| 摘要 |
A method for compressing and expanding source image representative data is disclosed. The method for compressing rasterized source image representative data comprises the following steps. The rasterized source image representative data is partitioned into a first plurality of sections each containing only blank lines, and a second plurality of sections each containing non-blank image representative data. Each section in the first plurality of sections is represented by a respective blank-line codeword. Each section in the second plurality of sections is further partitioned into a plurality of blocks, each having L lines of P pixels and a pattern. For each partitioned block, one of a plurality V of code vectors, each having L lines of P pixels and a predetermined pattern which most closely matches the pattern of the partitioned block, is selected. Each partitioned block is represented by a respective non-blank codeword representing the selected one of the plurality of code vectors. The compressed image, thus, is represented by successive codewords representing either blank lines or code vectors. The method for expanding the compressed image represented by the successive codewords comprises the following steps. Blank lines are inserted into rasterized reproduced image representative data in response to blank-line codewords. The pattern of the code vector represented by each non-blank codeword is inserted into the rasterized reproduced image representative data in response to each non-blank codeword. A rasterized reproduced image results from this expansion.
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