Study of the Contemporary Motion Estimation Techniques for Video Coding

Video compression is vital for efficient archival of entertainment based video (CD/DVD) as well as real-time reconnaissance / video conferencing applications. While ISO MPEG sets the standard for the former types of application, ITU sets the standards for latter low bit rate applications. In the entire motion based video compression process motion estimation is the most computationally expensive and time-consuming process. Motion estimation involves interframe predictive coding, one of the most powerful image coding techniques which calculates motion vectors and can eliminate redundancy in natural scenes. The research in the past few decades has focused on reducing both of these side effects of motion estimation. This paper reviews the literature pertaining to the different types of contemporary block matching algorithms used for motion estimation in video compression. The algorithms that are illustrated in this paper can be adopted by the video compressing community to be implemented in various standards. In addition, the advantages, limitations and applications of these techniques are revealed and guidelines for future research are discussed.