| 摘要 |
Input image data is coded into sets of two-dimensional sub band image data are run-length coded by a run-length coder 60. The run-length coder 60 assigns codes to runs of zero values terminated by a non-zero value, runs of constant non-zero values and particular individual data values. The output from the run-length cod or 60 is fed to a Huffman coder 62 where it is Huffman coded. The Huffman coding table 64 applied by the Huffman coder 62 and the type of run-length coding applied by the run-length coder 60 varies. Implementations need only use a sub-set of possible runs of zero values terminated by a non-zero value and runs of constant non-zero values without an undue loss in compression efficiency. <IMAGE> |
