Inspired by the framework of algorithm unrolling, we propose a scalable network architecture that computes layer patterns for light field displays, enabling control of the trade-off between the display quality and the computational cost on a single pre-trained network.

3D video contents depend on the shooting condition, which is camera positioning. Depth range control in the post-processing stage is not easy, but essential as the video from arbitrary camera positions must be generated. If light field information can be obtained, video from any viewpoint can be generated exactly and post-processing is possible. However, a light field has a huge amount of data, and capturing a light field is not easy. To compress data quantity, we proposed the visually equivalent light field (VELF), which uses the characteristics of human vision. Though a number of cameras are needed, VELF can be captured by a camera array. Since camera interpolation is made using linear blending, calculation is so simple that we can construct a ray distribution field of VELF by optical interpolation in the VELF3D display. It produces high image quality due to its high pixel usage efficiency. In this paper, we summarize the relationship between the characteristics of human vision, VELF and VELF3D display. We then propose a method to control the depth range for the observed image on the VELF3D display and discuss the effectiveness and limitations of displaying the processed image on the VELF3D display. Our method can be applied to other 3D displays. Since the calculation is just weighted averaging, it is suitable for real-time applications.

In this paper, we propose an accurate calibration method for glassless stereoscopic systems. The method uses a lenticular lens on a general display. Glassless stereoscopic displays are currently used in many fields; however, accurately adjusting their physical display position is difficult because an accuracy of several microns or one hundredth of a degree is required, particularly given their larger display area. The proposed method enables a dynamic adjustment of the positions of images on the display to match various physical conditions in three-dimensional (3D) displays. In particular, compared with existing approaches, this avoids degradation of the image quality due to the image location on the screen while improving the image quality by local mapping. Moreover, it is shown to decrease the calibration time by performing simultaneous processing for each local area. As a result of the calibration, the offset jitter representing the crosstalk reduces from 14.946 to 8.645 mm. It is shown that high-quality 3D videos can be generated. Finally, we construct a stereoscopic viewing system using a high-resolution display and lenticular lens and produce high-quality 3D images with automatic calibration.

We conducted experimental classes in an elementary school to examine how the advantages of using stereoscopic 3D images could be applied in education. More specifically, we selected a unit of the Tumulus period in Japan for sixth-graders as the source of our 3D educational materials. This unit represents part of the coursework for the topic of Japanese history. The educational materials used in our study included stereoscopic 3D images for examining the stone chambers and Haniwa (i.e., terracotta clay figures) of the Tumulus period. The results of our experimental class showed that 3D educational materials helped students focus on specific parts in images such as attached objects of the Haniwa and also understand 3D spaces and concavo-convex shapes. The experimental class revealed that 3D educational materials also helped students come up with novel questions regarding attached objects of the Haniwa, and Haniwa's spatial balance and spatial alignment. The results suggest that the educational use of stereoscopic 3D images is worthwhile in that they lead to question and hypothesis generation and an inquiry-based learning approach to history.

Liquid medium was investigated for creation of real 3D dynamic color images on a basis of laser breakdown effect experimentally. It was shown, that breakdown plasma flash in liquid can be used as a shining voxel of white color. Plasma flashing voxels were produced by means of YAG laser with repetition rate up to 2000 Hz of nanosecond mJ pulses. Breakdown bubbles were found to be not hampering the displaying by flashes. Tens of liquids were tested concerning the lowest breakdown threshold. Up to now, tap water was found to be an optimal medium for displaying due to its low breakdown threshold, low attenuation of laser beam and safety. Seeing through electronic driven color filter made a burst of voxels to be perceived like colored one. TFT matrix from LCD was successfully used for the test coloring. A kind of hysteresis was also found out for dependence of laser breakdown probability on laser repetition rate for fixed laser beam in tap water.

The visual reality of a holographic image has improved effectively by utilizing multicolor reconstruction procedure. This fact is applicable to a real-time three-dimensional display for a computer generated hologram (CGH). However, it is quite difficult to generate a CGH for multicolor imaging in real-time because a CGH contains essentially a huge amount of information, and increases further information produced by multiplying the number of primary colors for multicolor imaging. Moreover, the optical system is considerably complicated for the multicolor image reconstruction. In this paper, a new method is presented to reconstruct a three dimensional multicolor image from a CGH. In this method, three sub-holograms to reconstruct the primary color images are sampled respectively for reducing the amount of computation and realizing a simple optical system. Fringe patterns are displayed by only one spatial light modulator (SLM) and color crosstalk images are eliminated by a color filtering system for ensuring that each sub-hologram can be only illuminated by the light with an appropriate color. A multicolor imaging method from a CGH is proposed and also the experimental results are shown.

Three-dimensional display technologies that require special glasses are not suitable for telecommunications because wearing glasses is inconvenient and it is defficult to observe facial expressions. Our previous 6.3-inch 3D display was inadequate for presenting images with realistic sensation. In this paper, a direct view 15-inch 3D display is described. The display is made up of a l5-inch TFT LCD and a composite lenticular sheet (LS), and uses the head tracking technique. Quantitative evaluation of the stereoscopic sensation of the display was studied using the 3D display, and better stereoscopic sensation values were obtained compared with a 2D display mode, thus comfirming the display's usefulness.