Low power motion estimation based on non-uniform pixel truncation

Motion estimation consumes a large portion of computational resources in most video encoders, such as AVS, H.264/AVC and HEVC/H.265. Pixel truncation can effectively reduce the power consumption of motion estimation and it is usually performed uniformly within the search window, which unfortunately brings degradation to the compression efficiency. However, based on the observation of unequal distribution of motion vectors, we can apply different number of truncated bits in different search area to achieve a better tradeoff between compression efficiency and power consumption. The proposed algorithm saves approximately 64% of the hardware computational complexity than conventional full-bit pixel search and at the same time achieves almost the same compression efficiency, with only 0.04 dB loss.