diff --git a/MagickCore/channel.c b/MagickCore/channel.c
index b09bb47..4fd75d6 100644
--- a/MagickCore/channel.c
+++ b/MagickCore/channel.c
@@ -41,6 +41,11 @@
Include declarations.
*/
#include "MagickCore/studio.h"
+#include "MagickCore/image.h"
+#include "MagickCore/list.h"
+#include "MagickCore/log.h"
+#include "MagickCore/option.h"
+#include "MagickCore/token.h"
#include "MagickCore/utility.h"
#include "MagickCore/version.h"
@@ -59,20 +64,134 @@
%
% The format of the ChannelOperationImage method is:
%
-% Image *ChannelOperationImage(const Image *image,
+% Image *ChannelOperationImage(const Image *images,
% const char *expression,ExceptionInfo *exception)
%
% A description of each parameter follows:
%
-% o image: the image.
+% o images: the images.
%
% o expression: A channel expression.
%
% o exception: return any errors or warnings in this structure.
%
*/
-MagickExport Image *ChannelOperationImage(const Image *image,
+
+typedef enum
+{
+ ExtractChannelOp,
+ ExchangeChannelOp,
+ TransferChannelOp
+} ChannelOperation;
+
+static MagickBooleanType ChannelImage(Image *channel_image,const Image *image,
+ const ChannelOperation channel_op,const PixelChannel p_channel,
+ const PixelChannel q_channel,ExceptionInfo *exception)
+{
+ return(MagickTrue);
+}
+
+MagickExport Image *ChannelOperationImage(const Image *images,
const char *expression,ExceptionInfo *exception)
{
- return((Image *) NULL);
+ char
+ token[MaxTextExtent];
+
+ ChannelOperation
+ channel_op;
+
+ const char
+ *p;
+
+ Image
+ *channel_images;
+
+ PixelChannel
+ p_channel,
+ q_channel;
+
+ assert(images != (Image *) NULL);
+ assert(images->signature == MagickSignature);
+ if (images->debug != MagickFalse)
+ (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",images->filename);
+ channel_images=CloneImage(images,images->columns,images->columns,MagickTrue,
+ exception);
+ p=(char *) expression;
+ GetMagickToken(p,&p,token);
+ for (q_channel=RedPixelChannel; *p != '\0'; )
+ {
+ MagickBooleanType
+ status;
+
+ ssize_t
+ i;
+
+ /*
+ Interpret channel expression.
+ */
+ if (*token == ',')
+ {
+ q_channel=(PixelChannel) ((ssize_t) q_channel+1);
+ GetMagickToken(p,&p,token);
+ }
+ if (*token == '|')
+ {
+ if (GetNextImageInList(images) != (Image *) NULL)
+ images=GetNextImageInList(images);
+ else
+ images=GetFirstImageInList(images);
+ GetMagickToken(p,&p,token);
+ }
+ if (*token == ';')
+ {
+ AppendImageToList(&channel_images,CloneImage(images,
+ channel_images->columns,channel_images->rows,MagickTrue,exception));
+ channel_images=GetLastImageInList(channel_images);
+ GetMagickToken(p,&p,token);
+ }
+ i=ParsePixelChannelOption(token);
+ if (i < 0)
+ {
+ (void) ThrowMagickException(exception,GetMagickModule(),OptionError,
+ "UnableToParseExpression","`%s'",p);
+ channel_images=DestroyImageList(channel_images);
+ break;
+ }
+ p_channel=(PixelChannel) i;
+ channel_op=ExtractChannelOp;
+ GetMagickToken(p,&p,token);
+ if (*token == '<')
+ {
+ channel_op=ExchangeChannelOp;
+ GetMagickToken(p,&p,token);
+ }
+ if (*token == '=')
+ GetMagickToken(p,&p,token);
+ if (*token == '>')
+ {
+ if (channel_op != ExchangeChannelOp)
+ channel_op=TransferChannelOp;
+ GetMagickToken(p,&p,token);
+ }
+ if (channel_op != ExtractChannelOp)
+ {
+ i=ParsePixelChannelOption(token);
+ if (i < 0)
+ {
+ (void) ThrowMagickException(exception,GetMagickModule(),OptionError,
+ "UnableToParseExpression","`%s'",p);
+ channel_images=DestroyImageList(channel_images);
+ break;
+ }
+ q_channel=(PixelChannel) i;
+ }
+ status=ChannelImage(channel_images,images,channel_op,p_channel,q_channel,
+ exception);
+ if (status == MagickFalse)
+ {
+ channel_images=DestroyImageList(channel_images);
+ break;
+ }
+ }
+ return(channel_images);
}