Other Gradient Map Options
Some of the effects you can create using the Gradient Map tool are similar to effects that can be obtained by cross-processing regular or slide film. In this photographic process, chemicals designed for use on one type of film—for example, slide film—are used to process regular film, or vice versa. Such cross-processing, while random, can result in some extremely interesting colored images. With the benefit of Photoshop and the Gradient Map tool, you can easily experiment to obtain the equivalent of a cross-processed image—without having to commit to a result until you find one that you truly like.