An efficient law-of-cosine-based search for vector quantization

Vector quantization (VQ) is a well-known compression method. In the encoding phase, given a block represented as a vector, searching the closest codeword in the codebook is a time-consuming task. An efficient law-of-cosine-based search algorithm for VQ is presented in this correspondence. In our proposed algorithm, some new formulae and a dynamic rule for selecting the fixed vector are presented to speed up the search process. Experimental results reveal that our proposed search algorithm has better execution-time when compared to the current result by Mielikainen and the previous result by Huang et al.