The Channel Extract tool lets you to remove
            a channel from an image. You can remove the red, green, blue, or
            alpha channel.
         
         To extract a channel from an image:
         
         
            - Drag the Extract tool from the Channel
               folder on Tools tab onto the dependency graph in the Schematic view.
            
- Click the channel list button and select
               the channel you want to extract from the image.
            
NoteThe Channel Extract
               tool has a masking input—see 
                        Pixel Masking.