Modified READ
From Just Solve the File Format Problem
Modified READ (MR) is the name of the image compression algorithm used in 2-dimensional CCITT Group 3 format. READ stands for Relative Element Address Designate.
It first encodes most rows as the difference between the current row and the previous row, then uses run-length encoding, followed by Huffman coding.
For more information, see CCITT Group 3.
