H.264

the latest video coding standard

achieves significant improvement in coding efficiency compared with previous standards.The high coding efficiency is based on some new techniques which also lead to high computational-complexity.H.264 uses variable-block-size motion estimation

which is the most time-consuming module.In this paper

we propose a fast variable-block-size motion estimation algorithm for H.264.The algorithm is based on three schemes: stationary block prediction

predictive search for non-stationary blocks and adaptive refinement search in merging process.Experimental results show that our algorithm can reduce the computational-complexity to 3% of fast full search motion estimation algorithm

with negligible PSNR loss and bit rate increase.