write_buffer( VipsImage *in, void **obuf, size_t *olen,
 	pic.writer = WebPMemoryWrite;
 	pic.custom_ptr = &writer;
 
-	if( write_webp( &pic, in, Q, lossless, preset ) ) {
+	if( write_webp( &pic, in, Q, lossless, preset, smart_subsample ) ) {
 		WebPPictureFree( &pic );
 		WebPMemoryWriterClear( &writer );
 		return -1;
diff --git a/libvips/foreign/webp.h b/libvips/foreign/webp.h
index e1698239..0d934198 100644
--- a/libvips/foreign/webp.h
+++ b/libvips/foreign/webp.h
@@ -49,9 +49,11 @@ int vips__webp_read_buffer( const void *buf, size_t len,
 	VipsImage *out, int shrink ); 
 
 int vips__webp_write_file( VipsImage *out, const char *filename, 
-	int Q, gboolean lossless, VipsForeignWebpPreset preset );
+	int Q, gboolean lossless, VipsForeignWebpPreset preset,
+	gboolean smart_subsample );
 int vips__webp_write_buffer( VipsImage *out, void **buf, size_t *len, 
-	int Q, gboolean lossless, VipsForeignWebpPreset preset );
+	int Q, gboolean lossless, VipsForeignWebpPreset preset,
+	gboolean smart_subsample );
 
 #ifdef __cplusplus
 }
diff --git a/libvips/foreign/webpsave.c b/libvips/foreign/webpsave.c
index 2b411d21..29e647c7 100644
--- a/libvips/foreign/webpsave.c
+++ b/libvips/foreign/webpsave.c
@@ -64,6 +64,10 @@ typedef struct _VipsForeignSaveWebp {
 	 */
 	VipsForeignWebpPreset preset;
 
+	/* Enable smart chroma subsampling.
+	 */
+	gboolean smart_subsample;
+
 } VipsForeignSaveWebp;
 
 typedef VipsForeignSaveClass VipsForeignSaveWebpClass;
@@ -121,6 +125,13 @@ vips_foreign_save_webp_class_init( VipsForeignSaveWebpClass *class )
 		VIPS_TYPE_FOREIGN_WEBP_PRESET,
 		VIPS_FOREIGN_WEBP_PRESET_DEFAULT );
 
+	VIPS_ARG_BOOL( class, "smart_subsample", 13,
+		_( "Smart subsampling" ),
+		_( "Enable high quality chroma subsampling" ),
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsForeignSaveWebp, smart_subsample ),
+		FALSE );
+
 }
 
 static void
@@ -155,7 +166,8 @@ vips_foreign_save_webp_file_build( VipsObject *object )
 		return( -1 );
 
 	if( vips__webp_write_file( save->ready, file->filename, 
-		webp->Q, webp->lossless, webp->preset ) )
+		webp->Q, webp->lossless, webp->preset,
+		webp->smart_subsample ) )
 		return( -1 );
 
 	return( 0 );
@@ -217,7 +229,8 @@ vips_foreign_save_webp_buffer_build( VipsObject *object )
 		return( -1 );
 
 	if( vips__webp_write_buffer( save->ready, &obuf, &olen, 
-		webp->Q, webp->lossless, webp->preset ) )
+		webp->Q, webp->lossless, webp->preset,
+		webp->smart_subsample ) )
 		return( -1 );
 
 	blob = vips_blob_new( (VipsCallbackFn) vips_free, obuf, olen );
@@ -278,7 +291,8 @@ vips_foreign_save_webp_mime_build( VipsObject *object )
 		return( -1 );
 
 	if( vips__webp_write_buffer( save->ready, &obuf, &olen, 
-		webp->Q, webp->lossless, webp->preset ) )
+		webp->Q, webp->lossless, webp->preset,
+		webp->smart_subsample ) )
 		return( -1 );
 
 	printf( "Content-length: %zu\r\n", olen );

From c107066c4e69cc26e1ade838a8185572567fe94f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Felix=20Bu=CC=88nemann?= <buenemann@louis.info>
Date: Sat, 23 Apr 2016 02:00:32 +0200
Subject: [PATCH 04/34] Add webpsave near_lossless support, fix Q range

The near_lossless option allows to enable preprocessing for the lossless
mode. This is a boolean instead of an int, because the amount of
preprocessing is controlled using the Q factor parameter which is
otherwise unused in lossless mode. This allows to re-use the quality
setting in existing tools.
---
 libvips/foreign/foreign.c   |  2 ++
 libvips/foreign/vips2webp.c | 18 +++++++++++-------
 libvips/foreign/webp.h      |  4 ++--
 libvips/foreign/webpsave.c  | 19 +++++++++++++++----
 4 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/libvips/foreign/foreign.c b/libvips/foreign/foreign.c
index c97c2d10..d6000680 100644
--- a/libvips/foreign/foreign.c
+++ b/libvips/foreign/foreign.c
@@ -2461,6 +2461,7 @@ vips_webpload_buffer( void *buf, size_t len, VipsImage **out, ... )
  * @lossless: enables lossless compression
  * @preset: #VipsForeignWebpPreset choose lossy compression preset
  * @smart_subsample: enables high quality chroma subsampling
+ * @near_lossless: use preprocessing in lossless mode (controlled by Q)
  *
  * See also: vips_webpload(), vips_image_write_to_file().
  *
@@ -2492,6 +2493,7 @@ vips_webpsave( VipsImage *in, const char *filename, ... )
  * @lossless: enables lossless compression
  * @preset: #VipsForeignWebpPreset choose lossy compression preset
  * @smart_subsample: enables high quality chroma subsampling
+ * @near_lossless: use preprocessing in lossless mode (controlled by Q)
  *
  * See also: vips_webpsave().
  *
diff --git a/libvips/foreign/vips2webp.c b/libvips/foreign/vips2webp.c
index c0505f67..e8661cdd 100644
--- a/libvips/foreign/vips2webp.c
+++ b/libvips/foreign/vips2webp.c
@@ -85,7 +85,7 @@ get_preset( VipsForeignWebpPreset preset )
 static int
 write_webp( WebPPicture *pic, VipsImage *in,
 	int Q, gboolean lossless, VipsForeignWebpPreset preset,
-	gboolean smart_subsample )
+	gboolean smart_subsample, gboolean near_lossless )
 {
 	VipsImage *memory;
 	WebPConfig config;
@@ -97,9 +97,11 @@ write_webp( WebPPicture *pic, VipsImage *in,
 		return( -1 );
 	}
 
-	config.lossless = lossless;
+	config.lossless = lossless || near_lossless;
 	if( smart_subsample )
 		config.preprocessing |= 4;
+	if( near_lossless )
+		config.near_lossless = Q;
 
 	if( !WebPValidateConfig(&config) ) {
 		vips_error( "vips2webp",
@@ -113,7 +115,7 @@ write_webp( WebPPicture *pic, VipsImage *in,
 	/* Smart subsampling requires use_argb because
 	 * it is applied during RGB to YUV conversion.
 	 */
-	pic->use_argb = lossless || smart_subsample;
+	pic->use_argb = lossless || near_lossless || smart_subsample;
 	pic->width = memory->Xsize;
 	pic->height = memory->Ysize;
 
@@ -145,7 +147,7 @@ write_webp( WebPPicture *pic, VipsImage *in,
 int
 vips__webp_write_file( VipsImage *in, const char *filename, 
 	int Q, gboolean lossless, VipsForeignWebpPreset preset,
-	gboolean smart_subsample )
+	gboolean smart_subsample, gboolean near_lossless )
 {
 	WebPPicture pic;
 	WebPMemoryWriter writer;
@@ -161,7 +163,8 @@ vips__webp_write_file( VipsImage *in, const char *filename,
 	pic.writer = WebPMemoryWrite;
 	pic.custom_ptr = &writer;
 
-	if( write_webp( &pic, in, Q, lossless, preset, smart_subsample ) ) {
+	if( write_webp( &pic, in, Q, lossless, preset, smart_subsample,
+		near_lossless ) ) {
 		WebPPictureFree( &pic );
 		WebPMemoryWriterClear( &writer );
 		return -1;
@@ -189,7 +192,7 @@ vips__webp_write_file( VipsImage *in, const char *filename,
 int
 vips__webp_write_buffer( VipsImage *in, void **obuf, size_t *olen, 
 	int Q, gboolean lossless, VipsForeignWebpPreset preset,
-	gboolean smart_subsample )
+	gboolean smart_subsample, gboolean near_lossless )
 {
 	WebPPicture pic;
 	WebPMemoryWriter writer;
@@ -205,7 +208,8 @@ vips__webp_write_buffer( VipsImage *in, void **obuf, size_t *olen,
 	pic.writer = WebPMemoryWrite;
 	pic.custom_ptr = &writer;
 
-	if( write_webp( &pic, in, Q, lossless, preset, smart_subsample ) ) {
+	if( write_webp( &pic, in, Q, lossless, preset, smart_subsample,
+		near_lossless) ) {
 		WebPPictureFree( &pic );
 		WebPMemoryWriterClear( &writer );
 		return -1;
diff --git a/libvips/foreign/webp.h b/libvips/foreign/webp.h
index 0d934198..500b22b5 100644
--- a/libvips/foreign/webp.h
+++ b/libvips/foreign/webp.h
@@ -50,10 +50,10 @@ int vips__webp_read_buffer( const void *buf, size_t len,
 
 int vips__webp_write_file( VipsImage *out, const char *filename, 
 	int Q, gboolean lossless, VipsForeignWebpPreset preset,
-	gboolean smart_subsample );
+	gboolean smart_subsample, gboolean near_lossless );
 int vips__webp_write_buffer( VipsImage *out, void **buf, size_t *len, 
 	int Q, gboolean lossless, VipsForeignWebpPreset preset,
-	gboolean smart_subsample );
+	gboolean smart_subsample, gboolean near_lossless );
 
 #ifdef __cplusplus
 }
diff --git a/libvips/foreign/webpsave.c b/libvips/foreign/webpsave.c
index 29e647c7..5989c300 100644
--- a/libvips/foreign/webpsave.c
+++ b/libvips/foreign/webpsave.c
@@ -68,6 +68,10 @@ typedef struct _VipsForeignSaveWebp {
 	 */
 	gboolean smart_subsample;
 
+	/* Use preprocessing in lossless mode.
+	 */
+	gboolean near_lossless;
+
 } VipsForeignSaveWebp;
 
 typedef VipsForeignSaveClass VipsForeignSaveWebpClass;
@@ -108,7 +112,7 @@ vips_foreign_save_webp_class_init( VipsForeignSaveWebpClass *class )
 		_( "Q factor" ),
 		VIPS_ARGUMENT_OPTIONAL_INPUT,
 		G_STRUCT_OFFSET( VipsForeignSaveWebp, Q ),
-		1, 100, 75 );
+		0, 100, 75 );
 
 	VIPS_ARG_BOOL( class, "lossless", 11, 
 		_( "lossless" ), 
@@ -132,6 +136,13 @@ vips_foreign_save_webp_class_init( VipsForeignSaveWebpClass *class )
 		G_STRUCT_OFFSET( VipsForeignSaveWebp, smart_subsample ),
 		FALSE );
 
+	VIPS_ARG_BOOL( class, "near_lossless", 14,
+		_( "Near lossless" ),
+		_( "Enable preprocessing in lossless mode (uses Q)" ),
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsForeignSaveWebp, near_lossless ),
+		FALSE );
+
 }
 
 static void
@@ -167,7 +178,7 @@ vips_foreign_save_webp_file_build( VipsObject *object )
 
 	if( vips__webp_write_file( save->ready, file->filename, 
 		webp->Q, webp->lossless, webp->preset,
-		webp->smart_subsample ) )
+		webp->smart_subsample, webp->near_lossless ) )
 		return( -1 );
 
 	return( 0 );
@@ -230,7 +241,7 @@ vips_foreign_save_webp_buffer_build( VipsObject *object )
 
 	if( vips__webp_write_buffer( save->ready, &obuf, &olen, 
 		webp->Q, webp->lossless, webp->preset,
-		webp->smart_subsample ) )
+		webp->smart_subsample, webp->near_lossless ) )
 		return( -1 );
 
 	blob = vips_blob_new( (VipsCallbackFn) vips_free, obuf, olen );
@@ -292,7 +303,7 @@ vips_foreign_save_webp_mime_build( VipsObject *object )
 
 	if( vips__webp_write_buffer( save->ready, &obuf, &olen, 
 		webp->Q, webp->lossless, webp->preset,
-		webp->smart_subsample ) )
+		webp->smart_subsample, webp->near_lossless ) )
 		return( -1 );
 
 	printf( "Content-length: %zu\r\n", olen );

From 0a25f6efca64bf149253b0031c0d5ad9f80900b9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Felix=20Bu=CC=88nemann?= <buenemann@louis.info>
Date: Sat, 23 Apr 2016 02:41:59 +0200
Subject: [PATCH 05/34] Add alpha_q(uality) webpsave option, fix Q init

This allows to control the fidelity of the alpha channel by allowing
webp to reduce the number of palette entries from 256 at alpha_q=100
to 2 at alpha_q=0. This is most useful with cutout pictures where
something like alpha_q=30 or around 8 levels is usually sufficient
for smooth outlines.

For some reason webp->Q was intiailized to 80 even though the Q option
and libwebp use 75 by default. This was never used, so it's just to
avoid confusion about what default is used.
---
 libvips/foreign/foreign.c   |  2 ++
 libvips/foreign/vips2webp.c | 14 +++++++++-----
 libvips/foreign/webp.h      |  6 ++++--
 libvips/foreign/webpsave.c  | 22 ++++++++++++++++++----
 4 files changed, 33 insertions(+), 11 deletions(-)

diff --git a/libvips/foreign/foreign.c b/libvips/foreign/foreign.c
index d6000680..fa371a73 100644
--- a/libvips/foreign/foreign.c
+++ b/libvips/foreign/foreign.c
@@ -2462,6 +2462,7 @@ vips_webpload_buffer( void *buf, size_t len, VipsImage **out, ... )
  * @preset: #VipsForeignWebpPreset choose lossy compression preset
  * @smart_subsample: enables high quality chroma subsampling
  * @near_lossless: use preprocessing in lossless mode (controlled by Q)
+ * @alpha_q: set alpha quality in lossless mode
  *
  * See also: vips_webpload(), vips_image_write_to_file().
  *
@@ -2494,6 +2495,7 @@ vips_webpsave( VipsImage *in, const char *filename, ... )
  * @preset: #VipsForeignWebpPreset choose lossy compression preset
  * @smart_subsample: enables high quality chroma subsampling
  * @near_lossless: use preprocessing in lossless mode (controlled by Q)
+ * @alpha_q: set alpha quality in lossless mode
  *
  * See also: vips_webpsave().
  *
diff --git a/libvips/foreign/vips2webp.c b/libvips/foreign/vips2webp.c
index e8661cdd..1bc5787d 100644
--- a/libvips/foreign/vips2webp.c
+++ b/libvips/foreign/vips2webp.c
@@ -85,7 +85,8 @@ get_preset( VipsForeignWebpPreset preset )
 static int
 write_webp( WebPPicture *pic, VipsImage *in,
 	int Q, gboolean lossless, VipsForeignWebpPreset preset,
-	gboolean smart_subsample, gboolean near_lossless )
+	gboolean smart_subsample, gboolean near_lossless,
+	int alpha_q )
 {
 	VipsImage *memory;
 	WebPConfig config;
@@ -102,6 +103,7 @@ write_webp( WebPPicture *pic, VipsImage *in,
 		config.preprocessing |= 4;
 	if( near_lossless )
 		config.near_lossless = Q;
+	config.alpha_quality = alpha_q;
 
 	if( !WebPValidateConfig(&config) ) {
 		vips_error( "vips2webp",
@@ -147,7 +149,8 @@ write_webp( WebPPicture *pic, VipsImage *in,
 int
 vips__webp_write_file( VipsImage *in, const char *filename, 
 	int Q, gboolean lossless, VipsForeignWebpPreset preset,
-	gboolean smart_subsample, gboolean near_lossless )
+	gboolean smart_subsample, gboolean near_lossless,
+	int alpha_q )
 {
 	WebPPicture pic;
 	WebPMemoryWriter writer;
@@ -164,7 +167,7 @@ vips__webp_write_file( VipsImage *in, const char *filename,
 	pic.custom_ptr = &writer;
 
 	if( write_webp( &pic, in, Q, lossless, preset, smart_subsample,
-		near_lossless ) ) {
+		near_lossless, alpha_q ) ) {
 		WebPPictureFree( &pic );
 		WebPMemoryWriterClear( &writer );
 		return -1;
@@ -192,7 +195,8 @@ vips__webp_write_file( VipsImage *in, const char *filename,
 int
 vips__webp_write_buffer( VipsImage *in, void **obuf, size_t *olen, 
 	int Q, gboolean lossless, VipsForeignWebpPreset preset,
-	gboolean smart_subsample, gboolean near_lossless )
+	gboolean smart_subsample, gboolean near_lossless,
+	int alpha_q )
 {
 	WebPPicture pic;
 	WebPMemoryWriter writer;
@@ -209,7 +213,7 @@ vips__webp_write_buffer( VipsImage *in, void **obuf, size_t *olen,
 	pic.custom_ptr = &writer;
 
 	if( write_webp( &pic, in, Q, lossless, preset, smart_subsample,
-		near_lossless) ) {
+		near_lossless, alpha_q ) ) {
 		WebPPictureFree( &pic );
 		WebPMemoryWriterClear( &writer );
 		return -1;
diff --git a/libvips/foreign/webp.h b/libvips/foreign/webp.h
index 500b22b5..37f126e8 100644
--- a/libvips/foreign/webp.h
+++ b/libvips/foreign/webp.h
@@ -50,10 +50,12 @@ int vips__webp_read_buffer( const void *buf, size_t len,
 
 int vips__webp_write_file( VipsImage *out, const char *filename, 
 	int Q, gboolean lossless, VipsForeignWebpPreset preset,
-	gboolean smart_subsample, gboolean near_lossless );
+	gboolean smart_subsample, gboolean near_lossless,
+	int alpha_q );
 int vips__webp_write_buffer( VipsImage *out, void **buf, size_t *len, 
 	int Q, gboolean lossless, VipsForeignWebpPreset preset,
-	gboolean smart_subsample, gboolean near_lossless );
+	gboolean smart_subsample, gboolean near_lossless,
+	int alpha_q );
 
 #ifdef __cplusplus
 }
diff --git a/libvips/foreign/webpsave.c b/libvips/foreign/webpsave.c
index 5989c300..f677ff0e 100644
--- a/libvips/foreign/webpsave.c
+++ b/libvips/foreign/webpsave.c
@@ -72,6 +72,10 @@ typedef struct _VipsForeignSaveWebp {
 	 */
 	gboolean near_lossless;
 
+	/* Alpha quality.
+	 */
+	int alpha_q;
+
 } VipsForeignSaveWebp;
 
 typedef VipsForeignSaveClass VipsForeignSaveWebpClass;
@@ -143,12 +147,19 @@ vips_foreign_save_webp_class_init( VipsForeignSaveWebpClass *class )
 		G_STRUCT_OFFSET( VipsForeignSaveWebp, near_lossless ),
 		FALSE );
 
+	VIPS_ARG_INT( class, "alpha_q", 15,
+		_( "Alpha quality" ),
+		_( "Change alpha plane fidelity for lossy compression" ),
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsForeignSaveWebp, alpha_q ),
+		0, 100, 100 );
+
 }
 
 static void
 vips_foreign_save_webp_init( VipsForeignSaveWebp *webp )
 {
-	webp->Q = 80;
+	webp->Q = 75;
 }
 
 typedef struct _VipsForeignSaveWebpFile {
@@ -178,7 +189,8 @@ vips_foreign_save_webp_file_build( VipsObject *object )
 
 	if( vips__webp_write_file( save->ready, file->filename, 
 		webp->Q, webp->lossless, webp->preset,
-		webp->smart_subsample, webp->near_lossless ) )
+		webp->smart_subsample, webp->near_lossless,
+		webp->alpha_q ) )
 		return( -1 );
 
 	return( 0 );
@@ -241,7 +253,8 @@ vips_foreign_save_webp_buffer_build( VipsObject *object )
 
 	if( vips__webp_write_buffer( save->ready, &obuf, &olen, 
 		webp->Q, webp->lossless, webp->preset,
-		webp->smart_subsample, webp->near_lossless ) )
+		webp->smart_subsample, webp->near_lossless,
+		webp->alpha_q ) )
 		return( -1 );
 
 	blob = vips_blob_new( (VipsCallbackFn) vips_free, obuf, olen );
@@ -303,7 +316,8 @@ vips_foreign_save_webp_mime_build( VipsObject *object )
 
 	if( vips__webp_write_buffer( save->ready, &obuf, &olen, 
 		webp->Q, webp->lossless, webp->preset,
-		webp->smart_subsample, webp->near_lossless ) )
+		webp->smart_subsample, webp->near_lossless,
+		webp->alpha_q ) )
 		return( -1 );
 
 	printf( "Content-length: %zu\r\n", olen );

From 874cc8b31bf99257d1ef0078711a451f79b625d5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Felix=20Bu=CC=88nemann?= <buenemann@louis.info>
Date: Sat, 23 Apr 2016 07:00:42 +0200
Subject: [PATCH 06/34] Restore webpsave libwebp-0.1.3 compatility

* Add configure check for libwebp >= 0.1.3
* Add custom memory writer using GNOME memory allocation
* Add various ABI checks and warnings for unsupported features:
** smart_subsample and near_lossless require 0.5.0
** lossless requires at least 0.1.99
---
 configure.ac                |   3 +-
 libvips/foreign/foreign.c   |   6 +++
 libvips/foreign/vips2webp.c | 105 +++++++++++++++++++++++++++++-------
 3 files changed, 95 insertions(+), 19 deletions(-)

diff --git a/configure.ac b/configure.ac
index afd5f078..2d62bcd0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -677,7 +677,7 @@ AC_ARG_WITH([libwebp],
   AS_HELP_STRING([--without-libwebp], [build without libwebp (default: test)]))
 
 if test x"$with_libwebp" != "xno"; then
-  PKG_CHECK_MODULES(LIBWEBP, libwebp,
+  PKG_CHECK_MODULES(LIBWEBP, libwebp >= 0.1.3,
     [AC_DEFINE(HAVE_LIBWEBP,1,[define if you have libwebp installed.])
      with_libwebp=yes
      PACKAGES_USED="$PACKAGES_USED libwebp"],
@@ -972,6 +972,7 @@ SVG import with librsvg-2.0: 		$with_rsvg
   (requires librsvg-2.0 2.40.0 or later)
 file import with cfitsio: 		$with_cfitsio
 file import/export with libwebp:	$with_libwebp
+  (requires libwebp-0.1.3 or later)
 text rendering with pangoft2: 		$with_pangoft2
 file import/export with libpng: 	$with_png
   (requires libpng-1.2.9 or later)
diff --git a/libvips/foreign/foreign.c b/libvips/foreign/foreign.c
index fa371a73..af037279 100644
--- a/libvips/foreign/foreign.c
+++ b/libvips/foreign/foreign.c
@@ -2497,6 +2497,12 @@ vips_webpsave( VipsImage *in, const char *filename, ... )
  * @near_lossless: use preprocessing in lossless mode (controlled by Q)
  * @alpha_q: set alpha quality in lossless mode
  *
+ * As vips_webpsave(), but save to a memory buffer.
+ *
+ * The address of the buffer is returned in @obuf, the length of the buffer in
+ * @olen. You are responsible for freeing the buffer with g_free() when you
+ * are done with it. The buffer is freed for you on error.
+ *
  * See also: vips_webpsave().
  *
  * Returns: 0 on success, -1 on error.
diff --git a/libvips/foreign/vips2webp.c b/libvips/foreign/vips2webp.c
index 1bc5787d..17726218 100644
--- a/libvips/foreign/vips2webp.c
+++ b/libvips/foreign/vips2webp.c
@@ -46,6 +46,7 @@
 #ifdef HAVE_LIBWEBP
 
 #include <stdlib.h>
+#include <string.h>
 
 #include <vips/vips.h>
 
@@ -82,6 +83,55 @@ get_preset( VipsForeignWebpPreset preset )
 	return( -1 );
 }
 
+typedef struct {
+	uint8_t *mem;
+	size_t size;
+	size_t max_size;
+} VipsWebPMemoryWriter;
+
+static void
+init_memory_writer( VipsWebPMemoryWriter *writer ) {
+	writer->mem = NULL;
+	writer->size = 0;
+	writer->max_size = 0;
+}
+
+static int
+memory_write( const uint8_t *data, size_t data_size,
+	const WebPPicture *picture ) {
+	VipsWebPMemoryWriter* const w = (VipsWebPMemoryWriter*) picture->custom_ptr;
+	size_t next_size;
+
+	if( w == NULL )
+		return( 0 );
+
+	next_size = w->size + data_size;
+
+	if( next_size > w->max_size ) {
+		uint8_t *new_mem;
+		const size_t next_max_size =
+			VIPS_MAX( 8192, VIPS_MAX( next_size, w->max_size * 2 ) );
+
+		new_mem = (uint8_t*) g_try_malloc( next_max_size );
+		if( new_mem == NULL )
+			return( 0 );
+
+		if( w->size > 0 )
+			memcpy( new_mem, w->mem, w->size );
+
+		g_free( w->mem );
+		w->mem = new_mem;
+		w->max_size = next_max_size;
+	}
+
+	if( data_size > 0 ) {
+		memcpy( w->mem + w->size, data, data_size );
+		w->size += data_size;
+	}
+
+	return( 1 );
+}
+
 static int
 write_webp( WebPPicture *pic, VipsImage *in,
 	int Q, gboolean lossless, VipsForeignWebpPreset preset,
@@ -98,12 +148,35 @@ write_webp( WebPPicture *pic, VipsImage *in,
 		return( -1 );
 	}
 
+#if WEBP_ENCODER_ABI_VERSION >= 0x0100
 	config.lossless = lossless || near_lossless;
-	if( smart_subsample )
-		config.preprocessing |= 4;
+	config.alpha_quality = alpha_q;
+	/* Smart subsampling requires use_argb because
+	 * it is applied during RGB to YUV conversion.
+	 */
+	pic->use_argb = lossless || near_lossless || smart_subsample;
+#else
+	if( lossless || near_lossless )
+		vips_warn( "vips2webp", 
+			"%s", _( "lossless unsupported" ) );
+	if( alpha_q != 100 )
+		vips_warn( "vips2webp", 
+			"%s", _( "alpha_q unsupported" ) );
+#endif
+
+#if WEBP_ENCODER_ABI_VERSION >= 0x0209
 	if( near_lossless )
 		config.near_lossless = Q;
-	config.alpha_quality = alpha_q;
+	if( smart_subsample )
+		config.preprocessing |= 4;
+#else
+	if( near_lossless )
+		vips_warn( "vips2webp", 
+			"%s", _( "near_lossless unsupported" ) );
+	if( smart_subsample )
+		vips_warn( "vips2webp", 
+			"%s", _( "smart_subsample unsupported" ) );
+#endif
 
 	if( !WebPValidateConfig(&config) ) {
 		vips_error( "vips2webp",
@@ -114,10 +187,6 @@ write_webp( WebPPicture *pic, VipsImage *in,
 	if( !(memory = vips_image_copy_memory( in )) )
 		return( -1 );
 
-	/* Smart subsampling requires use_argb because
-	 * it is applied during RGB to YUV conversion.
-	 */
-	pic->use_argb = lossless || near_lossless || smart_subsample;
 	pic->width = memory->Xsize;
 	pic->height = memory->Ysize;
 
@@ -153,7 +222,7 @@ vips__webp_write_file( VipsImage *in, const char *filename,
 	int alpha_q )
 {
 	WebPPicture pic;
-	WebPMemoryWriter writer;
+	VipsWebPMemoryWriter writer;
 	FILE *fp;
 
 	if( !WebPPictureInit( &pic ) ) {
@@ -162,32 +231,32 @@ vips__webp_write_file( VipsImage *in, const char *filename,
 		return( -1 );
 	}
 
-	WebPMemoryWriterInit( &writer );
-	pic.writer = WebPMemoryWrite;
+	init_memory_writer( &writer );
+	pic.writer = memory_write;
 	pic.custom_ptr = &writer;
 
 	if( write_webp( &pic, in, Q, lossless, preset, smart_subsample,
 		near_lossless, alpha_q ) ) {
 		WebPPictureFree( &pic );
-		WebPMemoryWriterClear( &writer );
+		g_free( writer.mem );
 		return -1;
 	}
 
 	WebPPictureFree( &pic );
 
 	if( !(fp = vips__file_open_write( filename, FALSE )) ) {
-		WebPMemoryWriterClear( &writer );
+		g_free( writer.mem );
 		return( -1 );
 	}
 
 	if( vips__file_write( writer.mem, writer.size, 1, fp ) ) {
 		fclose( fp );
-		WebPMemoryWriterClear( &writer );
+		g_free( writer.mem );
 		return( -1 );
 	}
 
 	fclose( fp );
-	WebPMemoryWriterClear( &writer );
+	g_free( writer.mem );
 
 	return( 0 );
 }
@@ -199,7 +268,7 @@ vips__webp_write_buffer( VipsImage *in, void **obuf, size_t *olen,
 	int alpha_q )
 {
 	WebPPicture pic;
-	WebPMemoryWriter writer;
+	VipsWebPMemoryWriter writer;
 	FILE *fp;
 
 	if( !WebPPictureInit( &pic ) ) {
@@ -208,14 +277,14 @@ vips__webp_write_buffer( VipsImage *in, void **obuf, size_t *olen,
 		return( -1 );
 	}
 
-	WebPMemoryWriterInit( &writer );
-	pic.writer = WebPMemoryWrite;
+	init_memory_writer( &writer );
+	pic.writer = memory_write;
 	pic.custom_ptr = &writer;
 
 	if( write_webp( &pic, in, Q, lossless, preset, smart_subsample,
 		near_lossless, alpha_q ) ) {
 		WebPPictureFree( &pic );
-		WebPMemoryWriterClear( &writer );
+		g_free( writer.mem );
 		return -1;
 	}
 

From 27e319883352f952f1bcf90dbc73dd8e66e2618c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Felix=20Bu=CC=88nemann?= <buenemann@louis.info>
Date: Sat, 23 Apr 2016 23:36:49 +0200
Subject: [PATCH 07/34] Add webp save/load format tests for "make check"

---
 test/test_formats.sh | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/test/test_formats.sh b/test/test_formats.sh
index 28b0ba68..72af1ad4 100755
--- a/test/test_formats.sh
+++ b/test/test_formats.sh
@@ -186,6 +186,10 @@ fi
 if test_supported jpegload; then
 	test_format $image jpg 90
 fi
+if test_supported webpload; then
+	test_format $image webp 90
+	test_format $image webp 0 [lossless]
+fi
 test_format $image ppm 0
 test_format $image pfm 0
 if test_supported fitsload; then
@@ -220,4 +224,3 @@ if test_supported dzsave; then
 	test_saver copy $image .dz
 	test_saver copy $image .dz[container=zip]
 fi
-

From 73080bb4a5c219154b30faa4a97ab92336064a70 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Tue, 26 Apr 2016 10:41:04 +0100
Subject: [PATCH 08/34] try to improve mozjpeg test

save LIBS around test, test for ABI not header

see https://github.com/jcupitt/libvips/issues/431
---
 configure.ac | 52 +++++++++++++++++++++++-----------------------------
 1 file changed, 23 insertions(+), 29 deletions(-)

diff --git a/configure.ac b/configure.ac
index 915b9b77..201a893e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -439,66 +439,66 @@ fi
 if test x"$with_magick" != "xno"; then
   # we SetImageOption to disable some DICOM read processing, but that's only
   # in more recent imagemagicks and not in graphicsmagick
-  save_LIBS=$LIBS
+  save_LIBS="$LIBS"
   LIBS="$LIBS $MAGICK_LIBS"
   AC_CHECK_FUNCS(SetImageOption,
     AC_DEFINE(HAVE_SETIMAGEOPTION,1,
 	      [define if your magick has SetImageOption.]))
-  LIBS=$save_LIBS
+  LIBS="$save_LIBS"
 fi
 
 if test x"$with_magick" != "xno"; then
   # newer ImageMagicks use MagickCoreGenesis instead of InitializeMagick argh
-  save_LIBS=$LIBS
+  save_LIBS="$LIBS"
   LIBS="$LIBS $MAGICK_LIBS"
   AC_CHECK_FUNCS(MagickCoreGenesis,
     AC_DEFINE(HAVE_MAGICKCOREGENESIS,1,
 	      [define if your magick has MagickCoreGenesis.]))
-  LIBS=$save_LIBS
+  LIBS="$save_LIBS"
 fi
 
 if test x"$with_magick" != "xno"; then
   # newer ImageMagicks use ResetImagePropertyIterator instead of
   # ResetImageAttributeIterator argh
-  save_LIBS=$LIBS
+  save_LIBS="$LIBS"
   LIBS="$LIBS $MAGICK_LIBS"
   AC_CHECK_FUNCS(ResetImagePropertyIterator,
     AC_DEFINE(HAVE_RESETIMAGEPROPERTYITERATOR,1,
 	      [define if your magick has ResetImagePropertyIterator.]))
-  LIBS=$save_LIBS
+  LIBS="$save_LIBS"
 fi
 
 if test x"$with_magick" != "xno"; then
   # so ... do we have ResetImageAttributeIterator()? GM does not
-  save_LIBS=$LIBS
+  save_LIBS="$LIBS"
   LIBS="$LIBS $MAGICK_LIBS"
   AC_CHECK_FUNCS(ResetImageAttributeIterator,
     AC_DEFINE(HAVE_RESETIMAGEATTRIBUTEITERATOR,1,
 	      [define if your magick has ResetImageAttributeIterator.]))
-  LIBS=$save_LIBS
+  LIBS="$save_LIBS"
 fi
 
 if test x"$with_magick" != "xno"; then
   # more recent magicks have GetVirtualPixels rather than GetImagePixels
-  save_LIBS=$LIBS
+  save_LIBS="$LIBS"
   LIBS="$LIBS $MAGICK_LIBS"
   AC_CHECK_FUNCS(GetVirtualPixels,
     AC_DEFINE(HAVE_GETVIRTUALPIXELS,1,
 	      [define if your magick has GetVirtualPixels.]))
-  LIBS=$save_LIBS
+  LIBS="$save_LIBS"
 fi
 
 if test x"$with_magick" != "xno"; then
   # do we have number_scenes in image_info ... imagemagick uses this, gm
   # still uses subrange
-  save_CFLAGS=$CFLAGS
+  save_CFLAGS="$CFLAGS"
   CFLAGS="$CFLAGS $MAGICK_CFLAGS"
   AC_CHECK_MEMBER([struct _ImageInfo.number_scenes],
     AC_DEFINE(HAVE_NUMBER_SCENES,1,
 	      [define if your magick has ImageInfo.number_scenes.]),
     [],
     [#include <magick/api.h>])
-  CFLAGS=$save_CFLAGS
+  CFLAGS="$save_CFLAGS"
 fi
 
 # orc
@@ -511,12 +511,12 @@ if test x"$with_orc" != "xno"; then
     [AC_DEFINE(HAVE_ORC,1,[define if you have orc-0.4.11 or later installed.])
      with_orc=yes
      PACKAGES_USED="$PACKAGES_USED orc-0.4"
-     save_LIBS=$LIBS
+     save_LIBS="$LIBS"
      LIBS="$LIBS $ORC_LIBS"
      AC_CHECK_FUNCS(orc_program_get_error,
        AC_DEFINE(HAVE_ORC_PROGRAM_GET_ERROR,1,
 	      [define if your orc has orc_program_get_error.]))
-     LIBS=$save_LIBS
+     LIBS="$save_LIBS"
     ],
     [AC_MSG_WARN([orc-0.4.11 or later not found; disabling orc support])
      with_orc=no
@@ -791,19 +791,13 @@ FIND_JPEG(
   ])
 
 # JPEG extension parameters available in libjpeg-turbo >=1.5.0, mozjpeg >=3.0
-if test x"$with_jpeg" = "xyes"; then
-  AC_MSG_CHECKING([for JPEG extension parameters])
-  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
-    #include <stdio.h>
-    #include <jpeglib.h>
-  ]], [[
-    J_BOOLEAN_PARAM test;
-  ]])], [
-    AC_MSG_RESULT([yes])
-    AC_DEFINE([HAVE_JPEG_EXT_PARAMS],1,[libjpeg has extension parameters])
-  ], [
-    AC_MSG_RESULT([no])
-  ])
+if test x"$with_jpeg" != "xno"; then
+  save_LIBS="$LIBS"
+  LIBS="$LIBS $JPEG_LIBS"
+  AC_CHECK_FUNCS(jpeg_c_bool_param_supported,
+    AC_DEFINE(HAVE_JPEG_EXT_PARAMS,1,
+	      [define if your libjpeg has extension parameters.]))
+  LIBS="$save_LIBS"
 fi
 
 # libexif
@@ -824,11 +818,11 @@ fi
 # how annoying
 if test x"$with_libexif" != "xno"; then
   # cppflags not cflags because we want the preproc to see the -I as well
-  save_CPPFLAGS=$CPPFLAGS
+  save_CPPFLAGS="$CPPFLAGS"
   CPPFLAGS="$EXIF_CFLAGS $CPPFLAGS"
   AC_CHECK_HEADER(exif-data.h,
     AC_DEFINE(UNTAGGED_EXIF,1,[libexif includes don't need libexif prefix]))
-  CPPFLAGS=$save_CPPFLAGS
+  CPPFLAGS="$save_CPPFLAGS"
 fi
 
 # make python binding?

From c2d1de9a264cb71812bac1a5b0cb178807ddef0a Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Sun, 1 May 2016 12:03:13 +0100
Subject: [PATCH 09/34] allow mixed zoom and shrink in resize

vips_resize() now allows >1 on one axis, <1 on the other ... previously,
although you could have non-square ratios, you couldn't mix zoom and
shrink
---
 ChangeLog                 |  1 +
 libvips/resample/resize.c | 58 ++++++++++++++++++++++++++-------------
 libvips/resample/shrink.c |  5 ++--
 3 files changed, 42 insertions(+), 22 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 57ed412e..68a2bea9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -3,6 +3,7 @@
 - export C++ operator overloads for MSVC linking [Lovell]
 - fix magickload @page with GraphicsMagick
 - add giflib5 support
+- allow resize >1 on one axis, <1 on the other
 
 29/1/16 started 8.3
 - add vips_reduce*() ... a fast path for affine downsize
diff --git a/libvips/resample/resize.c b/libvips/resample/resize.c
index 8cea30dd..95255538 100644
--- a/libvips/resample/resize.c
+++ b/libvips/resample/resize.c
@@ -10,6 +10,8 @@
  * 	- shrink more affine less, now we have better anti-alias settings
  * 10/3/16
  * 	- revise again, using new vips_reduce() code
+ * 1/5/16
+ * 	- allow >1 on one axis, <1 on the other
  */
 
 /*
@@ -132,15 +134,20 @@ vips_resize_build( VipsObject *object )
 	else
 		int_vshrink = int_hshrink;
 
-	if( int_hshrink > 1 ||
-		int_vshrink > 1 ) { 
-		vips_info( class->nickname, "box shrink by %d x %d", 
-			int_hshrink, int_vshrink );
-		if( vips_shrink( in, &t[0], int_hshrink, int_vshrink, NULL ) )
+	if( int_vshrink > 1 ) { 
+		vips_info( class->nickname, "shrinkv by %d", int_vshrink );
+		if( vips_shrinkv( in, &t[0], int_vshrink, NULL ) )
 			return( -1 );
 		in = t[0];
 	}
 
+	if( int_hshrink > 1 ) { 
+		vips_info( class->nickname, "shrinkh by %d", int_hshrink );
+		if( vips_shrinkh( in, &t[1], int_hshrink, NULL ) )
+			return( -1 );
+		in = t[1];
+	}
+
 	/* Do we need a further size adjustment? It's the difference
 	 * between our target size and the size we have after vips_shrink().
 	 *
@@ -195,30 +202,43 @@ vips_resize_build( VipsObject *object )
 		in = t[6];
 	}
 
-	/* Any downsizing.
+	/* Any residual downsizing.
 	 */
-	if( hresidual < 1.0 || 
-		vresidual < 1.0 ) { 
-		vips_info( class->nickname, "residual reduce by %g x %g", 
-			hresidual, vresidual );
-
-		if( vips_reduce( in, &t[2], 
-			1.0 / hresidual, 1.0 / vresidual, NULL ) )  
+	if( vresidual < 1.0 ) { 
+		vips_info( class->nickname, "residual reducev by %g", 
+			vresidual );
+		if( vips_reducev( in, &t[2], 1.0 / vresidual, NULL ) )  
 			return( -1 );
 		in = t[2];
 	}
 
+	if( hresidual < 1.0 ) { 
+		vips_info( class->nickname, "residual reduceh by %g", 
+			hresidual );
+		if( vips_reduceh( in, &t[3], 1.0 / hresidual, NULL ) )  
+			return( -1 );
+		in = t[3];
+	}
+
 	/* Any upsizing.
 	 */
-	if( hresidual > 1.0 || 
-		vresidual > 1.0 ) { 
-		vips_info( class->nickname, "residual scale %g x %g", 
-			hresidual, vresidual );
-		if( vips_affine( in, &t[3], hresidual, 0, 0, vresidual, 
+	if( hresidual > 1.0 ) { 
+		vips_info( class->nickname, "residual scaleh %g", 
+			hresidual );
+		if( vips_affine( in, &t[4], hresidual, 0.0, 0.0, 1.0, 
 			"interpolate", vips_interpolate_nearest_static(), 
 			NULL ) )  
 			return( -1 );
-		in = t[3];
+		in = t[4];
+	}
+
+	if( vresidual > 1.0 ) { 
+		vips_info( class->nickname, "residual scalev %g", vresidual );
+		if( vips_affine( in, &t[5], 1.0, 0.0, 0.0, vresidual, 
+			"interpolate", vips_interpolate_nearest_static(), 
+			NULL ) )  
+			return( -1 );
+		in = t[5];
 	}
 
 	if( vips_image_write( in, resample->out ) )
diff --git a/libvips/resample/shrink.c b/libvips/resample/shrink.c
index b329daa5..59efc483 100644
--- a/libvips/resample/shrink.c
+++ b/libvips/resample/shrink.c
@@ -99,13 +99,12 @@ vips_shrink_build( VipsObject *object )
 		yresidual = (double) target_height / t[1]->Ysize;
 
 		if( vips_affine( t[1], &t[2], 
-				xresidual, 0.0, 0.0, yresidual, NULL ) ||
+			xresidual, 0.0, 0.0, yresidual, NULL ) ||
 			vips_image_write( t[2], resample->out ) )
 			return( -1 );
 	}
 	else {
-		if( vips_shrinkv( resample->in, &t[0], 
-				shrink->yshrink, NULL ) ||
+		if( vips_shrinkv( resample->in, &t[0], shrink->yshrink, NULL ) ||
 			vips_shrinkh( t[0], &t[1], shrink->xshrink, NULL ) ||
 			vips_image_write( t[1], resample->out ) )
 			return( -1 );

From 02821ae9e3b5de6162552e5f6f953b354c89b643 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Sun, 1 May 2016 12:33:49 +0100
Subject: [PATCH 10/34] expose @kernel setting for vips_resize()

a new optional arg lets you pick the downsizing kernel
---
 ChangeLog                 |  1 +
 libvips/resample/resize.c | 31 +++++++++++++++++++++++++------
 2 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 68a2bea9..cbb50c50 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -4,6 +4,7 @@
 - fix magickload @page with GraphicsMagick
 - add giflib5 support
 - allow resize >1 on one axis, <1 on the other
+- vips_resize has an optional @kernel argument
 
 29/1/16 started 8.3
 - add vips_reduce*() ... a fast path for affine downsize
diff --git a/libvips/resample/resize.c b/libvips/resample/resize.c
index 95255538..bff34d7c 100644
--- a/libvips/resample/resize.c
+++ b/libvips/resample/resize.c
@@ -12,6 +12,7 @@
  * 	- revise again, using new vips_reduce() code
  * 1/5/16
  * 	- allow >1 on one axis, <1 on the other
+ * 	- expose @kernel setting
  */
 
 /*
@@ -69,6 +70,7 @@ typedef struct _VipsResize {
 
 	double scale;
 	double vscale;
+	VipsKernel kernel;
 
 	/* Deprecated.
 	 */
@@ -207,7 +209,9 @@ vips_resize_build( VipsObject *object )
 	if( vresidual < 1.0 ) { 
 		vips_info( class->nickname, "residual reducev by %g", 
 			vresidual );
-		if( vips_reducev( in, &t[2], 1.0 / vresidual, NULL ) )  
+		if( vips_reducev( in, &t[2], 1.0 / vresidual, 
+			"kernel", resize->kernel, 
+			NULL ) )  
 			return( -1 );
 		in = t[2];
 	}
@@ -215,7 +219,9 @@ vips_resize_build( VipsObject *object )
 	if( hresidual < 1.0 ) { 
 		vips_info( class->nickname, "residual reduceh by %g", 
 			hresidual );
-		if( vips_reduceh( in, &t[3], 1.0 / hresidual, NULL ) )  
+		if( vips_reduceh( in, &t[3], 1.0 / hresidual, 
+			"kernel", resize->kernel, 
+			NULL ) )  
 			return( -1 );
 		in = t[3];
 	}
@@ -279,6 +285,13 @@ vips_resize_class_init( VipsResizeClass *class )
 		G_STRUCT_OFFSET( VipsResize, vscale ),
 		0, 10000000, 0 );
 
+	VIPS_ARG_ENUM( class, "kernel", 3, 
+		_( "Kernel" ), 
+		_( "Resampling kernel" ),
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsResize, kernel ),
+		VIPS_TYPE_KERNEL, VIPS_KERNEL_LANCZOS3 );
+
 	/* We used to let people set the input offset so you could pick centre
 	 * or corner interpolation, but it's not clear this was useful. 
 	 */
@@ -311,6 +324,7 @@ vips_resize_class_init( VipsResizeClass *class )
 static void
 vips_resize_init( VipsResize *resize )
 {
+	resize->kernel = VIPS_KERNEL_LANCZOS3;
 }
 
 /**
@@ -323,21 +337,26 @@ vips_resize_init( VipsResize *resize )
  * Optional arguments:
  *
  * @vscale: vertical scale factor
+ * @kernel: #VipsKernel to reduce with 
  *
  * Resize an image. When upsizing (@scale > 1), the image is simply block
  * upsized. When downsizing, the
- * image is block-shrunk with vips_shrink(), then an anti-alias blur is
- * applied with vips_gaussblur(), then the image is shrunk again to the 
- * target size with vips_reduce(). 
+ * image is block-shrunk with vips_shrink(), 
+ * then the image is shrunk again to the 
+ * target size with vips_reduce(). The operation will leave at least the final
+ * x2 to be done with vips_reduce().
  *
  * vips_resize() normally maintains the image apect ratio. If you set
  * @vscale, that factor is used for the vertical scale and @scale for the
  * horizontal.
  *
+ * vips_resize() normally uses #VIPS_KERNEL_LANCZOS3 for thre final shrink, you
+ * can change this with @kernel.
+ *
  * This operation does not change xres or yres. The image resolution needs to
  * be updated by the application. 
  *
- * See also: vips_shrink(), vips_reduce(), vips_gaussblur().
+ * See also: vips_shrink(), vips_reduce().
  *
  * Returns: 0 on success, -1 on error
  */

From 48ef2154790289fe3a4802f9313b83e7342fa7be Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Mon, 2 May 2016 09:55:16 +0100
Subject: [PATCH 11/34] tiny fixups for the webp commit

just small formatting changes, plus an unneeded var

see

	https://github.com/jcupitt/libvips/pull/430
---
 ChangeLog                      |  3 +++
 TODO                           |  2 ++
 configure.ac                   |  8 +++---
 libvips/foreign/foreign.c      | 46 ++++++++++++++++++++++++----------
 libvips/foreign/vips2webp.c    | 37 ++++++++++++++-------------
 libvips/include/vips/foreign.h |  6 ++---
 6 files changed, 64 insertions(+), 38 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index cbb50c50..859045b4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,6 @@
+1/5/16 started 8.4
+- many more wepsave options [Felix Bünemann]
+
 15/4/16 started 8.3.1
 - rename vips wrapper script, it was still vips-8.2, thanks Benjamin
 - export C++ operator overloads for MSVC linking [Lovell]
diff --git a/TODO b/TODO
index cf0dcd7a..c16cf38d 100644
--- a/TODO
+++ b/TODO
@@ -1,3 +1,5 @@
+- add "*" before each optional arg description
+
 - I like the new int mask creator in reducev, can we use it in im_vips2imask()
   as well?
 
diff --git a/configure.ac b/configure.ac
index 3bdf4466..4ddb37fe 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2,7 +2,7 @@
 
 # also update the version number in the m4 macros below
 
-AC_INIT([vips], [8.3.1], [vipsip@jiscmail.ac.uk])
+AC_INIT([vips], [8.4.0], [vipsip@jiscmail.ac.uk])
 # required for gobject-introspection
 AC_PREREQ(2.62)
 
@@ -17,8 +17,8 @@ AC_CONFIG_MACRO_DIR([m4])
 
 # user-visible library versioning
 m4_define([vips_major_version], [8])
-m4_define([vips_minor_version], [3])
-m4_define([vips_micro_version], [1])
+m4_define([vips_minor_version], [4])
+m4_define([vips_micro_version], [0])
 m4_define([vips_version],
           [vips_major_version.vips_minor_version.vips_micro_version])
 
@@ -38,7 +38,7 @@ VIPS_VERSION_STRING=$VIPS_VERSION-`date`
 #   binary interface changes not backwards compatible?: reset age to 0
 
 LIBRARY_CURRENT=46
-LIBRARY_REVISION=1
+LIBRARY_REVISION=2
 LIBRARY_AGE=4
 
 # patched into include/vips/version.h
diff --git a/libvips/foreign/foreign.c b/libvips/foreign/foreign.c
index e012cb2f..2b7cffdc 100644
--- a/libvips/foreign/foreign.c
+++ b/libvips/foreign/foreign.c
@@ -2457,12 +2457,27 @@ vips_webpload_buffer( void *buf, size_t len, VipsImage **out, ... )
  *
  * Optional arguments:
  *
- * @Q: quality factor
- * @lossless: enables lossless compression
- * @preset: #VipsForeignWebpPreset choose lossy compression preset
- * @smart_subsample: enables high quality chroma subsampling
- * @near_lossless: use preprocessing in lossless mode (controlled by Q)
- * @alpha_q: set alpha quality in lossless mode
+ * * @Q: %gint quality factor
+ * * @lossless: %gboolean enables lossless compression
+ * * @preset: #VipsForeignWebpPreset choose lossy compression preset
+ * * @smart_subsample: %gboolean enables high quality chroma subsampling
+ * * @near_lossless: %gboolean use preprocessing in lossless mode (controlled by Q)
+ * * @alpha_q: %gint set alpha quality in lossless mode
+ *
+ * Write an image to a file in WebP format. 
+ *
+ * Use @Q to set the WebP quality factor. It has the range 0 - 100, with the
+ * default 75.
+ *
+ * Use @preset to hint the image type to lossy compressor. The default is
+ * #VIPS_FOREIGN_WEBP_PRESET_DEFAULT. 
+ *
+ * Set @smart_subsample to enable high quality chroma subsampling.
+ *
+ * Use @alpha_q to set the quality for the alpha channel in lossy mode. It has
+ * the range 1 - 100, with the default 100.
+ *
+ * Set @lossless to enable lossless save. 
  *
  * See also: vips_webpload(), vips_image_write_to_file().
  *
@@ -2490,18 +2505,18 @@ vips_webpsave( VipsImage *in, const char *filename, ... )
  *
  * Optional arguments:
  *
- * @Q: JPEG quality factor
- * @lossless: enables lossless compression
+ * @Q: %gint quality factor
+ * @lossless: %gboolean enables lossless compression
  * @preset: #VipsForeignWebpPreset choose lossy compression preset
- * @smart_subsample: enables high quality chroma subsampling
- * @near_lossless: use preprocessing in lossless mode (controlled by Q)
- * @alpha_q: set alpha quality in lossless mode
+ * @smart_subsample: %gboolean enables high quality chroma subsampling
+ * @near_lossless: %gboolean use preprocessing in lossless mode (controlled by Q)
+ * @alpha_q: %gint set alpha quality in lossless mode
  *
  * As vips_webpsave(), but save to a memory buffer.
  *
  * The address of the buffer is returned in @obuf, the length of the buffer in
  * @olen. You are responsible for freeing the buffer with g_free() when you
- * are done with it. The buffer is freed for you on error.
+ * are done with it. 
  *
  * See also: vips_webpsave().
  *
@@ -2542,7 +2557,12 @@ vips_webpsave_buffer( VipsImage *in, void **buf, size_t *len, ... )
  *
  * Optional arguments:
  *
- * @Q: quality factor
+ * @Q: %gint quality factor
+ * @lossless: %gboolean enables lossless compression
+ * @preset: #VipsForeignWebpPreset choose lossy compression preset
+ * @smart_subsample: %gboolean enables high quality chroma subsampling
+ * @near_lossless: %gboolean use preprocessing in lossless mode (controlled by Q)
+ * @alpha_q: %gint set alpha quality in lossless mode
  *
  * As vips_webpsave(), but save as a mime webp on stdout.
  *
diff --git a/libvips/foreign/vips2webp.c b/libvips/foreign/vips2webp.c
index 17726218..05301d85 100644
--- a/libvips/foreign/vips2webp.c
+++ b/libvips/foreign/vips2webp.c
@@ -4,6 +4,8 @@
  * 	- from vips2jpeg.c
  * 31/5/16
  * 	- buffer write ignored lossless, thanks aaron42net
+ * 2/5/16 Felix Bünemann
+ * 	- used advanced encoding API, expose controls 
  */
 
 /*
@@ -99,34 +101,36 @@ init_memory_writer( VipsWebPMemoryWriter *writer ) {
 static int
 memory_write( const uint8_t *data, size_t data_size,
 	const WebPPicture *picture ) {
-	VipsWebPMemoryWriter* const w = (VipsWebPMemoryWriter*) picture->custom_ptr;
+	VipsWebPMemoryWriter * const writer = 
+		(VipsWebPMemoryWriter*) picture->custom_ptr;
+
 	size_t next_size;
 
-	if( w == NULL )
+	if( !writer )
 		return( 0 );
 
-	next_size = w->size + data_size;
+	next_size = writer->size + data_size;
 
-	if( next_size > w->max_size ) {
+	if( next_size > writer->max_size ) {
 		uint8_t *new_mem;
 		const size_t next_max_size =
-			VIPS_MAX( 8192, VIPS_MAX( next_size, w->max_size * 2 ) );
+			VIPS_MAX( 8192, VIPS_MAX( next_size, 
+				writer->max_size * 2 ) );
 
-		new_mem = (uint8_t*) g_try_malloc( next_max_size );
-		if( new_mem == NULL )
+		if( !(new_mem = (uint8_t*) g_try_malloc( next_max_size )) ) 
 			return( 0 );
 
-		if( w->size > 0 )
-			memcpy( new_mem, w->mem, w->size );
+		if( writer->size > 0 )
+			memcpy( new_mem, writer->mem, writer->size );
 
-		g_free( w->mem );
-		w->mem = new_mem;
-		w->max_size = next_max_size;
+		g_free( writer->mem );
+		writer->mem = new_mem;
+		writer->max_size = next_max_size;
 	}
 
 	if( data_size > 0 ) {
-		memcpy( w->mem + w->size, data, data_size );
-		w->size += data_size;
+		memcpy( writer->mem + writer->size, data, data_size );
+		writer->size += data_size;
 	}
 
 	return( 1 );
@@ -142,7 +146,7 @@ write_webp( WebPPicture *pic, VipsImage *in,
 	WebPConfig config;
 	webp_import import;
 
-	if ( !WebPConfigPreset(&config, get_preset( preset ), Q) ) {
+	if ( !WebPConfigPreset( &config, get_preset( preset ), Q ) ) {
 		vips_error( "vips2webp",
 			"%s", _( "config version error" ) );
 		return( -1 );
@@ -178,7 +182,7 @@ write_webp( WebPPicture *pic, VipsImage *in,
 			"%s", _( "smart_subsample unsupported" ) );
 #endif
 
-	if( !WebPValidateConfig(&config) ) {
+	if( !WebPValidateConfig( &config ) ) {
 		vips_error( "vips2webp",
 			"%s", _( "invalid configuration" ) );
 		return( -1 );
@@ -269,7 +273,6 @@ vips__webp_write_buffer( VipsImage *in, void **obuf, size_t *olen,
 {
 	WebPPicture pic;
 	VipsWebPMemoryWriter writer;
-	FILE *fp;
 
 	if( !WebPPictureInit( &pic ) ) {
 		vips_error( "vips2webp", 
diff --git a/libvips/include/vips/foreign.h b/libvips/include/vips/foreign.h
index a3a9af8e..218b7470 100644
--- a/libvips/include/vips/foreign.h
+++ b/libvips/include/vips/foreign.h
@@ -341,11 +341,9 @@ int vips_jpegsave_mime( VipsImage *in, ... )
 /**
  * VipsForeignWebpPreset:
  * @VIPS_FOREIGN_WEBP_PRESET_DEFAULT: default preset
- * @VIPS_FOREIGN_WEBP_PRESET_PICTURE: digital picture, like portrait,
- * inner shot
+ * @VIPS_FOREIGN_WEBP_PRESET_PICTURE: digital picture, like portrait, inner shot
  * @VIPS_FOREIGN_WEBP_PRESET_PHOTO: outdoor photograph, with natural lighting
- * @VIPS_FOREIGN_WEBP_PRESET_DRAWING: hand or line drawing, with high-contrast
- * details
+ * @VIPS_FOREIGN_WEBP_PRESET_DRAWING: hand or line drawing, with high-contrast details
  * @VIPS_FOREIGN_WEBP_PRESET_ICON: small-sized colorful images
  * @VIPS_FOREIGN_WEBP_PRESET_TEXT: text-like
  *

From 1ae92bb15ff5eed7f8aa33f7148e6ba9b7a800ef Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Mon, 2 May 2016 10:12:37 +0100
Subject: [PATCH 12/34] make optional args into bullets

make docs easier to read
---
 libvips/arithmetic/hist_find.c         |   2 +-
 libvips/arithmetic/hist_find_ndim.c    |   2 +-
 libvips/arithmetic/hough_circle.c      |   6 +-
 libvips/arithmetic/hough_line.c        |   4 +-
 libvips/arithmetic/linear.c            |   4 +-
 libvips/arithmetic/max.c               |  12 +-
 libvips/arithmetic/measure.c           |   8 +-
 libvips/arithmetic/min.c               |  12 +-
 libvips/colour/colourspace.c           |   2 +-
 libvips/colour/icc_transform.c         |  24 ++--
 libvips/colour/scRGB2BW.c              |   2 +-
 libvips/colour/scRGB2sRGB.c            |   2 +-
 libvips/conversion/arrayjoin.c         |  14 +-
 libvips/conversion/autorot.c           |   2 +-
 libvips/conversion/bandfold.c          |   2 +-
 libvips/conversion/bandrank.c          |   2 +-
 libvips/conversion/bandunfold.c        |   2 +-
 libvips/conversion/cache.c             |   6 +-
 libvips/conversion/cast.c              |   2 +-
 libvips/conversion/copy.c              |  20 +--
 libvips/conversion/embed.c             |   4 +-
 libvips/conversion/extract.c           |   2 +-
 libvips/conversion/flatten.c           |   4 +-
 libvips/conversion/gamma.c             |   2 +-
 libvips/conversion/ifthenelse.c        |   2 +-
 libvips/conversion/insert.c            |   4 +-
 libvips/conversion/join.c              |   8 +-
 libvips/conversion/msb.c               |   2 +-
 libvips/conversion/premultiply.c       |   2 +-
 libvips/conversion/rot45.c             |   2 +-
 libvips/conversion/scale.c             |   4 +-
 libvips/conversion/sequential.c        |   6 +-
 libvips/conversion/subsample.c         |   2 +-
 libvips/conversion/tilecache.c         |  18 +--
 libvips/conversion/unpremultiply.c     |   2 +-
 libvips/conversion/wrap.c              |   4 +-
 libvips/convolution/conv.c             |   6 +-
 libvips/convolution/convsep.c          |   6 +-
 libvips/convolution/gaussblur.c        |   4 +-
 libvips/convolution/sharpen.c          |  12 +-
 libvips/create/black.c                 |   2 +-
 libvips/create/eye.c                   |   4 +-
 libvips/create/gaussmat.c              |   4 +-
 libvips/create/gaussnoise.c            |   4 +-
 libvips/create/grey.c                  |   2 +-
 libvips/create/identity.c              |   6 +-
 libvips/create/invertlut.c             |   2 +-
 libvips/create/logmat.c                |   4 +-
 libvips/create/mask_butterworth.c      |   8 +-
 libvips/create/mask_butterworth_band.c |   8 +-
 libvips/create/mask_butterworth_ring.c |   8 +-
 libvips/create/mask_fractal.c          |   8 +-
 libvips/create/mask_gaussian.c         |   8 +-
 libvips/create/mask_gaussian_band.c    |   8 +-
 libvips/create/mask_gaussian_ring.c    |   8 +-
 libvips/create/mask_ideal.c            |   8 +-
 libvips/create/mask_ideal_band.c       |   8 +-
 libvips/create/mask_ideal_ring.c       |   8 +-
 libvips/create/sines.c                 |   6 +-
 libvips/create/text.c                  |  10 +-
 libvips/create/tonelut.c               |  20 +--
 libvips/create/xyz.c                   |   6 +-
 libvips/create/zone.c                  |   2 +-
 libvips/draw/draw_circle.c             |   4 +-
 libvips/draw/draw_flood.c              |  24 ++--
 libvips/draw/draw_image.c              |   2 +-
 libvips/draw/draw_rect.c               |   4 +-
 libvips/foreign/csvload.c              |   8 +-
 libvips/foreign/csvsave.c              |   2 +-
 libvips/foreign/dzsave.c               |  20 +--
 libvips/foreign/foreign.c              | 178 ++++++++++++-------------
 libvips/foreign/ppmsave.c              |   4 +-
 libvips/foreign/rawload.c              |   2 +-
 libvips/freqfilt/invfft.c              |   2 +-
 libvips/histogram/hist_equal.c         |   2 +-
 libvips/histogram/maplut.c             |   2 +-
 libvips/histogram/stdif.c              |   8 +-
 libvips/iofuncs/image.c                |   4 +-
 libvips/iofuncs/system.c               |  10 +-
 libvips/morphology/labelregions.c      |   2 +-
 libvips/mosaicing/global_balance.c     |   4 +-
 libvips/mosaicing/match.c              |   8 +-
 libvips/mosaicing/merge.c              |   2 +-
 libvips/mosaicing/mosaic.c             |   8 +-
 libvips/mosaicing/mosaic1.c            |  12 +-
 libvips/resample/affine.c              |  12 +-
 libvips/resample/mapim.c               |   2 +-
 libvips/resample/quadratic.c           |   2 +-
 libvips/resample/reduce.c              |   2 +-
 libvips/resample/resize.c              |   4 +-
 libvips/resample/similarity.c          |  14 +-
 91 files changed, 362 insertions(+), 364 deletions(-)

diff --git a/libvips/arithmetic/hist_find.c b/libvips/arithmetic/hist_find.c
index 465d3452..35227c4a 100644
--- a/libvips/arithmetic/hist_find.c
+++ b/libvips/arithmetic/hist_find.c
@@ -475,7 +475,7 @@ vips_hist_find_init( VipsHistFind *hist_find )
  *
  * Optional arguments:
  *
- * @band: band to equalise
+ * * @band: band to equalise
  *
  * Find the histogram of @in. Find the histogram for band @band (producing a
  * one-band histogram), or for all bands (producing an n-band histogram) if 
diff --git a/libvips/arithmetic/hist_find_ndim.c b/libvips/arithmetic/hist_find_ndim.c
index e0d930d8..b0b3ce5f 100644
--- a/libvips/arithmetic/hist_find_ndim.c
+++ b/libvips/arithmetic/hist_find_ndim.c
@@ -323,7 +323,7 @@ vips_hist_find_ndim_init( VipsHistFindNDim *ndim )
  *
  * Optional arguments:
  *
- * @bins: number of bins to make on each axis
+ * * @bins: number of bins to make on each axis
  *
  * Make a one, two or three dimensional histogram of a 1, 2 or
  * 3 band image. Divide each axis into @bins bins .. ie.
diff --git a/libvips/arithmetic/hough_circle.c b/libvips/arithmetic/hough_circle.c
index 620345e1..fd3fd248 100644
--- a/libvips/arithmetic/hough_circle.c
+++ b/libvips/arithmetic/hough_circle.c
@@ -275,9 +275,9 @@ vips_hough_circle_init( VipsHoughCircle *hough_circle )
  *
  * Optional arguments:
  *
- * @scale: scale down dimensions by this much
- * @min_radius: smallest radius to search for
- * @max_radius: largest radius to search for
+ * * @scale: scale down dimensions by this much
+ * * @min_radius: smallest radius to search for
+ * * @max_radius: largest radius to search for
  *
  * Find the circular Hough transform of an image. @in must be one band, with
  * non-zero pixels for image edges. @out is three-band, with the third channel 
diff --git a/libvips/arithmetic/hough_line.c b/libvips/arithmetic/hough_line.c
index eaa5b8bd..e32e4be4 100644
--- a/libvips/arithmetic/hough_line.c
+++ b/libvips/arithmetic/hough_line.c
@@ -169,8 +169,8 @@ vips_hough_line_init( VipsHoughLine *hough_line )
  *
  * Optional arguments:
  *
- * @width: horizontal size of parameter space
- * @height: vertical size of parameter space
+ * * @width: horizontal size of parameter space
+ * * @height: vertical size of parameter space
  *
  * Find the line Hough transform for @in. @in must have one band. @out has one
  * band, with pixels being the number of votes for that line. The X dimension
diff --git a/libvips/arithmetic/linear.c b/libvips/arithmetic/linear.c
index 9aba5054..cad7751d 100644
--- a/libvips/arithmetic/linear.c
+++ b/libvips/arithmetic/linear.c
@@ -448,7 +448,7 @@ vips_linearv( VipsImage *in, VipsImage **out,
  *
  * Optional arguments:
  *
- * @uchar: output uchar pixels
+ * * @uchar: output uchar pixels
  *
  * Pass an image through a linear transform, ie. (@out = @in * @a + @b). Output
  * is float for integer input, double for double input, complex for
@@ -489,7 +489,7 @@ vips_linear( VipsImage *in, VipsImage **out, double *a, double *b, int n, ... )
  *
  * Optional arguments:
  *
- * @uchar: output uchar pixels
+ * * @uchar: output uchar pixels
  *
  * Run vips_linear() with a single constant. 
  *
diff --git a/libvips/arithmetic/max.c b/libvips/arithmetic/max.c
index f5fefc1b..14ba6e0f 100644
--- a/libvips/arithmetic/max.c
+++ b/libvips/arithmetic/max.c
@@ -486,12 +486,12 @@ vips_max_init( VipsMax *max )
  *
  * Optional arguments:
  *
- * @x: horizontal position of maximum
- * @y: vertical position of maximum
- * @size: number of maxima to find
- * @out_array: return array of maximum values
- * @x_array: corresponding horizontal positions
- * @y_array: corresponding vertical positions
+ * * @x: horizontal position of maximum
+ * * @y: vertical position of maximum
+ * * @size: number of maxima to find
+ * * @out_array: return array of maximum values
+ * * @x_array: corresponding horizontal positions
+ * * @y_array: corresponding vertical positions
  *
  * This operation finds the maximum value in an image. 
  *
diff --git a/libvips/arithmetic/measure.c b/libvips/arithmetic/measure.c
index 67d6feb6..9e7c881e 100644
--- a/libvips/arithmetic/measure.c
+++ b/libvips/arithmetic/measure.c
@@ -269,10 +269,10 @@ vips_measure_init( VipsMeasure *measure )
  *
  * Optional arguments:
  *
- * @left: area of image containing chart
- * @top: area of image containing chart
- * @width: area of image containing chart
- * @height: area of image containing chart
+ * * @left: area of image containing chart
+ * * @top: area of image containing chart
+ * * @width: area of image containing chart
+ * * @height: area of image containing chart
  *
  * Analyse a grid of colour patches, producing an array of patch averages.
  * The mask has a row for each measured patch and a column for each image
diff --git a/libvips/arithmetic/min.c b/libvips/arithmetic/min.c
index 0c58145e..f2c24e55 100644
--- a/libvips/arithmetic/min.c
+++ b/libvips/arithmetic/min.c
@@ -489,12 +489,12 @@ vips_min_init( VipsMin *min )
  *
  * Optional arguments:
  *
- * @x: horizontal position of minimum
- * @y: vertical position of minimum
- * @size: number of minima to find
- * @out_array: return array of minimum values
- * @x_array: corresponding horizontal positions
- * @y_array: corresponding vertical positions
+ * * @x: horizontal position of minimum
+ * * @y: vertical position of minimum
+ * * @size: number of minima to find
+ * * @out_array: return array of minimum values
+ * * @x_array: corresponding horizontal positions
+ * * @y_array: corresponding vertical positions
  *
  * This operation finds the minimum value in an image. 
  *
diff --git a/libvips/colour/colourspace.c b/libvips/colour/colourspace.c
index 298ecc2e..1221c3c2 100644
--- a/libvips/colour/colourspace.c
+++ b/libvips/colour/colourspace.c
@@ -625,7 +625,7 @@ vips_colourspace_init( VipsColourspace *colourspace )
  *
  * Optional arguments:
  *
- * @source_space: input colour space
+ * * @source_space: input colour space
  *
  * This operation looks at the interpretation field of @in (or uses
  * @source_space, if set) and runs
diff --git a/libvips/colour/icc_transform.c b/libvips/colour/icc_transform.c
index b9fbdab7..92c29785 100644
--- a/libvips/colour/icc_transform.c
+++ b/libvips/colour/icc_transform.c
@@ -1255,10 +1255,10 @@ vips_icc_ac2rc( VipsImage *in, VipsImage **out, const char *profile_filename )
  *
  * Optional arguments:
  *
- * @input_profile: get the input profile from here
- * @intent: transform with this intent
- * @embedded: use profile embedded in input image
- * @pcs: use XYZ or LAB PCS
+ * * @input_profile: get the input profile from here
+ * * @intent: transform with this intent
+ * * @embedded: use profile embedded in input image
+ * * @pcs: use XYZ or LAB PCS
  *
  * Import an image from device space to D65 LAB with an ICC profile. If @pcs is
  * set to #VIPS_PCS_XYZ, use CIE XYZ PCS instead. 
@@ -1294,10 +1294,10 @@ vips_icc_import( VipsImage *in, VipsImage **out, ... )
  *
  * Optional arguments:
  *
- * @intent: transform with this intent
- * @depth: depth of output image in bits
- * @output_profile: get the output profile from here
- * @pcs: use XYZ or LAB PCS
+ * * @intent: transform with this intent
+ * * @depth: depth of output image in bits
+ * * @output_profile: get the output profile from here
+ * * @pcs: use XYZ or LAB PCS
  *
  * Export an image from D65 LAB to device space with an ICC profile. 
  * If @pcs is
@@ -1330,10 +1330,10 @@ vips_icc_export( VipsImage *in, VipsImage **out, ... )
  *
  * Optional arguments:
  *
- * @input_profile: get the input profile from here
- * @intent: transform with this intent
- * @depth: depth of output image in bits
- * @embedded: use profile embedded in input image
+ * * @input_profile: get the input profile from here
+ * * @intent: transform with this intent
+ * * @depth: depth of output image in bits
+ * * @embedded: use profile embedded in input image
  *
  * Transform an image with a pair of ICC profiles. The input image is moved to
  * profile-connection space with the input profile and then to the output
diff --git a/libvips/colour/scRGB2BW.c b/libvips/colour/scRGB2BW.c
index 3d5803a7..19ee0411 100644
--- a/libvips/colour/scRGB2BW.c
+++ b/libvips/colour/scRGB2BW.c
@@ -268,7 +268,7 @@ vips_scRGB2BW_init( VipsscRGB2BW *scRGB2BW )
  *
  * Optional arguments:
  *
- * @depth: depth of output image in bits
+ * * @depth: depth of output image in bits
  *
  * Convert an scRGB image to greyscale. Set @depth to 16 to get 16-bit output.
  *
diff --git a/libvips/colour/scRGB2sRGB.c b/libvips/colour/scRGB2sRGB.c
index 6e3f2a78..83702485 100644
--- a/libvips/colour/scRGB2sRGB.c
+++ b/libvips/colour/scRGB2sRGB.c
@@ -296,7 +296,7 @@ vips_scRGB2sRGB_init( VipsscRGB2sRGB *scRGB2sRGB )
  *
  * Optional arguments:
  *
- * @depth: depth of output image in bits
+ * * @depth: depth of output image in bits
  *
  * Convert an scRGB image to sRGB. Set @depth to 16 to get 16-bit output.
  *
diff --git a/libvips/conversion/arrayjoin.c b/libvips/conversion/arrayjoin.c
index 712791c2..227c28b4 100644
--- a/libvips/conversion/arrayjoin.c
+++ b/libvips/conversion/arrayjoin.c
@@ -397,13 +397,13 @@ vips_arrayjoinv( VipsImage **in, VipsImage **out, int n, va_list ap )
  *
  * Optional arguments:
  *
- * @across: number of images per row
- * @shim: space between images, in pixels
- * @background: background ink colour
- * @halign: low, centre or high alignment
- * @valign: low, centre or high alignment
- * @hspacing: horizontal distance between images
- * @vspacing: vertical distance between images
+ * * @across: number of images per row
+ * * @shim: space between images, in pixels
+ * * @background: background ink colour
+ * * @halign: low, centre or high alignment
+ * * @valign: low, centre or high alignment
+ * * @hspacing: horizontal distance between images
+ * * @vspacing: vertical distance between images
  *
  * Lay out the images in @in in a grid. The grid is @across images across and
  * however high is necessary to use up all of @in. Images are set down
diff --git a/libvips/conversion/autorot.c b/libvips/conversion/autorot.c
index 17ccb120..f25994ee 100644
--- a/libvips/conversion/autorot.c
+++ b/libvips/conversion/autorot.c
@@ -214,7 +214,7 @@ vips_autorot_init( VipsAutorot *autorot )
  *
  * Optional arguments:
  *
- * @angle: output #VipsAngle the image was rotated by
+ * * @angle: output #VipsAngle the image was rotated by
  *
  * Look at the exif tags and rotate the image to make it upright. The
  * orientation tag is removed from @out to prevent accidental double rotation. 
diff --git a/libvips/conversion/bandfold.c b/libvips/conversion/bandfold.c
index 81635784..b5a1d309 100644
--- a/libvips/conversion/bandfold.c
+++ b/libvips/conversion/bandfold.c
@@ -186,7 +186,7 @@ vips_bandfold_init( VipsBandfold *bandfold )
  *
  * Optional arguments:
  *
- * @factor: fold by this factor
+ * * @factor: fold by this factor
  *
  * Fold up an image horizontally: width is collapsed into bands. 
  * Use @factor to set how much to fold by: @factor 3, for example, will make
diff --git a/libvips/conversion/bandrank.c b/libvips/conversion/bandrank.c
index 8f25f501..06ceb969 100644
--- a/libvips/conversion/bandrank.c
+++ b/libvips/conversion/bandrank.c
@@ -286,7 +286,7 @@ vips_bandrankv( VipsImage **in, VipsImage **out, int n, va_list ap )
  *
  * Optional arguments:
  *
- * @index: pick this index from list of sorted values
+ * * @index: pick this index from list of sorted values
  *
  * Sorts the images @in band-element-wise, then outputs an 
  * image in which each band element is selected from the sorted list by the 
diff --git a/libvips/conversion/bandunfold.c b/libvips/conversion/bandunfold.c
index ebfb5d53..c0491031 100644
--- a/libvips/conversion/bandunfold.c
+++ b/libvips/conversion/bandunfold.c
@@ -189,7 +189,7 @@ vips_bandunfold_init( VipsBandunfold *bandunfold )
  *
  * Optional arguments:
  *
- * @factor: unfold by this factor
+ * * @factor: unfold by this factor
  *
  * Unfold image bands into x axis. 
  * Use @factor to set how much to unfold by: @factor 3, for example, will make
diff --git a/libvips/conversion/cache.c b/libvips/conversion/cache.c
index 52f31790..a7243030 100644
--- a/libvips/conversion/cache.c
+++ b/libvips/conversion/cache.c
@@ -144,9 +144,9 @@ vips_cache_init( VipsCache *cache )
  *
  * Optional arguments:
  *
- * @tile_width: width of tiles in cache
- * @tile_height: height of tiles in cache
- * @max_tiles: maximum number of tiles to cache
+ * * @tile_width: width of tiles in cache
+ * * @tile_height: height of tiles in cache
+ * * @max_tiles: maximum number of tiles to cache
  *
  * This operation behaves rather like vips_copy() between images
  * @in and @out, except that it keeps a cache of computed pixels. 
diff --git a/libvips/conversion/cast.c b/libvips/conversion/cast.c
index 4650f1db..f9197478 100644
--- a/libvips/conversion/cast.c
+++ b/libvips/conversion/cast.c
@@ -587,7 +587,7 @@ vips_castv( VipsImage *in, VipsImage **out, VipsBandFormat format, va_list ap )
  *
  * Optional arguments:
  *
- * @shift: integer values are shifted
+ * * @shift: integer values are shifted
  *
  * Convert @in to @format. You can convert between any pair of formats.
  * Floats are truncated (not rounded). Out of range values are clipped.
diff --git a/libvips/conversion/copy.c b/libvips/conversion/copy.c
index b02359bc..eecf9ef5 100644
--- a/libvips/conversion/copy.c
+++ b/libvips/conversion/copy.c
@@ -366,16 +366,16 @@ vips_copy_init( VipsCopy *copy )
  *
  * Optional arguments:
  *
- * @width: set image width
- * @height: set image height
- * @bands: set image bands
- * @format: set image format
- * @coding: set image coding
- * @interpretation: set image interpretation
- * @xres: set image xres
- * @yres: set image yres
- * @xoffset: set image xoffset
- * @yoffset: set image yoffset
+ * * @width: set image width
+ * * @height: set image height
+ * * @bands: set image bands
+ * * @format: set image format
+ * * @coding: set image coding
+ * * @interpretation: set image interpretation
+ * * @xres: set image xres
+ * * @yres: set image yres
+ * * @xoffset: set image xoffset
+ * * @yoffset: set image yoffset
  *
  * Copy an image, optionally modifying the header. VIPS copies images by 
  * copying pointers, so this operation is instant, even for very large images.
diff --git a/libvips/conversion/embed.c b/libvips/conversion/embed.c
index 9e77dc85..14c1071d 100644
--- a/libvips/conversion/embed.c
+++ b/libvips/conversion/embed.c
@@ -627,8 +627,8 @@ vips_embed_init( VipsEmbed *embed )
  *
  * Optional arguments:
  *
- * @extend: #VipsExtend to generate the edge pixels (default: black)
- * @background: #VipsArrayDouble colour for edge pixels
+ * * @extend: #VipsExtend to generate the edge pixels (default: black)
+ * * @background: #VipsArrayDouble colour for edge pixels
  *
  * The opposite of vips_extract_area(): embed @in within an image of size 
  * @width by @height at position @x, @y.  
diff --git a/libvips/conversion/extract.c b/libvips/conversion/extract.c
index 052ea5f5..879efae1 100644
--- a/libvips/conversion/extract.c
+++ b/libvips/conversion/extract.c
@@ -455,7 +455,7 @@ vips_extract_band_init( VipsExtractBand *extract )
  *
  * Optional arguments:
  *
- * @n: number of bands to extract
+ * * @n: number of bands to extract
  *
  * Extract a band or bands from an image. Extracting out of range is an error.
  *
diff --git a/libvips/conversion/flatten.c b/libvips/conversion/flatten.c
index b95e0237..486515d3 100644
--- a/libvips/conversion/flatten.c
+++ b/libvips/conversion/flatten.c
@@ -409,8 +409,8 @@ vips_flatten_init( VipsFlatten *flatten )
  *
  * Optional arguments:
  *
- * @background: #VipsArrayDouble colour for new pixels 
- * @max_alpha: %gdouble, maximum value for alpha
+ * * @background: #VipsArrayDouble colour for new pixels 
+ * * @max_alpha: %gdouble, maximum value for alpha
  *
  * Take the last band of @in as an alpha and use it to blend the
  * remaining channels with @background. 
diff --git a/libvips/conversion/gamma.c b/libvips/conversion/gamma.c
index 4fe6549f..91fe63af 100644
--- a/libvips/conversion/gamma.c
+++ b/libvips/conversion/gamma.c
@@ -168,7 +168,7 @@ vips_gamma_init( VipsGamma *gamma )
  *
  * Optional arguments:
  *
- * @exponent: gamma, default 1.0 / 2.4
+ * * @exponent: gamma, default 1.0 / 2.4
  *
  * Calculate @in ** (1 / @exponent), normalising to the maximum range of the
  * input type. For float types use 1.0 as the maximum. 
diff --git a/libvips/conversion/ifthenelse.c b/libvips/conversion/ifthenelse.c
index 4b056b2c..eb5bb2b7 100644
--- a/libvips/conversion/ifthenelse.c
+++ b/libvips/conversion/ifthenelse.c
@@ -517,7 +517,7 @@ vips_ifthenelse_init( VipsIfthenelse *ifthenelse )
  *
  * Optional arguments:
  *
- * @blend: blend smoothly between @in1 and @in2
+ * * @blend: blend smoothly between @in1 and @in2
  *
  * This operation scans the condition image @cond 
  * and uses it to select pixels from either the then image @in1 or the else
diff --git a/libvips/conversion/insert.c b/libvips/conversion/insert.c
index f37dbd68..872c71d4 100644
--- a/libvips/conversion/insert.c
+++ b/libvips/conversion/insert.c
@@ -573,8 +573,8 @@ vips_insert_init( VipsInsert *insert )
  *
  * Optional arguments:
  *
- * @expand: expand output to hold whole of both images
- * @background: colour for new pixels
+ * * @expand: expand output to hold whole of both images
+ * * @background: colour for new pixels
  *
  * Insert @sub into @main at position @x, @y. 
  *
diff --git a/libvips/conversion/join.c b/libvips/conversion/join.c
index 8229fbca..7c2ccc57 100644
--- a/libvips/conversion/join.c
+++ b/libvips/conversion/join.c
@@ -296,10 +296,10 @@ vips_join_init( VipsJoin *join )
  *
  * Optional arguments:
  *
- * @expand: %TRUE to expand the output image to hold all of the input pixels
- * @shim: space between images, in pixels
- * @background: background ink colour
- * @align: low, centre or high alignment
+ * * @expand: %TRUE to expand the output image to hold all of the input pixels
+ * * @shim: space between images, in pixels
+ * * @background: background ink colour
+ * * @align: low, centre or high alignment
  *
  * Join @in1 and @in2 together, left-right or up-down depending on the value 
  * of @direction.
diff --git a/libvips/conversion/msb.c b/libvips/conversion/msb.c
index 33f931c8..9aeae360 100644
--- a/libvips/conversion/msb.c
+++ b/libvips/conversion/msb.c
@@ -269,7 +269,7 @@ vips_msb_init( VipsMsb *msb )
  *
  * Optional arguments:
  *
- * @band: msb just this band
+ * * @band: msb just this band
  *
  * Turn any integer image to 8-bit unsigned char by discarding all but the most
  * significant byte. Signed values are converted to unsigned by adding 128.
diff --git a/libvips/conversion/premultiply.c b/libvips/conversion/premultiply.c
index 4d842de3..7923100e 100644
--- a/libvips/conversion/premultiply.c
+++ b/libvips/conversion/premultiply.c
@@ -273,7 +273,7 @@ vips_premultiply_init( VipsPremultiply *premultiply )
  *
  * Optional arguments:
  *
- * @max_alpha: %gdouble, maximum value for alpha
+ * * @max_alpha: %gdouble, maximum value for alpha
  *
  * Premultiplies any alpha channel. 
  * The final band is taken to be the alpha
diff --git a/libvips/conversion/rot45.c b/libvips/conversion/rot45.c
index c049a5aa..dc0b1be7 100644
--- a/libvips/conversion/rot45.c
+++ b/libvips/conversion/rot45.c
@@ -291,7 +291,7 @@ vips_rot45_init( VipsRot45 *rot45 )
  *
  * Optional arguments:
  *
- * @angle: rotation angle
+ * * @angle: rotation angle
  *
  * Rotate @in by a multiple of 45 degrees. Odd-length sides and square images
  * only. 
diff --git a/libvips/conversion/scale.c b/libvips/conversion/scale.c
index af9980a9..492e80a7 100644
--- a/libvips/conversion/scale.c
+++ b/libvips/conversion/scale.c
@@ -183,8 +183,8 @@ vips_scale_init( VipsScale *scale )
  *
  * Optional arguments:
  *
- * @log: log scale pixels
- * @exp: exponent for log scale
+ * * @log: log scale pixels
+ * * @exp: exponent for log scale
  *
  * Search the image for the maximum and minimum value, then return the image
  * as unsigned 8-bit, scaled so that the maximum value is 255 and the
diff --git a/libvips/conversion/sequential.c b/libvips/conversion/sequential.c
index 5db03b3a..c6a6bbfc 100644
--- a/libvips/conversion/sequential.c
+++ b/libvips/conversion/sequential.c
@@ -364,9 +364,9 @@ vips_sequential_init( VipsSequential *sequential )
  *
  * Optional arguments:
  *
- * @trace: trace requests
- * @strip_height: height of cache strips
- * @access: access pattern
+ * * @trace: trace requests
+ * * @strip_height: height of cache strips
+ * * @access: access pattern
  *
  * This operation behaves rather like vips_copy() between images
  * @in and @out, except that it checks that pixels are only requested
diff --git a/libvips/conversion/subsample.c b/libvips/conversion/subsample.c
index bcf1234c..0f5029ac 100644
--- a/libvips/conversion/subsample.c
+++ b/libvips/conversion/subsample.c
@@ -314,7 +314,7 @@ vips_subsample_init( VipsSubsample *subsample )
  *
  * Optional arguments:
  *
- * @point: turn on point sample mode
+ * * @point: turn on point sample mode
  *
  * Subsample an image by an integer fraction. This is fast, nearest-neighbour
  * shrink.
diff --git a/libvips/conversion/tilecache.c b/libvips/conversion/tilecache.c
index c6c6702d..75873485 100644
--- a/libvips/conversion/tilecache.c
+++ b/libvips/conversion/tilecache.c
@@ -824,12 +824,12 @@ vips_tile_cache_init( VipsTileCache *cache )
  *
  * Optional arguments:
  *
- * @tile_width: width of tiles in cache
- * @tile_height: height of tiles in cache
- * @max_tiles: maximum number of tiles to cache
- * @access: hint expected access pattern #VipsAccess
- * @threaded: allow many threads
- * @persistent: don't drop cache at end of computation
+ * * @tile_width: width of tiles in cache
+ * * @tile_height: height of tiles in cache
+ * * @max_tiles: maximum number of tiles to cache
+ * * @access: hint expected access pattern #VipsAccess
+ * * @threaded: allow many threads
+ * * @persistent: don't drop cache at end of computation
  *
  * This operation behaves rather like vips_copy() between images
  * @in and @out, except that it keeps a cache of computed pixels. 
@@ -1018,9 +1018,9 @@ vips_line_cache_init( VipsLineCache *cache )
  *
  * Optional arguments:
  *
- * @access: hint expected access pattern #VipsAccess
- * @tile_height: height of tiles in cache
- * @threaded: allow many threads
+ * * @access: hint expected access pattern #VipsAccess
+ * * @tile_height: height of tiles in cache
+ * * @threaded: allow many threads
  *
  * This operation behaves rather like vips_copy() between images
  * @in and @out, except that it keeps a cache of computed scanlines. 
diff --git a/libvips/conversion/unpremultiply.c b/libvips/conversion/unpremultiply.c
index 6105d1e5..39f1f86e 100644
--- a/libvips/conversion/unpremultiply.c
+++ b/libvips/conversion/unpremultiply.c
@@ -283,7 +283,7 @@ vips_unpremultiply_init( VipsUnpremultiply *unpremultiply )
  *
  * Optional arguments:
  *
- * @max_alpha: %gdouble, maximum value for alpha
+ * * @max_alpha: %gdouble, maximum value for alpha
  *
  * Unpremultiplies any alpha channel. 
  * The final band is taken to be the alpha
diff --git a/libvips/conversion/wrap.c b/libvips/conversion/wrap.c
index 7c02f208..e97ef491 100644
--- a/libvips/conversion/wrap.c
+++ b/libvips/conversion/wrap.c
@@ -150,8 +150,8 @@ vips_wrap_init( VipsWrap *wrap )
  *
  * Optional arguments:
  *
- * @x: horizontal displacement
- * @y: vertical displacement
+ * * @x: horizontal displacement
+ * * @y: vertical displacement
  *
  * Slice an image up and move the segments about so that the pixel that was
  * at 0, 0 is now at @x, @y. If @x and @y are not set, they default to the
diff --git a/libvips/convolution/conv.c b/libvips/convolution/conv.c
index 234e275c..ff7dfd51 100644
--- a/libvips/convolution/conv.c
+++ b/libvips/convolution/conv.c
@@ -175,9 +175,9 @@ vips_conv_init( VipsConv *conv )
  *
  * Optional arguments:
  *
- * @precision: calculation accuracy
- * @layers: number of layers for approximation
- * @cluster: cluster lines closer than this distance
+ * * @precision: calculation accuracy
+ * * @layers: number of layers for approximation
+ * * @cluster: cluster lines closer than this distance
  *
  * Convolution. 
  *
diff --git a/libvips/convolution/convsep.c b/libvips/convolution/convsep.c
index dc3ceea2..7838ec41 100644
--- a/libvips/convolution/convsep.c
+++ b/libvips/convolution/convsep.c
@@ -143,9 +143,9 @@ vips_convsep_init( VipsConvsep *convsep )
  *
  * Optional arguments:
  *
- * @precision: calculation accuracy
- * @layers: number of layers for approximation
- * @cluster: cluster lines closer than this distance
+ * * @precision: calculation accuracy
+ * * @layers: number of layers for approximation
+ * * @cluster: cluster lines closer than this distance
  *
  * Perform a separable convolution of @in with @mask.
  * See vips_conv() for a detailed description.
diff --git a/libvips/convolution/gaussblur.c b/libvips/convolution/gaussblur.c
index ccb8c1d9..41800097 100644
--- a/libvips/convolution/gaussblur.c
+++ b/libvips/convolution/gaussblur.c
@@ -168,8 +168,8 @@ vips_gaussblur_init( VipsGaussblur *gaussblur )
  *
  * Optional arguments:
  *
- * @precision: #VipsPrecision for blur, default VIPS_PRECISION_INTEGER
- * @min_ampl: minimum amplitude, default 0.2
+ * * @precision: #VipsPrecision for blur, default VIPS_PRECISION_INTEGER
+ * * @min_ampl: minimum amplitude, default 0.2
  *
  * This operator runs vips_gaussmat() and vips_convsep() for you on an image.
  * Set @min_ampl smaller to generate a larger, more accurate mask. Set @sigma
diff --git a/libvips/convolution/sharpen.c b/libvips/convolution/sharpen.c
index 05e6abff..6a260fbe 100644
--- a/libvips/convolution/sharpen.c
+++ b/libvips/convolution/sharpen.c
@@ -394,12 +394,12 @@ vips_sharpen_init( VipsSharpen *sharpen )
  *
  * Optional arguments:
  *
- * @sigma: sigma of gaussian
- * @x1: flat/jaggy threshold
- * @y2: maximum amount of brightening
- * @y3: maximum amount of darkening
- * @m1: slope for flat areas
- * @m2: slope for jaggy areas
+ * * @sigma: sigma of gaussian
+ * * @x1: flat/jaggy threshold
+ * * @y2: maximum amount of brightening
+ * * @y3: maximum amount of darkening
+ * * @m1: slope for flat areas
+ * * @m2: slope for jaggy areas
  *
  * Selectively sharpen the L channel of a LAB image. The input image is
  * transformed to #VIPS_INTERPRETATION_LABS. 
diff --git a/libvips/create/black.c b/libvips/create/black.c
index dfa2ede2..65b567ac 100644
--- a/libvips/create/black.c
+++ b/libvips/create/black.c
@@ -162,7 +162,7 @@ vips_black_init( VipsBlack *black )
  *
  * Optional arguments:
  *
- * @bands: output bands
+ * * @bands: output bands
  *
  * Make a black unsigned char image of a specified size.
  *
diff --git a/libvips/create/eye.c b/libvips/create/eye.c
index c429b68e..edac0d3a 100644
--- a/libvips/create/eye.c
+++ b/libvips/create/eye.c
@@ -123,8 +123,8 @@ vips_eye_init( VipsEye *eye )
  *
  * Optional arguments:
  *
- * @factor: maximum spatial frequency
- * @uchar: output a uchar image
+ * * @factor: maximum spatial frequency
+ * * @uchar: output a uchar image
  *
  * Create a test pattern with increasing spatial frequence in X and 
  * amplitude in Y. @factor should be between 0 and 1 and determines the 
diff --git a/libvips/create/gaussmat.c b/libvips/create/gaussmat.c
index 93623d12..ba41013b 100644
--- a/libvips/create/gaussmat.c
+++ b/libvips/create/gaussmat.c
@@ -234,8 +234,8 @@ vips_gaussmat_init( VipsGaussmat *gaussmat )
  *
  * Optional arguments:
  *
- * @separable: generate a separable gaussian
- * @precision: #VipsPrecision for @out
+ * * @separable: generate a separable gaussian
+ * * @precision: #VipsPrecision for @out
  *
  * Creates a circularly symmetric Gaussian image of radius 
  * @sigma.  The size of the mask is determined by the variable @min_ampl; 
diff --git a/libvips/create/gaussnoise.c b/libvips/create/gaussnoise.c
index 5fee656e..1530905e 100644
--- a/libvips/create/gaussnoise.c
+++ b/libvips/create/gaussnoise.c
@@ -195,8 +195,8 @@ vips_gaussnoise_init( VipsGaussnoise *gaussnoise )
  *
  * Optional arguments:
  *
- * @mean: mean of generated pixels
- * @sigma: standard deviation of generated pixels
+ * * @mean: mean of generated pixels
+ * * @sigma: standard deviation of generated pixels
  *
  * Make a one band float image of gaussian noise with the specified
  * distribution. The noise distribution is created by averaging 12 random 
diff --git a/libvips/create/grey.c b/libvips/create/grey.c
index 2c602833..1ec5c58c 100644
--- a/libvips/create/grey.c
+++ b/libvips/create/grey.c
@@ -107,7 +107,7 @@ vips_grey_init( VipsGrey *grey )
  *
  * Optional arguments:
  *
- * @uchar: output a uchar image
+ * * @uchar: output a uchar image
  *
  * Create a one-band float image with the left-most column zero and the
  * right-most 1. Intermediate pixels are a linear ramp.
diff --git a/libvips/create/identity.c b/libvips/create/identity.c
index d596bd12..90241667 100644
--- a/libvips/create/identity.c
+++ b/libvips/create/identity.c
@@ -178,9 +178,9 @@ vips_identity_init( VipsIdentity *identity )
  *
  * Optional arguments:
  *
- * @bands: number of bands to create
- * @ushort: %TRUE for an unsigned short identity
- * @size: number of LUT elements for a ushort image
+ * * @bands: number of bands to create
+ * * @ushort: %TRUE for an unsigned short identity
+ * * @size: number of LUT elements for a ushort image
  *
  * Creates an identity lookup table, ie. one which will leave an image
  * unchanged when applied with vips_maplut(). Each entry in the table has a
diff --git a/libvips/create/invertlut.c b/libvips/create/invertlut.c
index e9c9b2b0..d2e99795 100644
--- a/libvips/create/invertlut.c
+++ b/libvips/create/invertlut.c
@@ -314,7 +314,7 @@ vips_invertlut_init( VipsInvertlut *lut )
  *
  * Optional arguments:
  *
- * @size: generate this much
+ * * @size: generate this much
  *
  * Given a mask of target values and real values, generate a LUT which
  * will map reals to targets. Handy for linearising images from
diff --git a/libvips/create/logmat.c b/libvips/create/logmat.c
index 64520504..db4384eb 100644
--- a/libvips/create/logmat.c
+++ b/libvips/create/logmat.c
@@ -251,8 +251,8 @@ vips_logmat_init( VipsLogmat *logmat )
  *
  * Optional arguments:
  *
- * @separable: generate a separable mask
- * @precision: #VipsPrecision for @out
+ * * @separable: generate a separable mask
+ * * @precision: #VipsPrecision for @out
  *
  * Creates a circularly symmetric Laplacian of Gaussian mask 
  * of radius 
diff --git a/libvips/create/mask_butterworth.c b/libvips/create/mask_butterworth.c
index 3e6c7f0a..35a75316 100644
--- a/libvips/create/mask_butterworth.c
+++ b/libvips/create/mask_butterworth.c
@@ -127,10 +127,10 @@ vips_mask_butterworth_init( VipsMaskButterworth *butterworth )
  *
  * Optional arguments:
  *
- * @nodc: don't set the DC pixel
- * @reject: invert the filter sense
- * @optical: coordinates in optical space
- * @uchar: output a uchar image
+ * * @nodc: don't set the DC pixel
+ * * @reject: invert the filter sense
+ * * @optical: coordinates in optical space
+ * * @uchar: output a uchar image
  *
  * Make an butterworth high- or low-pass filter, that is, one with a variable,
  * smooth transition
diff --git a/libvips/create/mask_butterworth_band.c b/libvips/create/mask_butterworth_band.c
index e29347d9..dd3e8865 100644
--- a/libvips/create/mask_butterworth_band.c
+++ b/libvips/create/mask_butterworth_band.c
@@ -171,10 +171,10 @@ vips_mask_butterworth_band_init(
  *
  * Optional arguments:
  *
- * @nodc: don't set the DC pixel
- * @reject: invert the filter sense
- * @optical: coordinates in optical space
- * @uchar: output a uchar image
+ * * @nodc: don't set the DC pixel
+ * * @reject: invert the filter sense
+ * * @optical: coordinates in optical space
+ * * @uchar: output a uchar image
  *
  * Make an butterworth band-pass or band-reject filter, that is, one with a 
  * variable, smooth transition positioned at @frequency_cutoff_x, 
diff --git a/libvips/create/mask_butterworth_ring.c b/libvips/create/mask_butterworth_ring.c
index cd3e7ec9..b5b252de 100644
--- a/libvips/create/mask_butterworth_ring.c
+++ b/libvips/create/mask_butterworth_ring.c
@@ -131,10 +131,10 @@ vips_mask_butterworth_ring_init(
  *
  * Optional arguments:
  *
- * @nodc: don't set the DC pixel
- * @reject: invert the filter sense
- * @optical: coordinates in optical space
- * @uchar: output a uchar image
+ * * @nodc: don't set the DC pixel
+ * * @reject: invert the filter sense
+ * * @optical: coordinates in optical space
+ * * @uchar: output a uchar image
  *
  * Make a butterworth ring-pass or ring-reject filter, that is, one with a 
  * variable,
diff --git a/libvips/create/mask_fractal.c b/libvips/create/mask_fractal.c
index 48b08b96..9031a415 100644
--- a/libvips/create/mask_fractal.c
+++ b/libvips/create/mask_fractal.c
@@ -114,10 +114,10 @@ vips_mask_fractal_init( VipsMaskFractal *fractal )
  *
  * Optional arguments:
  *
- * @nodc: don't set the DC pixel
- * @reject: invert the filter sense
- * @optical: coordinates in optical space
- * @uchar: output a uchar image
+ * * @nodc: don't set the DC pixel
+ * * @reject: invert the filter sense
+ * * @optical: coordinates in optical space
+ * * @uchar: output a uchar image
  *
  * This operation should be used to create fractal images by filtering the
  * power spectrum of Gaussian white noise. See vips_gaussnoise(). 
diff --git a/libvips/create/mask_gaussian.c b/libvips/create/mask_gaussian.c
index d59f5fc8..6dcf7372 100644
--- a/libvips/create/mask_gaussian.c
+++ b/libvips/create/mask_gaussian.c
@@ -116,10 +116,10 @@ vips_mask_gaussian_init( VipsMaskGaussian *gaussian )
  *
  * Optional arguments:
  *
- * @nodc: don't set the DC pixel
- * @reject: invert the filter sense
- * @optical: coordinates in optical space
- * @uchar: output a uchar image
+ * * @nodc: don't set the DC pixel
+ * * @reject: invert the filter sense
+ * * @optical: coordinates in optical space
+ * * @uchar: output a uchar image
  *
  * Make a gaussian high- or low-pass filter, that is, one with a variable,
  * smooth transition positioned at @frequency_cutoff.
diff --git a/libvips/create/mask_gaussian_band.c b/libvips/create/mask_gaussian_band.c
index 22dda78c..7218affd 100644
--- a/libvips/create/mask_gaussian_band.c
+++ b/libvips/create/mask_gaussian_band.c
@@ -155,10 +155,10 @@ vips_mask_gaussian_band_init( VipsMaskGaussianBand *gaussian_band )
  *
  * Optional arguments:
  *
- * @nodc: don't set the DC pixel
- * @reject: invert the filter sense
- * @optical: coordinates in optical space
- * @uchar: output a uchar image
+ * * @nodc: don't set the DC pixel
+ * * @reject: invert the filter sense
+ * * @optical: coordinates in optical space
+ * * @uchar: output a uchar image
  *
  * Make a gaussian band-pass or band-reject filter, that is, one with a 
  * variable, smooth transition positioned at @frequency_cutoff_x, 
diff --git a/libvips/create/mask_gaussian_ring.c b/libvips/create/mask_gaussian_ring.c
index c99a0b18..8afcf5d2 100644
--- a/libvips/create/mask_gaussian_ring.c
+++ b/libvips/create/mask_gaussian_ring.c
@@ -124,10 +124,10 @@ vips_mask_gaussian_ring_init( VipsMaskGaussianRing *gaussian_ring )
  *
  * Optional arguments:
  *
- * @nodc: don't set the DC pixel
- * @reject: invert the filter sense
- * @optical: coordinates in optical space
- * @uchar: output a uchar image
+ * * @nodc: don't set the DC pixel
+ * * @reject: invert the filter sense
+ * * @optical: coordinates in optical space
+ * * @uchar: output a uchar image
  *
  * Make a gaussian ring-pass or ring-reject filter, that is, one with a 
  * variable, smooth transition positioned at @frequency_cutoff of width
diff --git a/libvips/create/mask_ideal.c b/libvips/create/mask_ideal.c
index d8c5fc92..cce19192 100644
--- a/libvips/create/mask_ideal.c
+++ b/libvips/create/mask_ideal.c
@@ -105,10 +105,10 @@ vips_mask_ideal_init( VipsMaskIdeal *ideal )
  *
  * Optional arguments:
  *
- * @nodc: don't set the DC pixel
- * @reject: invert the filter sense
- * @optical: coordinates in optical space
- * @uchar: output a uchar image
+ * * @nodc: don't set the DC pixel
+ * * @reject: invert the filter sense
+ * * @optical: coordinates in optical space
+ * * @uchar: output a uchar image
  *
  * Make an ideal high- or low-pass filter, that is, one with a sharp cutoff
  * positioned at @frequency_cutoff, where @frequency_cutoff is in
diff --git a/libvips/create/mask_ideal_band.c b/libvips/create/mask_ideal_band.c
index 365712f0..6675b44e 100644
--- a/libvips/create/mask_ideal_band.c
+++ b/libvips/create/mask_ideal_band.c
@@ -137,10 +137,10 @@ vips_mask_ideal_band_init( VipsMaskIdealBand *ideal_band )
  *
  * Optional arguments:
  *
- * @nodc: don't set the DC pixel
- * @reject: invert the filter sense
- * @optical: coordinates in optical space
- * @uchar: output a uchar image
+ * * @nodc: don't set the DC pixel
+ * * @reject: invert the filter sense
+ * * @optical: coordinates in optical space
+ * * @uchar: output a uchar image
  *
  * Make an ideal band-pass or band-reject filter, that is, one with a 
  * sharp cutoff around the point @frequency_cutoff_x, @frequency_cutoff_y, 
diff --git a/libvips/create/mask_ideal_ring.c b/libvips/create/mask_ideal_ring.c
index 32e5b4ee..20e3831b 100644
--- a/libvips/create/mask_ideal_ring.c
+++ b/libvips/create/mask_ideal_ring.c
@@ -120,10 +120,10 @@ vips_mask_ideal_ring_init( VipsMaskIdealRing *ideal_ring )
  *
  * Optional arguments:
  *
- * @nodc: don't set the DC pixel
- * @reject: invert the filter sense
- * @optical: coordinates in optical space
- * @uchar: output a uchar image
+ * * @nodc: don't set the DC pixel
+ * * @reject: invert the filter sense
+ * * @optical: coordinates in optical space
+ * * @uchar: output a uchar image
  *
  * Make an ideal ring-pass or ring-reject filter, that is, one with a sharp 
  * ring positioned at @frequency_cutoff of width @width, where 
diff --git a/libvips/create/sines.c b/libvips/create/sines.c
index 5511b984..8a60cfb8 100644
--- a/libvips/create/sines.c
+++ b/libvips/create/sines.c
@@ -154,9 +154,9 @@ vips_sines_init( VipsSines *sines )
  *
  * Optional arguments:
  *
- * @hfreq: horizontal frequency
- * @vreq: vertical frequency
- * @uchar: output a uchar image
+ * * @hfreq: horizontal frequency
+ * * @vreq: vertical frequency
+ * * @uchar: output a uchar image
  *
  * Creates a float one band image of the a sine waveform in two
  * dimensions.  
diff --git a/libvips/create/text.c b/libvips/create/text.c
index 4ca4e000..90344c6c 100644
--- a/libvips/create/text.c
+++ b/libvips/create/text.c
@@ -341,11 +341,11 @@ vips_text_init( VipsText *text )
  *
  * Optional arguments:
  *
- * @font: font to render with
- * @width: render within this many pixels across
- * @alignment: left/centre/right alignment
- * @dpi: render at this resolution
- * @spacing: space lines by this in points
+ * * @font: font to render with
+ * * @width: render within this many pixels across
+ * * @alignment: left/centre/right alignment
+ * * @dpi: render at this resolution
+ * * @spacing: space lines by this in points
  *
  * Draw the string @text to an image. @out is a one-band 8-bit
  * unsigned char image, with 0 for no text and 255 for text. Values inbetween
diff --git a/libvips/create/tonelut.c b/libvips/create/tonelut.c
index 096221ae..b0e724c2 100644
--- a/libvips/create/tonelut.c
+++ b/libvips/create/tonelut.c
@@ -315,16 +315,16 @@ vips_tonelut_init( VipsTonelut *lut )
  *
  * Optional arguments:
  *
- * @in_max: input range 
- * @out_max: output range
- * @Lb: black-point [0-100]
- * @Lw: white-point [0-100]
- * @Ps: shadow point (eg. 0.2)
- * @Pm: mid-tone point (eg. 0.5)
- * @Ph: highlight point (eg. 0.8)
- * @S: shadow adjustment (+/- 30)
- * @M: mid-tone adjustment (+/- 30)
- * @H: highlight adjustment (+/- 30)
+ * * @in_max: input range 
+ * * @out_max: output range
+ * * @Lb: black-point [0-100]
+ * * @Lw: white-point [0-100]
+ * * @Ps: shadow point (eg. 0.2)
+ * * @Pm: mid-tone point (eg. 0.5)
+ * * @Ph: highlight point (eg. 0.8)
+ * * @S: shadow adjustment (+/- 30)
+ * * @M: mid-tone adjustment (+/- 30)
+ * * @H: highlight adjustment (+/- 30)
  *
  * vips_tonelut() generates a tone curve for the adjustment of image 
  * levels. It is mostly designed for adjusting the L* part of a LAB image in
diff --git a/libvips/create/xyz.c b/libvips/create/xyz.c
index 852de729..e00b5b22 100644
--- a/libvips/create/xyz.c
+++ b/libvips/create/xyz.c
@@ -246,9 +246,9 @@ vips_xyz_init( VipsXyz *xyz )
  *
  * Optional arguments:
  *
- * @csize: size for third dimension
- * @dsize: size for fourth dimension
- * @esize: size for fifth dimension
+ * * @csize: size for third dimension
+ * * @dsize: size for fourth dimension
+ * * @esize: size for fifth dimension
  *
  * Create a two-band uint32 image where the elements in the first band have the
  * value of their x coordinate and elements in the second band have their y
diff --git a/libvips/create/zone.c b/libvips/create/zone.c
index 53f90494..1f44afdb 100644
--- a/libvips/create/zone.c
+++ b/libvips/create/zone.c
@@ -106,7 +106,7 @@ vips_zone_init( VipsZone *zone )
  *
  * Optional arguments:
  *
- * @uchar: output a uchar image
+ * * @uchar: output a uchar image
  *
  * Create a one-band image of a zone plate. 
  *
diff --git a/libvips/draw/draw_circle.c b/libvips/draw/draw_circle.c
index a772e753..dee81e6f 100644
--- a/libvips/draw/draw_circle.c
+++ b/libvips/draw/draw_circle.c
@@ -294,7 +294,7 @@ vips_draw_circlev( VipsImage *image,
  *
  * Optional arguments:
  *
- * @fill: fill the draw_circle
+ * * @fill: fill the draw_circle
  *
  * Draws a circle on @image. If @fill is %TRUE then the circle is filled,
  * otherwise a 1-pixel-wide perimeter is drawn.
@@ -330,7 +330,7 @@ vips_draw_circle( VipsImage *image,
  *
  * Optional arguments:
  *
- * @fill: fill the draw_circle
+ * * @fill: fill the draw_circle
  *
  * As vips_draw_circle(), but just takes a single double for @ink. 
  *
diff --git a/libvips/draw/draw_flood.c b/libvips/draw/draw_flood.c
index 8f5f5029..7c1bf36f 100644
--- a/libvips/draw/draw_flood.c
+++ b/libvips/draw/draw_flood.c
@@ -685,12 +685,12 @@ vips_draw_floodv( VipsImage *image,
  *
  * Optional arguments:
  *
- * @test: test this image
- * @equal: fill while equal to edge
- * @left: output left edge of bounding box of modified area
- * @top: output top edge of bounding box of modified area
- * @width: output width of bounding box of modified area
- * @height: output height of bounding box of modified area
+ * * @test: test this image
+ * * @equal: fill while equal to edge
+ * * @left: output left edge of bounding box of modified area
+ * * @top: output top edge of bounding box of modified area
+ * * @width: output width of bounding box of modified area
+ * * @height: output height of bounding box of modified area
  *
  * Flood-fill @image with @ink, starting at position @x, @y. The filled area is
  * bounded by pixels that are equal to the ink colour, in other words, it
@@ -736,12 +736,12 @@ vips_draw_flood( VipsImage *image,
  *
  * Optional arguments:
  *
- * @test: test this image
- * @equal: fill while equal to edge
- * @left: output left edge of bounding box of modified area
- * @top: output top edge of bounding box of modified area
- * @width: output width of bounding box of modified area
- * @height: output height of bounding box of modified area
+ * * @test: test this image
+ * * @equal: fill while equal to edge
+ * * @left: output left edge of bounding box of modified area
+ * * @top: output top edge of bounding box of modified area
+ * * @width: output width of bounding box of modified area
+ * * @height: output height of bounding box of modified area
  *
  * As vips_draw_flood(), but just takes a single double for @ink. 
  *
diff --git a/libvips/draw/draw_image.c b/libvips/draw/draw_image.c
index c56bd486..3f9aa053 100644
--- a/libvips/draw/draw_image.c
+++ b/libvips/draw/draw_image.c
@@ -300,7 +300,7 @@ vips_draw_image_init( VipsDrawImage *draw_image )
  *
  * Optional arguments:
  *
- * @mode: how to combine pixels 
+ * * @mode: how to combine pixels 
  *
  * Draw @sub on top of @image at position @x, @y. The two images must have the 
  * same Coding. If @sub has 1 band, the bands will be duplicated to match the
diff --git a/libvips/draw/draw_rect.c b/libvips/draw/draw_rect.c
index decb1cc5..261c6517 100644
--- a/libvips/draw/draw_rect.c
+++ b/libvips/draw/draw_rect.c
@@ -240,7 +240,7 @@ vips_draw_rectv( VipsImage *image,
  *
  * Optional arguments:
  *
- * @fill: fill the rect
+ * * @fill: fill the rect
  *
  * Paint pixels within @left, @top, @width, @height in @image with @ink. If
  * @fill is zero, just paint a 1-pixel-wide outline.
@@ -276,7 +276,7 @@ vips_draw_rect( VipsImage *image,
  *
  * Optional arguments:
  *
- * @fill: fill the rect
+ * * @fill: fill the rect
  *
  * As vips_draw_rect(), but just take a single double for @ink. 
  *
diff --git a/libvips/foreign/csvload.c b/libvips/foreign/csvload.c
index ad1b3646..d4deed4b 100644
--- a/libvips/foreign/csvload.c
+++ b/libvips/foreign/csvload.c
@@ -187,10 +187,10 @@ vips_foreign_load_csv_init( VipsForeignLoadCsv *csv )
  *
  * Optional arguments:
  *
- * @skip: skip this many lines at start of file
- * @lines: read this many lines from file
- * @whitespace: set of whitespace characters
- * @separator: set of separator characters
+ * * @skip: skip this many lines at start of file
+ * * @lines: read this many lines from file
+ * * @whitespace: set of whitespace characters
+ * * @separator: set of separator characters
  *
  * Load a CSV (comma-separated values) file. The output image is always 1 
  * band (monochrome), #VIPS_FORMAT_DOUBLE. Use vips_bandfold() to turn
diff --git a/libvips/foreign/csvsave.c b/libvips/foreign/csvsave.c
index 11aa2ae6..483d2fb3 100644
--- a/libvips/foreign/csvsave.c
+++ b/libvips/foreign/csvsave.c
@@ -128,7 +128,7 @@ vips_foreign_save_csv_init( VipsForeignSaveCsv *csv )
  *
  * Optional arguments:
  *
- * @separator: separator string
+ * * @separator: separator string
  *
  * Writes the pixels in @in to the @filename as CSV (comma-separated values).
  * The image is written
diff --git a/libvips/foreign/dzsave.c b/libvips/foreign/dzsave.c
index 44b321e3..c4eee553 100644
--- a/libvips/foreign/dzsave.c
+++ b/libvips/foreign/dzsave.c
@@ -2047,16 +2047,16 @@ vips_foreign_save_dz_init( VipsForeignSaveDz *dz )
  *
  * Optional arguments:
  *
- * @layout; directory layout convention
- * @suffix: suffix for tile tiles 
- * @overlap; set tile overlap 
- * @tile_size; set tile size 
- * @background: background colour
- * @depth: how deep to make the pyramid
- * @centre: centre the tiles 
- * @angle: rotate the image by this much
- * @container: set container type
- * @properties: write a properties file
+ * * @layout; directory layout convention
+ * * @suffix: suffix for tile tiles 
+ * * @overlap; set tile overlap 
+ * * @tile_size; set tile size 
+ * * @background: background colour
+ * * @depth: how deep to make the pyramid
+ * * @centre: centre the tiles 
+ * * @angle: rotate the image by this much
+ * * @container: set container type
+ * * @properties: write a properties file
  *
  * Save an image as a set of tiles at various resolutions. By default dzsave
  * uses DeepZoom layout -- use @layout to pick other conventions.
diff --git a/libvips/foreign/foreign.c b/libvips/foreign/foreign.c
index 2b7cffdc..2a92516b 100644
--- a/libvips/foreign/foreign.c
+++ b/libvips/foreign/foreign.c
@@ -1823,8 +1823,8 @@ vips_vipssave( VipsImage *in, const char *filename, ... )
  *
  * Optional arguments:
  *
- * @all_frames: %gboolean, load all frames in sequence
- * @density: string, canvas resolution for rendering vector formats like SVG
+ * * @all_frames: %gboolean, load all frames in sequence
+ * * @density: string, canvas resolution for rendering vector formats like SVG
  *
  * Read in an image using libMagick, the ImageMagick library. This library can
  * read more than 80 file formats, including SVG, BMP, EPS, DICOM and many 
@@ -1870,8 +1870,8 @@ vips_magickload( const char *filename, VipsImage **out, ... )
  *
  * Optional arguments:
  *
- * @all_frames: %gboolean, load all frames in sequence
- * @density: string, canvas resolution for rendering vector formats like SVG
+ * * @all_frames: %gboolean, load all frames in sequence
+ * * @density: string, canvas resolution for rendering vector formats like SVG
  *
  * Read an image memory block using libMagick into a VIPS image. Exactly as
  * vips_magickload(), but read from a memory source. 
@@ -1911,7 +1911,7 @@ vips_magickload_buffer( void *buf, size_t len, VipsImage **out, ... )
  *
  * Optional arguments:
  *
- * @page: int, load this page
+ * * @page: int, load this page
  *
  * Read a TIFF file into a VIPS image. It is a full baseline TIFF 6 reader, 
  * with extensions for tiled images, multipage images, LAB colour space, 
@@ -1949,7 +1949,7 @@ vips_tiffload( const char *filename, VipsImage **out, ... )
  *
  * Optional arguments:
  *
- * @page: %gint, load this page
+ * * @page: %gint, load this page
  *
  * Read a TIFF-formatted memory block into a VIPS image. Exactly as
  * vips_tiffload(), but read from a memory source. 
@@ -1989,20 +1989,20 @@ vips_tiffload_buffer( void *buf, size_t len, VipsImage **out, ... )
  *
  * Optional arguments:
  *
- * @compression: use this #VipsForeignTiffCompression
- * @Q: %gint quality factor
- * @predictor: use this #VipsForeignTiffPredictor
- * @profile: filename of ICC profile to attach
- * @tile: set %TRUE to write a tiled tiff
- * @tile_width: %gint for tile size
- * @tile_height: %gint for tile size
- * @pyramid: set %TRUE to write an image pyramid
- * @squash: set %TRUE to squash 8-bit images down to 1 bit
- * @miniswhite: set %TRUE to write 1-bit images as MINISWHITE
- * @resunit: #VipsForeignTiffResunit for resolution unit
- * @xres: %gdouble horizontal resolution in pixels/mm
- * @yres: %gdouble vertical resolution in pixels/mm
- * @bigtiff: set %TRUE to write a BigTiff file
+ * * @compression: use this #VipsForeignTiffCompression
+ * * @Q: %gint quality factor
+ * * @predictor: use this #VipsForeignTiffPredictor
+ * * @profile: filename of ICC profile to attach
+ * * @tile: set %TRUE to write a tiled tiff
+ * * @tile_width: %gint for tile size
+ * * @tile_height: %gint for tile size
+ * * @pyramid: set %TRUE to write an image pyramid
+ * * @squash: set %TRUE to squash 8-bit images down to 1 bit
+ * * @miniswhite: set %TRUE to write 1-bit images as MINISWHITE
+ * * @resunit: #VipsForeignTiffResunit for resolution unit
+ * * @xres: %gdouble horizontal resolution in pixels/mm
+ * * @yres: %gdouble vertical resolution in pixels/mm
+ * * @bigtiff: set %TRUE to write a BigTiff file
  *
  * Write a VIPS image to a file as TIFF.
  *
@@ -2089,9 +2089,9 @@ vips_tiffsave( VipsImage *in, const char *filename, ... )
  *
  * Optional arguments:
  *
- * @shrink: %gint, shrink by this much on load
- * @fail: %gboolean, fail on warnings
- * @autorotate: %gboolean, use exif Orientation tag to rotate the image during load
+ * * @shrink: %gint, shrink by this much on load
+ * * @fail: %gboolean, fail on warnings
+ * * @autorotate: %gboolean, use exif Orientation tag to rotate the image during load
  *
  * Read a JPEG file into a VIPS image. It can read most 8-bit JPEG images, 
  * including CMYK and YCbCr.
@@ -2167,8 +2167,8 @@ vips_jpegload( const char *filename, VipsImage **out, ... )
  *
  * Optional arguments:
  *
- * @shrink: %gint, shrink by this much on load
- * @fail: %gboolean, fail on warnings
+ * * @shrink: %gint, shrink by this much on load
+ * * @fail: %gboolean, fail on warnings
  *
  * Read a JPEG-formatted memory block into a VIPS image. Exactly as
  * vips_jpegload(), but read from a memory buffer. 
@@ -2208,15 +2208,15 @@ vips_jpegload_buffer( void *buf, size_t len, VipsImage **out, ... )
  *
  * Optional arguments:
  *
- * @Q: %gint, quality factor
- * @profile: filename of ICC profile to attach
- * @optimize_coding: %gboolean, compute optimal Huffman coding tables
- * @interlace: %gboolean, write an interlaced (progressive) jpeg
- * @strip: %gboolean, remove all metadata from image
- * @no-subsample: %gboolean, disable chroma subsampling
- * @trellis_quant: %gboolean, apply trellis quantisation to each 8x8 block
- * @overshoot_deringing: %gboolean, overshoot samples with extreme values
- * @optimize_scans: %gboolean, split DCT coefficients into separate scans
+ * * @Q: %gint, quality factor
+ * * @profile: filename of ICC profile to attach
+ * * @optimize_coding: %gboolean, compute optimal Huffman coding tables
+ * * @interlace: %gboolean, write an interlaced (progressive) jpeg
+ * * @strip: %gboolean, remove all metadata from image
+ * * @no-subsample: %gboolean, disable chroma subsampling
+ * * @trellis_quant: %gboolean, apply trellis quantisation to each 8x8 block
+ * * @overshoot_deringing: %gboolean, overshoot samples with extreme values
+ * * @optimize_scans: %gboolean, split DCT coefficients into separate scans
  *
  * Write a VIPS image to a file as JPEG.
  *
@@ -2294,15 +2294,15 @@ vips_jpegsave( VipsImage *in, const char *filename, ... )
  *
  * Optional arguments:
  *
- * @Q: JPEG quality factor
- * @profile: attach this ICC profile
- * @optimize_coding: compute optimal Huffman coding tables
- * @interlace: write an interlaced (progressive) jpeg
- * @strip: remove all metadata from image
- * @no-subsample: disable chroma subsampling
- * @trellis_quant: %gboolean, apply trellis quantisation to each 8x8 block
- * @overshoot_deringing: %gboolean, overshoot samples with extreme values
- * @optimize_scans: %gboolean, split DCT coefficients into separate scans
+ * * @Q: JPEG quality factor
+ * * @profile: attach this ICC profile
+ * * @optimize_coding: compute optimal Huffman coding tables
+ * * @interlace: write an interlaced (progressive) jpeg
+ * * @strip: remove all metadata from image
+ * * @no-subsample: disable chroma subsampling
+ * * @trellis_quant: %gboolean, apply trellis quantisation to each 8x8 block
+ * * @overshoot_deringing: %gboolean, overshoot samples with extreme values
+ * * @optimize_scans: %gboolean, split DCT coefficients into separate scans
  *
  * As vips_jpegsave(), but save to a memory buffer. 
  *
@@ -2349,14 +2349,14 @@ vips_jpegsave_buffer( VipsImage *in, void **buf, size_t *len, ... )
  *
  * Optional arguments:
  *
- * @Q: JPEG quality factor
- * @profile: attach this ICC profile
- * @optimize_coding: compute optimal Huffman coding tables
- * @strip: remove all metadata from image
- * @no-subsample: disable chroma subsampling
- * @trellis_quant: %gboolean, apply trellis quantisation to each 8x8 block
- * @overshoot_deringing: %gboolean, overshoot samples with extreme values
- * @optimize_scans: %gboolean, split DCT coefficients into separate scans
+ * * @Q: JPEG quality factor
+ * * @profile: attach this ICC profile
+ * * @optimize_coding: compute optimal Huffman coding tables
+ * * @strip: remove all metadata from image
+ * * @no-subsample: disable chroma subsampling
+ * * @trellis_quant: %gboolean, apply trellis quantisation to each 8x8 block
+ * * @overshoot_deringing: %gboolean, overshoot samples with extreme values
+ * * @optimize_scans: %gboolean, split DCT coefficients into separate scans
  *
  * As vips_jpegsave(), but save as a mime jpeg on stdout.
  *
@@ -2385,7 +2385,7 @@ vips_jpegsave_mime( VipsImage *in, ... )
  *
  * Optional arguments:
  *
- * @shrink: %gint, shrink by this much on load
+ * * @shrink: %gint, shrink by this much on load
  *
  * Read a WebP file into a VIPS image. 
  *
@@ -2417,7 +2417,7 @@ vips_webpload( const char *filename, VipsImage **out, ... )
  *
  * Optional arguments:
  *
- * @shrink: %gint, shrink by this much on load
+ * * @shrink: %gint, shrink by this much on load
  *
  * Read a WebP-formatted memory block into a VIPS image. Exactly as
  * vips_webpload(), but read from a memory buffer. 
@@ -2505,12 +2505,12 @@ vips_webpsave( VipsImage *in, const char *filename, ... )
  *
  * Optional arguments:
  *
- * @Q: %gint quality factor
- * @lossless: %gboolean enables lossless compression
- * @preset: #VipsForeignWebpPreset choose lossy compression preset
- * @smart_subsample: %gboolean enables high quality chroma subsampling
- * @near_lossless: %gboolean use preprocessing in lossless mode (controlled by Q)
- * @alpha_q: %gint set alpha quality in lossless mode
+ * * @Q: %gint quality factor
+ * * @lossless: %gboolean enables lossless compression
+ * * @preset: #VipsForeignWebpPreset choose lossy compression preset
+ * * @smart_subsample: %gboolean enables high quality chroma subsampling
+ * * @near_lossless: %gboolean use preprocessing in lossless mode (controlled by Q)
+ * * @alpha_q: %gint set alpha quality in lossless mode
  *
  * As vips_webpsave(), but save to a memory buffer.
  *
@@ -2557,12 +2557,12 @@ vips_webpsave_buffer( VipsImage *in, void **buf, size_t *len, ... )
  *
  * Optional arguments:
  *
- * @Q: %gint quality factor
- * @lossless: %gboolean enables lossless compression
- * @preset: #VipsForeignWebpPreset choose lossy compression preset
- * @smart_subsample: %gboolean enables high quality chroma subsampling
- * @near_lossless: %gboolean use preprocessing in lossless mode (controlled by Q)
- * @alpha_q: %gint set alpha quality in lossless mode
+ * * @Q: %gint quality factor
+ * * @lossless: %gboolean enables lossless compression
+ * * @preset: #VipsForeignWebpPreset choose lossy compression preset
+ * * @smart_subsample: %gboolean enables high quality chroma subsampling
+ * * @near_lossless: %gboolean use preprocessing in lossless mode (controlled by Q)
+ * * @alpha_q: %gint set alpha quality in lossless mode
  *
  * As vips_webpsave(), but save as a mime webp on stdout.
  *
@@ -2623,9 +2623,9 @@ vips_openexrload( const char *filename, VipsImage **out, ... )
  *
  * Optional arguments:
  *
- * @level: load this level
- * @associated: load this associated image
- * @autocrop: crop to image bounds
+ * * @level: load this level
+ * * @associated: load this associated image
+ * * @autocrop: crop to image bounds
  *
  * Read a virtual slide supported by the OpenSlide library into a VIPS image.
  * OpenSlide supports images in Aperio, Hamamatsu, MIRAX, Sakura, Trestle,
@@ -2726,8 +2726,6 @@ vips_fitssave( VipsImage *in, const char *filename, ... )
  * @out: decompressed image
  * @...: %NULL-terminated list of optional named arguments
  *
- * Optional arguments:
- *
  * Read a PNG file into a VIPS image. It can read all png images, including 8-
  * and 16-bit images, 1 and 3 channel, with and without an alpha channel.
  *
@@ -2798,10 +2796,10 @@ vips_pngload_buffer( void *buf, size_t len, VipsImage **out, ... )
  *
  * Optional arguments:
  *
- * @compression: compression level
- * @interlace: interlace image
- * @profile: ICC profile to embed
- * @filter: #VipsForeignPngFilter row filter flag(s)
+ * * @compression: compression level
+ * * @interlace: interlace image
+ * * @profile: ICC profile to embed
+ * * @filter: #VipsForeignPngFilter row filter flag(s)
  *
  * Write a VIPS image to a file as PNG.
  *
@@ -2854,10 +2852,10 @@ vips_pngsave( VipsImage *in, const char *filename, ... )
  *
  * Optional arguments:
  *
- * @compression: compression level
- * @interlace: interlace image
- * @profile: ICC profile to embed
- * @filter: libpng row filter flag(s)
+ * * @compression: compression level
+ * * @interlace: interlace image
+ * * @profile: ICC profile to embed
+ * * @filter: libpng row filter flag(s)
  *
  * As vips_pngsave(), but save to a memory buffer. 
  *
@@ -2935,9 +2933,9 @@ vips_matload( const char *filename, VipsImage **out, ... )
  *
  * Optional arguments:
  *
- * @page: %gint, load this page, numbered from zero
- * @dpi: %gdouble, render at this DPI
- * @scale: %gdouble, scale render by this factor
+ * * @page: %gint, load this page, numbered from zero
+ * * @dpi: %gdouble, render at this DPI
+ * * @scale: %gdouble, scale render by this factor
  *
  * Render a PDF file into a VIPS image. Rendering uses the libpoppler library
  * and should be fast. 
@@ -2996,9 +2994,9 @@ vips_pdfload( const char *filename, VipsImage **out, ... )
  *
  * Optional arguments:
  *
- * @page: %gint, load this page, numbered from zero
- * @dpi: %gdouble, render at this DPI
- * @scale: %gdouble, scale render by this factor
+ * * @page: %gint, load this page, numbered from zero
+ * * @dpi: %gdouble, render at this DPI
+ * * @scale: %gdouble, scale render by this factor
  *
  * Read a PDF-formatted memory block into a VIPS image. Exactly as
  * vips_pdfload(), but read from a memory buffer. 
@@ -3038,8 +3036,8 @@ vips_pdfload_buffer( void *buf, size_t len, VipsImage **out, ... )
  *
  * Optional arguments:
  *
- * @dpi: %gdouble, render at this DPI
- * @scale: %gdouble, scale render by this factor
+ * * @dpi: %gdouble, render at this DPI
+ * * @scale: %gdouble, scale render by this factor
  *
  * Render a SVG file into a VIPS image.  Rendering uses the librsvg library
  * and should be fast.
@@ -3076,8 +3074,8 @@ vips_svgload( const char *filename, VipsImage **out, ... )
  *
  * Optional arguments:
  *
- * @dpi: %gdouble, render at this DPI
- * @scale: %gdouble, scale render by this factor
+ * * @dpi: %gdouble, render at this DPI
+ * * @scale: %gdouble, scale render by this factor
  *
  * Read a SVG-formatted memory block into a VIPS image. Exactly as
  * vips_svgload(), but read from a memory buffer. 
@@ -3117,7 +3115,7 @@ vips_svgload_buffer( void *buf, size_t len, VipsImage **out, ... )
  *
  * Optional arguments:
  *
- * @page: %ginit, page (frame) to read
+ * * @page: %ginit, page (frame) to read
  *
  * Read a GIF file into a VIPS image.  Rendering uses the giflib library.
  *
@@ -3152,7 +3150,7 @@ vips_gifload( const char *filename, VipsImage **out, ... )
  *
  * Optional arguments:
  *
- * @page: %ginit, page (frame) to read
+ * * @page: %ginit, page (frame) to read
  *
  * Read a GIF-formatted memory block into a VIPS image. Exactly as
  * vips_gifload(), but read from a memory buffer. 
diff --git a/libvips/foreign/ppmsave.c b/libvips/foreign/ppmsave.c
index 178011af..f6ac8988 100644
--- a/libvips/foreign/ppmsave.c
+++ b/libvips/foreign/ppmsave.c
@@ -156,8 +156,8 @@ vips_foreign_save_ppm_init( VipsForeignSavePpm *ppm )
  *
  * Optional arguments:
  *
- * @ascii: save as ASCII rather than binary
- * @squash: squash 8-bit images down to one bit
+ * * @ascii: save as ASCII rather than binary
+ * * @squash: squash 8-bit images down to one bit
  *
  * Write a VIPS image to a file as PPM. It can write 1, 8, 16 or
  * 32 bit unsigned integer images, float images, colour or monochrome, 
diff --git a/libvips/foreign/rawload.c b/libvips/foreign/rawload.c
index 98cf4ec5..e6dd73d5 100644
--- a/libvips/foreign/rawload.c
+++ b/libvips/foreign/rawload.c
@@ -165,7 +165,7 @@ vips_foreign_load_raw_init( VipsForeignLoadRaw *raw )
  *
  * Optional arguments:
  *
- * @offset: offset in bytes from start of file
+ * * @offset: offset in bytes from start of file
  *
  * This operation mmaps the file, setting @out so that access to that 
  * image will read from the file. 
diff --git a/libvips/freqfilt/invfft.c b/libvips/freqfilt/invfft.c
index c3d8c45b..80ebfa30 100644
--- a/libvips/freqfilt/invfft.c
+++ b/libvips/freqfilt/invfft.c
@@ -276,7 +276,7 @@ vips_invfft_init( VipsInvfft *invfft )
  *
  * Optional arguments:
  *
- * @real: only output the real part
+ * * @real: only output the real part
  *
  * Transform an image from Fourier space to real space. The result is complex.
  * If you are OK with a real result, set @real, it's quicker.
diff --git a/libvips/histogram/hist_equal.c b/libvips/histogram/hist_equal.c
index 9c380c54..b6d527dc 100644
--- a/libvips/histogram/hist_equal.c
+++ b/libvips/histogram/hist_equal.c
@@ -138,7 +138,7 @@ vips_hist_equal_init( VipsHistEqual *equal )
  *
  * Optional arguments:
  *
- * @band: band to equalise
+ * * @band: band to equalise
  *
  * Histogram-equalise @in. Equalise using band @bandno, or if @bandno is -1,
  * equalise bands independently.
diff --git a/libvips/histogram/maplut.c b/libvips/histogram/maplut.c
index 14154c35..09631b95 100644
--- a/libvips/histogram/maplut.c
+++ b/libvips/histogram/maplut.c
@@ -735,7 +735,7 @@ vips_maplut_init( VipsMaplut *maplut )
  *
  * Optional arguments:
  *
- * @band: apply one-band @lut to this band of @in
+ * * @band: apply one-band @lut to this band of @in
  *
  * Map an image through another image acting as a LUT (Look Up Table). 
  * The lut may have any type and the output image will be that type.
diff --git a/libvips/histogram/stdif.c b/libvips/histogram/stdif.c
index 6f0977b3..da701555 100644
--- a/libvips/histogram/stdif.c
+++ b/libvips/histogram/stdif.c
@@ -367,10 +367,10 @@ vips_stdif_init( VipsStdif *stdif )
  *
  * Optional arguments:
  *
- * @a: weight of new mean
- * @m0: target mean
- * @b: weight of new deviation
- * @s0: target deviation
+ * * @a: weight of new mean
+ * * @m0: target mean
+ * * @b: weight of new deviation
+ * * @s0: target deviation
  *
  * vips_stdif() preforms statistical differencing according to the formula
  * given in page 45 of the book "An Introduction to Digital Image 
diff --git a/libvips/iofuncs/image.c b/libvips/iofuncs/image.c
index 3fc640e5..bf33c6cc 100644
--- a/libvips/iofuncs/image.c
+++ b/libvips/iofuncs/image.c
@@ -1837,8 +1837,8 @@ vips_filename_get_options( const char *vips_filename )
  *
  * Optional arguments:
  *
- * @access: hint #VipsAccess mode to loader
- * @disc: load via a temporary disc file
+ * * @access: hint #VipsAccess mode to loader
+ * * @disc: load via a temporary disc file
  *
  * vips_image_new_from_file() opens @name for reading. It can load files
  * in many image formats, including VIPS, TIFF, PNG, JPEG, FITS, Matlab,
diff --git a/libvips/iofuncs/system.c b/libvips/iofuncs/system.c
index 39ddff2d..6357f869 100644
--- a/libvips/iofuncs/system.c
+++ b/libvips/iofuncs/system.c
@@ -329,11 +329,11 @@ vips_system_init( VipsSystem *system )
  *
  * Optional arguments:
  *
- * @in: array of input images
- * @out: output image
- * @in_format: write input files like this
- * @out_format: write output filename like this
- * @log: stdout of command is returned here
+ * * @in: array of input images
+ * * @out: output image
+ * * @in_format: write input files like this
+ * * @out_format: write output filename like this
+ * * @log: stdout of command is returned here
  *
  * vips_system() runs a command, optionally passing a set of images in and 
  * optionally getting an image back. The command's stdout is returned in @log. 
diff --git a/libvips/morphology/labelregions.c b/libvips/morphology/labelregions.c
index ff9311d2..880b21be 100644
--- a/libvips/morphology/labelregions.c
+++ b/libvips/morphology/labelregions.c
@@ -149,7 +149,7 @@ vips_labelregions_init( VipsLabelregions *labelregions )
  *
  * Optional arguments:
  *
- * @segments: return number of regions found here
+ * * @segments: return number of regions found here
  *
  * Repeatedly scans @in for regions of 4-connected pixels
  * with the same pixel value. Every time a region is discovered, those
diff --git a/libvips/mosaicing/global_balance.c b/libvips/mosaicing/global_balance.c
index f1c4630f..053330b1 100644
--- a/libvips/mosaicing/global_balance.c
+++ b/libvips/mosaicing/global_balance.c
@@ -1809,8 +1809,8 @@ vips_globalbalance_init( VipsGlobalbalance *globalbalance )
  * 
  * Optional arguments:
  *
- * @gamma: gamma of source images
- * @int_output: %TRUE for integer image output
+ * * @gamma: gamma of source images
+ * * @int_output: %TRUE for integer image output
  *
  * vips_globalbalance() can be used to remove contrast differences in 
  * an assembled mosaic.
diff --git a/libvips/mosaicing/match.c b/libvips/mosaicing/match.c
index 21fa91ca..60b77594 100644
--- a/libvips/mosaicing/match.c
+++ b/libvips/mosaicing/match.c
@@ -328,10 +328,10 @@ vips_match_init( VipsMatch *match )
  * 
  * Optional arguments:
  *
- * @search: search to improve tie-points
- * @hwindow: half window size
- * @harea: half search size 
- * @interpolate: interpolate pixels with this
+ * * @search: search to improve tie-points
+ * * @hwindow: half window size
+ * * @harea: half search size 
+ * * @interpolate: interpolate pixels with this
  *
  * Scale, rotate and translate @sec so that the tie-points line up.
  *
diff --git a/libvips/mosaicing/merge.c b/libvips/mosaicing/merge.c
index bf7b1e9c..3062c760 100644
--- a/libvips/mosaicing/merge.c
+++ b/libvips/mosaicing/merge.c
@@ -171,7 +171,7 @@ vips_merge_init( VipsMerge *merge )
  * 
  * Optional arguments:
  *
- * @mblend: maximum blend size 
+ * * @mblend: maximum blend size 
  *
  * This operation joins two images left-right (with @ref on the left) or
  * up-down (with @ref above) with a smooth seam.
diff --git a/libvips/mosaicing/mosaic.c b/libvips/mosaicing/mosaic.c
index cea6cd90..c8897e50 100644
--- a/libvips/mosaicing/mosaic.c
+++ b/libvips/mosaicing/mosaic.c
@@ -324,10 +324,10 @@ vips_mosaic_init( VipsMosaic *mosaic )
  * 
  * Optional arguments:
  *
- * @bandno: band to search for features
- * @hwindow: half window size
- * @harea: half search size 
- * @mblend: maximum blend size
+ * * @bandno: band to search for features
+ * * @hwindow: half window size
+ * * @harea: half search size 
+ * * @mblend: maximum blend size
  *
  * This operation joins two images left-right (with @ref on the left) or
  * top-bottom (with @ref above) given an approximate overlap.
diff --git a/libvips/mosaicing/mosaic1.c b/libvips/mosaicing/mosaic1.c
index 2fa468f7..651db3c9 100644
--- a/libvips/mosaicing/mosaic1.c
+++ b/libvips/mosaicing/mosaic1.c
@@ -635,12 +635,12 @@ vips_mosaic1_init( VipsMosaic1 *mosaic1 )
  * 
  * Optional arguments:
  *
- * @search: search to improve tie-points
- * @hwindow: half window size
- * @harea: half search size 
- * @interpolate: interpolate pixels with this
- * @mblend: maximum blend size 
- * @bandno: band to search for features
+ * * @search: search to improve tie-points
+ * * @hwindow: half window size
+ * * @harea: half search size 
+ * * @interpolate: interpolate pixels with this
+ * * @mblend: maximum blend size 
+ * * @bandno: band to search for features
  *
  * This operation joins two images top-bottom (with @sec on the right) 
  * or left-right (with @sec at the bottom)
diff --git a/libvips/resample/affine.c b/libvips/resample/affine.c
index de9ded32..d67c184b 100644
--- a/libvips/resample/affine.c
+++ b/libvips/resample/affine.c
@@ -623,12 +623,12 @@ vips_affine_init( VipsAffine *affine )
  *
  * Optional arguments:
  *
- * @interpolate: interpolate pixels with this
- * @oarea: output rectangle
- * @idx: input horizontal offset
- * @idy: input vertical offset
- * @odx: output horizontal offset
- * @ody: output vertical offset
+ * * @interpolate: interpolate pixels with this
+ * * @oarea: output rectangle
+ * * @idx: input horizontal offset
+ * * @idy: input vertical offset
+ * * @odx: output horizontal offset
+ * * @ody: output vertical offset
  *
  * This operator performs an affine transform on an image using @interpolate.
  *
diff --git a/libvips/resample/mapim.c b/libvips/resample/mapim.c
index 9187153a..8592363e 100644
--- a/libvips/resample/mapim.c
+++ b/libvips/resample/mapim.c
@@ -415,7 +415,7 @@ vips_mapim_init( VipsMapim *mapim )
  *
  * Optional arguments:
  *
- * @interpolate: interpolate pixels with this
+ * * @interpolate: interpolate pixels with this
  *
  * This operator resamples @in using @index to look up pixels. @out is
  * the same size as @index, with each pixel being fetched from that position in
diff --git a/libvips/resample/quadratic.c b/libvips/resample/quadratic.c
index e4741af8..8db0fd6a 100644
--- a/libvips/resample/quadratic.c
+++ b/libvips/resample/quadratic.c
@@ -371,7 +371,7 @@ vips_quadratic_init( VipsQuadratic *quadratic )
  *
  * Optional arguments:
  *
- * @interpolate: use this interpolator (default bilinear)
+ * * @interpolate: use this interpolator (default bilinear)
  *
  * This operation is unfinished and unusable, sorry. 
  *
diff --git a/libvips/resample/reduce.c b/libvips/resample/reduce.c
index 6f63bcda..1304e609 100644
--- a/libvips/resample/reduce.c
+++ b/libvips/resample/reduce.c
@@ -146,7 +146,7 @@ vips_reduce_init( VipsReduce *reduce )
  *
  * Optional arguments:
  *
- * @kernel: #VipsKernel to use to interpolate (default: lanczos3)
+ * * @kernel: #VipsKernel to use to interpolate (default: lanczos3)
  *
  * Reduce @in by a pair of factors with a pair of 1D interpolators. This 
  * will not work well for shrink factors greater than two.
diff --git a/libvips/resample/resize.c b/libvips/resample/resize.c
index bff34d7c..34df769a 100644
--- a/libvips/resample/resize.c
+++ b/libvips/resample/resize.c
@@ -336,8 +336,8 @@ vips_resize_init( VipsResize *resize )
  *
  * Optional arguments:
  *
- * @vscale: vertical scale factor
- * @kernel: #VipsKernel to reduce with 
+ * * @vscale: vertical scale factor
+ * * @kernel: #VipsKernel to reduce with 
  *
  * Resize an image. When upsizing (@scale > 1), the image is simply block
  * upsized. When downsizing, the
diff --git a/libvips/resample/similarity.c b/libvips/resample/similarity.c
index 9259cbdd..a0e59e86 100644
--- a/libvips/resample/similarity.c
+++ b/libvips/resample/similarity.c
@@ -236,13 +236,13 @@ vips_similarity_init( VipsSimilarity *similarity )
  *
  * Optional arguments:
  *
- * @scale: scale by this factor
- * @angle: rotate by this many degrees anticlockwise
- * @interpolate: interpolate pixels with this
- * @idx: input horizontal offset
- * @idy: input vertical offset
- * @odx: output horizontal offset
- * @ody: output vertical offset
+ * * @scale: scale by this factor
+ * * @angle: rotate by this many degrees anticlockwise
+ * * @interpolate: interpolate pixels with this
+ * * @idx: input horizontal offset
+ * * @idy: input vertical offset
+ * * @odx: output horizontal offset
+ * * @ody: output vertical offset
  *
  * This operator calls vips_affine() for you, calculating the matrix for the
  * affine transform from @scale and @angle. Other parameters are passed on to

From 37c716be89c9228af39780d5e44bd96796e133fb Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Tue, 3 May 2016 09:36:49 +0100
Subject: [PATCH 13/34] more webp doc improvements

---
 TODO                      |  2 --
 libvips/foreign/foreign.c | 11 ++++++-----
 2 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/TODO b/TODO
index c16cf38d..cf0dcd7a 100644
--- a/TODO
+++ b/TODO
@@ -1,5 +1,3 @@
-- add "*" before each optional arg description
-
 - I like the new int mask creator in reducev, can we use it in im_vips2imask()
   as well?
 
diff --git a/libvips/foreign/foreign.c b/libvips/foreign/foreign.c
index 2a92516b..7389fbf5 100644
--- a/libvips/foreign/foreign.c
+++ b/libvips/foreign/foreign.c
@@ -2466,18 +2466,19 @@ vips_webpload_buffer( void *buf, size_t len, VipsImage **out, ... )
  *
  * Write an image to a file in WebP format. 
  *
- * Use @Q to set the WebP quality factor. It has the range 0 - 100, with the
+ * By default, images are saved in lossy format, with 
+ * @Q giving the WebP quality factor. It has the range 0 - 100, with the
  * default 75.
  *
- * Use @preset to hint the image type to lossy compressor. The default is
+ * Use @preset to hint the image type to the lossy compressor. The default is
  * #VIPS_FOREIGN_WEBP_PRESET_DEFAULT. 
- *
  * Set @smart_subsample to enable high quality chroma subsampling.
- *
  * Use @alpha_q to set the quality for the alpha channel in lossy mode. It has
  * the range 1 - 100, with the default 100.
  *
- * Set @lossless to enable lossless save. 
+ * Set @lossless to use lossless compression, or combine @near_lossless
+ * with @Q 80, 60, 40 or 20 to apply increasing amounts of preprocessing
+ * which improves the near-lossless compression ratio by up to 50%.
  *
  * See also: vips_webpload(), vips_image_write_to_file().
  *

From c081f51ffc7c0076c90f58945f9469a54b2982d5 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Wed, 4 May 2016 13:20:19 +0100
Subject: [PATCH 14/34] fix a compiler warning

---
 libvips/colour/colour.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/libvips/colour/colour.c b/libvips/colour/colour.c
index 848032d4..ed5666a1 100644
--- a/libvips/colour/colour.c
+++ b/libvips/colour/colour.c
@@ -228,7 +228,6 @@ vips_colour_gen( VipsRegion *or,
 {
 	VipsRegion **ir = (VipsRegion **) seq;
 	VipsColour *colour = VIPS_COLOUR( b ); 
-	VipsObjectClass *object_class = VIPS_OBJECT_GET_CLASS( colour ); 
 	VipsColourClass *class = VIPS_COLOUR_GET_CLASS( colour ); 
 	VipsRect *r = &or->valid;
 
@@ -252,7 +251,7 @@ vips_colour_gen( VipsRegion *or,
 
 	VIPS_GATE_STOP( "vips_colour_gen: work" ); 
 
-	VIPS_COUNT_PIXELS( or, object_class->nickname ); 
+	VIPS_COUNT_PIXELS( or, VIPS_OBJECT_GET_CLASS( colour )->nickname ); 
 
 	return( 0 );
 }

From 1366d0af6d4be19983fa678cb4f84270f9795ffe Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Thu, 5 May 2016 09:14:58 +0100
Subject: [PATCH 15/34] note --with-modules flag for IM

---
 README.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/README.md b/README.md
index b9b0ff3e..3f5112e9 100644
--- a/README.md
+++ b/README.md
@@ -234,6 +234,10 @@ If available, libvips adds support for loading all libMagick-supported
 image file types. Use `--with-magickpackage=GraphicsMagick` to build against 
 graphicsmagick instead.
 
+Imagemagick 6.9+ needs to have been built with `--with-modules`. Most packaged
+IMs are, I think, but if you are rolling your own, you'll need to pass
+this flag to configure. 
+
 ### pangoft2
 
 If available, libvips adds support for text rendering. You need the

From c5fa0e1feb75c76b7a1eed6c859acd6e363a5561 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Felix=20Bu=CC=88nemann?= <buenemann@louis.info>
Date: Sat, 7 May 2016 03:13:52 +0200
Subject: [PATCH 16/34] Add mozjpeg quant_table option to jpegsave

This allows to choose from several predefined quantization tables when
libvips is compiled against mozjpeg 3.0+.
Tuning the quantization table helps to improve file size in the higher
quality range and avoid artefacts in the lower range.
---
 libvips/foreign/foreign.c   | 27 +++++++++++++++++++++++++++
 libvips/foreign/jpegsave.c  | 20 +++++++++++++++++---
 libvips/foreign/vips2jpeg.c | 33 ++++++++++++++++++++++++++-------
 libvips/foreign/vipsjpeg.h  |  4 ++--
 4 files changed, 72 insertions(+), 12 deletions(-)

diff --git a/libvips/foreign/foreign.c b/libvips/foreign/foreign.c
index 7389fbf5..10fb231c 100644
--- a/libvips/foreign/foreign.c
+++ b/libvips/foreign/foreign.c
@@ -2217,6 +2217,7 @@ vips_jpegload_buffer( void *buf, size_t len, VipsImage **out, ... )
  * * @trellis_quant: %gboolean, apply trellis quantisation to each 8x8 block
  * * @overshoot_deringing: %gboolean, overshoot samples with extreme values
  * * @optimize_scans: %gboolean, split DCT coefficients into separate scans
+ * * @quant_table: %gint, quantization table index
  *
  * Write a VIPS image to a file as JPEG.
  *
@@ -2268,6 +2269,30 @@ vips_jpegload_buffer( void *buf, size_t len, VipsImage **out, ... )
  * (e.g. mozjpeg >= 3.0), split the spectrum of DCT coefficients into
  * separate scans. Reduces file size but increases compression time.
  *
+ * If @quant_table is set and the version of libjpeg supports it
+ * (e.g. mozjpeg >= 3.0) it selects the quantization table to use:
+ *
+ * * 0 Tables from JPEG Annex K (vips and libjpeg default)
+ * * 1 Flat table
+ * * 2 Table tuned for MSSIM on Kodak image set
+ * * 3 Table from ImageMagick by N. Robidoux (current mozjpeg default)
+ * * 4 Table tuned for PSNR-HVS-M on Kodak image set
+ * * 5 Table from Relevance of Human Vision to JPEG-DCT Compression (1992)
+ * * 6 Table from DCTune Perceptual Optimization of Compressed Dental X-Rays (1997)
+ * * 7 Table from A Visual Detection Model for DCT Coefficient Quantization (1993)
+ * * 8 Table from An Improved Detection Model for DCT Coefficient Quantization (1993)
+ *
+ * Quantization table 0 is the default in vips and libjpeg(-turbo), but it
+ * tends to favor detail over color accuracy, producting colored patches and
+ * stripes as well as heavy banding in flat areas at high compression ratios.
+ * Quantization table 2 is a good candidate to try if the default quantization
+ * table produces banding or color shifts and is well suited for hires images.
+ * Quantization table 3 is the default in mozjpeg and has been tuned to produce
+ * good results at the default quality setting; banding at high compression.
+ * Quantization table 4 is the most accurate at the cost of compression ratio.
+ * Tables 5-7 are based on older research papers, but generally achieve worse
+ * compression ratios and/or quality than 2 or 4.
+ *
  * See also: vips_jpegsave_buffer(), vips_image_write_to_file().
  *
  * Returns: 0 on success, -1 on error.
@@ -2303,6 +2328,7 @@ vips_jpegsave( VipsImage *in, const char *filename, ... )
  * * @trellis_quant: %gboolean, apply trellis quantisation to each 8x8 block
  * * @overshoot_deringing: %gboolean, overshoot samples with extreme values
  * * @optimize_scans: %gboolean, split DCT coefficients into separate scans
+ * * @quant_table: %gint, quantization table index
  *
  * As vips_jpegsave(), but save to a memory buffer. 
  *
@@ -2357,6 +2383,7 @@ vips_jpegsave_buffer( VipsImage *in, void **buf, size_t *len, ... )
  * * @trellis_quant: %gboolean, apply trellis quantisation to each 8x8 block
  * * @overshoot_deringing: %gboolean, overshoot samples with extreme values
  * * @optimize_scans: %gboolean, split DCT coefficients into separate scans
+ * * @quant_table: %gint, quantization table index
  *
  * As vips_jpegsave(), but save as a mime jpeg on stdout.
  *
diff --git a/libvips/foreign/jpegsave.c b/libvips/foreign/jpegsave.c
index 2cc29a6a..4fac9b99 100644
--- a/libvips/foreign/jpegsave.c
+++ b/libvips/foreign/jpegsave.c
@@ -103,6 +103,10 @@ typedef struct _VipsForeignSaveJpeg {
 	 */
 	gboolean optimize_scans;
 
+	/* Use predefined quantization table with given index.
+	 */
+	int quant_table;
+
 } VipsForeignSaveJpeg;
 
 typedef VipsForeignSaveClass VipsForeignSaveJpegClass;
@@ -194,6 +198,13 @@ vips_foreign_save_jpeg_class_init( VipsForeignSaveJpegClass *class )
 		G_STRUCT_OFFSET( VipsForeignSaveJpeg, optimize_scans ),
 		FALSE );
 
+	VIPS_ARG_INT( class, "quant_table", 18,
+		_( "Quantization table" ),
+		_( "Use predefined quantization table with given index" ),
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsForeignSaveJpeg, quant_table ),
+		0, 8, 0 );
+
 }
 
 static void
@@ -230,7 +241,8 @@ vips_foreign_save_jpeg_file_build( VipsObject *object )
 	if( vips__jpeg_write_file( save->ready, file->filename,
 		jpeg->Q, jpeg->profile, jpeg->optimize_coding, 
 		jpeg->interlace, save->strip, jpeg->no_subsample,
-		jpeg->trellis_quant, jpeg->overshoot_deringing, jpeg->optimize_scans) )
+		jpeg->trellis_quant, jpeg->overshoot_deringing,
+		jpeg->optimize_scans, jpeg->quant_table ) )
 		return( -1 );
 
 	return( 0 );
@@ -294,7 +306,8 @@ vips_foreign_save_jpeg_buffer_build( VipsObject *object )
 	if( vips__jpeg_write_buffer( save->ready, 
 		&obuf, &olen, jpeg->Q, jpeg->profile, jpeg->optimize_coding, 
 		jpeg->interlace, save->strip, jpeg->no_subsample,
-		jpeg->trellis_quant, jpeg->overshoot_deringing, jpeg->optimize_scans) )
+		jpeg->trellis_quant, jpeg->overshoot_deringing,
+		jpeg->optimize_scans, jpeg->quant_table ) )
 		return( -1 );
 
 	blob = vips_blob_new( (VipsCallbackFn) vips_free, obuf, olen );
@@ -357,7 +370,8 @@ vips_foreign_save_jpeg_mime_build( VipsObject *object )
 	if( vips__jpeg_write_buffer( save->ready, 
 		&obuf, &olen, jpeg->Q, jpeg->profile, jpeg->optimize_coding, 
 		jpeg->interlace, save->strip, jpeg->no_subsample,
-		jpeg->trellis_quant, jpeg->overshoot_deringing, jpeg->optimize_scans) )
+		jpeg->trellis_quant, jpeg->overshoot_deringing,
+		jpeg->optimize_scans, jpeg->quant_table ) )
 		return( -1 );
 
 	printf( "Content-length: %zu\r\n", olen );
diff --git a/libvips/foreign/vips2jpeg.c b/libvips/foreign/vips2jpeg.c
index d714cfc9..0c7bda5b 100644
--- a/libvips/foreign/vips2jpeg.c
+++ b/libvips/foreign/vips2jpeg.c
@@ -966,7 +966,7 @@ static int
 write_vips( Write *write, int qfac, const char *profile, 
 	gboolean optimize_coding, gboolean progressive, gboolean strip, 
 	gboolean no_subsample, gboolean trellis_quant,
-	gboolean overshoot_deringing, gboolean optimize_scans )
+	gboolean overshoot_deringing, gboolean optimize_scans, int quant_table )
 {
 	VipsImage *in;
 	J_COLOR_SPACE space;
@@ -1022,10 +1022,9 @@ write_vips( Write *write, int qfac, const char *profile,
 			JINT_COMPRESS_PROFILE, JCP_FASTEST );
 #endif
 
-	/* Rest to default. 
+	/* Reset to default.
 	 */
         jpeg_set_defaults( &write->cinfo );
-        jpeg_set_quality( &write->cinfo, qfac, TRUE );
 
  	/* Compute optimal Huffman coding tables.
 	 */
@@ -1077,6 +1076,20 @@ write_vips( Write *write, int qfac, const char *profile,
 			vips_warn( "vips2jpeg", "%s",
 				_( "Ignoring optimize_scans for baseline" ) );
 	}
+
+	/* Use predefined quantization table.
+	 */
+	if( quant_table > 0 ) {
+		if( jpeg_c_int_param_supported( &write->cinfo,
+			JINT_BASE_QUANT_TBL_IDX ) )
+			jpeg_c_set_int_param( &write->cinfo,
+				JINT_BASE_QUANT_TBL_IDX, quant_table );
+		else
+			vips_warn( "vips2jpeg",
+				"%s", _( "Setting quant_table unsupported" ) );
+	}
+	vips_warn( "vips2jpeg", "quant_table %d",
+		jpeg_c_get_int_param( &write->cinfo, JINT_BASE_QUANT_TBL_IDX ) );
 #else
 	/* Using jpeglib.h without extension parameters, warn of ignored 
 	 * options.
@@ -1088,8 +1101,14 @@ write_vips( Write *write, int qfac, const char *profile,
 			"%s", _( "Ignoring overshoot_deringing" ) );
 	if( optimize_scans ) 
 		vips_warn( "vips2jpeg", "%s", _( "Ignoring optimize_scans" ) );
+	if( quant_table > 0 )
+		vips_warn( "vips2jpeg", "%s", _( "Ignoring quant_table" ) );
 #endif
 
+	/* Set compression quality. Must be called after setting params above.
+	 */
+        jpeg_set_quality( &write->cinfo, qfac, TRUE );
+
 	/* Enable progressive write.
 	 */
 	if( progressive ) 
@@ -1160,7 +1179,7 @@ vips__jpeg_write_file( VipsImage *in,
 	const char *filename, int Q, const char *profile, 
 	gboolean optimize_coding, gboolean progressive, gboolean strip, 
 	gboolean no_subsample, gboolean trellis_quant,
-	gboolean overshoot_deringing, gboolean optimize_scans )
+	gboolean overshoot_deringing, gboolean optimize_scans, int quant_table )
 {
 	Write *write;
 
@@ -1192,7 +1211,7 @@ vips__jpeg_write_file( VipsImage *in,
 	 */
 	if( write_vips( write, 
 		Q, profile, optimize_coding, progressive, strip, no_subsample,
-		trellis_quant, overshoot_deringing, optimize_scans ) ) {
+		trellis_quant, overshoot_deringing, optimize_scans, quant_table ) ) {
 		write_destroy( write );
 		return( -1 );
 	}
@@ -1446,7 +1465,7 @@ vips__jpeg_write_buffer( VipsImage *in,
 	void **obuf, size_t *olen, int Q, const char *profile, 
 	gboolean optimize_coding, gboolean progressive,
 	gboolean strip, gboolean no_subsample, gboolean trellis_quant,
-	gboolean overshoot_deringing, gboolean optimize_scans )
+	gboolean overshoot_deringing, gboolean optimize_scans, int quant_table )
 {
 	Write *write;
 
@@ -1477,7 +1496,7 @@ vips__jpeg_write_buffer( VipsImage *in,
 	 */
 	if( write_vips( write, 
 		Q, profile, optimize_coding, progressive, strip, no_subsample,
-		trellis_quant, overshoot_deringing, optimize_scans ) ) {
+		trellis_quant, overshoot_deringing, optimize_scans, quant_table ) ) {
 		write_destroy( write );
 
 		return( -1 );
diff --git a/libvips/foreign/vipsjpeg.h b/libvips/foreign/vipsjpeg.h
index 9c86cb5c..a9bf86e6 100644
--- a/libvips/foreign/vipsjpeg.h
+++ b/libvips/foreign/vipsjpeg.h
@@ -41,12 +41,12 @@ int vips__jpeg_write_file( VipsImage *in,
 	const char *filename, int Q, const char *profile, 
 	gboolean optimize_coding, gboolean progressive, gboolean strip,
 	gboolean no_subsample, gboolean trellis_quant,
-	gboolean overshoot_deringing, gboolean optimize_scans );
+	gboolean overshoot_deringing, gboolean optimize_scans, int quant_table );
 int vips__jpeg_write_buffer( VipsImage *in, 
 	void **obuf, size_t *olen, int Q, const char *profile, 
 	gboolean optimize_coding, gboolean progressive, gboolean strip,
 	gboolean no_subsample, gboolean trellis_quant,
-	gboolean overshoot_deringing, gboolean optimize_scans );
+	gboolean overshoot_deringing, gboolean optimize_scans, int quant_table );
 
 int vips__isjpeg_buffer( const void *buf, size_t len );
 int vips__isjpeg( const char *filename );

From 948d1103d4062c67afe3d92f639b2ee730922a33 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Sat, 7 May 2016 19:53:00 +0100
Subject: [PATCH 17/34] note more webp tests needed

---
 TODO                      | 2 ++
 libvips/resample/resize.c | 4 +---
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/TODO b/TODO
index cf0dcd7a..18b3339a 100644
--- a/TODO
+++ b/TODO
@@ -1,3 +1,5 @@
+- add more webp tests to py suite
+
 - I like the new int mask creator in reducev, can we use it in im_vips2imask()
   as well?
 
diff --git a/libvips/resample/resize.c b/libvips/resample/resize.c
index 34df769a..c35b1ef3 100644
--- a/libvips/resample/resize.c
+++ b/libvips/resample/resize.c
@@ -309,9 +309,7 @@ vips_resize_class_init( VipsResizeClass *class )
 		G_STRUCT_OFFSET( VipsResize, idy ),
 		-10000000, 10000000, 0 );
 
-	/* We used to let people set the interpolator, but it's not clear this
-	 * was useful. Anyway, vips_reduce() no longer has an interpolator
-	 * param.
+	/* It's a kernel now we use vips_reduce() not vips_affine().
 	 */
 	VIPS_ARG_INTERPOLATE( class, "interpolate", 2, 
 		_( "Interpolate" ), 

From b03ad51ae36586f1925c2c72d32972ddae57d105 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Sat, 7 May 2016 21:01:04 +0100
Subject: [PATCH 18/34] oops, fix error reporting from giflib

---
 libvips/foreign/gifload.c | 36 +++++++++++++++++++++++++++---------
 1 file changed, 27 insertions(+), 9 deletions(-)

diff --git a/libvips/foreign/gifload.c b/libvips/foreign/gifload.c
index 202ad674..2481526d 100644
--- a/libvips/foreign/gifload.c
+++ b/libvips/foreign/gifload.c
@@ -153,15 +153,33 @@ vips_foreign_load_gif_errstr( int error_code )
 #endif /*HAVE_GIFLIB_5*/
 }
 
+static void
+vips_foreign_load_gif_error_vips( VipsForeignLoadGif *gif, int error )
+{
+	VipsObjectClass *class = VIPS_OBJECT_GET_CLASS( gif );
+
+	const char *message;
+
+	if( (message = vips_foreign_load_gif_errstr( gif->file->Error )) )
+		vips_error( class->nickname, "%s", message ); 
+}
+
 static void
 vips_foreign_load_gif_error( VipsForeignLoadGif *gif )
 {
+	int error;
+
+	error = 0;
+
 #ifdef HAVE_GIFLIB_5
 	if( gif->file ) 
-		vips_foreign_load_gif_errstr( gif->file->Error ); 
+		error = gif->file->Error;
 #else 
-	vips_foreign_load_gif_errstr( GifLastError() ); 
+	error = GifLastError(); 
 #endif
+
+	if( error ) 
+		vips_foreign_load_gif_error_vips( gif, error ); 
 }
 
 static void
@@ -172,13 +190,13 @@ vips_foreign_load_gif_close( VipsForeignLoadGif *gif )
 		int error; 
 
 		if( DGifCloseFile( gif->file, &error ) ) 
-			vips_foreign_load_gif_errstr( error );
+			vips_foreign_load_gif_error_vips( gif, error );
 		gif->file = NULL;
 	}
 #else 
 	if( gif->file ) {
 		if( DGifCloseFile( gif->file ) ) 
-			vips_foreign_load_gif_errstr( GifLastError() ); 
+			vips_foreign_load_gif_error_vips( gif, GifLastError() ); 
 		gif->file = NULL;
 	}
 #endif
@@ -194,13 +212,13 @@ vips_foreign_load_gif_open( VipsForeignLoadGif *gif, const char *filename )
 	int error; 
 
 	if( !(gif->file = DGifOpenFileName( filename, &error )) ) {
-		vips_foreign_load_gif_errstr( error );
+		vips_foreign_load_gif_error_vips( gif, error );
 		return( -1 ); 
 	}
 }
 #else 
 	if( !(gif->file = DGifOpenFileName( filename )) ) { 
-		vips_foreign_load_gif_errstr( GifLastError() ); 
+		vips_foreign_load_gif_error_vips( gif, GifLastError() ); 
 		return( -1 ); 
 	}
 #endif
@@ -218,13 +236,13 @@ vips_foreign_load_gif_open_buffer( VipsForeignLoadGif *gif, InputFunc read_fn )
 	int error;
 
 	if( !(gif->file = DGifOpen( gif, read_fn, &error )) ) {
-		vips_foreign_load_gif_errstr( error );
+		vips_foreign_load_gif_error_vips( gif, error );
 		return( -1 ); 
 	}
 }
 #else 
 	if( !(gif->file = DGifOpen( gif, read_fn )) ) { 
-		vips_foreign_load_gif_errstr( GifLastError() ); 
+		vips_foreign_load_gif_error_vips( gif, GifLastError() ); 
 		return( -1 ); 
 	}
 #endif
@@ -435,7 +453,7 @@ vips_foreign_load_gif_load( VipsForeignLoad *load )
 		GifByteType *extension;
 		int ext_code;
 
-		if( DGifGetRecordType( gif->file, &record) == GIF_ERROR ) {
+		if( DGifGetRecordType( gif->file, &record ) == GIF_ERROR ) {
 			vips_foreign_load_gif_error( gif ); 
 			return( -1 ); 
 		}

From a342fdbeeb60357349dfc33a99fba319af653f3f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Felix=20Bu=CC=88nemann?= <buenemann@louis.info>
Date: Sun, 8 May 2016 03:23:00 +0200
Subject: [PATCH 19/34] Fix configure check for giflib4

This uses a combination of the old giflib4 and the new giflib5 checks.
---
 acinclude.m4 | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/acinclude.m4 b/acinclude.m4
index 4f17b2ab..568c2734 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -631,14 +631,26 @@ if test "$GIFLIB_LIBS" = ""; then
   INCLUDES="$GIFLIB_INCLUDES $INCLUDES"
 
   # Try the standard search path first
-  AC_TRY_LINK([#include <gif_lib.h>],[EGifSetGifVersion(0,0)], [
+  AC_TRY_LINK([#include <gif_lib.h>],[
+    #if defined(GIFLIB_MAJOR) && GIFLIB_MAJOR > 4
+    EGifSetGifVersion(0,0);
+    #else
+    GifLastError();
+    #endif
+  ], [
     GIFLIB_LIBS="-lgif"
   ], [
     # giflib is not in the standard search path, try $prefix
 
     LIBS="-L${prefix}/lib $LIBS"
 
-    AC_TRY_LINK([#include <gif_lib.h>],[EGifSetGifVersion(0,0)], [
+    AC_TRY_LINK([#include <gif_lib.h>],[
+      #if defined(GIFLIB_MAJOR) && GIFLIB_MAJOR > 4
+      EGifSetGifVersion(0,0);
+      #else
+      GifLastError();
+      #endif
+    ], [
       GIFLIB_LIBS="-L${prefix}/lib -lgif"
     ], [
       GIFLIB_LIBS=no

From 379b69fda881d487fbf117b7865876c30aa2bfef Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Sun, 8 May 2016 10:02:34 +0100
Subject: [PATCH 20/34] note on test suite failure

---
 TODO | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/TODO b/TODO
index cf0dcd7a..1f1a7cfc 100644
--- a/TODO
+++ b/TODO
@@ -1,3 +1,10 @@
+- the gif tests in the suite sometimes fail with giflib5 because of an
+  uninitialized struct in giflib, see
+
+	https://sourceforge.net/p/giflib/bugs/94/
+
+  sadly ubuntu 16.04 only comes with giflib5, and giflib5 is currently broken
+
 - I like the new int mask creator in reducev, can we use it in im_vips2imask()
   as well?
 

From f7a6a02ee8017f02cde73af6da4d319d64841b5a Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Sun, 8 May 2016 11:02:21 +0100
Subject: [PATCH 21/34] fix giflib4 detection

and a problem in giflib4 error handling
---
 ChangeLog                 | 1 +
 acinclude.m4              | 4 ++--
 libvips/foreign/gifload.c | 2 +-
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index cbb50c50..1b926428 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -5,6 +5,7 @@
 - add giflib5 support
 - allow resize >1 on one axis, <1 on the other
 - vips_resize has an optional @kernel argument
+- fix giflib4 detection [felixbuenemann]
 
 29/1/16 started 8.3
 - add vips_reduce*() ... a fast path for affine downsize
diff --git a/acinclude.m4 b/acinclude.m4
index 4f17b2ab..d1bbc58f 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -631,14 +631,14 @@ if test "$GIFLIB_LIBS" = ""; then
   INCLUDES="$GIFLIB_INCLUDES $INCLUDES"
 
   # Try the standard search path first
-  AC_TRY_LINK([#include <gif_lib.h>],[EGifSetGifVersion(0,0)], [
+  AC_TRY_LINK([#include <gif_lib.h>],[DGifSlurp(0)], [
     GIFLIB_LIBS="-lgif"
   ], [
     # giflib is not in the standard search path, try $prefix
 
     LIBS="-L${prefix}/lib $LIBS"
 
-    AC_TRY_LINK([#include <gif_lib.h>],[EGifSetGifVersion(0,0)], [
+    AC_TRY_LINK([#include <gif_lib.h>],[DGifSlurp(0)], [
       GIFLIB_LIBS="-L${prefix}/lib -lgif"
     ], [
       GIFLIB_LIBS=no
diff --git a/libvips/foreign/gifload.c b/libvips/foreign/gifload.c
index 2481526d..5fc317db 100644
--- a/libvips/foreign/gifload.c
+++ b/libvips/foreign/gifload.c
@@ -160,7 +160,7 @@ vips_foreign_load_gif_error_vips( VipsForeignLoadGif *gif, int error )
 
 	const char *message;
 
-	if( (message = vips_foreign_load_gif_errstr( gif->file->Error )) )
+	if( (message = vips_foreign_load_gif_errstr( error )) )
 		vips_error( class->nickname, "%s", message ); 
 }
 

From bec6b174c99bb8121318834b79618cf948447ff6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Felix=20Bu=CC=88nemann?= <buenemann@louis.info>
Date: Sun, 8 May 2016 22:39:08 +0200
Subject: [PATCH 22/34] Fix poppler version requirement, add loader check

This fixes the poppler-glib version requirement to version 0.16, which
is the lowest version that compiles and works properly with pdfload.

Also added a check for pdfload and enabled testing on Travis CI.
---
 .travis.yml               |   2 +-
 configure.ac              |   8 ++++----
 test/images/blankpage.pdf |  37 +++++++++++++++++++++++++++++++++++++
 test/images/blankpage.png | Bin 0 -> 3795 bytes
 test/test_formats.sh      |   8 ++++++++
 5 files changed, 50 insertions(+), 5 deletions(-)
 create mode 100755 test/images/blankpage.pdf
 create mode 100644 test/images/blankpage.png

diff --git a/.travis.yml b/.travis.yml
index d7d39749..2ca5238d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -8,7 +8,7 @@ before_install:
   - sudo apt-get install libpng12-dev libwebp-dev libtiff4-dev libxml2-dev 
   - sudo apt-get install swig libmagick++-dev bc 
   - sudo apt-get install libcfitsio3-dev libgsl0-dev libmatio-dev
-  - sudo apt-get install liborc-0.4-dev liblcms2-dev 
+  - sudo apt-get install liborc-0.4-dev liblcms2-dev libpoppler-glib-dev
 before_script:
   - ./bootstrap.sh
   - ./configure 
diff --git a/configure.ac b/configure.ac
index 4ddb37fe..7aecb252 100644
--- a/configure.ac
+++ b/configure.ac
@@ -563,12 +563,12 @@ AC_ARG_WITH([poppler],
   AS_HELP_STRING([--without-poppler], [build without poppler (default: test)]))
 
 if test x"$with_poppler" != x"no"; then
-  PKG_CHECK_MODULES(POPPLER, [poppler-glib >= 0.30.0 cairo >= 1.2],
-    [AC_DEFINE(HAVE_POPPLER,1,[define if you have poppler-glib >= 0.30.0 and cairo >= 1.2 installed.])
+  PKG_CHECK_MODULES(POPPLER, [poppler-glib >= 0.16.0 cairo >= 1.2],
+    [AC_DEFINE(HAVE_POPPLER,1,[define if you have poppler-glib >= 0.16.0 and cairo >= 1.2 installed.])
      with_poppler=yes
      PACKAGES_USED="$PACKAGES_USED poppler-glib cairo"
     ],
-    [AC_MSG_WARN([poppler-glib >= 0.30.0 or cairo >= 1.2 not found; disabling PDF load via poppler])
+    [AC_MSG_WARN([poppler-glib >= 0.16.0 or cairo >= 1.2 not found; disabling PDF load via poppler])
      with_poppler=no
     ]
   )
@@ -961,7 +961,7 @@ file import with OpenSlide:		$with_openslide
   (requires openslide-3.3.0 or later)
 file import with matio: 		$with_matio
 PDF import with poppler-glib: 		$with_poppler
-  (requires poppler-glib 0.30.0 or later)
+  (requires poppler-glib 0.16.0 or later)
 SVG import with librsvg-2.0: 		$with_rsvg
   (requires librsvg-2.0 2.40.0 or later)
 file import with cfitsio: 		$with_cfitsio
diff --git a/test/images/blankpage.pdf b/test/images/blankpage.pdf
new file mode 100755
index 00000000..5884469c
--- /dev/null
+++ b/test/images/blankpage.pdf
@@ -0,0 +1,37 @@
+%PDF-1.1
+%âãÏÓ
+1 0 obj 
+<<
+/Pages 2 0 R
+/Type /Catalog
+>>
+endobj 
+2 0 obj 
+<<
+/MediaBox [0 0 595 842]
+/Kids [3 0 R]
+/Count 1
+/Type /Pages
+>>
+endobj 
+3 0 obj 
+<<
+/Parent 2 0 R
+/MediaBox [0 0 595 842]
+/Type /Page
+>>
+endobj xref
+0 4
+0000000000 65535 f 
+0000000015 00000 n 
+0000000066 00000 n 
+0000000149 00000 n 
+trailer
+
+<<
+/Root 1 0 R
+/Size 4
+>>
+startxref
+221
+%%EOF
diff --git a/test/images/blankpage.png b/test/images/blankpage.png
new file mode 100644
index 0000000000000000000000000000000000000000..00478276b6c929424245b9540189366b020172a3
GIT binary patch
literal 3795
zcmeAS@N?(olHy`uVBq!ia0y~yU<zhnVD{o*1B$GBf0`diaTa()7Bet#3xhBt!>l<H
z3=Dj&o-U3d6?5KRJIKkPC~)9_^Sb}juFIWqZkfsT>5RScXGVsCl)HQk3>7nHGBI$R
z5n*shSOzrQn3X|bh9*P90Ut&NmNYH~1p}aUjiX9N!(}uvjAoM2l3}zs9IYls>&DRr
t!DvHiv~@VzY98$>jP{T4^cxSd^|f<No?o$kIk1<?;OXk;vd$@?2>?V9|6c$A

literal 0
HcmV?d00001

diff --git a/test/test_formats.sh b/test/test_formats.sh
index 72af1ad4..bce44af1 100755
--- a/test/test_formats.sh
+++ b/test/test_formats.sh
@@ -7,6 +7,10 @@
 
 . ./variables.sh
 
+# poppler / pdfload reference image
+poppler=$test_images/blankpage.pdf
+poppler_ref=$test_images/blankpage.png
+
 # the matlab image and reference image
 matlab=$test_images/sample.mat
 matlab_ref=$test_images/sample.png
@@ -215,6 +219,10 @@ test_rad $rad
 test_raw $mono 
 test_raw $image 
 
+if test_supported pdfload; then
+	test_loader $poppler_ref $poppler pdfload
+fi
+
 if test_supported matload; then
 	test_loader $matlab_ref $matlab matlab
 fi

From 6418ab230757b36a831019972f24cfa6db54cbdd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Felix=20Bu=CC=88nemann?= <buenemann@louis.info>
Date: Sun, 8 May 2016 23:26:10 +0200
Subject: [PATCH 23/34] Extract shared pdfload/svgload code into cairo.c

---
 libvips/foreign/Makefile.am |  1 +
 libvips/foreign/cairo.c     | 68 +++++++++++++++++++++++++++++++++++++
 libvips/foreign/svgload.c   | 28 ---------------
 3 files changed, 69 insertions(+), 28 deletions(-)
 create mode 100644 libvips/foreign/cairo.c

diff --git a/libvips/foreign/Makefile.am b/libvips/foreign/Makefile.am
index 004ba7f4..f1ccb01e 100644
--- a/libvips/foreign/Makefile.am
+++ b/libvips/foreign/Makefile.am
@@ -2,6 +2,7 @@ noinst_LTLIBRARIES = libforeign.la
 
 libforeign_la_SOURCES = \
 	gifload.c \
+	cairo.c \
 	pdfload.c \
 	svgload.c \
 	radiance.h \
diff --git a/libvips/foreign/cairo.c b/libvips/foreign/cairo.c
new file mode 100644
index 00000000..f8f6dec5
--- /dev/null
+++ b/libvips/foreign/cairo.c
@@ -0,0 +1,68 @@
+/* Shared code for cairo based loaders like svgload and pdfload.
+ */
+
+/*
+
+    This file is part of VIPS.
+    
+    VIPS is free software; you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+    02110-1301  USA
+
+ */
+
+/*
+
+    These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
+
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif /*HAVE_CONFIG_H*/
+
+#if defined(HAVE_RSVG) || defined(HAVE_POPPLER)
+
+#include <vips/vips.h>
+#include <vips/internal.h>
+
+/* Convert from ARGB to RGBA and undo premultiplication. 
+ */
+void
+vips__cairo2rgba( guint32 * restrict buf, int n )
+{
+	int i;
+
+	for( i = 0; i < n; i++ ) {
+		guint32 * restrict p = buf + i;
+		guint32 x = *p;
+		guint8 a = x >> 24;
+		VipsPel * restrict out = (VipsPel *) p;
+
+		if( a == 255 ) 
+			*p = GUINT32_TO_BE( (x << 8) | 255 );
+		else if( a == 0 ) 
+			*p = GUINT32_TO_BE( x << 8 );
+		else {
+			/* Undo premultiplication.
+			 */
+			out[0] = 255 * ((x >> 16) & 255) / a;
+			out[1] = 255 * ((x >> 8) & 255) / a;
+			out[2] = 255 * (x & 255) / a;
+			out[3] = a;
+		}
+	}
+}
+
+#endif
diff --git a/libvips/foreign/svgload.c b/libvips/foreign/svgload.c
index 929b7a64..7b41e31a 100644
--- a/libvips/foreign/svgload.c
+++ b/libvips/foreign/svgload.c
@@ -149,34 +149,6 @@ vips_foreign_load_svg_header( VipsForeignLoad *load )
 	return( 0 );
 }
 
-/* Convert from ARGB to RGBA and undo premultiplication. 
- */
-void
-vips__cairo2rgba( guint32 * restrict buf, int n )
-{
-	int i;
-
-	for( i = 0; i < n; i++ ) {
-		guint32 * restrict p = buf + i;
-		guint32 x = *p;
-		guint8 a = x >> 24;
-		VipsPel * restrict out = (VipsPel *) p;
-
-		if( a == 255 ) 
-			*p = GUINT32_TO_BE( (x << 8) | 255 );
-		else if( a == 0 ) 
-			*p = GUINT32_TO_BE( x << 8 );
-		else {
-			/* Undo premultiplication.
-			 */
-			out[0] = 255 * ((x >> 16) & 255) / a;
-			out[1] = 255 * ((x >> 8) & 255) / a;
-			out[2] = 255 * (x & 255) / a;
-			out[3] = a;
-		}
-	}
-}
-
 static int
 vips_foreign_load_svg_generate( VipsRegion *or, 
 	void *seq, void *a, void *b, gboolean *stop )

From 8b3bb10b00e0cbfdd59dd70045c916a989ef1fcb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Felix=20Bu=CC=88nemann?= <buenemann@louis.info>
Date: Mon, 9 May 2016 00:48:37 +0200
Subject: [PATCH 24/34] Fix test_{threading,thumbnail}.sh without install

Both scripts were not using the $vips variables required to use vips
from the source directory instead of from the system.
---
 test/test_threading.sh | 12 ++++++------
 test/test_thumbnail.sh | 26 +++++++++++++-------------
 2 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/test/test_threading.sh b/test/test_threading.sh
index ec335335..a7e7beb2 100755
--- a/test/test_threading.sh
+++ b/test/test_threading.sh
@@ -7,22 +7,22 @@
 chain=1
 
 # im_benchmark needs a labq
-vips colourspace $image $tmp/t3.v labq
+$vips colourspace $image $tmp/t3.v labq
 
 for tile in 10 64 128 512; do
 	# benchmark includes a dither which will vary with tile size
-	vips --vips-concurrency=1 \
+	$vips --vips-concurrency=1 \
 		--vips-tile-width=$tile --vips-tile-height=$tile \
 		im_benchmarkn $tmp/t3.v $tmp/t5.v $chain
 
 	for cpus in 2 3 4 5 6 7 8 99; do
 		echo trying cpus = $cpus, tile = $tile ...
-		vips --vips-concurrency=$cpus \
+		$vips --vips-concurrency=$cpus \
 			--vips-tile-width=$tile --vips-tile-height=$tile \
 			im_benchmarkn $tmp/t3.v $tmp/t7.v $chain
-		vips subtract $tmp/t5.v $tmp/t7.v $tmp/t8.v
-		vips abs $tmp/t8.v $tmp/t9.v
-		max=$(vips max $tmp/t9.v)
+		$vips subtract $tmp/t5.v $tmp/t7.v $tmp/t8.v
+		$vips abs $tmp/t8.v $tmp/t9.v
+		max=$($vips max $tmp/t9.v)
 		if [ $(echo "$max > 0" | bc) -eq 1 ]; then
 			break
 		fi
diff --git a/test/test_thumbnail.sh b/test/test_thumbnail.sh
index 5044d0a0..73912e8c 100755
--- a/test/test_thumbnail.sh
+++ b/test/test_thumbnail.sh
@@ -11,10 +11,10 @@
 # make a 1000x1000 mono test image ... add a bit so the image should not 
 # contain any zeros, helps to spot missing tiles and bad pixels
 echo building test image ...
-vips extract_band $image $tmp/t1.v 1
-vips linear $tmp/t1.v $tmp/t2.v 1 20 --uchar
-vips replicate $tmp/t2.v $tmp/t1.v 2 2
-vips crop $tmp/t1.v $tmp/t2.v 10 10 1000 1000
+$vips extract_band $image $tmp/t1.v 1
+$vips linear $tmp/t1.v $tmp/t2.v 1 20 --uchar
+$vips replicate $tmp/t2.v $tmp/t1.v 2 2
+$vips crop $tmp/t1.v $tmp/t2.v 10 10 1000 1000
 
 # is a difference beyond a threshold? return 0 (meaning all ok) or 1 (meaning
 # error, or outside threshold)
@@ -27,33 +27,33 @@ break_threshold() {
 size=1000
 while [ $size -gt 99 ]; do
 	printf "testing size to $size ... "
-	vipsthumbnail $tmp/t2.v -o $tmp/t1.v --size $size 
-	if [ $(vipsheader -f width $tmp/t1.v) -ne $size ]; then
+	$vipsthumbnail $tmp/t2.v -o $tmp/t1.v --size $size 
+	if [ $($vipsheader -f width $tmp/t1.v) -ne $size ]; then
 		echo $tmp/t1.v failed -- bad size
-		echo output width is $(vipsheader -f width $tmp/t1.v) 
+		echo output width is $($vipsheader -f width $tmp/t1.v) 
 		exit
 	fi
-	if [ $(vipsheader -f height $tmp/t1.v) -ne $size ]; then
+	if [ $($vipsheader -f height $tmp/t1.v) -ne $size ]; then
 		echo $tmp/t1.v failed -- bad size
-		echo output height is $(vipsheader -f width $tmp/t1.v) 
+		echo output height is $($vipsheader -f width $tmp/t1.v) 
 		exit
 	fi
 
-	vips project $tmp/t1.v $tmp/cols.v $tmp/rows.v
+	$vips project $tmp/t1.v $tmp/cols.v $tmp/rows.v
 
-	min=$(vips min $tmp/cols.v)
+	min=$($vips min $tmp/cols.v)
 	if break_threshold $min 0; then
 		echo $tmp/t1.v failed -- has a black column
 		exit
 	fi
 
-	min=$(vips min $tmp/rows.v)
+	min=$($vips min $tmp/rows.v)
 	if break_threshold $min 0; then
 		echo $tmp/t1.v failed -- has a black row
 		exit
 	fi
 
-	min=$(vips min $tmp/t1.v)
+	min=$($vips min $tmp/t1.v)
 	if break_threshold $min 0; then
 		echo $tmp/t1.v failed -- has black pixels
 		exit

From d307e38863af84f91fbfd83c05ac54a8cbf556aa Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Mon, 9 May 2016 09:51:05 +0100
Subject: [PATCH 25/34] add FIND_LIBWEBP

some platforms are missing a .pc file for libwebp ... add a FIND_LIBWEBP
macro as a fallback

see https://github.com/jcupitt/libvips/issues/440
---
 acinclude.m4 | 120 +++++++++++++++++++++++++++++++++++++++++++++++++++
 configure.ac |  13 ++++--
 2 files changed, 130 insertions(+), 3 deletions(-)

diff --git a/acinclude.m4 b/acinclude.m4
index d1bbc58f..3e260465 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -684,3 +684,123 @@ fi
 
 ])dnl
 
+
+dnl From FIND_MOTIF and ACX_PTHREAD, without much understanding
+dnl
+dnl FIND_LIBWEBP[ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]]
+dnl ---------------------------------------------------
+dnl
+dnl Find webp libraries and headers ... useful for platforms which are missing
+dnl the webp .pc file
+dnl
+dnl Put compile stuff in LIBWEBP_INCLUDES
+dnl Put link stuff in LIBWEBP_LIBS
+dnl Define HAVE_LIBWEBP if found.
+dnl
+AC_DEFUN([FIND_LIBWEBP], [
+AC_REQUIRE([AC_PATH_XTRA])
+
+LIBWEBP_INCLUDES=""
+LIBWEBP_LIBS=""
+
+AC_ARG_WITH(libwebp, 
+  AS_HELP_STRING([--without-libwebp], [build without libwebp (default: test)]))
+# Treat --without-libwebp like --without-libwebp-includes --without-libwebp-libraries.
+if test "$with_libwebp" = "no"; then
+  LIBWEBP_INCLUDES=no
+  LIBWEBP_LIBS=no
+fi
+
+AC_ARG_WITH(libwebp-includes,
+  AS_HELP_STRING([--with-libwebp-includes=DIR], [libwebp includes are in DIR]),
+  LIBWEBP_INCLUDES="-I$withval")
+AC_ARG_WITH(libwebp-libraries,
+  AS_HELP_STRING([--with-libwebp-libraries=DIR], [libwebp libraries are in DIR]),
+  LIBWEBP_LIBS="-L$withval -lwebp")
+
+AC_MSG_CHECKING(for libwebp)
+
+# Look for webp/decode.h
+if test "$LIBWEBP_INCLUDES" = ""; then
+  # Check the standard search path
+  AC_TRY_COMPILE([#include <webp/decode.h>],[int a;],[
+    LIBWEBP_INCLUDES=""
+  ], [
+    # webp/decode.h is not in the standard search path, try
+    # $prefix
+    libwebp_save_INCLUDES="$INCLUDES"
+
+    INCLUDES="-I${prefix}/include $INCLUDES"
+
+    AC_TRY_COMPILE([#include <webp/decode.h>],[int a;],[
+      LIBWEBP_INCLUDES="-I${prefix}/include"
+    ], [
+      LIBWEBP_INCLUDES="no"
+    ])
+
+    INCLUDES=$libwebp_save_INCLUDES
+  ])
+fi
+
+# Now for the libraries
+if test "$LIBWEBP_LIBS" = ""; then
+  libwebp_save_LIBS="$LIBS"
+  libwebp_save_INCLUDES="$INCLUDES"
+
+  LIBS="-lwebp $LIBS"
+  INCLUDES="$LIBWEBP_INCLUDES $INCLUDES"
+
+  # Try the standard search path first
+  AC_TRY_LINK([#include <webp/decode.h>],[WebPInitDecoderConfig(0)], [
+    LIBWEBP_LIBS="-lwebp"
+  ], [
+    # libwebp is not in the standard search path, try $prefix
+
+    LIBS="-L${prefix}/lib $LIBS"
+
+    AC_TRY_LINK([#include <webp/decode.h>],[WebPInitDecoderConfig(0)], [
+      LIBWEBP_LIBS="-L${prefix}/lib -lwebp"
+    ], [
+      LIBWEBP_LIBS=no
+    ])
+  ])
+
+  LIBS="$libwebp_save_LIBS"
+  INCLUDES="$libwebp_save_INCLUDES"
+fi
+
+AC_SUBST(LIBWEBP_LIBS)
+AC_SUBST(LIBWEBP_INCLUDES)
+
+# Print a helpful message
+libwebp_libraries_result="$LIBWEBP_LIBS"
+libwebp_includes_result="$LIBWEBP_INCLUDES"
+
+if test x"$libwebp_libraries_result" = x""; then
+  libwebp_libraries_result="in default path"
+fi
+if test x"$libwebp_includes_result" = x""; then
+  libwebp_includes_result="in default path"
+fi
+
+if test "$libwebp_libraries_result" = "no"; then
+  libwebp_libraries_result="(none)"
+fi
+if test "$libwebp_includes_result" = "no"; then
+  libwebp_includes_result="(none)"
+fi
+
+AC_MSG_RESULT([libraries $libwebp_libraries_result, headers $libwebp_includes_result])
+
+# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
+if test "$LIBWEBP_INCLUDES" != "no" && test "$LIBWEBP_LIBS" != "no"; then
+  AC_DEFINE(HAVE_LIBWEBP,1,[Define if you have libwebp libraries and header files.])
+  $1
+else
+  LIBWEBP_INCLUDES=""
+  LIBWEBP_LIBS=""
+  $2
+fi
+
+])dnl
+
diff --git a/configure.ac b/configure.ac
index 4ddb37fe..8bbe6492 100644
--- a/configure.ac
+++ b/configure.ac
@@ -673,6 +673,8 @@ if test x"$with_cfitsio" != "xno"; then
 fi
 
 # libwebp
+# some platforms, like ubuntu 12.04, are missing the .pc files for libwebp, so
+# we fall back to FIND_LIBWEBP
 AC_ARG_WITH([libwebp], 
   AS_HELP_STRING([--without-libwebp], [build without libwebp (default: test)]))
 
@@ -681,9 +683,14 @@ if test x"$with_libwebp" != "xno"; then
     [AC_DEFINE(HAVE_LIBWEBP,1,[define if you have libwebp installed.])
      with_libwebp=yes
      PACKAGES_USED="$PACKAGES_USED libwebp"],
-    [AC_MSG_WARN([libwebp not found; disabling libwebp support])
-     with_libwebp=no
-    ])
+    [FIND_LIBWEBP([
+       with_libwebp="yes (found by search)"
+     ], [
+       AC_MSG_WARN([libwebp not found; disabling WEBP support])
+       with_libwebp=no
+     ])
+    ]
+  )
 fi
 
 # pangoft2

From bab11cec1d40be38151e34262f107359a94e2730 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Mon, 9 May 2016 10:44:32 +0100
Subject: [PATCH 26/34] always build cairo.c

---
 libvips/foreign/cairo.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/libvips/foreign/cairo.c b/libvips/foreign/cairo.c
index f8f6dec5..b242ab49 100644
--- a/libvips/foreign/cairo.c
+++ b/libvips/foreign/cairo.c
@@ -32,12 +32,12 @@
 #include <config.h>
 #endif /*HAVE_CONFIG_H*/
 
-#if defined(HAVE_RSVG) || defined(HAVE_POPPLER)
-
 #include <vips/vips.h>
 #include <vips/internal.h>
 
 /* Convert from ARGB to RGBA and undo premultiplication. 
+ *
+ * See also openslide's argb2rgba().
  */
 void
 vips__cairo2rgba( guint32 * restrict buf, int n )
@@ -64,5 +64,3 @@ vips__cairo2rgba( guint32 * restrict buf, int n )
 		}
 	}
 }
-
-#endif

From 143593d6a6b157b439813245d2e939be72d73287 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Mon, 9 May 2016 11:07:48 +0100
Subject: [PATCH 27/34] comment reformat

---
 ChangeLog                   |  1 +
 libvips/foreign/foreign.c   | 21 ++++++++++++---------
 libvips/foreign/vips2jpeg.c |  2 ++
 3 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index e16f8162..02a3eb77 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,6 @@
 1/5/16 started 8.4
 - many more wepsave options [Felix Bünemann]
+- added quant_table option to wepsave [Felix Bünemann]
 
 15/4/16 started 8.3.1
 - rename vips wrapper script, it was still vips-8.2, thanks Benjamin
diff --git a/libvips/foreign/foreign.c b/libvips/foreign/foreign.c
index 10fb231c..78b8ea76 100644
--- a/libvips/foreign/foreign.c
+++ b/libvips/foreign/foreign.c
@@ -2272,15 +2272,18 @@ vips_jpegload_buffer( void *buf, size_t len, VipsImage **out, ... )
  * If @quant_table is set and the version of libjpeg supports it
  * (e.g. mozjpeg >= 3.0) it selects the quantization table to use:
  *
- * * 0 Tables from JPEG Annex K (vips and libjpeg default)
- * * 1 Flat table
- * * 2 Table tuned for MSSIM on Kodak image set
- * * 3 Table from ImageMagick by N. Robidoux (current mozjpeg default)
- * * 4 Table tuned for PSNR-HVS-M on Kodak image set
- * * 5 Table from Relevance of Human Vision to JPEG-DCT Compression (1992)
- * * 6 Table from DCTune Perceptual Optimization of Compressed Dental X-Rays (1997)
- * * 7 Table from A Visual Detection Model for DCT Coefficient Quantization (1993)
- * * 8 Table from An Improved Detection Model for DCT Coefficient Quantization (1993)
+ * * 0 — Tables from JPEG Annex K (vips and libjpeg default)
+ * * 1 — Flat table
+ * * 2 — Table tuned for MSSIM on Kodak image set
+ * * 3 — Table from ImageMagick by N. Robidoux (current mozjpeg default)
+ * * 4 — Table tuned for PSNR-HVS-M on Kodak image set
+ * * 5 — Table from Relevance of Human Vision to JPEG-DCT Compression (1992)
+ * * 6 — Table from DCTune Perceptual Optimization of Compressed Dental 
+ *   X-Rays (1997)
+ * * 7 — Table from A Visual Detection Model for DCT Coefficient 
+ *   Quantization (1993)
+ * * 8 — Table from An Improved Detection Model for DCT Coefficient 
+ *   Quantization (1993)
  *
  * Quantization table 0 is the default in vips and libjpeg(-turbo), but it
  * tends to favor detail over color accuracy, producting colored patches and
diff --git a/libvips/foreign/vips2jpeg.c b/libvips/foreign/vips2jpeg.c
index 0c7bda5b..0f60a9ef 100644
--- a/libvips/foreign/vips2jpeg.c
+++ b/libvips/foreign/vips2jpeg.c
@@ -74,6 +74,8 @@
  * 	- don't write JFIF headers if we are stripping, thanks Benjamin
  * 13/4/16
  * 	- remove deleted exif fields more carefully
+ * 9/5/16 felixbuenemann
+ * 	- add quant_table
  */
 
 /*

From 4640aab38825de8536e24b16d5c86961cc895da6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Felix=20Bu=CC=88nemann?= <buenemann@louis.info>
Date: Mon, 9 May 2016 12:29:23 +0200
Subject: [PATCH 28/34] Test against system libwebp on Travis CI

* Dropped custom ppa used only for libwebp backport
* Dropped lossless test from `make check` (not supported in 0.1.3)
---
 .travis.yml          | 1 -
 test/test_formats.sh | 1 -
 2 files changed, 2 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 2ca5238d..3852c822 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,5 @@
 language: cpp
 before_install:
-  - sudo add-apt-repository ppa:lyrasis/precise-backports -y
   - sudo apt-get update -qq
   - sudo apt-get install automake gtk-doc-tools 
   - sudo apt-get install gobject-introspection
diff --git a/test/test_formats.sh b/test/test_formats.sh
index bce44af1..c44ce02e 100755
--- a/test/test_formats.sh
+++ b/test/test_formats.sh
@@ -192,7 +192,6 @@ if test_supported jpegload; then
 fi
 if test_supported webpload; then
 	test_format $image webp 90
-	test_format $image webp 0 [lossless]
 fi
 test_format $image ppm 0
 test_format $image pfm 0

From 3b7242f74355119acc32a27b760294046c74787d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Felix=20Bu=CC=88nemann?= <buenemann@louis.info>
Date: Mon, 9 May 2016 13:08:11 +0200
Subject: [PATCH 29/34] Fix webpsave alpha_q default value

---
 libvips/foreign/webpsave.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/libvips/foreign/webpsave.c b/libvips/foreign/webpsave.c
index f677ff0e..77e65108 100644
--- a/libvips/foreign/webpsave.c
+++ b/libvips/foreign/webpsave.c
@@ -160,6 +160,7 @@ static void
 vips_foreign_save_webp_init( VipsForeignSaveWebp *webp )
 {
 	webp->Q = 75;
+	webp->alpha_q = 100;
 }
 
 typedef struct _VipsForeignSaveWebpFile {

From 9db05c30c2629c06a21a642ad47d362599cf6e93 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Mon, 9 May 2016 14:06:44 +0100
Subject: [PATCH 30/34] tiny README fixes

---
 README.md | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index 3f5112e9..fed316b3 100644
--- a/README.md
+++ b/README.md
@@ -150,12 +150,14 @@ libraries automatically. See `./configure --help` for a set of flags to
 control library detection. Packages are generally found with `pkg-config`,
 so make sure that is working.
 
-libtiff and libjpeg do not usually use `pkg-config` so libvips looks for
+libtiff, giflib and libjpeg do not usually use `pkg-config` so libvips looks for
 them in the default path and in `$prefix`. If you have installed your own
 versions of these libraries in a different location, libvips will not see
 them. Use switches to libvips configure like:
 
 	./configure --prefix=/Users/john/vips \
+		--with-giflib-includes=/opt/local/include \
+		--with-giflib-libraries=/opt/local/lib \
 		--with-tiff-includes=/opt/local/include \
 		--with-tiff-libraries=/opt/local/lib \
 		--with-jpeg-includes=/opt/local/include \
@@ -187,8 +189,6 @@ If available, libvips adds support for EXIF metadata in JPEG files.
 The standard gif loader. If this is not present, vips will try to load gifs
 via imagemagick instead.
 
-vips will only work with giflib 4. 
-
 ### librsvg
 
 The usual SVG loader. If this is not present, vips will try to load SVGs
@@ -238,6 +238,11 @@ Imagemagick 6.9+ needs to have been built with `--with-modules`. Most packaged
 IMs are, I think, but if you are rolling your own, you'll need to pass
 this flag to configure. 
 
+If you are going to be using libvips with untrusted images, perhaps in a
+web-server, for example, you should consider the security implications of
+using a package with such a large attack surface. You might prefer not to
+enable Magick support. 
+
 ### pangoft2
 
 If available, libvips adds support for text rendering. You need the

From cb97d3d7868e13afa7fb1c5e3818e34e11bddd0d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Felix=20Bu=CC=88nemann?= <buenemann@louis.info>
Date: Mon, 9 May 2016 18:37:00 +0200
Subject: [PATCH 31/34] Remove jpegsave default quant_table debug print

This was only ut in for debugging which quant_table is used in the
JCP_FASTEST profile and should've never been committed.
---
 libvips/foreign/vips2jpeg.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/libvips/foreign/vips2jpeg.c b/libvips/foreign/vips2jpeg.c
index 0f60a9ef..1345bae8 100644
--- a/libvips/foreign/vips2jpeg.c
+++ b/libvips/foreign/vips2jpeg.c
@@ -1090,8 +1090,6 @@ write_vips( Write *write, int qfac, const char *profile,
 			vips_warn( "vips2jpeg",
 				"%s", _( "Setting quant_table unsupported" ) );
 	}
-	vips_warn( "vips2jpeg", "quant_table %d",
-		jpeg_c_get_int_param( &write->cinfo, JINT_BASE_QUANT_TBL_IDX ) );
 #else
 	/* Using jpeglib.h without extension parameters, warn of ignored 
 	 * options.

From 9fba3b55770a976f54f06eff0ed17b238717b905 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Thu, 12 May 2016 08:55:19 +0100
Subject: [PATCH 32/34] notes on TODO

---
 TODO | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/TODO b/TODO
index ebbd8c6d..d8dfc955 100644
--- a/TODO
+++ b/TODO
@@ -1,3 +1,10 @@
+- this seems to not work:
+
+	$ vips copy k2.jpg x.dz[suffix=.jpg[Q=90]]
+	dzsave: not , or ) after parameter
+
+- add n_pages to pdfload
+
 - add more webp tests to py suite
 
 - the gif tests in the suite sometimes fail with giflib5 because of an

From 24a51098b178b67eb8051d04cb1cdcfa365d8af8 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Thu, 12 May 2016 14:54:28 +0100
Subject: [PATCH 33/34] compiler warning

---
 TODO                     |  2 --
 libvips/iofuncs/header.c | 15 ++++++++-------
 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/TODO b/TODO
index d8dfc955..cd1ab676 100644
--- a/TODO
+++ b/TODO
@@ -3,8 +3,6 @@
 	$ vips copy k2.jpg x.dz[suffix=.jpg[Q=90]]
 	dzsave: not , or ) after parameter
 
-- add n_pages to pdfload
-
 - add more webp tests to py suite
 
 - the gif tests in the suite sometimes fail with giflib5 because of an
diff --git a/libvips/iofuncs/header.c b/libvips/iofuncs/header.c
index 5e913759..61d5b177 100644
--- a/libvips/iofuncs/header.c
+++ b/libvips/iofuncs/header.c
@@ -433,10 +433,10 @@ vips_image_guess_format( const VipsImage *image )
 		break;
 
 	case VIPS_INTERPRETATION_CMYK: 
-		if( image->BandFmt != VIPS_FORMAT_USHORT )
-			format = VIPS_FORMAT_UCHAR;
+		if( image->BandFmt == VIPS_FORMAT_USHORT )
+			format = VIPS_FORMAT_USHORT;
 		else
-			format = image->BandFmt;
+			format = VIPS_FORMAT_UCHAR;
 		break;
 
 	case  VIPS_INTERPRETATION_LABQ:
@@ -453,14 +453,15 @@ vips_image_guess_format( const VipsImage *image )
 		break;
 
 	case  VIPS_INTERPRETATION_MATRIX:
-		if( image->BandFmt != VIPS_FORMAT_DOUBLE )
-			format = VIPS_FORMAT_FLOAT;
+		if( image->BandFmt == VIPS_FORMAT_DOUBLE )
+			format = VIPS_FORMAT_DOUBLE;
 		else
-			format = image->BandFmt;
+			format = VIPS_FORMAT_FLOAT;
 		break;
 
 	default:
-		g_assert_not_reached();
+		format = VIPS_FORMAT_NOTSET;
+		break; 
 	}
 
 	return( format );

From 2cfe4842d3b16470f10504e475a2a41abf42e66d Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Sun, 15 May 2016 09:48:02 +0100
Subject: [PATCH 34/34] notes

---
 TODO | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/TODO b/TODO
index cd1ab676..6692c7f0 100644
--- a/TODO
+++ b/TODO
@@ -5,6 +5,8 @@
 
 - add more webp tests to py suite
 
+- try moving some more of the CLI tests to py
+
 - the gif tests in the suite sometimes fail with giflib5 because of an
   uninitialized struct in giflib, see