• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.2
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• pp.140-146
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• 1989

An efficient quantization and encoding of BTC (Block Truncation Coding) parameters {($Y_{\alpha},\;Y_{\beta}),\;P_{{\beta}/{\beta}}$} are investigated, In our algorithm 4${\times}$4 blocks are classified into flat or edge block. While edge block is represented by two approximation level $Y_{\alpha},\;Y_{\beta}$ with label plane $P_{{\beta}/{\beta}}$, flat block is represented by single approximation level Y. The approximation levels Y, $Y_{\alpha}$ and $Y_{\beta}$ are encoded by predictive quatization specially designed, and the label plane $P_{{\beta}/{\beta}}$ is tried to be encoded using stored 32 reference plantes. The performance of the proposed scheme has appeared comparable to much more complex transform coding in terms of SNR, although it requires more study on the representation of small slope in background.

• Journal of Korea Multimedia Society
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• v.7 no.5
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• pp.640-647
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• 2004

This paper presents a method that, by using a tree splay, dynamically modifies the fixed table of a VLC used in the standards and thus improves the performance of a video encoder. The previous standards, which drew up tables by using a limited number of images, were not able to accommodate the characteristics of new image input. The new method proposed in this paper employs the probabilistic characteristics of an image input, thus making encoding more effective. Furthermore, the present study also proposes a method to regulate the weight in order that the accumulated probabilities can make a dominant symbol emerge, while keeping the probability adequate and thus maximally accommodating the characteristics of the image input. The results from applying the proposed method to a variety of image sequences showed that, while various types of images yielded slightly different results, it improved the performance up to a maximum of 0.23㏈, compared to MPEG-4 standard.