Fractal image coding schemes using nonlinear grey scale functions

In this paper, an image coding model based on nonlinear grey scale functions is proposed. Centered vertex parabolas have been considered, instead of affine functions, widely used by most of the scientific community. The proposed model has been applied on several 8 bits test images with promising results. Both, the bit-rate and the quality are comparable to the affine case, but the different quadtree partitioning in the encoding phase can be utilized to build a hybrid model employing both the approaches. (C) 2001 Elsevier Science B.V. All rights reserved.