A 3-D head mounted display (HMD) system is useful for constructing a virtual space. We have developed a 3-D HMD system. Traditional displays have drawbacks in that the lightness of real and virtual images is insufficient for spatial viewing. This problem can be solved by using the simultaneous perception of the human vision and a 3-D vision system. We also describe a newly developed monocular stereoscopic 3-D display system for a 3-D HMD system.
A computer-generated hologram (CGH) is made for three-dimensional image reconstruction of a virtual object. The error diffusion method is used to improve the reconstructed image. The selection of the diffusion coefficient affects the image quality of the reconstructed image. We optimized the diffusion coefficient using a genetic algorithm (GA). In this simulation, the diffusion coefficient found by the GA could reduce the mean squared error of the reconstructed image by 40% compared with stochastic searching.
In a virtual-space walk-through system, collisions between three-dimensional objects should be detected in real time. Generally, such collision detection is done by using the intersections of the surfaces of the objects. When the objects become complex, however, collision detection in real time is difficult because of its heavy calculation cost. Therefore, collision detection is done by approximating each object as a group of spheres. To improve the approximation, the spheres must be made smaller, but doing so makes collision detection in real time more difficult. To solve this problem, we have developed a fast collision-detection method that reduces the number of spheres. Experimental results showed that it is faster than conventional methods.
A realtime marker-less motion-capture system is described that can easily and seamlessly map objects in the real world into a virtual environment. In general, virtual environment applications, such as man-machine seamless interaction, require the system to estimate the motion parameters for natural objects such as human bodies in realtime.To achieve this, the developed motion-capture system achieves multiple-camera fusion and reconstructs the parameters for complete human-body motion using real-time inverse kinematics. Implementation of this system demonstrated its ability to work in realtime and online on a pc-cluster.
The effectiveness of using a PLUGE (picture line-up generating equipment) signal to improve a display's grayscale reproduction under ambient illumination was investigated using two new metrics. Experimental results showed that adjusting a display's brightness with a PLUGE signal enables more precise adjustment than with a general image. A metric for the volume of reproducible color space was used to describe the area that a display can reproduce in the color space. A metric for the color reproduction reduction rate was used to describe how gray-scale reproduction deteriorates under ambient illumination. The values obtained for these metrics showed that adjusting the brightness with a PLUGE signal improves grayscale reproduction.
We have developed a field-sequential stereoscopic display system with a 42-inch diagonal HDTV DC-type plasma display panel (PDP). This system uses an LCD shutter stereoscopic eyeglass, synchronized with the L and R pictures on the display by infrared signals. A 12 sub-field light-emission scheme for stereoscopic display and a signal-processing method for improving gray-scale expression in stereoscopic display are described. Stereoscopic images were displayed on the PDP by the proposed emission scheme. The effectiveness of the signal-processing method was confirmed by subjective evaluation.