Abstract
A method of generating the representative vectors for encoding still images efficiently using a vector quantizer, is proposed in this paper. A conventional codebook is generated by clustering many training images. But, many representative vectors are registered in the codebook for obtaining the high quality reconstructed image, thus the index of the representative vector becomes long. To solve this problem, the conventional methods encode the index efficiently. The proposed method is another approach for reducing the number of representative vectors by using two codebooks adapted to edges and flat regions of the image respectively. It uses a specific codebook which is generated by filtering the representative vectors from the source image, and a universal codebook which is generated by using random numbers. It is shown that the coding efficiency of the proposed method is comparable to the conventional methods without encoding the index efficiently.
