diff --git a/MagickCore/threshold.h b/MagickCore/threshold.h
index 2743d46..c8c7230 100644
--- a/MagickCore/threshold.h
+++ b/MagickCore/threshold.h
@@ -35,20 +35,12 @@
extern MagickExport MagickBooleanType
BilevelImage(Image *,const double),
- BilevelImageChannel(Image *,const ChannelType,const double),
- BlackThresholdImage(Image *,const char *),
- BlackThresholdImageChannel(Image *,const ChannelType,const char *,
- ExceptionInfo *),
+ BlackThresholdImage(Image *,const char *,ExceptionInfo *),
ClampImage(Image *),
- ClampImageChannel(Image *,const ChannelType),
ListThresholdMaps(FILE *,ExceptionInfo *),
OrderedPosterizeImage(Image *,const char *,ExceptionInfo *),
RandomThresholdImage(Image *,const char *,ExceptionInfo *),
- RandomThresholdImageChannel(Image *,const ChannelType,const char *,
- ExceptionInfo *),
- WhiteThresholdImage(Image *,const char *),
- WhiteThresholdImageChannel(Image *,const ChannelType,const char *,
- ExceptionInfo *);
+ WhiteThresholdImage(Image *,const char *,ExceptionInfo *);
#if defined(__cplusplus) || defined(c_plusplus)
}