释义 |
MH (Modified Huffman) A relatively simple encoding and compression algorithm used in facsimile machines that eliminates signal redundancy using a one-dimensional run-length encoding process to digitize and compress a document prior to transmission. The transmitting machine scans a document from top-to-bottom and left-to-right, sensing dots of black and white color at an interval that depends on the resolution setting. Rather than transmitting a set of bits identifying the value (black or white, grayscale, or color) of each dot of each line, the scanning machine looks for redundancy, or runs, of dots of the same value.The machine then can transmit a set of bits identifying that value and the length of the run before the value changes from black to white, then transmit the length of the run of white, and so on.The receiving machine reverses the 74570c13.qxd 9/11/07 12:25 PM Page 310 |