Adaptive selection of contrast scaling α and grey level β for the quality improvements of fractal image compression

This paper proposes an independent approach to image coding based on basic fractal theory of iterated transformations. The main characteristics of this approach are that : 1) image redundancy can be efficiently exploited through self transformability on block wise basis, and 2) it approximates an original image by a fractal image. A fractal code when iterated on any initial image produces a sequence of images which converges to α fractal approximation of the original. This fractal block coder has comparable to vector quantizer with which it shares some aspects. This paper highlights the quality improvement approach by selection of α and β values for distance measurement between all domains with respect each range. The main purpose of this paper is to present an efficient implementation of the algorithm with same reconstructed image quality. This efficient method of contrast calculation can compute corresponding difference between range block and the transformed domain block efficiently and exactly.