An equal-average equal-norm nearest neighbor codeword search algorithm(EENNS)is presented for vector quantization in this paper.Before encoding

the mean value and norm are first computed for each codeword

and then codewords are ordered according to the ascending order of their mean values.During the encoding process

the algorithm first selects the codeword that has minimum mean distance from the input vector as the tentative matching codeword

and then applies two efficient elimination criteria to search the nearest codeword close to the tentative matching codeword up and down.Experimental result shows that this algorithm is more efficient than the equal-average nearest neighbor search algorithm(ENNS)and recently-presented norm-ordered search algorithm(NOS).