ThresholdBlackEvaluateOperator  544 Magick++/lib/Magick++/Include.h   using MagickCore::ThresholdBlackEvaluateOperator;
ThresholdBlackEvaluateOperator 1055 magick/option.c     { "ThresholdBlack", ThresholdBlackEvaluateOperator, UndefinedOptionFlag, MagickFalse },
ThresholdBlackEvaluateOperator  389 magick/statistic.c     case ThresholdBlackEvaluateOperator: