run-length encoding

A data compression technique for storing raster or gridded data. Run-length encoding stores data by row. If two or more adjacent cells in a row have the same value, the 'run' is recorded, as opposed to recording an individual value for each cell. The more adjacent columns having the same value, the greater the compression.

A redundancy-reduction technique for facsimile in which a run of consecutive picture elements having the same state (gray scale or color) is encoded into a single code word.