Recent and prospective decorrelation techniques for image processing

Abstract

This paper is devoted to the description of recent and prospective decorrelation techniques used in image processing. Two classes are taken into consideration : the universal or generic methods and the adaptive methods. The first class performs signal processing independently of its specificity. These methods only rely on statistical properties of the signal. They are principally based on orthogonal transforms and subband coding. In opposition, the adaptive techniques take the a posteriori contents of the images into account. Some of them adapt universal techniques to the signal content (i.e. adaptive subband coding or hybrid methods). Others are based on feature extraction processes which include more physical entities like edges and regions. For example, object approaches attempt to describe images as collections of regions characterized by their shape and their aspect.