Space-frequency adaptive trellis-coded wavelet image coding
Veyis Nuri · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1996
In this paper, a high-quality, space-frequency adaptive, trellis coded wavelet image codec is presented. The algorithm seeks jointly optimal space and frequency segmentation of an image. For this, first, wavelet packets are formed to localize the high-energy frequency bands. Then, the wavelet coefficients are further classified to maximize the coding gain. Design target is set to minimize Lagrangian cost functions which are formed with distortion in l2 norm being the cost and coding rate as constraint. Resultant mapping is used to quantize the wavelet coefficients with trellis code quantization. This is followed by adaptive arithmetic coding producing the final compressed bitstream. Described approach is tested on several ISO standard images and results are compared to other compression techniques. Representative examples are included.