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Title A Practical Light Field Representation and Coding Scheme with an Emphasis on Refocu
Authors (Chun Zhao) ; (Byeungwoo Jeon)
DOI https://doi.org/10.5573/IEIESPC.2022.11.5.305
Page pp.305-315
ISSN 2287-5255
Keywords Light field representation; Light field coding; All-in-focus image; Depth map; Focal stack reconstruction
Abstract Light field images have drawn a great deal of interest owing to their flexible postprocessing and versatile functionalities. However, the tremendous data volume has imposed a practical limit in applications, which requires a better way to represent and compress the data. In this paper, we propose a practical representation and coding scheme for light field data with a special emphasis on retaining the refocusing functionality as much as possible. Under the proposed method, light field data are represented and compressed in the form of a rendered all-in-focus image and a depth map. Before encoding, the all-in-focus image is rendered accurately based on the depth map using the proposed difference focus measure. At the decoder, a focal stack comprising multiple images having different focus levels can be reconstructed by applying a defocusing function to the compressed all-in-focus image where the defocusing function parameter depends on the selected depth level of the compressed depth map. Compared with well-known state-of-the-art methods that compress the Fourier Disparity Layer or the focal stack, the proposed coding scheme shows much smaller loss in the refocusing capability (16.2% and 17.8% less than two state-of-theart methods) and provides PSNR improvements of 1.60dB to 2.38dB at the same compression ratio.