Image coding by using trimming modified vector quantization

A new coding technique, the trimming vector quantization (TVQ) is introduced in this paper, which provides a low coding bit rate as well as high reconstruction quality to image compression. It is well known that in conventional VQ and many other image coding techniques, if the bit rate is lower than 0.2 bit/pixel, the quality of the encoded image may dramatically decline due to the artificial block effects and/or blurry edges. The TVQ may overcome those disadvantages by trimming a coarsely encoded image, removing the artificial block contours and sharpening the major edges, based on the features of the different image regions. By using the TVQ we can encode an image at a compression ratio higher than 50 and the reconstructed image still has a satisfactory perceptual quality with SNR=31 dB