Hiroaki Koga

Sense of Virtual Reality: Effectiveness of Replacing 3D Imagery with 2D-3D Hybrid Imagery

This paper proposed the advantages of using a 2D/3D hybrid imagery system over the use of 3D by itself. A hybrid imagery system was created by projecting a 3D (stereo) image in between and overlapping onto two adjacent 2D images. The negative effect where 2D and 3D images overlap was studied and resolved. Then sensations subject experienced from the visual cues under the different conditions were attained. Participants sensations while looking at the different forms of imagery on both a flat screen and a flat/inclined screen combination were then attained. The data for the 2D/3D hybrid system were compared with that attained for a 3D image system on its own (without 2D images). Results indicate that there are benefits to using a 2D/3D hybrid system over 3D by itself.

Design of Comfortable Working Environment on Bed for Bedridden People

This paper proposes a bed environment where user can actively work in bedridden posture. The proposed bed environment is using a nursing bed as the base, and has an overhead lighting, a screen, and a projector. The environmental conditions, such as bed angle, table angle, and screen distance and angle, and the number of electric bulbs of lightings and its angle, were evaluated by performing questionnaire. As a result, the proposed environment is well suited for watching movies, using personal computer, and conversation with person in distant place.

Moving Picture Creation Based on Physical and Kansei Information of Music

This paper proposes a novel system to create the moving picture based on music physical parameters and its Kansei factors. The moving picture is created to have equivalent Kansei with the music. The Kansei factors we derived are as follows: rhythmical sensation, mellow sensation, brilliant sensation, and powerful sensation. The system was evaluated by using fireworks picture. As a result, the proposed system can improve the Kansei compared with the reference picture except for the mellow factor.

Characteristics of Human Speed Sensation for Flying-Ball Pictures

This paper describes characteristics of human speed sensation for flying-ball pictures. Flying-ball is arranged with a certain density, and its velocity is constant. First, we arranged flying-ball regularly and measured a relationship between density, velocity, and sensation of speed. As a result, we clarified that sensation of speed relates to the number offlying-balls which pass through on display. Next, we also measured characteristics of a speed sensation when arranged flying-ball irregularly. The result is the same as the regular case.

Effect of Image-size Differences on 3D Giant Stereo Image Screen and of 2-Projector Images on Visual Fatigue

A 3D stereo image makes a more powerful and realistic impression than a 2D image. We want to clarify the optimal projection conditions for educational facilities and amusement arcades that use 3D stereo images. First, we clarified the degree of impression due to screen for 2D and 3D stereo images. The impressions of 3D stereo images became more powerful and realistic than those of 2D images as the screen size was widened. We statistically examined the opinions of viewers of 2D and 3D stereo images, which were obtained from questionnaires. Visual fatigue sometimes appeared after they watched 3D stereo images, specially when a projection method using two projectors (one for the right-eye and the other for the left-eye) was used. This fatigue appears to be partially related to the projection-size difference. Visual fatigue became more serious when the difference extended beyond 1% of the original size. Using these results, we designed an assembly rack for two projectors (3D stereo projectors) to keep the size difference below 1%.