Scalable coding of shape contours in scale

A method of improving the traditional polygonal approximation methods is described. It has properties such as scalability, resilience to noise, controlled levels of approximation and good visual representation. These properties are a direct result of the use of scale space information to derive the vertices positions of the polygonal approximation. The vertices are situated on the contour points where the changes of the contour directions are at their major sharp positions. An encoding method with a scalable polygonal approximation of shapes is defined, which results in a good relation between the distortion and the bit rate.