https://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=31377&

diff --git a/MagickCore/fx.c b/MagickCore/fx.c
index bb035e5293555da74d69d45b30a539e9b23a3e5f..f968f410fe137e49e399159de49390cfc0b84090 100644 (file)
--- a/MagickCore/fx.c
+++ b/MagickCore/fx.c
@@ -1130,8 +1130,7 @@ static double FxChannelStatistics(FxInfo *fx_info,Image *image,
       if (option >= 0)
         {
           channel=(PixelChannel) option;
-          channel_mask=(ChannelType) (channel_mask | (1 << channel));
-          (void) SetPixelChannelMask(image,channel_mask);
+          channel_mask=SetPixelChannelMask(image,(ChannelType) (1 << channel));
         }
     }
   (void) FormatLocaleString(key,MagickPathExtent,"%p.%.20g.%s",(void *) image,