Low-overhead segment based motion compensation for H.26L

In this paper, we describe a low-overhead MB based motion model proposed to a coding candidate architecture of emerging ITU-T video coding standard H.26L and show that it outperforms the current H.26L motion model at a lower range (e.g., 16Kbps-64Kbps) of bitrate. The current H.26L's motion compensation employs a granularity scaling strategy, which scales accuracy of motion compensation depending on an available bitrate. This results in the degradation of the prediction performance in case of lower bitrate coding, where the bit budget for motion representation has to be reduced. We propose a better harmony of overhead and gain in prediction, by introducing a motion boundary model in place of H.26L's motion compensation, that provides a better prediction performance at the lower bitrates. Our experimental results show that the proposed model achieves bit-rate saving up to 5% compared with H.26L. A Rate-Distortion analysis verifies the advantage of the proposed motion model.