Gu Huarong, Jin Guofan
Opt Express. 2018 Dec 24;26(26):33592-33603. doi: 10.1364/OE.26.033592.
In holographic three-dimensional (3D) display, holograms for reconstructing 3D scenes require huge storage space and high transmission bandwidth. Holographic data must be compressed for practical applications. The holograms for 3D display are commonly represented in pure-phase format. Existing hologram compression techniques are generally not designed to handle phase-only holograms. In this paper, we propose a phase-difference-based compression method to compress phase-only holograms for holographic 3D display. Phase-only holograms are decomposed into grayscale images representing the phase distance and binary images containing the sign information of the phase difference. The grayscale images can be better handled by common image compression algorithms since their pixel values are proportional to the phase distance reflecting the distance between complex amplitudes. The binary images are compressed by lossless bi-level image coding. The compressed grayscale images and binary images can be synthesized to recover the phase-only holograms and reconstruct the 3D scenes. The advantages of the proposed method over existing image coding standards are verified by numerical simulations.
在全息三维（3D）显示中，用于重建3D场景的全息图需要巨大的存储空间和高传输带宽。为了实际应用，全息数据必须进行压缩。用于3D显示的全息图通常以纯相位格式表示。现有的全息图压缩技术通常并非设计用于处理纯相位全息图。在本文中，我们提出了一种基于相位差的压缩方法，用于压缩用于全息3D显示的纯相位全息图。纯相位全息图被分解为表示相位距离的灰度图像和包含相位差符号信息的二值图像。由于灰度图像的像素值与反映复振幅之间距离的相位距离成正比，因此普通图像压缩算法可以更好地处理它们。二值图像通过无损二值图像编码进行压缩。压缩后的灰度图像和二值图像可以合成以恢复纯相位全息图并重建3D场景。数值模拟验证了所提方法相对于现有图像编码标准的优势。
