What is Group 4 Compression (ITU-T T.6)?
Last Update: August 9th, 2021
Group 4 Compression works through a combination of two methods:
– Using vertical features to allow further compression
– Encoding each scan line in the bitmap with a series of variable length codes to represent the sequence of changes between white and black that can be found in the scan line. In this sense, it is similar to Huffman compression.