Hideaki Takahira

Dependence on the display methods of change in accommodation and convergence when a target moves along the depth direction

We have studied human behavior while using a small tablet or a digital book in terms of eye movement. These display media are widely used in conditions that cause hand movement, like on a moving bus or train. Therefore, we focused on the tracking accuracy of accommodation and convergence while subjects viewed a display that was moving in the depth direction. We developed an experimental device that measures the lens accommodation and convergence eye movement simultaneously and can be combined with equipment that moves a small tablet or a digital book linearly in the depth direction. We then evaluated changes in accommodation and convergence angle during depth-direction movement with different kinds of display media, fonts and font sizes. The amount of change in accommodation showed a tendency to depend on the display medium and the size of the font, and the type of font to the motion of a depth direction. The change in the angle of convergence was not dependent on the type of display medium, and the size of the font and the type of font depended only on the depth movement of the target. The tendency overshot in the direction approaching a subject was seen.

Extraction of slant character candidates from maps using circular templates

The paper proposes a method for extracting slant characters from complicated background figures efficiently and rapidly. In this method, slant character candidates are extracted using the black pixel density features, that is, matching rate of two different sized circular templates, which are inscribing and circumscribing a target character, with an original image. In order to estimate performance of the proposed method, the method was applied to 41 topographic map images (512/spl times/512 pixels) involving 1032 slant characters. As a result, the average number of character candidates per character was reduced to about 41 candidates, and 94.3% of 1032 slant characters were extracted correctly.

Measurement system of accommodation and convergence at the same time

We have studied human behavior while using a small tablet or a digital book in terms of eye movement. We developed an experimental device that measures the lens accommodation and convergence eye movement simultaneously and can be combined with equipment that moves visual target in the depth direction. We also evaluated its measurement accuracy.

Development of Measurement System of Changes in Accommodation and Convergence at the Same Time and Measurement of Its Accuracy

We have studied human behavior while using a small tablet or a digital book in terms of eye movement. We developed an experimental device that measures the lens accommodation and convergence eye movement simultaneously and can be combined with equipment that moves visual target in the depth direction. We also evaluated its measurement accuracy.

Analysis of Gazing Points while Viewing Super-High-Definition Images at Various Viewing Positions

We conducted an experiment in which subjects viewed a 4K-resolution image shown on a big screen displayed at different viewing positions, we then analyzed gazing point at the respective positions. The study design included two viewing distances 0.75H (51cm, H is the display height) and 1.5H (102cm), and three viewing positions (center, right and left) as the parameters for subjects viewing the experimental images. Gaze movement while viewing three types of image at each of the 6 positions was measured by the viewers eye and head movements. Results showed the distributions of gazing points were spread over the whole screen, and the locations of average gazing points were gathered in the screen center irrespective of the picture, viewing distance, or viewing position. However there was a significant difference in viewing position on the screen depending on the kind of picture, viewing distance, and viewing position as a result of 3-factor analysis of variance.

Development of an Empathy Measuring System while Watching Images

Gaze movement is the combination of head movement and eye movement when viewing images. The development of big screen displays in recent years has been remarkable, and it is thought that people move their heads more aggressively when viewing images on a big screen. Moreover, people can often view more than one image at a time on a big screen display, or on the big screen in a movie theater. It is assumed that there is a change in gaze movement depending on viewing location. Based on this, we developed a measuring system that can measure the gaze movement of two people simultaneously. The system is based on head and eye movement measures we developed previously. We hypothesize that it will be possible to measure the degree of coincidence of the viewing location and cooperativeness of the gaze movement of the two viewers using this measuring system.