...

diff --git a/MagickCore/enhance.c b/MagickCore/enhance.c
index 315cb24e45b05ca83cf3d01634a9721c826a4558..b55a5fc9f9ae7e28bfc1abd819e904bff802117f 100644 (file)
--- a/MagickCore/enhance.c
+++ b/MagickCore/enhance.c
@@ -3317,6 +3317,11 @@ MagickExport MagickBooleanType ModulateImage(Image *image,const char *modulate,
         green,
         red;
 
+      if (GetPixelReadMask(image,q) == 0)
+        {
+          q+=GetPixelChannels(image);
+          continue;
+        }
       red=(double) GetPixelRed(image,q);
       green=(double) GetPixelGreen(image,q);
       blue=(double) GetPixelBlue(image,q);