Novel fast half pixel motion estimation for low bit rate video coding
Junli Zheng · Journal of Tsinghua University(Science and Technology) · 2001
In hybrid video coding schemes, the motion estimation is the most computationally expensive module. Typical motion estimation is composed of two stages: one at integer pixel accuracy and the other at half pixel accuracy. Since the motion estimation complexity at the integer pixel accuracy level has continually decreased, the computation complexity for the full half pixel search has taken a relatively large part of the whole motion estimation. The efficiency of the half pixel search is improved by using a paraboloid prediction based fast half pixel motion estimation algorithm. Experimental results show that the proposed algorithm gives almost the same image quality and bit rate as that of the full half pixel search and it reduces the computational load by about 57% for the QCIF H.263 encoder. Furthermore the simple prediction process in the proposed algorithm makes the algorithm be easily integrated into existing video coding systems.