Index: image-private.h
===================================================================
--- image-private.h	(revision 3595)
+++ image-private.h	(working copy)
@@ -78,6 +78,16 @@
   return((unsigned char) (((color) << 2) | ((color) >> 4)));
 }
 
+static inline unsigned long ScaleColor8to5(const unsigned char color)
+{
+  return((unsigned long) (((color) & ~0x07) >> 3));
+}
+
+static inline unsigned long ScaleColor8to6(const unsigned char color)
+{
+  return((unsigned long) (((color) & ~0x03) >> 2));
+}
+
 #if defined(__cplusplus) || defined(c_plusplus)
 }
 #endif