Fast VQ Codebook Generation Method Using Codeword Stability Check and Finite State Concept

The codebook design in the vector quantization scheme is important because it affects the image quality of the encoded image. The Linde-Buzo-Gray (LBG) codebook generation algorithm is well known and a popular choice among codebook users. However, a heavy computational complexity is consumed for the iteratively clustering process in the LBG algorithm. In this paper, the similarity of codewords in consecutive rounds of the LBG algorithm is exploited to reduce the computational complexity. By checking the stability of codewords, the status of each codeword in the codebook can be determined. Only the unstable codewords are refined to generate the new codebook. The proposed method can be further improved by cooperating with the finite state technique. Experimental results show that the computational complexity of the proposed method is reduced to about 4% of the LBG algorithm while achieving a slightly worse image quality.