Calculation of computer-generated hologram for 3D display using light-ray sampling plane

In this paper, we propose a new algorism for calculating computer-generated hologram (CGH) for 3D image display. The wavefront is calculated from light-ray information, which can be obtained by artificial computer graphics or image-based renderings using the data captured by a camera array. The view interpolation, hidden surface removal, and gloss reproduction are easily implemented by utilizing the techniques of image-based rendering or light-field rendering. The method is similar to the CGH based on the principle of Holographic Stereogram (HS), but using HS based CGH, the image far from the hologram plane is blurred due to the light-ray sampling and the diffraction at the hologram surface, so it is not suitable for the display of deep scene. Thus we proposed the use of virtual "Ray-Sampling (RS) plane" near the object, and the wavefront at the RS plane is calculated from the light-rays. The wavefront propagation is then simulated based on Fresnel diffraction from the RS plane to the hologram. The hologram pattern is obtained from the complex amplitude distribution on the hologram plane. Even if the RS plane is distant from the hologram, the resolution of the reconstructed image is not degraded since the long distance light propagation is calculated by diffraction theory. In the experiment, we obtained high resolution, deep 3D image with gloss appearance with using the image data generated by commercial rendering software.