Feature difference classification method in fractal image coding

In this paper, we present a classification algorithm in fractal image coding. Based on the contraction characteristics of transformations in fractal image coding, the algorithm uses the notion of feature difference to speed up the domain-range matching routine of the coding. The algorithm can effectively exclude pseudo matches during the process of domain-range matching and result in significant improvement of the rate-distortion performance. It can also be easily realized in cooperation with many other speedup schemes.