Masanori Takemoto

The virtual image presented with Augmented Reality (AR) device is superimposed on the real world, and we can perceive it as if actually existing there. However, it is still unclear whether we could perceive a virtual image with the setting values for depth (distance and size). In this study, we examined the basic characteristics of depth perception for the AR images by the adjustment method (compared between an AR object and a real object) and the constant method (compared between an AR object and reference of distance). The results of experiments showed the overestimation of depth for a virtual image. In addition, the monocular observation would induce much overestimation than the binocular observation, while the sensitivity of depth improved with occlusion for another side of the eye where the virtual image was not presented. These results would help more appropriate presentation of the virtual image in the AR devices.

We compared the visual fatigue experienced during viewing on a 2D and a 3D television. Twenty participants were individually shown an 80-min clip of the motion picture Avatar on a 2D and a 3D television. Before and after each viewing, the participants completed a questionnaire assessing visual fatigue and discomfort. The visual acuity, accommodation speed and heterophoria of each participant were measured on another day. The results show that the 3D television caused greater visual fatigue than when the 2D television was viewed. Substantial individual differences in visual fatigue were found between participants in the 3D case and these differences varied with the accommodation speed for the non-dominant eye, the difference in visual acuity between eyes and the amount of horizontal heterophoria. Relationships between visual functions and visual fatigue during movie viewing on 3D televisions are discussed.

A method is described for analyzing the image disparity of 3D video. This method was used to analyze the image disparity characteristics of forty 3D movies. The percentage of image disparities that were out-of-range by one degree or more was higher in the convergent direction than in the divergent direction. Characteristics of the image disparity for 3D video are discussed in relation to the results.

To prevent vehicle-pedestrian accident, this paper aimed to reveal the characteristics of unsafe driver behaviors when passing through a parked vehicle. Based on the interview with a driving instructor concerning desirable driver behavior, the lateral distance to a parked vehicle, driver's vehicle speed, and the completion timing of safety checking around a parked vehicle were used as evaluation indices. The instructor extracted unsafe driver behaviors of typical drivers with sitting on the passenger seat. These unsafe behaviors were analyzed in comparison with the instructor's behavior. The analysis revealed the characteristics of unsafe driver behaviors of typical drivers–they do not keep sufficient lateral distance, they do not decrease the speed sufficiently, and they finished a safety checking around a parked vehicle before they can see the blind spot. These unsafe driver behaviors must occur because unsafe typical drivers cannot correctly predict when a pedestrian appears that may crash against the driver's vehicle, or they cannot correctly understand how they should keep the vehicle speed and the lateral distance to a parked vehicle in order to avoid the crash. Finally, the examination of driver behavior patterns estimated the proportion of these factors in relation to the whole unsafe driver behaviors.