Presents a simple but effective algorithm to speed up the codebook search in a vector quantization scheme when a MSE criterion is used. A considerable reduction in the number of operations is achieved. This algorithm was originally designed for image vector quantization in which the samples of the image signal (pixels) are positive, although it can be used with any positive-negative signal with only minor modifications.
Torres, L., Huguet, J. An improvement on codebook search for vector quantization. "IEEE transactions on communications", Febrer 1994, vol. 42, núm. 2/3/4, p. 208-210.