A fast hierarchical 1/4-pel fractional pixel search algorithm based on video coding standard H.264/AVC

作者：Zhou Xin^*; Duan Zhemin; Zhou Wei

来源：Journal of Northwestern Polytechnical University, 2011, 29(2): 300-304.

• Computation complexity
• Distribution characteristics
• Error surface
• Fractional pixel
• H.264/AVC
• Integer pixel
• Matching error
• Motion Vectors
• Motion-compensated video
• Polynomial model
• Polynomial models
• Search Algorithms
• Searching strategy
• Searching windows
• Vertical direction
• Video coding standard H.264

Motion estimation plays an important role in motion compensated video coding. Motion estimation is generally conducted in two steps: (1) integer pixel motion vector search; (2) fractional pixel refinement. 1/4-pel fractional pixel search is adopted in H.264/AVC to further reduce residual coefficients. A fast hierarchical 1/4-pel fractional pixel search algorithm based on polynomial model is proposed in this paper. We first analyze the distribution characteristics of motion compensation error surface inside the fractional pixel searching Then, the matching error is fitted with a parabola along horizontal and vertical direction respectively. With the proposed searching strategy, only 5 points is to be checked, while in the traditional Hierarchical Fractional Pel Search (HFPS) algorithm for 1/4 pel search, 16 points is to be checked. The experimental results show that, compared with HFPS algorithm, the computation complexity is reduced by 64.82% when the proposed algorithm is adopted.

• 出版日期2011
• 单位西北工业大学