IMAGE CODING USING 2D WAVELET TRANSFORM

In this paper，an image coding scheme combining the advantages of both discrete wavelet transform (DWT) and classified vector quantization (CVQ) is proposed. We decompose an image into a multifrequency channel representation on a set of orthonormal wavelet base and then use classified vector quantization technique to code the coefficients and enable the system to compress an image to a low bit rate.simulation results showed that the proposed approach allow good subjective image quality to be obtained. The improvement in quality is even more pronounced at low bit rates，if this algorithm is compared to those algorithm employing CVQ or DCT alone.