pack Radiance images to and from 0-1

so this now works:

$ vips copy uffizi_probe.hdr x.jpg
$ eog x.jpg
$ vips copy x.jpg x.hdr
$ vips copy x.hdr x2.jpg
$ eog x2.jpg

ChangeLog

@@ -1,5 +1,6 @@
 19/1/14 started 7.38.1
 - bump soname, thanks benjamin
+- better conversion to and from scrgb/xyz for rad (hdr) 
 
 18/1/14 started 7.38.0
 - version bump

TODO

@@ -1,3 +1,4 @@
+
 - need to do mosaicing and inplace, plus im_label_regions in morph
 
 - now vips_linear() has uchar output, can we do something with orc?

libvips/colour/colourspace.c

@@ -6,6 +6,8 @@
  * 	- add B_W as a source / dest
  * 	- add GREY16 as a source / dest
  * 	- add RGB16 as a source
+ * 19/1/14
+ * 	- auto-decode RAD images
  */
 
 /*
@@ -399,11 +401,13 @@ vips_colourspace_build( VipsObject *object )
 
 	int i, j;
 	VipsImage *x;
-	VipsImage **t;
+	VipsImage **t = (VipsImage **) 
+		vips_object_local_array( object, 1 );
+	VipsImage **pipe = (VipsImage **) 
+		vips_object_local_array( object, MAX_STEPS );
 
 	VipsInterpretation interpretation;
 
-	t = (VipsImage **) vips_object_local_array( object, MAX_STEPS );
 
 	/* Verify that all input args have been set.
 	 */
@@ -411,7 +415,18 @@ vips_colourspace_build( VipsObject *object )
 		build( object ) )
 		return( -1 );
 
-	interpretation = vips_image_guess_interpretation( colourspace->in );
+	x = colourspace->in;
+
+	/* Unpack radiance-coded images. We can't use interpretation for this,
+	 * since rad images can be scRGB or XYZ.
+	 */
+	if( x->Coding == VIPS_CODING_RAD ) {
+		if( vips_rad2float( x, &t[0], NULL ) )
+			return( -1 );
+		x = t[0]; 
+	}
+
+	interpretation = vips_image_guess_interpretation( x );
 
 	/* Treat RGB and RGB16 as sRGB. If you want some other treatment,
 	 * you'll need to use the icc funcs.
@@ -430,8 +445,6 @@ vips_colourspace_build( VipsObject *object )
 		return( vips_image_write( colourspace->in, colourspace->out ) );
 	}
 
-	x = colourspace->in;
-
 	for( i = 0; i < VIPS_NUMBER( vips_colour_routes ); i++ )
 		if( vips_colour_routes[i].from == interpretation &&
 			vips_colour_routes[i].to == colourspace->space )
@@ -447,9 +460,9 @@ vips_colourspace_build( VipsObject *object )
 	}
 
 	for( j = 0; vips_colour_routes[i].route[j]; j++ ) {
-		if( vips_colour_routes[i].route[j]( x, &t[j], NULL ) ) 
+		if( vips_colour_routes[i].route[j]( x, &pipe[j], NULL ) ) 
 			return( -1 );
-		x = t[j];
+		x = pipe[j];
 	}
 
 	g_object_set( colourspace, "out", vips_image_new(), NULL ); 

libvips/foreign/foreign.c

@@ -6,6 +6,8 @@
  * 	- flatten alpha with vips_flatten()
  * 28/5/13
  * 	- auto rshift down to 8 bits during save
+ * 19/1/14
+ * 	- pack and unpack rad to scrgb
  */
 
 /*
@@ -1149,8 +1151,8 @@ vips_foreign_convert_saveable( VipsForeignSave *save )
 		in = out;
 	}
 
-	/* If this is an VIPS_CODING_RAD, we go to float RGB or XYZ. We should
-	 * probably un-gamma-correct the RGB :(
+	/* If this is an VIPS_CODING_RAD, we unpack to float. This could be
+	 * scRGB or XYZ. 
 	 */
 	if( in->Coding == VIPS_CODING_RAD ) {
 		VipsImage *out;
@@ -1248,10 +1250,27 @@ vips_foreign_convert_saveable( VipsForeignSave *save )
 		 */
 	}
 
-	/* Interpret the Type field for colorimetric images.
+	/* If the saver supports RAD, we need to go to scRGB or XYZ. 
 	 */
-	if( in->Bands == 3 &&
+	if( class->coding[VIPS_CODING_RAD] ) {
+		if( in->Type != VIPS_INTERPRETATION_scRGB &&
+			in->Type != VIPS_INTERPRETATION_XYZ ) {
+			VipsImage *out;
+
+			if( vips_colourspace( in, &out, 
+				VIPS_INTERPRETATION_scRGB, NULL ) ) {
+				g_object_unref( in );
+				return( -1 );
+			}
+			g_object_unref( in );
+
+			in = out;
+		}
+	}
+	else if( in->Bands == 3 &&
 		vips_colourspace_issupported( in ) ) {
+		/* Interpret the Type field for colorimetric images.
+		 */
 		VipsImage *out;
 
 		if( vips_colourspace( in, &out, 
@@ -1307,10 +1326,10 @@ vips_foreign_convert_saveable( VipsForeignSave *save )
 		/* Already NONE, nothing to do.
 		 */
 	}
-	else if( class->coding[VIPS_CODING_RAD] ) {
+	else if( class->coding[VIPS_CODING_LABQ] ) {
 		VipsImage *out;
 
-		if( vips_float2rad( in, &out, NULL ) ) {
+		if( vips_Lab2LabQ( in, &out, NULL ) ) {
 			g_object_unref( in );
 			return( -1 );
 		}
@@ -1318,10 +1337,10 @@ vips_foreign_convert_saveable( VipsForeignSave *save )
 
 		in = out;
 	}
-	else if( class->coding[VIPS_CODING_LABQ] ) {
+	else if( class->coding[VIPS_CODING_RAD] ) {
 		VipsImage *out;
 
-		if( vips_Lab2LabQ( in, &out, NULL ) ) {
+		if( vips_float2rad( in, &out, NULL ) ) {
 			g_object_unref( in );
 			return( -1 );
 		}

libvips/foreign/radiance.c

@@ -1162,7 +1162,7 @@ vips2rad_put_header( Write *write )
 
 	if( !vips_image_get_string( write->in, "rad-format", &str ) )
 		vips_strncpy( write->format, str, 256 );
-	if( write->in->Type == VIPS_INTERPRETATION_RGB )
+	if( write->in->Type == VIPS_INTERPRETATION_scRGB )
 		strcpy( write->format, COLRFMT );
 	if( write->in->Type == VIPS_INTERPRETATION_XYZ )
 		strcpy( write->format, CIEFMT );

libvips/foreign/radsave.c

@@ -89,7 +89,7 @@ vips_foreign_save_rad_build( VipsObject *object )
 #define D VIPS_FORMAT_DOUBLE
 #define DX VIPS_FORMAT_DPCOMPLEX
 
-static int bandfmt_rad[10] = {
+static int vips_foreign_save_rad_format_table[10] = {
 /* UC  C   US  S   UI  I   F   X   D   DX */
    F,  F,  F,  F,  F,  F,  F,  F,  F,  F
 };
@@ -112,7 +112,7 @@ vips_foreign_save_rad_class_init( VipsForeignSaveRadClass *class )
 	foreign_class->suffs = vips__rad_suffs;
 
 	save_class->saveable = VIPS_SAVEABLE_RGB;
-	save_class->format_table = bandfmt_rad;
+	save_class->format_table = vips_foreign_save_rad_format_table;
 	save_class->coding[VIPS_CODING_NONE] = FALSE;
 	save_class->coding[VIPS_CODING_RAD] = TRUE;