JPEG2000: Quality Scalability and Windows of Interest Transmission

Quality scalability is one important feature of JPEG2000, used, for instance, in interactive image transmissions to deliver windows of interest (WOI) at increasing qualities. JPEG2000 achieves quality scalability through the use of quality layers, that are constructed during the encoding process by means of rate-distortion optimization techniques. Although quality layers provide optimal rate-distortion representations of the complete image area, their optimality holding WOIs remains to be investigated. This paper evaluates the coding performance of quality layers to hold WOIs; in addition, a novel mechanism for providing competitive quality scalability for WOIs extraction is presented. The proposed mechanism can be applied even when the code-stream contains a single quality layer, it is computationally simple, and experimental results suggest that it may achieve close to optimal results in terms of rate-distortion.