A modified VQ algorithm based on"Structure Constraint Matrix"is presented in this paper. After image decomposition
a multiresolution pyramidial representaion is yielded and the geometric image structure is preserved.We use Vector Quantization to code the wavelet coefficients."Structure Constraint Matrix" is proposed tO describe the correlationship caused by the space-frequency localization property of wavelet transform
and to reduce the computational load in VQ algorithm.Experimental results are given to show its better perfomance.