fix vips_hist_match()

it wasn't upcasting input to uint due to a mix-up with VipsHistogram

ChangeLog

@@ -1,12 +1,13 @@
-20/11/13	started 7.36.5
+20/11/13 started 7.36.5
 - better cache sizing in unbuffered sequential mode
 - allow larger tile_size in dzsave
 - remove use of PATH_MAX to help gnu hurd
+- fix vips_hist_match()
 
-15/11/13	started 7.36.4
+15/11/13 started 7.36.4
 - improve compat with im_init_world()
 
-18/10/13	started 7.36.3
+18/10/13 started 7.36.3
 - fix compiler warnings in ubuntu 13.10
 - reverse similarity rotation direction to match the convention used 
   elsewhere in vips

libvips/histogram/hist_match.c

@@ -14,6 +14,8 @@
  * 	- small cleanups
  * 12/8/13	
  * 	- redone im_histspec() as a class, vips_hist_match()
+ * 19/12/13
+ * 	- oop, upcast input
  */
 
 /*
@@ -138,13 +140,6 @@ vips_hist_match_build( VipsObject *object )
 	return( 0 );
 }
 
-#define UI VIPS_FORMAT_UINT
-
-static const VipsBandFormat vips_hist_match_format_table[10] = {
-/* UC  C   US  S   UI  I   F   X   D   DX */
-   UI, UI, UI, UI, UI, UI, UI, UI, UI, UI 
-};
-
 static void
 vips_hist_match_class_init( VipsHistMatchClass *class )
 {
@@ -159,7 +154,7 @@ vips_hist_match_class_init( VipsHistMatchClass *class )
 	vobject_class->description = _( "match two histograms" );
 	vobject_class->build = vips_hist_match_build;
 
-	hclass->format_table = vips_hist_match_format_table;
+	hclass->input_format = VIPS_FORMAT_UINT; 
 	hclass->process = vips_hist_match_process;
 
 	VIPS_ARG_IMAGE( class, "in", 1, 

libvips/histogram/histogram.c

@@ -145,11 +145,23 @@ vips_histogram_build( VipsObject *object )
 			vips_check_hist( class->nickname, histogram->in[i] ) )
 			return( -1 ); 
 
-	/* Cast our input images up to a common format, bands and size.
+	/* Cast our input images up to a common format, bands and size. If
+	 * input_format is set, cast to a fixed input type.
 	 */
-	if( vips__formatalike_vec( histogram->in, format, histogram->n ) ||
-		vips__bandalike_vec( class->nickname, 
-			format, band, histogram->n, 1 ) ||
+	if( hclass->input_format != VIPS_FORMAT_NOTSET ) {
+		for( i = 0; i < histogram->n; i++ ) 
+			if( vips_cast( histogram->in[i], &format[i],
+				hclass->input_format, NULL ) )
+				return( -1 ); 
+	}
+	else {
+		if( vips__formatalike_vec( histogram->in, 
+			format, histogram->n ) )
+			return( -1 );
+	}
+		
+	if( vips__bandalike_vec( class->nickname, 
+		format, band, histogram->n, 1 ) ||
 		vips__hist_sizealike_vec( band, size, histogram->n ) ) 
 		return( -1 );
 
@@ -203,6 +215,8 @@ vips_histogram_class_init( VipsHistogramClass *class )
 	vobject_class->description = _( "histogram operations" );
 	vobject_class->build = vips_histogram_build;
 
+	class->input_format = VIPS_FORMAT_NOTSET;
+
 	/* Inputs set by subclassess.
 	 */
 

libvips/histogram/phistogram.h

@@ -81,6 +81,10 @@ typedef struct _VipsHistogramClass {
 	 */
 	const VipsBandFormat *format_table;
 
+	/* If not VIPS_FORMAT_NOTSET, upcast all ins to this.
+	 */
+	VipsBandFormat input_format;
+
 	VipsHistogramProcessFn process;
 
 } VipsHistogramClass;