An Adaptive Search Algorithm for Vector Quantization Using Wavelet Transform and Principle Component Analysis

In order to simplify the encoding process in vector quantization (VQ) image compression, a novel fast codebook search algorithm is presented in this paper. This algorithm integrates the technique of principle component analysis (PCA) with discrete wavelet transform (DWT) to quickly locate a reasonable initial codeword. Due to the smooth property of natural images, in addition, an adaptive search scope can be chosen by referring to the neighboring wavelet amplitudes and further used for the image block to be encoded. Experimental results showed that the proposed algorithm can indeed help providing a fast VQ encoder that only requires a few candidates for full comparison.