Run-length encoding

Run-length encoding (RLE) is a simple kind of data compression, in which a run of consecutive equal data values is replaced by a code indicating the run length and the data value.

RLE can be effective for some types of data, or as part of a more sophisticated algorithm, but by itself it is a poor general-purpose compression algorithm.

RLE is used in countless raster graphics formats.

Related formats
Algorithms and compressed data formats based primarily on RLE:
 * NeXT 2-bit RLE
 * PackBits
 * RLE90
 * Run-length colour encoding
 * ThunderScan compression

Note that most RLE implementations are used in only one format, and are not documented in a separate article.

Links

 * Wikipedia article
 * Run-Length Encoding (RLE), from the Encyclopedia of Graphics File Formats