Lenslet image compression based on image reshaping and macro-pixel Intra prediction

Lenslet images that record both spatial and angular light radiance in a super high definition with distinct macropixel structures desire efficient compression methods for promoting the applications of handheld plenoptic cameras urgently. In this paper, a lenslet image compression method is proposed. First, a reversible image reshaping and adaptive interpolation is proposed to align the macropixel structures with coding unit grids in the block based video coding standards. Then, based on the reshaped and regularized lenslet images, a macro-pixel Intra prediction mode, in which the coding unit is predicted by minimizing spatial boundary error among the adjacent macropixels, is proposed to fully exploit spatial correlations among the pixels beneath the neighboring microlens. The proposed approach outperforms HEVC by an average of 35.56% bitrate reduction. Compared with the existing coding approaches, like Intra block coding (IBC) and locally linear embedding-based (LLE) prediction, it achieves an average of 17.72%/23.06% bitrate reduction, which demonstrates its efficiency explicitly.