Hybrid approach for fast occlusion processing in computer-generated hologram calculation

Abstract

A hybrid approach for fast occlusion processing in computer-generated hologram calculation is studied in this paper. The proposed method is based on the combination of two commonly used approaches that complement one another: the point-source and wave-field approaches. By using these two approaches together, the proposed method thus takes advantage of both of them. In this method, the 3D scene is first sliced into several depth layers parallel to the hologram plane. Light scattered by the scene is then propagated and shielded from one layer to another using either a point-source or a wave-field approach according to a threshold criterion on the number of points within the layer. Finally, the hologram is obtained by computing the propagation of light from the nearest layer to the hologram plane. Experimental results reveal that the proposed method does not produce any visible artifact and outperforms both the point-source and wave-field approaches.

Progressive hologram transmission using a view-dependent scalable compression scheme

“…Table 1 summarizes the parameters of two color CGHs. These holograms are generated from synthetic scenes using the methods described in [34,47]. The chrominance format of CGH is set to 4:4:4 with 8bit depth for each color's channel (R, G and B).…”

JPEG Pleno: Providing representation interoperability for holographic applications and devices

“…Currently, the main databases are as follows: Interfere database Consist of two sets of computer generated holograms, which may be one of the most important applications of holography. This database has two sets of computed generated holograms: an original one and a more recent one that enlarges the diversity (represented in Figures and respectively). b<>com holographic database This database is composed of colored computer generated holograms, calculated from synthetic 3D models or multiview‐plus‐depth data (Figure ). Some of them were computed from 3D videos of real‐existing scenes.…”

“…This database has two sets of computed generated holograms: an original one and a more recent one that enlarges the diversity (represented in Figures 5 and 6 respectively). • b<>com holographic database [46,47] This database is composed of colored computer generated holograms, calculated from synthetic 3D models or multiview-plusdepth data (Figure 7). Some of them were computed from 3D videos of real-existing scenes.…”

Recent Advances in the Processing and Rendering Algorithms for Computer-Generated Holography

“…If compared to other methods, such as the point-cloud approach, the layer-based synthesis turns out to be faster, because the number of layers could be lower than the number of points that describe the scene. Despite this fact, to ensure that the depth of the scene is acquired without visual-perceptible discontinuities, the number of layers required may be high [37], then different acceleration techniques have been proposed to improve the generation process, such as those proposed in [39] and in [40]. Recently, an acceleration method based on LUTs has been proposed [41], enabling the generation of CGH video sequences, minimizing the memory required and the overall hologram generation process complexity.…”

“…The Institute of Research and Technology B-com has developed a color CGH dataset, generated with two different algorithms, described in [40,61]: the former is a hybrid technique that combines the point-cloud and the layer-based approach and includes occlusion effect support, while the latter is based on multiple 2D-with-depth images of the scene acquired from different viewpoints from which a point cloud is derived. The algorithm takes also into account specular reflections.…”