https://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=32525

diff --git a/MagickCore/property.c b/MagickCore/property.c
index 1e6d04c2a82f72a9aed890ef7c3fc6c7e179ea36..9dc09ebe11f8f67ab3f4282dd94344d72d194913 100644 (file)
--- a/MagickCore/property.c
+++ b/MagickCore/property.c
@@ -3624,7 +3624,7 @@ RestoreMSCWarning
               continue; /* else no image to retrieve artifact */
             }
           GetPixelInfo(image,&pixel);
-          fx_info=AcquireFxInfo(image,pattern+6,exception);
+          fx_info=AcquireFxInfo(image,pattern+4,exception);
           status=FxEvaluateChannelExpression(fx_info,RedPixelChannel,0,0,
             &value,exception);
           pixel.red=(double) QuantumRange*value;