A fast half-pixel motion estimation algorithm based on hardware implementation
Fang Zhang · Journal of Circuits and Systems · 2005
The internal relation between full-pixel block matching and half-pixel block matching under the block distortion measure of sum of absolute difference (SAD) is studied. The SAD is modeled by mathematical curves, through which the half-pixel position that has the minimal SAD is predicted and the best half-pixel accuracy motion vector is calculated. A fast half-pixel motion estimation algorithm is proposed after analyzing three different mathematical prediction models based on concave functions. The result of half-pixel motion estimation is directly deduced from that of full-pixel motion estimation, which greatly reduces the computational complexity of half-pixel motion estimation and eases the implementation of low bit-rate real-time video encoder. Experimental results show that this algorithm can keep good quality of reconstructed images as well. The algorithm can be easily integrated into video encoders available.