Run-length encoding

File Format
Name	Run-length encoding
Ontology	Electronic File Formats Compression Run-length encoding
PRONOM	x-cmp/13

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
• RLE Compression article on the Shikadi Modding Wiki, with a list of RLE variants used in proprietary game file formats.