Fast generation of CGH of 3D video images by using block-based motion compensation techniques

A new approach for fast generation of computer-generated-holograms (CGHs) by combined use of the N-LUT method and block matching motion compensation technique is proposed. Here, we apply block matching-based motion compensation algorithm to N-LUT-based CGH generation method by which a higher similarity between adjacent frames can be obtained. In the proposed method, the input video images are divided into blocks of fixed size and the CGHs of every block in reference frames are pre-calculated with the N-LUT method. The motion vectors of every block in the reference frame are extracted between reference frame and current frame, and a compensated frame image can be obtained by shifting every block’s position according to the motion vectors. Through this process, 3-D objects data to be calculated for its video holograms are dramatically reduced leading to the greater reduction of the calculation time compared with the conventional temporal redundancy-based N-LUT (TR-N-LUT) method. The experiments have found that the average number of calculated object points for one frame and the average calculation time for one object point of the proposed method are reduced by 30.05% and 21.23% respectively compared to those with the conventional TRNLUT method.