The wavelet transform of images can supply information about localization of both space andfrequency.Data compression of vector quantization involved in the wavelet transform domain has been widelyused.After the multresolution pyramidal decomposition of wavelet transform
there aze correlation and spatialconstraints among the wavelet coefficients of subbands. Based upon the more sensivity of human vision to hori-zontal and vertical high-frequency components than diagonal ones
in this paper space-constrained vector quanti-zation using wavelet transform is proposed
which supplies improvements on both coding efficiency and quality ofdecoded images.