Looks like all the relevant patents have expired:
Japanese Patent 2128110, Jan. 1989 (expired)
Mitsubishi Electric Corp., Ono (F.) et al.: CODING METHOD OF IMAGE INFORMATION
Japanese Patent 2128115, Feb. 1990 (expired)
Mitsubishi Electric Corp., Ono (F.) et al.: CODING SYSTEM
US Patent 4286256, filed November 28, 1979 (expired)
IBM, Method and means for arithmetic coding using a reduced number of operations
US Patent 4295125, filed April 28, 1980 (expired)
IBM, A method and means for pipeline decoding of the high to low order pairwise combined digits of a decodable set of relatively shifted finite number of strings
US Patent 4410916, filed July 9, 1981 (expired)
Compression Labs Inc, Dual mode facsimile coding system and method
US Patent 4463342, filed June 14, 1979 (expired)
IBM, A method and means for carry-over control in a high order to low order combining of digits of a decodable set of relatively shifted finite number strings
US Patent 4463386, filed May 3, 1982 (expired)
IBM, Facsimile data reduction
US Patent 4467317, filed March 30, 1981 (expired)
IBM, High-speed arithmetic compression using concurrent value updating
US Patent 4633490, filed March 15, 1984 (expired)
IBM, Symmetrical adaptive data compression/decompression system
US Patent 4652856, filed February 4, 1986 (expired)
IBM, A multiplication-free multi-alphabet arithmetic code
US Patent 4749983, filed April 29, 1986 (expired)
IBM, Compression of multilevel signals
US Patent 4891643, filed September 15, 1986 (expired)
IBM, Arithmetic coding data compression/de compression by selectively employed, diverse arithmetic encoders and decoders
US Patent 4901363, filed September 28, 1988 (expired)
IBM, System for compressing bi-level data
US Patent 4905297, filed November 18, 1988 (expired)
IBM, Arithmetic coding encoder and decoder system
US Patent 4922545, filed February 10, 1989 (expired)
KDD, Facsimile image encoding method
US Patent 4935882, filed July 20, 1988 (expired)
IBM, Probability adaptation for arithmetic coders
US Patent 5099440, filed January 5, 1990 (expired)
IBM, Probability adaptation for arithmetic coders
US Patent 5884014, filed May 23, 1996 (expired)
Xerox, Fontless structured document image representations for efficient rendering
US Patent 6020972, filed November 14, 1997 (expired)
Xerox, System for performing collective symbol-based compression of a corpus of documents