Complexity reduction algorithm for region-of-interest based H.264 encoding

This paper proposes a computation complexity reduction algorithm for region-of-interest (ROI) based H.264 encoding. Smaller partition is preferred in both higher visual quality and ROI situation so that inter mode selection is applied according to the ROI based quality difference. An unequal coding efficiency degradation scheme is proposed according to the unequal bits allocation in ROI based video coding. Our ROI detection algorithm can detect accurate ROI boundary and an ROI boundary enhancement scheme is applied to further reduce the computation complexity in ROI. Experimental results show that 76.09% simulation time can be saved. Bit rate increases for only 1.07% while PSNR decreases for 0.05dB.