Embedded image coding using optimized significance tree quantization

Abstract

A number of embedded transform coders, including Shapiro's (1993) EZW coder, Said and Pearlman's (1996) SPIHT coder, and Xiong et al.'s (1996) EZDCT coder employ a common algorithm called significance tree quantization (STQ). Each of these coders have been selected from a large family of significance tree quantizers based on empirical work and a priori knowledge about transform coefficient behavior. We describe an algorithm for selecting a particular form of STQ that is optimized for a given class of images. We apply our optimization procedure to the task of quantizing 8/spl times/8 DCT blocks. Our algorithm yields a fully embedded, low-complexity coder with PSNRs up to 2.0 dB better than baseline JPEG for standard test images.