...

diff --git a/MagickCore/channel.c b/MagickCore/channel.c
index c46b8125532bee58cdda2e746dc7fc0e22ee842a..3c9b65c469b434d215d882845719b1e3c7c56cbe 100644 (file)
--- a/MagickCore/channel.c
+++ b/MagickCore/channel.c
@@ -358,7 +358,8 @@ MagickExport Image *ChannelFxImage(const Image *image,const char *expression,
             break;
           case AlphaPixelChannel:
           {
-            destination_image->alpha_trait=BlendPixelTrait;
+            if (image->colorspace != UndefinedColorspace)_
+              destination_image->alpha_trait=BlendPixelTrait;
             break;
           }
           case ReadMaskPixelChannel: