An Embedded Dct Approach To Progressive Image Compression

Motivated by Shapiro's embedded zerotree wavelet coding (EZW) and Taubman and Zakhor's layered zero coding (LZC), we propose a layered DCT image compression scheme, which generates an embedded bit stream for DCT coefficients according to their importance. The new method allows progressive image transmission and simplifies the rate-control problem. In addition to these functionalities, it provides a substantial rate-distortion improvement over the JPEG standard when the bit rates become low. For example, we observe a bit rate reduction with respect to the JPEG Huffman and arithmetic coders by about 60% and 20%, respectively, for a bit rate around 0.1bpp. Keywords: Layered coding, progressive transmission, arithmetic coder, JPEG. 1. INTRODUCTION The JPEG [1] compression standard is widely adopted in still images coding. The process consists of three stages: the block DCT transform, uniform quantization with a quantization table, and the Huffman (used in the baseline system) or the arit..