The present invention concerns a way of compressing an initial data structure that defines an image as an array of pixel elements. The method includes generating a new data structure that defines contours at least some of which are contours having a constant color value to within a tolerance. ...http://www.google.com/patents/US20030063812?utm_source=gb-gplus-sharePatent US20030063812 - System and method for compressing image files while preserving visually significant aspects
