This procedure mirrors the colormap destructively and horizontally thus exchanging right and left like a RL-mirror.
The colormap is modified.
The mirrored colormap is returned.
> (define image (colormap-readjpg "horses.jpg")) image > (colormap-writejpg (colormap-hmirror! image) "horses-hmirrored.jpg") ok >
The input image displays as follows (horses.jpg, JPG, 2400x1600):
The horizontally mirrored image looks like this: