fix openslide read

previously it returned Cairo-style pre-multiplied argb, now it always
unpacks to png-style rgba for you

there was no real use for the coded form and it was annoying to have to
call im_argb2rgba() explicitly

ChangeLog

@@ -1,6 +1,8 @@
 6/4/12 started 7.28.3
 - vips_divide() failed for int arguments
 - fix warning for unused vips7 gvalue argument
+- fix openslide read: always return png-style rgba, im_argb2rgba() becomes a
+  NOP
 
 13/3/12 started 7.28.2
 - xres/yres tiffsave args were broken

libvips/colour/Makefile.am

@@ -6,7 +6,6 @@ libcolour_la_SOURCES = \
 	colour_dispatch.c \
 	derived.c \
 	im_icc_transform.c \
-	im_argb2rgba.c \
 	im_LCh2Lab.c \
 	im_LCh2UCS.c \
 	im_Lab2LCh.c \

libvips/colour/colour_dispatch.c

@@ -640,25 +640,6 @@ static im_function rad2float_desc = {
 	one_in_one_out 			/* Arg list */
 };
 
-/* Call im_argb2rgba() via arg vector.
- */
-static int
-argb2rgba_vec( im_object *argv )
-{
-	return( im_argb2rgba( argv[0], argv[1] ) );
-}
-
-/* Description of im_argb2rgba.
- */ 
-static im_function argb2rgba_desc = {
-	"im_argb2rgba", 		/* Name */
-	"convert pre-multipled argb to png-style rgba",	/* Description */
-	IM_FN_PIO,			/* Flags */
-	argb2rgba_vec, 			/* Dispatch function */
-	IM_NUMBER( one_in_one_out ), 	/* Size of arg list */
-	one_in_one_out 			/* Arg list */
-};
-
 /* Call im_float2rad() via arg vector.
  */
 static int
@@ -1204,7 +1185,6 @@ static im_function *colour_list[] = {
 	&disp2Lab_desc,
 	&disp2XYZ_desc,
 	&float2rad_desc,
-	&argb2rgba_desc,
 	&icc_ac2rc_desc,
 	&icc_export_depth_desc,
 	&icc_import_desc,

libvips/colour/im_argb2rgba.c

@@ -1,110 +0,0 @@
-/* Convert pre-multipled argb to rgba
- *
- * 11/12/11
- * 	- from im_rad2float.c
- */
-
-/*
-
-    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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  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*/
-#include <vips/intl.h>
-
-#include <stdio.h>
-#include <math.h>
-
-#include <vips/vips.h>
-
-static void
-argb2rgba( guint32 *in, VipsPel *out, int n, void *_bg )
-{
-	guint32 bg = GPOINTER_TO_UINT( _bg );
-
-	int i;
-
-	for( i = 0; i < n; i++ ) {
-		guint32 x = in[i];
-		guint8 a = x >> 24;
-
-		/* Convert from ARGB to RGBA and undo premultiplication.
-		 */
-		if( a != 0 ) {
-			out[0] = 255 * ((x >> 16) & 255) / a;
-			out[1] = 255 * ((x >> 8) & 255) / a;
-			out[2] = 255 * (x & 255) / a;
-		} 
-		else {
-			/* Use background color.
-			 */
-			out[0] = (bg >> 16) & 255;
-			out[1] = (bg >> 8) & 255;
-			out[2] = bg & 255;
-		}
-		out[3] = a;
-
-		out += 4;
-	}
-}
-
-/**
- * im_argb2rgba:
- * @in: input image
- * @out: output image
- *
- * Convert Cairo-style pre-multiplied argb to png-style rgba. Background
- * pixels are painted with the metadata item "background-rgb".
- *
- * See also: im_openslide2vips().
- *
- * Returns: 0 on success, -1 on error.
- */
-int
-im_argb2rgba( VipsImage *in, IMAGE *out )
-{
-	guint32 bg;
-
-	/* check for RAD coding 
-	if( in->Coding != IM_CODING_RAD ) {
-		im_error( "im_rad2float", "%s", _( "not a RAD image" ) );
-		return( -1 );
-	}
-	 */
-
-	if( im_cp_desc( out, in ) )
-		return( -1 );
-	out->Coding = IM_CODING_NONE;
-
-	if( vips_image_get_int( in, VIPS_META_BACKGROUND_RGB, (int *) &bg ) )
-		bg = 0xffffff;
-
-	if( im_wrapone( in, out, 
-		(im_wrapone_fn) argb2rgba, GUINT_TO_POINTER( bg ), NULL ) )
-		return( -1 );
-
-	return( 0 );
-}

libvips/deprecated/deprecated_dispatch.c

@@ -2188,10 +2188,30 @@ static im_function ifthenelse_desc = {
 	ifthenelse_args 		/* Arg list */
 };
 
+/* Call im_argb2rgba() via arg vector.
+ */
+static int
+argb2rgba_vec( im_object *argv )
+{
+	return( im_argb2rgba( argv[0], argv[1] ) );
+}
+
+/* Description of im_argb2rgba.
+ */ 
+static im_function argb2rgba_desc = {
+	"im_argb2rgba", 		/* Name */
+	"convert pre-multipled argb to png-style rgba",	/* Description */
+	IM_FN_PIO,			/* Flags */
+	argb2rgba_vec, 			/* Dispatch function */
+	IM_NUMBER( one_in_one_out ), 	/* Size of arg list */
+	one_in_one_out 			/* Arg list */
+};
+
 
 /* Package up all these functions.
  */
 static im_function *deprecated_list[] = {
+	&argb2rgba_desc,
 	&flood_copy_desc,
 	&flood_blob_copy_desc,
 	&flood_other_copy_desc,

libvips/deprecated/vips7compat.c

@@ -2098,3 +2098,11 @@ im_cache( VipsImage *in, VipsImage *out,
 	return( vips_sink_screen( in, out, NULL, 
 		width, height, max, 0, NULL, NULL ) );
 }
+
+int
+im_argb2rgba( VipsImage *in, VipsImage *out )
+{
+	/* No longer exists, just a null op.
+	 */
+	return( im_copy( in, out ) );
+}

libvips/foreign/openslide2vips.c

@@ -26,6 +26,9 @@
  * 	- turn into a set of read fns ready to be called from a class
  * 28/2/12
  * 	- convert "layer" to "level" where externally visible
+ * 9/4/12
+ * 	- move argb2rgba back in here, we don't have a use for coded pixels
+ * 	- small cleanups
  */
 
 /*
@@ -83,8 +86,9 @@ typedef struct {
 
 	/* Only valid if associated == NULL.
 	 */
-	int32_t layer;
+	int32_t level;
 	double downsample;
+	uint32_t bg;
 } ReadSlide;
 
 int
@@ -138,7 +142,7 @@ check_associated_image( openslide_t *osr, const char *name )
 
 static ReadSlide *
 readslide_new( const char *filename, VipsImage *out, 
-	int layer, const char *associated )
+	int level, const char *associated )
 {
 	ReadSlide *rslide;
 	int64_t w, h;
@@ -150,7 +154,7 @@ readslide_new( const char *filename, VipsImage *out,
 	g_signal_connect( out, "close", G_CALLBACK( readslide_destroy_cb ),
 		rslide );
 
-	rslide->layer = layer;
+	rslide->level = level;
 	rslide->associated = g_strdup( associated );
 
 	rslide->osr = openslide_open( filename );
@@ -160,8 +164,8 @@ readslide_new( const char *filename, VipsImage *out,
 		return( NULL );
 	}
 
-	if( layer < 0 || 
+	if( level < 0 || 
-		layer >= openslide_get_layer_count( rslide->osr ) ) {
+		level >= openslide_get_layer_count( rslide->osr ) ) {
 		vips_error( "openslide2vips",
 			"%s", _( "invalid slide level" ) );
 		return( NULL );
@@ -180,23 +184,17 @@ readslide_new( const char *filename, VipsImage *out,
 	} 
 	else {
 		openslide_get_layer_dimensions( rslide->osr, 
-			layer, &w, &h );
+			level, &w, &h );
 		rslide->downsample = openslide_get_layer_downsample(
-			rslide->osr, layer );
+			rslide->osr, level );
-		vips_image_set_int( out, "slide-level", layer );
+		vips_image_set_int( out, "slide-level", level );
 		vips_demand_hint( out, VIPS_DEMAND_STYLE_SMALLTILE, NULL );
 	}
 
-	/* This tag is used by argb2rgba() to paint fully-transparent pixels.
+	rslide->bg = 0xffffff;
-	 */
+	if( (background = openslide_get_property_value( rslide->osr,
-	background = openslide_get_property_value( rslide->osr,
+		OPENSLIDE_PROPERTY_NAME_BACKGROUND_COLOR )) )
-		OPENSLIDE_PROPERTY_NAME_BACKGROUND_COLOR );
+		rslide->bg = strtoul( background, NULL, 16 );
-	if( background != NULL )
-		vips_image_set_int( out, 
-			VIPS_META_BACKGROUND_RGB, 
-			strtoul( background, NULL, 16 ) );
-	else
-		vips_image_set_int( out, VIPS_META_BACKGROUND_RGB, 0xffffff );
 
 	if( w < 0 || h < 0 || rslide->downsample < 0 ) {
 		vips_error( "openslide2vips", _( "getting dimensions: %s" ),
@@ -228,11 +226,11 @@ readslide_new( const char *filename, VipsImage *out,
 
 int
 vips__openslide_read_header( const char *filename, VipsImage *out, 
-	int layer, char *associated )
+	int level, char *associated )
 {
 	ReadSlide *rslide;
 
-	if( !(rslide = readslide_new( filename, out, layer, associated )) )
+	if( !(rslide = readslide_new( filename, out, level, associated )) )
 		return( -1 );
 
 	return( 0 );
@@ -243,30 +241,31 @@ vips__openslide_generate( VipsRegion *out,
 	void *seq, void *_rslide, void *unused, gboolean *stop )
 {
 	ReadSlide *rslide = _rslide;
+	uint32_t bg = rslide->bg;
 	VipsRect *r = &out->valid;
+	int n = r->width * r->height;
+	uint32_t *buf = (uint32_t *) VIPS_REGION_ADDR( out, r->left, r->top );
 
 	const char *error;
-	int x, y;
+	int i;
 
 	VIPS_DEBUG_MSG( "vips__openslide_generate: %dx%d @ %dx%d\n",
 		r->width, r->height, r->left, r->top );
 
-	/* Fill in tile-sized chunks. Some versions of OpenSlide can fail for
+	/* We're inside a cache, so requests should always be TILE_WIDTH by
-	 * very large requests.
+	 * TILE_HEIGHT pixels and on a tile boundary.
 	 */
-	for( y = 0; y < r->height; y += TILE_HEIGHT ) 
+	g_assert( (r->left % TILE_WIDTH) == 0 );
-		for( x = 0; x < r->width; x += TILE_WIDTH ) {
+	g_assert( (r->height % TILE_HEIGHT) == 0 );
-			int w = VIPS_MIN( TILE_WIDTH, r->width - x );
+	g_assert( r->width <= TILE_WIDTH );
-			int h = VIPS_MIN( TILE_HEIGHT, r->height - y );
+	g_assert( r->height <= TILE_HEIGHT );
 
 	openslide_read_region( rslide->osr, 
-				(uint32_t *) VIPS_REGION_ADDR( out, 
+		buf,
-					r->left + x, r->top + y ),
+		r->left * rslide->downsample, 
-				(r->left + x) * rslide->downsample, 
+		r->top * rslide->downsample, 
-				(r->top + y) * rslide->downsample, 
+		rslide->level,
-				rslide->layer,
+		r->width, r->height ); 
-				w, h ); 
-		}
 
 	error = openslide_get_error( rslide->osr );
 	if( error ) {
@@ -276,18 +275,41 @@ vips__openslide_generate( VipsRegion *out,
 		return( -1 );
 	}
 
+	/* Convert from ARGB to RGBA and undo premultiplication.
+	 */
+	for( i = 0; i < n; i++ ) {
+		uint32_t x = buf[i];
+		uint8_t a = x >> 24;
+		VipsPel *out = (VipsPel *) (buf + i);
+
+		if( a != 0 ) {
+			out[0] = 255 * ((x >> 16) & 255) / a;
+			out[1] = 255 * ((x >> 8) & 255) / a;
+			out[2] = 255 * (x & 255) / a;
+			out[3] = a;
+		} 
+		else {
+			/* Use background color.
+			 */
+			out[0] = (bg >> 16) & 255;
+			out[1] = (bg >> 8) & 255;
+			out[2] = bg & 255;
+			out[3] = 0;
+		}
+	}
+
 	return( 0 );
 }
 
 int
-vips__openslide_read( const char *filename, VipsImage *out, int layer )
+vips__openslide_read( const char *filename, VipsImage *out, int level )
 {
 	ReadSlide *rslide;
 	VipsImage *raw;
 	VipsImage *t;
 
 	VIPS_DEBUG_MSG( "vips__openslide_read: %s %d\n", 
-		filename, layer );
+		filename, level );
 
 	/* Tile cache: keep enough for two complete rows of tiles. OpenSlide
 	 * has its own tile cache, but it's not large enough for a complete
@@ -296,7 +318,7 @@ vips__openslide_read( const char *filename, VipsImage *out, int layer )
 	raw = vips_image_new();
 	vips_object_local( out, raw );
 
-	if( !(rslide = readslide_new( filename, raw, layer, NULL )) )
+	if( !(rslide = readslide_new( filename, raw, level, NULL )) )
 		return( -1 );
 
 	if( vips_image_generate( raw, 

libvips/include/vips/colour.h

@@ -146,7 +146,6 @@ float im_col_dE00(
 int im_LCh2Lab( VipsImage *in, VipsImage *out );
 int im_LabQ2XYZ( VipsImage *in, VipsImage *out );
 int im_rad2float( VipsImage *in, VipsImage *out );
-int im_argb2rgba( VipsImage *in, VipsImage *out );
 int im_float2rad( VipsImage *in, VipsImage *out );
 int im_LCh2UCS( VipsImage *in, VipsImage *out );
 int im_Lab2LCh( VipsImage *in, VipsImage *out );

libvips/include/vips/header.h

@@ -77,14 +77,6 @@ extern "C" {
  */
 #define VIPS_META_RESOLUTION_UNIT "resolution-unit"
 
-/**
- * VIPS_META_BACKGROUND_RGB:
- *
- * The OpenSlide load operator uses this to note the colour to use to paint
- * transparent pixels in pre-multiplied ARGB format. See im_argb2rgba().
- */
-#define VIPS_META_BACKGROUND_RGB "background-rgb"
-
 guint64 vips_format_sizeof( VipsBandFormat format );
 
 int vips_image_get_width( const VipsImage *image );

libvips/include/vips/vips7compat.h

@@ -648,6 +648,7 @@ int im_mask2vips( DOUBLEMASK *in, VipsImage *out );
 int im_bandmean( VipsImage *in, VipsImage *out );
 int im_recomb( VipsImage *in, VipsImage *out, DOUBLEMASK *recomb );
 
+int im_argb2rgba( VipsImage *in, VipsImage *out );
 
 /* ruby-vips uses this
  */