Motion vector prediction for improving one bit transform based motion estimation
One bit transforms (1BT) have been proposed for lowering the complexity of motion estimation (ME) in video coding. These transforms generate a one bit representation of each pixel in the video that is used in the motion search. This approach can greatly reduce the silicon area and power required for hardware based video encoding. However 1BT methods under-perform traditional Sum of absolute differences (SAD) based motion estimation, particularly for smaller block sizes. In this paper, it is proposed to improve 1BT based ME by predicting the motion vector for each block based on the vectors from previous blocks and modifying the cost function to favor motion vectors close to the predicted one. This takes advantage of the spatial correlation between motion vectors and produces a more uniform motion field. Simulation results show the proposed method can improve the PSNR of frames reconstructed through motion compensation by up to 1 dB and substantially improve the subjective video quality by reducing blocking artifacts.