Global motion compensation for compressing holographic videos

Large high-resolution digital holographic displays may become feasible in the near future, and they will need considerable amounts of data. Handling this bandwidth is particularly challenging for dynamic content operating at video rates. Conventional motion compensation algorithms from classical video coders are ineffective on holograms because, in contrast to natural imagery, each pixel contains partial information from the whole scene. We propose an accurate motion compensation model predicting how hologram content changes with respect to 3D rigid-body motion that arises in natural scenes. Using diffraction theory, we derive tractable closed form expressions for transforming 2D complex-valued holographic video frames. Our experiments use computer generated hologram videos with known ground truth motion. We integrated the proposed motion compensation model into the HEVC codec. We report Bjøntegaard delta-PSNR ratio gains of 8 dB over standard HEVC.