This paper presents a real-time entropy compression/decompression unit for disparity map information used in 3D teleconferencing systems. The disparity map data form a constant bit rate data stream which has to be transmitted through an ATM channel supporting lower data rates. The selection of the proper compression algorithm must be based on the durability of the regenerated data to various types of errors, generated mainly due to the limited available bandwidth. Initially we present the disparity map formats, why they should be coded losslessly, some well-known entropy algorithms and their performance in terms of compression rate and throughput. All algorithms are evaluated according to the application requirements which are: good compression rate, real-time implementability and fast convergence during the compression initialization phase. Feasible implementation are proposed for the algorithms selected using commercially available digital signal processors (DSPs) and field programmable gate arrays (FPGAs).