GetImageChannelDifference 2259 magick/command.c     status&=GetImageChannelDifference(reference_image,compare_image,metric,
GetImageChannelDifference  681 magick/compare.c   status=GetImageChannelDifference(reference_image,compare_image,metric,
GetImageChannelDifference   76 magick/compare.h   GetImageChannelDifference(const Image *reference_image,