Discrete directional wavelet image coder based on fast R-D optimized quadtree decomposition

Abstract

A new image coding method based on discrete directional wavelet transform (S-WT) and quadtree decomposition is proposed here. The S-WT is a kind of transform proposed in [1], which is based on lattice theory, and with the difference with the standard wavelet transform is that the former allows more transform directions. Because the directional property in a small region is more regular than in a big block generally, in order to sufficient make use of the multidirectionality and directional vanishing moment (DVM) of S-WT, the input image is divided into many small regions by means of the popular quadtree segmentation, and the splitting criterion is on the rate-distortion sense. After the optimal quadtree is obtained, a resource bit allocation algorithm is fast implemented utilizing the model proposed in [15]. Experiment results indicate that our algorithms perform better compared to some state-of-the-art image coders. © Springer-Verlag Berlin Heidelberg 2007.