COMPARATIVE PERFORMANCE OF PYRAMID DATA-STRUCTURES FOR PROGRESSIVE IMAGE TRANSMISSION

Progressive image transmission is receiving attention for application in interactive image communication over low-bandwidth channels. In progressive image transmission, a low-resolution image is first transmitted. Upon the user's request, the low-resolution image can be then refined with further transmission until the original image is losslessly reproduced. One important class of encoding for progressive image transmission is based upon pyramid data structures where the intermediate levels correspond to reduced-resolution approximations. Progressive image transmission is achieved by sending the data stored in the pyramid starting from the top level. In this paper, we present a review of various pyramid data structures for progressive image transmission, focusing on the steps involved in forming the pyramids and the performance comparisons. The simulation results demonstrate that the reduced-difference pyramid achieves the best performance in terms of three criteria: the equivalent entropy, rate distortion performance and total lossless transmission bit rate. We also demonstrate that the coding performance can be improved by using an appropriate interpolation function.