Wavefront printing technique has a potential to record a digitally designed complex amplitude distribution at high accuracy. In this paper, some critical degradation factors of wavefront, namely a phase discontinuity and visible split line of sub-hologram by divided recording method, are discussed and an overlapping approach to reduce these degradations is introduced. Then an application of three-dimensional data visualization of both real and virtual objects is demonstrated. Finally holographic projection technique in which a holographic projector and a screen of holographic optical element fabricated by wavefront printing technique is introduced.
Tracking a ball in volleyball video sequences is a difficult problem due to unpredictable motions and motion blurs of the ball in an image coordinates. We propose a robust ball tracking method in volleyball videos by using multi-view cameras. The system calculates 3D position of a ball for predicting ball position in the next frame for all camera image coordinates. Experimental results showed that the method can robustly track a volleyball for a long video sequence.
In order to display full-parallax super multi-view images to both eyes, we propose the configuration of a two-channel scanning super multi-view display which can generate two-dimensional viewing points to both eyes. The number of viewpoints and the interval of viewpoints can be flexibly altered to enable the researches exploring comfortable super multi-view display conditions. The DMD which can generate images at a high frame rate is used to display parallax images. A large number of viewing points are generated by scanning the viewing points two-dimensionally. The galvano mirror is used for the horizontal scanning, and the rotating slit array is used for the vertical scanning.
Proper video coding techniques that correspond to integral imaging need to be continuously developed in order to transmit or record elemental images. We have been investigating the most suitable video coding for an integral 3D image, and in this study, we performed experiments on the moving picture of elemental images coded by 3D-HEVC and describe its coding performance. We compared coding performance of 3D-HEVC and HEVC for moving elemental images. The results showed that the coding by 3D-HEVC enhanced the efficient compression performance compared to the coding to the picture of elemental images by HEVC.
Displaying a variety of scenes with deep depth is a major challenge in integral 3D display technologies since their
depth-reconstruction range is very restrictive. Here we attempt to develop a method 'depth-compression expression,' in which the depth of 3D scenes are compressed, or modified in the axial direction, so that the appearances of the depth-compressed scenes are kept natural for viewers. Based on the subjective evaluation experiments using an integral 3D simulator that provided binocular and motion disparities, we show that scenes can naturally be expressed within shallower depth ranges than ones of originals. Specifically, by using the non-linear depth compression method to generate depth-compressed scenes, a variety of scenes, even with more than 100 m of depth, were expressed only within 1 m of depth-ranges without inducing unnaturalness for viewers. These results suggest that our method would allow integral 3D displays to show any scenes with deep depth if developments of integral 3D displays can achieve at least 1 m of depth reconstruction.