Computer systems with all their potential could be employed as powerful tools to assist the artist during the creative process of picture making. The complex process of picture making is tentative, indeterminate, explorative and unpredictable. Perceptual uncertainty of patterns on the canvas may have an important role during such a process. For the artist, the perception of a new or alternative structure in an already structured image is plausible, his subsequent interaction with the media being consistent with this revised view of the image. Therefore, it is essential for the computer system to be able to structure and restructure the image in terms of the interpretations perceived by the artist.