An embedded wavelet image coder with parallel encoding and sequential decoding of bit-planes

Abstract

Wavelet based coders are widely used in image and video compression. Many popular embedded wavelet coders are based on a data structure known as zerotree. However, there exists a category of embedded wavelet coders that are fast and efficient even without zerotrees. These coders are based on three key concepts: (1) wavelet coefficient reordering; (2) bit-plane partition; and (3) encoding of bit-planes with efficient run-length coding. In this paper, we propose a bit-plane encoder that can be used in these non-zerotree algorithms. Instead of encoding the bit-planes sequentially, the bit-plane encoding process can be completed in one pass when multiple bit-plane encoders are used simultaneously. This bit-plane encoder is inherently suitable for parallel processing architecture. The decoding process is treated sequentially since each bit-plane stream can only be synchronized upon the correct decoding of higher bit-planes. To the best of our knowledge, this paper is the first to realize parallelization through encoding multiple bit-planes simultaneously.