Enhanced modified orthogonal search for motion estimation

Motion estimation is an important part of video encoding systems. This paper presents a novel enhanced modified orthogonal search (EMOS) algorithm for block based motion estimation. The performance of this algorithm is evaluated with various video sequences and the results are compared to a traditional well-known full search algorithm (FSA), three step search (3SS), orthogonal search (OS), and modified orthogonal search (MOS). This paper introduces a half way stop technique to reduce computational complexity in the existing OS & MOS. The centre biased search pattern is facilitated for small motions. The enhanced modified orthogonal based search pattern is investigated in comparison with orthogonal and modified orthogonal search pattern and demonstrates significant speedup gain over them. The proposed EMOS algorithm can find the same motion vector with fewer search points than the OS & MOS algorithm. The quality of the reconstructed frame is comparable with that of the full search method, 3SS, OS & MOS. The advantage of proposed motion estimation technique is further justified by experimental results.