Application of image contours to three aspects of image processing: compression, shape recognition and stereopsis

The value of image contours in three important areas of image processing and analysis is illustrated. The three areas are those of image compression, shape recognition and stereopsis. The compression ratios of classical image coding techniques such as linear prediction and transform coding appear to have reached a saturation level of around 10:1. It is a widely accepted view that radical new coding schemes must be developed if the real-time transmission of digital images is to be achieved. Contours have been used for many years in cartography, where a sparse set of smooth connected curves convey a very accurate impression of the landscape. A method is outlined of storing digital images in terms of their constant intensity contours. As the images are stored directly in terms of the shapes contained within them it is possible to carry out both object recognition and stereopsis using the compressed form of the image. Examples of compression, shape recognition and stereo matching based on contours are presented.<>