fix extra band handling in colour

backport of new colour.c from 7.41

ChangeLog

@@ -1,3 +1,6 @@
+8/10/14 started 7.40.10
+- rework extra band handling for colour functions
+
 8/9/14 started 7.40.10
 - icc_import and icc_transform checks the input profile for compatibility 
   with the image, thanks James

configure.ac

@@ -2,7 +2,7 @@
 
 # also update the version number in the m4 macros below
 
-AC_INIT([vips], [7.40.10], [vipsip@jiscmail.ac.uk])
+AC_INIT([vips], [7.40.11], [vipsip@jiscmail.ac.uk])
 # required for gobject-introspection
 AC_PREREQ(2.62)
 
@@ -18,7 +18,7 @@ AC_CONFIG_MACRO_DIR([m4])
 # user-visible library versioning
 m4_define([vips_major_version], [7])
 m4_define([vips_minor_version], [40])
-m4_define([vips_micro_version], [10])
+m4_define([vips_micro_version], [11])
 m4_define([vips_version],
           [vips_major_version.vips_minor_version.vips_micro_version])
 

libvips/colour/Lab2LabQ.c

@@ -149,11 +149,11 @@ vips_Lab2LabQ_init( VipsLab2LabQ *Lab2LabQ )
 	colour->coding = VIPS_CODING_LABQ;
 	colour->interpretation = VIPS_INTERPRETATION_LABQ;
 	colour->format = VIPS_FORMAT_UCHAR;
+	colour->input_bands = 3;
 	colour->bands = 4;
 
 	code->input_coding = VIPS_CODING_NONE;
 	code->input_format = VIPS_FORMAT_FLOAT;
-	code->input_bands = 3;
 }
 
 /**

libvips/colour/Lab2LabS.c

@@ -90,11 +90,11 @@ vips_Lab2LabS_init( VipsLab2LabS *Lab2LabS )
 
 	colour->interpretation = VIPS_INTERPRETATION_LABS;
 	colour->format = VIPS_FORMAT_SHORT;
+	colour->input_bands = 3;
 	colour->bands = 3;
 
 	code->input_coding = VIPS_CODING_NONE;
 	code->input_format = VIPS_FORMAT_FLOAT;
-	code->input_bands = 3;
 }
 
 /**

libvips/colour/LabS2Lab.c

@@ -89,10 +89,10 @@ vips_LabS2Lab_init( VipsLabS2Lab *LabS2Lab )
 	colour->interpretation = VIPS_INTERPRETATION_LAB;
 	colour->format = VIPS_FORMAT_FLOAT;
 	colour->bands = 3;
+	colour->input_bands = 3;
 
 	code->input_coding = VIPS_CODING_NONE;
 	code->input_format = VIPS_FORMAT_SHORT;
-	code->input_bands = 3;
 }
 
 /**

libvips/colour/LabS2LabQ.c

@@ -137,11 +137,11 @@ vips_LabS2LabQ_init( VipsLabS2LabQ *LabS2LabQ )
 	colour->coding = VIPS_CODING_LABQ;
 	colour->interpretation = VIPS_INTERPRETATION_LABQ;
 	colour->format = VIPS_FORMAT_UCHAR;
+	colour->input_bands = 3;
 	colour->bands = 4;
 
 	code->input_coding = VIPS_CODING_NONE;
 	code->input_format = VIPS_FORMAT_SHORT;
-	code->input_bands = 3;
 }
 
 /**

libvips/colour/colour.c

@@ -165,6 +165,12 @@
  *       This is a highly uniform colour space, much better than CIELAB for 
  *       expressing small differences. 
  *
+ * The CMC colourspace is described in "Uniform Colour Space Based on the
+ * CMC(l:c) Colour-difference Formula", M R Luo and B Rigg, Journal of the
+ * Society of Dyers and Colourists, vol 102, 1986. Distances in this 
+ * colourspace approximate, within 10% or so, differences in the CMC(l:c)
+ * colour difference formula.
+ *
  *       You can calculate metrics like CMC(2:1) by scaling the spaces before
  *       finding differences. 
  *     </para>
@@ -294,6 +300,10 @@ vips_colour_build( VipsObject *object )
 	VipsObjectClass *class = VIPS_OBJECT_GET_CLASS( object ); 
 	VipsColour *colour = VIPS_COLOUR( object );
 
+	VipsImage **in;
+	VipsImage **extra_bands; 
+	VipsImage *out;
+
 	int i;
 
 #ifdef DEBUG
@@ -306,8 +316,6 @@ vips_colour_build( VipsObject *object )
 		build( object ) ) 
 		return( -1 );
 
-	g_object_set( colour, "out", vips_image_new(), NULL ); 
-
 	if( colour->n > MAX_INPUT_IMAGES ) {
 		vips_error( class->nickname,
 			"%s", _( "too many input images" ) );
@@ -317,28 +325,102 @@ vips_colour_build( VipsObject *object )
 		if( vips_image_pio_input( colour->in[i] ) )
 			return( -1 );
 
-	/* colour->in[] must be NULL-terminated, we use it as an arg to
+	/* colour->in[] must be NULL-terminated, we can use it as an arg to
 	 * vips_start_many().
 	 */
 	g_assert( !colour->in[colour->n] ); 
 
-	if( vips_image_pipeline_array( colour->out, 
+	in = colour->in;
-		VIPS_DEMAND_STYLE_THINSTRIP, colour->in ) ) 
+	extra_bands = (VipsImage **) 
+		vips_object_local_array( object, colour->n );
+
+	/* If there are more than @input_bands bands, we detach and reattach
+	 * after processing.
+	 */
+	if( colour->input_bands > 0 ) {
+		VipsImage **new_in = (VipsImage **) 
+			vips_object_local_array( object, colour->n );
+
+		for( i = 0; i < colour->n; i++ ) {
+			if( vips_check_bands_atleast( class->nickname, 
+				in[i], colour->input_bands ) )
+				return( -1 ); 
+
+			if( vips_extract_band( in[i], &new_in[i], 0, 
+				"n", colour->input_bands, 
+				NULL ) )
+				return( -1 ); 
+
+			if( in[i]->Bands > colour->input_bands ) 
+				if( vips_extract_band( in[i], &extra_bands[i], 
+					colour->input_bands, 
+					"n", in[i]->Bands - 
+						colour->input_bands, 
+					NULL ) )
+					return( -1 );
+		}
+
+		in = new_in;
+	}
+
+	out = vips_image_new();
+	if( vips_image_pipeline_array( out, 
+		VIPS_DEMAND_STYLE_THINSTRIP, in ) ) {
+		g_object_unref( out );
 		return( -1 );
-	colour->out->Coding = colour->coding;
+	}
-	colour->out->Type = colour->interpretation;
+	out->Coding = colour->coding;
-	colour->out->BandFmt = colour->format;
+	out->Type = colour->interpretation;
-	colour->out->Bands = colour->bands;
+	out->BandFmt = colour->format;
+	out->Bands = colour->bands;
 
 	if( colour->profile_filename ) 
-		if( vips_colour_attach_profile( colour->out, 
+		if( vips_colour_attach_profile( out, 
-			colour->profile_filename ) )
+			colour->profile_filename ) ) {
+			g_object_unref( out );
 			return( -1 );
+		}
 
-	if( vips_image_generate( colour->out,
+	if( vips_image_generate( out,
 		vips_start_many, vips_colour_gen, vips_stop_many, 
-		colour->in, colour ) ) 
+		in, colour ) ) {
+		g_object_unref( out );
 		return( -1 );
+	}
+
+	/* Reattach higher bands, if necessary. If we have more than one input
+	 * image, just use the first extra bands. 
+	 */
+	for( i = 0; i < colour->n; i++ ) 
+		if( extra_bands[i] ) {
+			VipsImage *t1, *t2;
+
+			/* We can't just reattach the extra bands: they might
+			 * be float (for example) and we might be trying to
+			 * make a short image. Cast extra to match the body of
+			 * the image.
+			 */
+
+			if( vips_cast( extra_bands[i], &t1, out->BandFmt,
+				NULL ) ) {
+				g_object_unref( out );
+				return( -1 );
+			}
+
+			if( vips_bandjoin2( out, t1, &t2,
+				NULL ) ) {
+				g_object_unref( t1 );
+				g_object_unref( out );
+				return( -1 );
+			}
+			g_object_unref( out );
+			g_object_unref( t1 );
+			out = t2;
+
+			break;
+		}
+
+	g_object_set( colour, "out", out, NULL ); 
 
 	return( 0 );
 }
@@ -373,6 +455,7 @@ vips_colour_init( VipsColour *colour )
 	colour->interpretation = VIPS_INTERPRETATION_sRGB;
 	colour->format = VIPS_FORMAT_UCHAR;
 	colour->bands = 3;
+	colour->input_bands = -1;
 }
 
 G_DEFINE_ABSTRACT_TYPE( VipsColourSpace, vips_colour_space, VIPS_TYPE_COLOUR );
@@ -382,62 +465,24 @@ vips_colour_space_build( VipsObject *object )
 {
 	VipsColour *colour = VIPS_COLOUR( object );
 	VipsColourSpace *space = VIPS_COLOUR_SPACE( object );
-
+	VipsImage **t = (VipsImage **) vips_object_local_array( object, 1 );
-	VipsImage **t;
-	VipsImage *in;
-	VipsImage *extra;
-
-	t = (VipsImage **) vips_object_local_array( object, 4 );
-
-	in = space->in;
-	extra = NULL;
 
 	/* We only process float.
 	 */
-	if( vips_cast_float( in, &t[0], NULL ) )
+	if( vips_cast_float( space->in, &t[0], NULL ) )
 		return( -1 );
-	in = t[0];
 
-	/* If there are more than n bands, process just the first three and
+	/* We always do 3 bands -> 3 bands. 
-	 * reattach the rest after. This lets us handle RGBA etc. 
 	 */
-	if( in->Bands > 3 ) {
+	colour->input_bands = 3;
-		if( vips_extract_band( in, &t[1], 0, "n", 3, NULL ) ||
-			vips_extract_band( in, &t[2], 3, 
-				"n", in->Bands - 3, NULL ) )
-			return( -1 );
-
-		in = t[1];
-		extra = t[2];
-	}
-	else if( vips_check_bands_atleast( 
-		VIPS_OBJECT_GET_CLASS( object )->nickname, in, 3 ) )
-		return( -1 );
 
 	colour->n = 1;
-	colour->in = (VipsImage **) vips_object_local_array( object, 2 );
+	colour->in = t;
-	colour->in[0] = in;
-	colour->in[1] = NULL;
-	if( colour->in[0] )
-		g_object_ref( colour->in[0] );
 
 	if( VIPS_OBJECT_CLASS( vips_colour_space_parent_class )->
 		build( object ) )
 		return( -1 );
 
-	/* Reattach higher bands, if necessary.
-	 */
-	if( extra ) {
-		VipsImage *x;
-
-		if( vips_bandjoin2( colour->out, extra, &x, NULL ) )
-			return( -1 );
-
-		VIPS_UNREF( colour->out );
-
-		colour->out = x;
-	}
-
 	return( 0 );
 }
 
@@ -486,11 +531,8 @@ vips_colour_code_build( VipsObject *object )
 	VipsImage **t = (VipsImage **) vips_object_local_array( object, 6 );
 
 	VipsImage *in;
-	VipsImage *extra;
-
 
 	in = code->in;
-	extra = NULL;
 
 	/* If this is a LABQ and the coder wants uncoded, unpack.
 	 */
@@ -507,30 +549,6 @@ vips_colour_code_build( VipsObject *object )
 			in, code->input_coding ) )
 		return( -1 );
 
-	/* Extra band processing. don't do automatic detach/reattach if either
-	 * input or output will be coded.
-	 */
-	if( in &&
-		code->input_coding == VIPS_CODING_NONE &&
-		colour->coding == VIPS_CODING_NONE &&
-		code->input_bands > 0 ) { 
-		if( in->Bands > code->input_bands ) { 
-			if( vips_extract_band( in, &t[1], 0, 
-				"n", code->input_bands, NULL ) )
-				return( -1 );
-			if( vips_extract_band( in, &t[2], code->input_bands, 
-				"n", in->Bands - code->input_bands, 
-				NULL ) )
-				return( -1 );
-			in = t[1];
-			extra = t[2];
-		}
-		else if( vips_check_bands_atleast( 
-			VIPS_OBJECT_CLASS( class )->nickname,
-			in, code->input_bands ) )
-			return( -1 );
-	}
-
 	if( in &&
 		code->input_coding == VIPS_CODING_NONE &&
 		code->input_format != VIPS_FORMAT_NOTSET ) {
@@ -549,33 +567,14 @@ vips_colour_code_build( VipsObject *object )
 	}
 
 	colour->n = 1;
-	colour->in = (VipsImage **) vips_object_local_array( object, 2 );
+	colour->in = VIPS_ARRAY( object, 2, VipsImage * );
 	colour->in[0] = in;
 	colour->in[1] = NULL;
-	if( colour->in[0] )
-		g_object_ref( colour->in[0] );
 
-	if( VIPS_OBJECT_CLASS( vips_colour_space_parent_class )->
+	if( VIPS_OBJECT_CLASS( vips_colour_code_parent_class )->
 		build( object ) )
 		return( -1 );
 
-	/* Reattach higher bands, if necessary.
-	 *
-	 * Our processing on the first three bands may have changed the image
-	 * format. For example, converting LAB to LABS will make a short
-	 * image. We need to force the extra bands to match this new type. 
-	 */
-	if( extra ) {
-		VipsImage *x;
-
-		if( vips_cast( extra, &t[5], colour->out->BandFmt, NULL ) ||
-			vips_bandjoin2( colour->out, t[5], &x, NULL ) )
-			return( -1 );
-
-		VIPS_UNREF( colour->out );
-		colour->out = x;
-	}
-
 	return( 0 );
 }
 
@@ -613,19 +612,15 @@ vips_colour_difference_build( VipsObject *object )
 {
 	VipsColour *colour = VIPS_COLOUR( object );
 	VipsColourDifference *difference = VIPS_COLOUR_DIFFERENCE( object );
-	VipsColourDifferenceClass *class = 
-		VIPS_COLOUR_DIFFERENCE_GET_CLASS( object ); 
 
 	VipsImage **t;
 	VipsImage *left;
 	VipsImage *right;
-	VipsImage *extra;
 
 	t = (VipsImage **) vips_object_local_array( object, 12 );
 
 	left = difference->left;
 	right = difference->right;
-	extra = NULL;
 
 	if( left ) {
 		if( vips_image_decode( left, &t[0] ) )
@@ -639,52 +634,9 @@ vips_colour_difference_build( VipsObject *object )
 		right = t[1];
 	}
 
-	/* Detach and reattach extra bands, if any. If both left and right
+	/* Detach and reattach any extra bands. 
-	 * have extra bands, give up.
 	 */
-	if( left &&
+	colour->input_bands = 3;
-		left->Bands > 3 &&
-		right &&
-		right->Bands > 3 ) {
-		vips_error( VIPS_OBJECT_CLASS( class )->nickname,
-			"%s", "both images have extra bands" );
-		return( -1 );
-	}
-
-	if( left &&
-		left->Bands > 3 ) {
-		if( vips_extract_band( left, &t[2], 0, 
-			"n", 3, 
-			NULL ) )
-			return( -1 );
-		if( vips_extract_band( left, &t[3], 3, 
-			"n", left->Bands - 3, 
-			NULL ) )
-			return( -1 );
-		left = t[2];
-		extra = t[3];
-	}
-
-	if( right &&
-		right->Bands > 3 ) {
-		if( vips_extract_band( right, &t[4], 0, 
-			"n", 3, 
-			NULL ) )
-			return( -1 );
-		if( vips_extract_band( right, &t[5], 3, 
-			"n", right->Bands - 3, 
-			NULL ) )
-			return( -1 );
-		right = t[4];
-		extra = t[5];
-	}
-
-	if( vips_check_bands_atleast( VIPS_OBJECT_CLASS( class )->nickname,
-		left, 3 ) )
-		return( -1 );
-	if( vips_check_bands_atleast( VIPS_OBJECT_CLASS( class )->nickname,
-		right, 3 ) )
-		return( -1 );
 
 	if( vips_colourspace( left, &t[6], difference->interpretation, NULL ) )
 		return( -1 );
@@ -708,32 +660,15 @@ vips_colour_difference_build( VipsObject *object )
 	right = t[11];
 
 	colour->n = 2;
-	colour->in = (VipsImage **) vips_object_local_array( object, 3 );
+	colour->in = VIPS_ARRAY( object, 3, VipsImage * );
 	colour->in[0] = left;
 	colour->in[1] = right;
 	colour->in[2] = NULL;
-	if( colour->in[0] )
-		g_object_ref( colour->in[0] );
-	if( colour->in[1] )
-		g_object_ref( colour->in[1] );
 
-	if( VIPS_OBJECT_CLASS( vips_colour_space_parent_class )->
+	if( VIPS_OBJECT_CLASS( vips_colour_difference_parent_class )->
 		build( object ) )
 		return( -1 );
 
-	/* Reattach higher bands, if necessary.
-	 */
-	if( extra ) {
-		VipsImage *x;
-
-		if( vips_bandjoin2( colour->out, extra, &x, NULL ) )
-			return( -1 );
-
-		VIPS_UNREF( colour->out );
-
-		colour->out = x;
-	}
-
 	return( 0 );
 }
 

libvips/colour/float2rad.c

@@ -212,11 +212,11 @@ vips_float2rad_init( VipsFloat2rad *float2rad )
 	colour->coding = VIPS_CODING_RAD;
 	colour->interpretation = VIPS_INTERPRETATION_scRGB;
 	colour->format = VIPS_FORMAT_UCHAR;
+	colour->input_bands = 3;
 	colour->bands = 4;
 
 	code->input_coding = VIPS_CODING_NONE;
 	code->input_format = VIPS_FORMAT_FLOAT;
-	code->input_bands = 3;
 }
 
 /**

libvips/colour/icc_transform.c

@@ -241,7 +241,7 @@ vips_icc_build( VipsObject *object )
 		code->in ) {
 		switch( cmsGetColorSpace( icc->in_profile ) ) {
 		case cmsSigRgbData:
-			code->input_bands = 3;
+			colour->input_bands = 3;
 			code->input_format = 
 				code->in->BandFmt == VIPS_FORMAT_USHORT ? 
 				VIPS_FORMAT_USHORT : VIPS_FORMAT_UCHAR;
@@ -252,7 +252,7 @@ vips_icc_build( VipsObject *object )
 
 #ifdef HAVE_LCMS2
 		case cmsSigGrayData:
-			code->input_bands = 1;
+			colour->input_bands = 1;
 			code->input_format = 
 				code->in->BandFmt == VIPS_FORMAT_USHORT ? 
 				VIPS_FORMAT_USHORT : VIPS_FORMAT_UCHAR;
@@ -263,7 +263,7 @@ vips_icc_build( VipsObject *object )
 #endif /*HAVE_LCMS2*/
 
 		case cmsSigCmykData:
-			code->input_bands = 4;
+			colour->input_bands = 4;
 			code->input_format = 
 				code->in->BandFmt == VIPS_FORMAT_USHORT ? 
 				VIPS_FORMAT_USHORT : VIPS_FORMAT_UCHAR;
@@ -273,7 +273,7 @@ vips_icc_build( VipsObject *object )
 			break;
 
 		case cmsSigLabData:
-			code->input_bands = 3;
+			colour->input_bands = 3;
 			code->input_format = VIPS_FORMAT_FLOAT;
 			code->input_interpretation = 
 				VIPS_INTERPRETATION_LAB;
@@ -281,7 +281,7 @@ vips_icc_build( VipsObject *object )
 			break;
 
 		case cmsSigXYZData:
-			code->input_bands = 3;
+			colour->input_bands = 3;
 			code->input_format = VIPS_FORMAT_FLOAT;
 			icc->in_icc_format = TYPE_XYZ_16;
 			break;
@@ -506,7 +506,9 @@ vips_icc_load_profile_image( const char *domain, VipsImage *image )
 		return( NULL ); 
 	}
 
-	if( image->Bands != vips_icc_profile_needs_bands( profile ) ) {
+	/* We allow extra bands for eg. alpha.
+	 */
+	if( image->Bands < vips_icc_profile_needs_bands( profile ) ) {
 		VIPS_FREEF( cmsCloseProfile, profile );
 		vips_warn( domain, 
 			"%s", _( "embedded profile incompatible with image" ) );
@@ -528,7 +530,9 @@ vips_icc_load_profile_file( const char *domain,
 		return( NULL );
 	}
 
-	if( image->Bands != vips_icc_profile_needs_bands( profile ) ) {
+	/* We allow extra bands for eg. alpha.
+	 */
+	if( image->Bands < vips_icc_profile_needs_bands( profile ) ) {
 		VIPS_FREEF( cmsCloseProfile, profile );
 		vips_warn( domain, 
 			_( "profile \"%s\" incompatible with image" ),

libvips/colour/pcolour.h

@@ -65,6 +65,11 @@ typedef struct _VipsColour {
 	VipsImage **in;
 	int n;
 
+	/* If this is >0, only process this many bands from the input. Extra
+	 * bands are removed and reattached after processing.
+	 */
+	int input_bands; 
+
 	VipsImage *out;
 
 	/* Set fields on ->out from these.
@@ -149,7 +154,6 @@ typedef struct _VipsColourCode {
 	 */
 	VipsCoding input_coding;
 	VipsBandFormat input_format;
-	int input_bands;
 	VipsInterpretation input_interpretation;
 
 } VipsColourCode;

libvips/colour/sRGB2scRGB.c

@@ -163,10 +163,10 @@ vips_sRGB2scRGB_init( VipssRGB2scRGB *sRGB2scRGB )
 	colour->coding = VIPS_CODING_NONE;
 	colour->interpretation = VIPS_INTERPRETATION_scRGB;
 	colour->format = VIPS_FORMAT_FLOAT;
+	colour->input_bands = 3;
 	colour->bands = 3;
 
 	code->input_coding = VIPS_CODING_NONE;
-	code->input_bands = 3;
 
 	/* The default. This can get changed above ^^ if we see a 
 	 * 16-bit input.

libvips/colour/scRGB2sRGB.c

@@ -208,10 +208,10 @@ vips_scRGB2sRGB_init( VipsscRGB2sRGB *scRGB2sRGB )
 	colour->coding = VIPS_CODING_NONE;
 	colour->interpretation = VIPS_INTERPRETATION_sRGB;
 	colour->format = VIPS_FORMAT_UCHAR;
+	colour->input_bands = 3;
 	colour->bands = 3;
 
 	code->input_coding = VIPS_CODING_NONE;
-	code->input_bands = 3;
 	code->input_format = VIPS_FORMAT_FLOAT;
 
 	scRGB2sRGB->depth = 8;