Entropy-constrained motion estimation: algorithm and implementation
Parthasarathy Sriram, Subramania I. Sudharsanan · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1998
Block-based motion estimation (ME) has been a very active area of research in the field of video signal processing and coding. Traditional ME techniques consider only the sum of the absolute differences between the current and the reference blocks to find the motion vectors (MV). Recently, several rate-constrained ME techniques have been proposed which considers the effect of encoding the MV by adding an entropy constraint to the distortion measure. Such techniques show an improved performance at low bit-rates. The displaced frame difference blocks are typically transformed using discrete cosine transform and then quantized in the transform domain. In our proposed scheme, an entropy-constrained ME algorithm is proposed which considers the number of bits allotted for coding the DFD's in addition to those used for encoding the MV and the MB mode information. Simulation results show that the proposed technique performs significantly better than the standard technique for a wide range of bit-rates. In addition, a computationally less complex scheme is also proposed, although with reduced performance improvements over the conventional scheme. The implementation aspects of the proposed schemes are also briefly discussed.