Validation of dynamic subjective quality assessment methodology for holographic coding solutions

In preparation of the Call for Proposals on JPEG Pleno Holography, multiple exploration studies are ongoing to define the general procedure for performance assessment of proposed coding solutions. The performance of proposals will be compared against JPEG 2000 and H.265/HEVC intra coding, both serving as anchor codecs. In this paper, we report on the results of a dynamic subjective visual quality assessment procedure. A subset of 8 holograms, selected from the JPEG Pleno Database, is compressed both in hologram and object plane at three different bit rates. Chosen bit rates vary per hologram depending on their content characteristics. Then, for each hologram and its compressed versions, pseudo-video sequences are generated from the reconstructed views along a scan path that involves focus and viewing angle changes and that is hologram specific. A double stimulus simultaneous test, combined with a 5-level impairment-scale scoring protocol is deployed where videos created from the reference and the decoded holograms are visualized side by side on a professional 4K display. Results demonstrate that this test procedure requires deep scenes and sufficient scene complexity throughout the depth stack to allow for adequate stress testing of the codecs under test, particularly those solutions that adhere to compression in the object plane.