Merge branch '8.10'

ChangeLog

@@ -30,6 +30,9 @@
 - fix includes of glib headers in C++ [lovell]
 - fix build with more modern librsvg [lovell]
 - fix a possible segv with very wide images [f1ac]
+- revise premultiply, again [jjonesrs]
+- revise profile handling in vipsthumbnail
+- fix tiff deflate predictor setting [Adios]
 
 18/12/20 started 8.10.5
 - fix potential /0 in animated webp load [lovell]

configure.ac

@@ -1060,7 +1060,7 @@ if test x"$with_tiff" != x"no"; then
   )
 fi
 
-# WEBP in TIFF added in libtiff 4.0.10
+# ZSTD and WEBP in TIFF added in libtiff 4.0.10
 if test x"$with_tiff" != x"no"; then
   save_INCLUDES="$INCLUDES"
   INCLUDES="$INCLUDES $TIFF_INCLUDES"

libvips/conversion/flatten.c

@@ -67,7 +67,7 @@ typedef struct _VipsFlatten {
 	 */
 	VipsArrayDouble *background;
 
-	/* The [double] converted to the input image format.
+	/* The [double] background converted to the input image format.
 	 */
 	VipsPel *ink;
 

libvips/conversion/unpremultiply.c

@@ -7,6 +7,8 @@
  * 	- max_alpha defaults to 65535 for RGB16/GREY16
  * 24/11/17 lovell
  * 	- match normalised alpha to output type
+ * 27/2/21 jjonesrs
+ * 	- revise range clipping and 1/x, again
  */
 
 /*
@@ -70,7 +72,8 @@ typedef VipsConversionClass VipsUnpremultiplyClass;
 
 G_DEFINE_TYPE( VipsUnpremultiply, vips_unpremultiply, VIPS_TYPE_CONVERSION );
 
-/* Unpremultiply an N-band image.
+/* Unpremultiply an N-band image. Don't use clip_alpha to calculate factor: we
+ * want over and undershoots on alpha and RGB to cancel.
  */
 #define UNPRE_MANY( IN, OUT ) { \
 	IN * restrict p = (IN *) in; \
@@ -78,18 +81,11 @@ G_DEFINE_TYPE( VipsUnpremultiply, vips_unpremultiply, VIPS_TYPE_CONVERSION );
 	\
 	for( x = 0; x < width; x++ ) { \
 		IN alpha = p[alpha_band]; \
+		OUT factor = alpha == 0 ? 0 : max_alpha / alpha; \
 		\
-		if( alpha != 0 ) { \
-			OUT factor = max_alpha / alpha; \
-			\
-			for( i = 0; i < alpha_band; i++ ) \
-				q[i] = factor * p[i]; \
-			q[alpha_band] = alpha; \
-		} \
-		else \
-			for( i = 0; i < alpha_band + 1; i++ ) \
-				q[i] = 0; \
-		\
+		for( i = 0; i < alpha_band; i++ ) \
+			q[i] = factor * p[i]; \
+		q[alpha_band] = VIPS_CLIP( 0, alpha, max_alpha ); \
 		for( i = alpha_band + 1; i < bands; i++ ) \
 			q[i] = p[i]; \
 		\
@@ -106,21 +102,12 @@ G_DEFINE_TYPE( VipsUnpremultiply, vips_unpremultiply, VIPS_TYPE_CONVERSION );
 	\
 	for( x = 0; x < width; x++ ) { \
 		IN alpha = p[3]; \
+		OUT factor = alpha == 0 ? 0 : max_alpha / alpha; \
 		\
-		if( alpha != 0 ) { \
-			OUT factor = max_alpha / alpha; \
-			\
-			q[0] = factor * p[0]; \
-			q[1] = factor * p[1]; \
-			q[2] = factor * p[2]; \
-			q[3] = alpha; \
-		} \
-		else { \
-			q[0] = 0; \
-			q[1] = 0; \
-			q[2] = 0; \
-			q[3] = 0; \
-		} \
+		q[0] = factor * p[0]; \
+		q[1] = factor * p[1]; \
+		q[2] = factor * p[2]; \
+		q[3] = VIPS_CLIP( 0, alpha, max_alpha ); \
 		\
 		p += 4; \
 		q += 4; \

libvips/foreign/tiffsave.c

@@ -590,8 +590,8 @@ vips_foreign_save_tiff_buffer_init( VipsForeignSaveTiffBuffer *buffer )
  * User @level to set the ZSTD compression level. Use @lossless to
  * set WEBP lossless mode on. Use @Q to set the WEBP compression level.
  *
- * Use @predictor to set the predictor for lzw and deflate compression. It
- * defaults to #VIPS_FOREIGN_TIFF_PREDICTOR_HORIZONTAL, meaning horizontal
+ * Use @predictor to set the predictor for lzw, deflate and zstd compression.
+ * It defaults to #VIPS_FOREIGN_TIFF_PREDICTOR_HORIZONTAL, meaning horizontal
  * differencing. Please refer to the libtiff 
  * specifications for further discussion of various predictors. 
  *

libvips/foreign/vips2tiff.c

@@ -333,9 +333,9 @@ struct _Wtiff {
 	VipsPel *tbuf;			/* TIFF output buffer */
 	int tls;			/* Tile line size */
 
-	int compression;		/* Compression type */
+	int compression;		/* libtiff compression type */
 	int Q;				/* JPEG q-factor, webp level */
-	int predictor;			/* Predictor value */
+	int predictor;			/* libtiff predictor type */
 	int tile;			/* Tile or not */
 	int tilew, tileh;		/* Tile size */
 	int pyramid;			/* Wtiff pyramid */
@@ -659,12 +659,16 @@ wtiff_write_header( Wtiff *wtiff, Layer *layer )
 		TIFFSetField( tif, TIFFTAG_WEBP_LEVEL, wtiff->Q );
 		TIFFSetField( tif, TIFFTAG_WEBP_LOSSLESS, wtiff->lossless );
 	}
-	if( wtiff->compression == COMPRESSION_ZSTD ) 
+	if( wtiff->compression == COMPRESSION_ZSTD ) {
 		TIFFSetField( tif, TIFFTAG_ZSTD_LEVEL, wtiff->level );
+		if( wtiff->predictor != VIPS_FOREIGN_TIFF_PREDICTOR_NONE ) 
+			TIFFSetField( tif, 
+				TIFFTAG_PREDICTOR, wtiff->predictor );
+	}
 #endif /*HAVE_TIFF_COMPRESSION_WEBP*/
 
-	if( (wtiff->compression == VIPS_FOREIGN_TIFF_COMPRESSION_DEFLATE ||
-		wtiff->compression == VIPS_FOREIGN_TIFF_COMPRESSION_LZW) &&
+	if( (wtiff->compression == COMPRESSION_ADOBE_DEFLATE ||
+		wtiff->compression == COMPRESSION_LZW) &&
 		wtiff->predictor != VIPS_FOREIGN_TIFF_PREDICTOR_NONE ) 
 		TIFFSetField( tif, TIFFTAG_PREDICTOR, wtiff->predictor );
 
@@ -1862,10 +1866,19 @@ wtiff_copy_tiff( Wtiff *wtiff, TIFF *out, TIFF *in )
 		TIFFSetField( out, TIFFTAG_WEBP_LEVEL, wtiff->Q );
 		TIFFSetField( out, TIFFTAG_WEBP_LOSSLESS, wtiff->lossless );
 	}
-	if( wtiff->compression == COMPRESSION_ZSTD ) 
+	if( wtiff->compression == COMPRESSION_ZSTD ) {
 		TIFFSetField( out, TIFFTAG_ZSTD_LEVEL, wtiff->level );
+		if( wtiff->predictor != VIPS_FOREIGN_TIFF_PREDICTOR_NONE ) 
+			TIFFSetField( out, 
+				TIFFTAG_PREDICTOR, wtiff->predictor );
+	}
 #endif /*HAVE_TIFF_COMPRESSION_WEBP*/
 
+	if( (wtiff->compression == COMPRESSION_ADOBE_DEFLATE ||
+		wtiff->compression == COMPRESSION_LZW) &&
+		wtiff->predictor != VIPS_FOREIGN_TIFF_PREDICTOR_NONE ) 
+		TIFFSetField( out, TIFFTAG_PREDICTOR, wtiff->predictor );
+
 	/* We can't copy profiles or xmp :( Set again from wtiff.
 	 */
 	if( !wtiff->strip ) 

libvips/resample/thumbnail.c

@@ -30,6 +30,9 @@
  * 	- add thumbnail_source
  * 2/6/20
  * 	- add subifd pyr support
+ * 27/2/21
+ * 	- simplify rules re. processing space, colour management and linear
+ * 	  mode
  */
 
 /*
@@ -624,16 +627,19 @@ vips_thumbnail_build( VipsObject *object )
 	int preshrunk_page_height;
 	double hshrink;
 	double vshrink;
-	VipsInterpretation interpretation;
 
 	/* TRUE if we've done the import of an ICC transform and still need to
 	 * export.
 	 */
 	gboolean have_imported;
 
-	/* TRUE if we've premultiplied and need to unpremultiply.
+	/* If we shrink in linear space, we need to return to the input
+	 * colourspace after the shrink.
+	 */
+	VipsInterpretation input_interpretation;
+
+	/* The format we need to revert to after unpremultiply.
 	 */
-	gboolean have_premultiplied;
 	VipsBandFormat unpremultiplied_format;
 
 #ifdef DEBUG
@@ -679,60 +685,78 @@ vips_thumbnail_build( VipsObject *object )
 		in = t[12];
 	}
 
-	/* In linear mode, we import right at the start. 
-	 *
-	 * We also have to import the whole image if it's CMYK, since
-	 * vips_colourspace() (see below) doesn't let you specify the fallback
-	 * profile.
-	 *
-	 * This is only going to work for images in device space. If you have
-	 * an image in PCS which also has an attached profile, strange things
-	 * will happen. 
+	/* In linear mode, we need to transform to a linear space before 
+	 * vips_resize(). 
 	 */
 	have_imported = FALSE;
-	if( thumbnail->linear &&
-		in->Coding == VIPS_CODING_NONE &&
-		(in->BandFmt == VIPS_FORMAT_UCHAR ||
-		 in->BandFmt == VIPS_FORMAT_USHORT) &&
-		(vips_image_get_typeof( in, VIPS_META_ICC_NAME ) || 
-		 thumbnail->import_profile) ) {
-		g_info( "importing to XYZ PCS" );
-		if( thumbnail->import_profile ) 
-			g_info( "fallback input profile %s", 
-				thumbnail->import_profile );
+	if( thumbnail->linear ) {
+		/* If we are doing colour management (there's an import 
+		 * profile), then we can use XYZ PCS as the resize space.
+		 */
+		if( in->Coding == VIPS_CODING_NONE &&
+			(in->BandFmt == VIPS_FORMAT_UCHAR ||
+			 in->BandFmt == VIPS_FORMAT_USHORT) &&
+			(vips_image_get_typeof( in, VIPS_META_ICC_NAME ) || 
+			 thumbnail->import_profile) ) {
+			g_info( "importing to XYZ PCS" );
+			if( thumbnail->import_profile ) 
+				g_info( "fallback input profile %s", 
+					thumbnail->import_profile );
 
-		if( vips_icc_import( in, &t[1], 
-			"input_profile", thumbnail->import_profile,
-			"embedded", TRUE,
-			"intent", thumbnail->intent,
-			"pcs", VIPS_PCS_XYZ,
-			NULL ) )  
-			return( -1 );
+			if( vips_icc_import( in, &t[1], 
+				"input_profile", thumbnail->import_profile,
+				"embedded", TRUE,
+				"intent", thumbnail->intent,
+				"pcs", VIPS_PCS_XYZ,
+				NULL ) )  
+				return( -1 );
+			in = t[1];
 
-		in = t[1];
+			have_imported = TRUE;
+		}
+		else {
+			/* Otherwise, use scRGB or GREY16 for linear shrink.
+			 */
+			VipsInterpretation interpretation;
 
-		have_imported = TRUE;
+			/* Note the interpretation we will revert to after 
+			 * linear.
+			 */
+			input_interpretation = in->Type;
+
+			if( in->Bands < 3 )
+				interpretation = VIPS_INTERPRETATION_GREY16; 
+			else 
+				interpretation = VIPS_INTERPRETATION_scRGB; 
+
+			g_info( "converting to processing space %s",
+				vips_enum_nick( VIPS_TYPE_INTERPRETATION, 
+					interpretation ) ); 
+			if( vips_colourspace( in, &t[2], interpretation, 
+				NULL ) ) 
+				return( -1 ); 
+			in = t[2];
+		}
 	}
+	else {
+		/* In non-linear mode, use sRGB or B_W as the processing
+		 * space.
+		 */
+		VipsInterpretation interpretation;
 
-	/* To the processing colourspace. This will unpack LABQ, import CMYK,
-	 * etc.
-	 *
-	 * If this is a CMYK image, we need to set have_imported since we only
-	 * want to export at the end.
-	 */
-	if( in->Type == VIPS_INTERPRETATION_CMYK )
-		have_imported = TRUE;
-	if( thumbnail->linear )
-		interpretation = VIPS_INTERPRETATION_scRGB;
-	else if( in->Bands < 3 )
-		interpretation = VIPS_INTERPRETATION_B_W; 
-	else 
-		interpretation = VIPS_INTERPRETATION_sRGB; 
-	g_info( "converting to processing space %s",
-		vips_enum_nick( VIPS_TYPE_INTERPRETATION, interpretation ) ); 
-	if( vips_colourspace( in, &t[2], interpretation, NULL ) ) 
-		return( -1 ); 
-	in = t[2];
+		if( in->Bands < 3 )
+			interpretation = VIPS_INTERPRETATION_B_W; 
+		else 
+			interpretation = VIPS_INTERPRETATION_sRGB; 
+
+		g_info( "converting to processing space %s",
+			vips_enum_nick( VIPS_TYPE_INTERPRETATION, 
+				interpretation ) ); 
+		if( vips_colourspace( in, &t[2], interpretation, 
+			NULL ) ) 
+			return( -1 ); 
+		in = t[2];
+	}
 
 	/* Shrink to preshrunk_page_height, so we work for multi-page images.
 	 */
@@ -751,23 +775,23 @@ vips_thumbnail_build( VipsObject *object )
 		vshrink = (double) in->Ysize / target_image_height;
 	}
 
+	/* vips_premultiply() makes a float image, so when we unpremultiply
+	 * below we must cast back to the original format. Use NOTSET to
+	 * meran no pre/unmultiply.
+	 */
+	unpremultiplied_format = VIPS_FORMAT_NOTSET;
+
 	/* If there's an alpha, we have to premultiply before shrinking. See
 	 * https://github.com/libvips/libvips/issues/291
 	 */
-	have_premultiplied = FALSE;
 	if( vips_image_hasalpha( in ) && 
 	 	hshrink != 1.0 &&
 		vshrink != 1.0  ) { 
 		g_info( "premultiplying alpha" ); 
+		unpremultiplied_format = in->BandFmt;
+
 		if( vips_premultiply( in, &t[3], NULL ) ) 
 			return( -1 );
-		have_premultiplied = TRUE;
-
-		/* vips_premultiply() makes a float image. When we
-		 * vips_unpremultiply() below, we need to cast back to the
-		 * pre-premultiply format.
-		 */
-		unpremultiplied_format = in->BandFmt;
 		in = t[3];
 	}
 
@@ -777,6 +801,14 @@ vips_thumbnail_build( VipsObject *object )
 		return( -1 );
 	in = t[4];
 
+	if( unpremultiplied_format != VIPS_FORMAT_NOTSET ) {
+		g_info( "unpremultiplying alpha" ); 
+		if( vips_unpremultiply( in, &t[5], NULL ) || 
+			vips_cast( t[5], &t[6], unpremultiplied_format, NULL ) )
+			return( -1 );
+		in = t[6];
+	}
+
 	/* Only set page-height if we have more than one page, or this could
 	 * accidentally turn into an animated image later.
 	 */
@@ -792,21 +824,12 @@ vips_thumbnail_build( VipsObject *object )
 			VIPS_META_PAGE_HEIGHT, output_page_height );
 	}
 
-	if( have_premultiplied ) {
-		g_info( "unpremultiplying alpha" ); 
-		if( vips_unpremultiply( in, &t[5], NULL ) || 
-			vips_cast( t[5], &t[6], unpremultiplied_format, NULL ) )
-			return( -1 );
-		in = t[6];
-	}
-
 	/* Colour management.
-	 *
-	 * If we've already imported, just export. Otherwise, we're in 
-	 * device space and we need a combined import/export to transform to 
-	 * the target space.
 	 */
 	if( have_imported ) { 
+		/* We've already imported, just export. Go to sRGB if there's
+		 * no export profile.
+		 */
 		if( thumbnail->export_profile ||
 			vips_image_get_typeof( in, VIPS_META_ICC_NAME ) ) {
 			g_info( "exporting to device space with a profile" );
@@ -825,21 +848,54 @@ vips_thumbnail_build( VipsObject *object )
 			in = t[7];
 		}
 	}
-	else if( thumbnail->export_profile &&
-		(vips_image_get_typeof( in, VIPS_META_ICC_NAME ) || 
-		 thumbnail->import_profile) ) {
+	else if( thumbnail->export_profile ) {
+		/* Not imported, but we are doing colour management. Transform
+		 * to the output space.
+		 */
 		g_info( "transforming to %s", thumbnail->export_profile );
-		if( thumbnail->import_profile ) 
-			g_info( "fallback input profile %s", 
-				thumbnail->import_profile );
 
-		if( vips_icc_transform( in, &t[7], 
-			thumbnail->export_profile,
-			"input_profile", thumbnail->import_profile,
-			"intent", thumbnail->intent,
-			"embedded", TRUE,
-			NULL ) ) 
-			return( -1 );
+		/* If there's some kind of import profile, we can transform to
+		 * the output. Otherwise we have to convert to PCS and then
+		 * export.
+		 */
+		if( thumbnail->import_profile ||
+			(vips_image_get_typeof( in, VIPS_META_ICC_NAME ) ||
+			 thumbnail->import_profile) ) {
+			g_info( "transforming with supplied profiles" ); 
+			if( vips_icc_transform( in, &t[7], 
+				thumbnail->export_profile,
+				"input_profile", thumbnail->import_profile,
+				"intent", thumbnail->intent,
+				"embedded", TRUE,
+				NULL ) ) 
+				return( -1 );
+
+			in = t[7];
+		}
+		else {
+			g_info( "exporting with %s", 
+				thumbnail->export_profile ); 
+			if( vips_colourspace( in, &t[7], 
+				VIPS_INTERPRETATION_XYZ, NULL ) || 
+				vips_icc_export( t[7], &t[8], 
+					"output_profile", 
+						thumbnail->export_profile,
+					"intent", thumbnail->intent,
+					NULL ) )  
+				return( -1 ); 
+			in = t[8];
+		}
+	}
+	else if( thumbnail->linear ) {
+		/* Linear mode, no colour management. We went to scRGB for
+		 * processing, so we now revert to the input colourspace.
+		 */
+		g_info( "reverting to input space %s",
+			vips_enum_nick( VIPS_TYPE_INTERPRETATION, 
+				input_interpretation ) ); 
+		if( vips_colourspace( in, &t[7], 
+			input_interpretation, NULL ) ) 
+			return( -1 ); 
 		in = t[7];
 	}
 
@@ -1368,7 +1424,7 @@ vips_thumbnail_buffer_init( VipsThumbnailBuffer *buffer )
  * * @intent: #VipsIntent, rendering intent
  * * @option_string: %gchararray, extra loader options
  *
- * Exacty as vips_thumbnail(), but read from a memory buffer. One extra
+ * Exactly as vips_thumbnail(), but read from a memory buffer. One extra
  * optional argument, @option_string, lets you pass options to the underlying
  * loader.
  *
@@ -1564,7 +1620,7 @@ vips_thumbnail_source_init( VipsThumbnailSource *source )
  * * @intent: #VipsIntent, rendering intent
  * * @option_string: %gchararray, extra loader options
  *
- * Exacty as vips_thumbnail(), but read from a source. One extra
+ * Exactly as vips_thumbnail(), but read from a source. One extra
  * optional argument, @option_string, lets you pass options to the underlying
  * loader.
  *
@@ -1671,7 +1727,7 @@ vips_thumbnail_image_init( VipsThumbnailImage *image )
  * * @export_profile: %gchararray, export ICC profile
  * * @intent: #VipsIntent, rendering intent
  *
- * Exacty as vips_thumbnail(), but read from an existing image. 
+ * Exactly as vips_thumbnail(), but read from an existing image. 
  *
  * This operation
  * is not able to exploit shrink-on-load features of image load libraries, so

test/test-suite/helpers/helpers.py

@@ -42,6 +42,9 @@ BMP_FILE = os.path.join(IMAGES, "MARBLES.BMP")
 NIFTI_FILE = os.path.join(IMAGES, "avg152T1_LR_nifti.nii.gz")
 ICO_FILE = os.path.join(IMAGES, "favicon.ico")
 AVIF_FILE = os.path.join(IMAGES, "avif-orientation-6.avif")
+HEIC_FILE = os.path.join(IMAGES, "heic-orientation-6.heic")
+RGBA_FILE = os.path.join(IMAGES, "rgba.png")
+RGBA_CORRECT_FILE = os.path.join(IMAGES, "rgba-correct.ppm")
 MOSAIC_FILES = [os.path.join(IMAGES, "cd1.1.jpg"), os.path.join(IMAGES, "cd1.2.jpg"),
                 os.path.join(IMAGES, "cd2.1.jpg"), os.path.join(IMAGES, "cd2.2.jpg"),
                 os.path.join(IMAGES, "cd3.1.jpg"), os.path.join(IMAGES, "cd3.2.jpg"),

test/test-suite/test_resample.py

@@ -2,7 +2,8 @@
 import pytest
 
 import pyvips
-from helpers import JPEG_FILE, OME_FILE, AVIF_FILE, TIF_FILE, all_formats, have
+from helpers import JPEG_FILE, OME_FILE, HEIC_FILE, TIF_FILE, all_formats, \
+    have, RGBA_FILE, RGBA_CORRECT_FILE, AVIF_FILE
 
 
 # Run a function expecting a complex image on a two-band image
@@ -193,6 +194,11 @@ class TestResample:
         im2 = pyvips.Image.thumbnail_buffer(buf, 100)
         assert abs(im1.avg() - im2.avg()) < 1
 
+        # linear shrink should work on rgba images
+        im1 = pyvips.Image.thumbnail(RGBA_FILE, 64, linear=True)
+        im2 = pyvips.Image.new_from_file(RGBA_CORRECT_FILE)
+        assert abs(im1.flatten(background=255).avg() - im2.avg()) < 1
+
         if have("heifload"):
             # this image is orientation 6 ... thumbnail should flip it
             im = pyvips.Image.new_from_file(AVIF_FILE)