CCITT

CCITT (Comite Consultatif International Telephonique et Telegraphique) is a lossless compression format, which was used for compressing, for example, two-color images or simply black-and-white ones. The format has varieties; the common one is Group 3 which encodes each line at all and Group 4 which uses references from the previous line for compression.

This technique is mainly applied in TIFF compression. CCITT actually calls a procedure known as Huffman encoding to compress the data and reduce the stream to one of a much smaller size. This method is very efficient if there are long sequences of single-color pixels in the image in question.

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