<title>Regional adaptive resolution-based fractal block coding</title>

Abstract

ABSTRACT In this paper, the fractal function is used for the image representation and compression. By introducmg a searching strategyinto the fractal-function-based image coding, the image representation accuracy is improved by 10%. A regional adaptiveresolution-based fractal block coding is formed by combining the encoding and the decoding processes together with aquadtree structure to perform image compression. It is shown by the experiments that the image compression ratio isincreased up to 1 2 without a great loss of visual quality.Keywords: Image coding; image compression; fractal function. 1. INTRODUCTION AND THEORETICAL FOUNDATION Fractal has been stimulating great interests since John Hutchinson introduced the theory of iterated function system(IFS) [1] to model collections of contractive transformations in a metric space as dynamical systems. After the work of M.Barnsley and A. E. Jacquin [2]-[3] in using the partitioned iterated function system (PIFS) to do fractal-based imagecompression, many works have been done either to improve the compression ratio or to reduce the encoding time. F.Dudbridge[4]-[5] developed a method which is quite different from the traditional fractal (TF) image coding. He proposedusing a new fractal function (FF) for the image representation.Before the concept of fractal function is introduced the following preliminaries are needed: (1) w1 ,