Fast motion estimation using modified orthogonal search algorithm for video compression

This paper presents a novel method named as Modified Orthogonal Search Algorithm (MOSA) for the block based motion estimation. Recently fast search algorithm for video coding using Orthogonal Logarithmic Search Algorithm (OSA) has been proposed by Soongsathitanon et al. (IEEE Trans Consum Electron 51(2): 552-559, 2005). We introduce the center biased search point pattern for the estimation of small motions and a half way stop technique to reduce the computational complexity in the existing OSA. This feature improves the speed performance of the algorithm by 80% as compared to the Full Search Algorithm, 50% over the Three Step Search algorithm and 2% faster than the OSA. However, the Mean Square Error and Signal to Noise Ratio did not show significant deviation from the orthogonal logarithmic search algorithm and the three step search algorithm. The experimental results based on the number of video sequences were presented to demonstrate the advantages of proposed motion estimation technique.