摘要 |
<p>An apparatus encodes a binary shape signal and decodes the encoded binary shape signal by using a modified binary arithmetic coding and decoding method. In accordance with the modified binary arithmetic coding method, the binary shape signal is first scanned in a predetermined scanning order and a pixel value of its first scanned pixel is provided as one bit data. Then, the apparatus compares each of pixels in the binary shape signal with its precedingly scanned and adjacent pixel by using the scanned binary shape signal and produces a first or a second comparison signal. In response to the first or the second comparison signal, the apparatus assigns one of two mapping values to each of the pixels in the binary shape signal to thereby produce a mapping signal by using the assigned mapping values corresponding to the pixels in the binary shape signal. The mapping signal is arithmetically encoded based on probabilities corresponding to the two mapping values to thereby produce the encoded mapping signal. Finally, the one bit data and the encoded mapping signal are combined so that the encoded binary shape signal is outputted. At a decoding part, the encoded binary shape signal is reconstructed through the use of a reverse manner to the encoding process illustrated above.</p> |