Merge branch 'master' into add-tiffload-n-pages

ChangeLog

@@ -8,7 +8,7 @@
 - added vips_thumbnail() / vips_thumbnail_buffer()
 - better >4gb detect for zip dzsave output [Felix Bünemann]
 - all loaders have a @fail option, meaning fail on first warning, though it
-  only does anything for jpg, csv, openslide
+  only does anything for jpg and csv
 - add vips_image_get_fields() to help bindings
 - add multi-page read to tiffload
 

libvips/foreign/openslide2vips.c

@@ -47,8 +47,6 @@
  * 	- do argb -> rgba for associated as well 
  * 27/1/15
  * 	- unpremultiplication speedups for fully opaque/transparent pixels
- * 11/7/16
- * 	- just warn on tile read error
  */
 
 /*
@@ -115,10 +113,6 @@ typedef struct {
 	 */
 	int tile_width;
 	int tile_height;
-
-	/* Quit on warning.
-	 */
-	gboolean fail;
 } ReadSlide;
 
 int
@@ -227,7 +221,7 @@ get_bounds( openslide_t *osr, VipsRect *rect )
 
 static ReadSlide *
 readslide_new( const char *filename, VipsImage *out, 
-	int level, gboolean autocrop, const char *associated, gboolean fail )
+	int level, gboolean autocrop, const char *associated )
 {
 	ReadSlide *rslide;
 	int64_t w, h;
@@ -395,9 +389,9 @@ readslide_new( const char *filename, VipsImage *out,
 
 int
 vips__openslide_read_header( const char *filename, VipsImage *out, 
-	int level, gboolean autocrop, char *associated, gboolean fail )
+	int level, gboolean autocrop, char *associated )
 {
-	if( !readslide_new( filename, out, level, autocrop, associated, fail ) )
+	if( !readslide_new( filename, out, level, autocrop, associated ) )
 		return( -1 );
 
 	return( 0 );
@@ -477,15 +471,18 @@ vips__openslide_generate( VipsRegion *out,
 		rslide->level,
 		r->width, r->height ); 
 
-	/* Only warn on error: we don't want to make the whole image unreadable
-	 * because of one broken tile.
+	/* openslide errors are terminal. To support
+	 * @fail we'd have to close the openslide_t and reopen, perhaps 
+	 * somehow marking this tile as unreadable.
+	 *
+	 * See
+	 * https://github.com/jcupitt/libvips/commit/bb0a6643f94e69294e36d2b253f9bdd60c8c40ed#commitcomment-19838911
 	 */
 	error = openslide_get_error( rslide->osr );
 	if( error ) {
-		vips_warn( "openslide2vips", 
+		vips_error( "openslide2vips", 
 			_( "reading region: %s" ), error );
-		if( rslide->fail )
-			return( -1 );
+		return( -1 );
 	}
 
 	/* Since we are inside a cache, we know buf must be continuous.
@@ -497,7 +494,7 @@ vips__openslide_generate( VipsRegion *out,
 
 int
 vips__openslide_read( const char *filename, VipsImage *out, 
-	int level, gboolean autocrop, gboolean fail )
+	int level, gboolean autocrop )
 {
 	ReadSlide *rslide;
 	VipsImage *raw;
@@ -510,7 +507,7 @@ vips__openslide_read( const char *filename, VipsImage *out,
 	vips_object_local( out, raw );
 
 	if( !(rslide = readslide_new( filename, raw, 
-		level, autocrop, NULL, fail )) )
+		level, autocrop, NULL )) )
 		return( -1 );
 
 	if( vips_image_generate( raw, 
@@ -539,7 +536,7 @@ vips__openslide_read( const char *filename, VipsImage *out,
 
 int
 vips__openslide_read_associated( const char *filename, VipsImage *out, 
-	const char *associated, gboolean fail )
+	const char *associated )
 {
 	ReadSlide *rslide;
 	VipsImage *raw;
@@ -554,8 +551,7 @@ vips__openslide_read_associated( const char *filename, VipsImage *out,
 	raw = vips_image_new_memory();
 	vips_object_local( out, raw );
 
-	if( !(rslide = readslide_new( filename, raw, 
-		0, FALSE, associated, fail )) ||
+	if( !(rslide = readslide_new( filename, raw, 0, FALSE, associated )) ||
 		vips_image_write_prepare( raw ) )
 		return( -1 );
 	buf = (uint32_t *) VIPS_IMAGE_ADDR( raw, 0, 0 );

libvips/foreign/openslideload.c

@@ -114,7 +114,7 @@ vips_foreign_load_openslide_header( VipsForeignLoad *load )
 
 	if( vips__openslide_read_header( openslide->filename, load->out, 
 		openslide->level, openslide->autocrop, 
-		openslide->associated, load->fail ) )
+		openslide->associated ) )
 		return( -1 );
 
 	VIPS_SETSTR( load->out->filename, openslide->filename );
@@ -129,13 +129,12 @@ vips_foreign_load_openslide_load( VipsForeignLoad *load )
 
 	if( !openslide->associated ) {
 		if( vips__openslide_read( openslide->filename, load->real, 
-			openslide->level, openslide->autocrop, load->fail ) )
+			openslide->level, openslide->autocrop ) )
 			return( -1 );
 	}
 	else {
-		if( vips__openslide_read_associated( 
-			openslide->filename, load->real, 
-			openslide->associated, load->fail ) )
+		if( vips__openslide_read_associated( openslide->filename, 
+			load->real, openslide->associated ) )
 			return( -1 );
 	}
 
@@ -231,7 +230,6 @@ vips_foreign_load_openslide_init( VipsForeignLoadOpenslide *openslide )
  * * @level: load this level
  * * @associated: load this associated image
  * * @autocrop: crop to image bounds
- * * @fail: %gboolean, fail on warnings
  *
  * Read a virtual slide supported by the OpenSlide library into a VIPS image.
  * OpenSlide supports images in Aperio, Hamamatsu, MIRAX, Sakura, Trestle,
@@ -251,8 +249,6 @@ vips_foreign_load_openslide_init( VipsForeignLoadOpenslide *openslide )
  *
  * The output of this operator is always RGBA.
  *
- * Setting @fail to %TRUE makes the reader fail on any warnings. 
- *
  * See also: vips_image_new_from_file().
  *
  * Returns: 0 on success, -1 on error.

libvips/foreign/pforeign.h

@@ -217,11 +217,11 @@ int vips__webp_write_buffer( VipsImage *out, void **buf, size_t *len,
 
 int vips__openslide_isslide( const char *filename );
 int vips__openslide_read_header( const char *filename, VipsImage *out, 
-	int level, gboolean autocrop, char *associated, gboolean fail );
+	int level, gboolean autocrop, char *associated );
 int vips__openslide_read( const char *filename, VipsImage *out, 
-	int level, gboolean autocrop, gboolean fail );
+	int level, gboolean autocrop );
 int vips__openslide_read_associated( const char *filename, VipsImage *out, 
-	const char *associated, gboolean fail );
+	const char *associated );
 
 #ifdef __cplusplus
 }

libvips/include/vips/header.h

@@ -190,6 +190,7 @@ int vips_image_get_string( const VipsImage *image,
 	const char *name, const char **out );
 void vips_image_set_string( VipsImage *image, 
 	const char *name, const char *str );
+void vips_image_print_field( const VipsImage *image, const char *field );
 
 int vips_image_history_printf( VipsImage *image, const char *format, ... )
 	__attribute__((format(printf, 2, 3)));

libvips/iofuncs/header.c

@@ -893,8 +893,11 @@ vips__image_copy_fields_array( VipsImage *out, VipsImage *in[] )
 
 	/* Need to copy last-to-first so that in0 meta will override any
 	 * earlier meta.
+	 *
+	 * Don't destroy the meta on out. Things like foreign.c like setting
+	 * image properties before calling a subclass loader, and those
+	 * subclass loaders will sometimes write to an image. 
 	 */
-	vips__meta_destroy( out );
 	for( i = ni - 1; i >= 0; i-- ) 
 		if( meta_cp( out, in[i] ) )
 			return( -1 );
@@ -1573,6 +1576,28 @@ vips_image_get_as_string( const VipsImage *image,
 	return( 0 );
 }
 
+/**
+ * vips_image_print_field:
+ * @image: image to get the header field from
+ * @field: field name
+ *
+ * Prints a field to stdout as ASCII. Handy for debugging. 
+ */
+void
+vips_image_print_field( const VipsImage *image, const char *field )
+{
+	char *str;
+
+	if( vips_image_get_as_string( image, field, &str ) ) {
+		printf( "vips_image_print_field: unable to read field\n" );
+		return;
+	}
+
+	printf( ".%s: %s\n", field, str );
+
+	g_free( str ); 
+}
+
 /**
  * vips_image_history_printf:
  * @image: add history line to this image

libvips/resample/resample.c

@@ -64,7 +64,15 @@
  * sort of 2D transform which preserves straight lines; so any combination of 
  * stretch, sheer, rotate and translate. You supply an interpolator for it to
  * use to generate pixels, see vips_interpolate_new(). It will not produce
- * good results for very large shrinks.
+ * good results for very large shrinks: you'll see aliasing.
+ *
+ * vips_reduce() is like vips_affine(), but it can only shrink images, it can't
+ * enlarge, rotate, or skew. It's very fast and uses an adaptive kernel for
+ * interpolation. Again, it will give poor results for large size reductions.
+ *
+ * vips_shrink() is a fast block shrinker. It can quickly reduce images by
+ * large integer factors. It will give poor results for small size reductions:
+ * again, you'll see aliasing. 
  *
  * Next, vips_resize() specialises in the common task of image reduce and 
  * enlarge. It strings together combinations of vips_shrink(), vips_reduce(),