Method and apparatus for double run-length encoding of binary data

摘要

A method and apparatus for losslessly compressing binary data using a technique referred to as Double Run-Length Encoding (DRLE). DRLE has particular application to the compression of gray-scale data as it is being processed for printing by a laser printer or other continuous raster scan device. DRLE records repeating patterns of ones and zeros with little computational complexity. Compression ratios that may be an order of magnitude or more are obtained frequently on data that may not compress well using traditional Run-Length Encoding (RLE). DRLE uses a sequential history of order-pairs that denote variable-length patterns of zeros and ones, and then encodes these patterns as they repeat themselves.