Title :
Image vector quantizer based on a classification in the DCT domain
Author :
Kim, Dong Sik ; Lee, Sang Uk
Author_Institution :
Dept. of Control & Instrum. Eng., Seoul Nat. Univ., South Korea
fDate :
4/1/1991 12:00:00 AM
Abstract :
A classification algorithm in the discrete cosine transform (DCT) domain for the classified vector quantization (CVQ) technique is proposed. The classifier employs four DCT coefficients of 4×4 subblock as edge-oriented features. The classifier is designed using a cluster-seeking algorithm to ensure that the centroid of a set of vectors in a class always belong to that class. Since the classification is performed in the DCT domain, this approach can be easily extended to the DCT transform coding technique. Simulation results show that a good visual quality of the coded image at fixed rates in the 0.625-0.813 b/pixel (bpp) range is obtained with comparable complexity. The weighted MSE (WMSE) analysis in conjunction with the proposed classifier is discussed
Keywords :
data compression; encoding; picture processing; transforms; CVQ; DCT coefficients; DCT domain; DCT transform coding; centroid; classification algorithm; classified vector quantization; cluster-seeking algorithm; discrete cosine transform; image vector quantiser; simulation results; visual quality; weighted MSE; Bit rate; Clustering algorithms; Degradation; Discrete cosine transforms; Distortion measurement; Image coding; Image quality; Mean square error methods; Pixel; Vector quantization;
Journal_Title :
Communications, IEEE Transactions on
