Hidden background cameras used to realize Di-minished Reality (DR), which allows the observer to see through obstacles, are installed behind the obstacles. In order to realize DR, it is necessary to measure the positions of these cameras with respect to the observer's position, but this is difficult because the cameras cannot be seen directly from the observer's position. In this study, two calibration methods, the intersection method and the P4P method, which use the directions of radio waves from radio sources mounted on each camera to measure the positions of the hidden background cameras, are proposed. The intersection method measures the direction from several different points to the hidden background cameras and estimate the 3D position of the hidden background camera as the intersection of the measured directions. The P4P method measures the relative pose between multiple hidden background cameras in advance and uses it as a constraint to estimate the 3D poses of the hidden background cameras. The results showed that the P4P method was more accurate than the intersection method, and able to calibrate the camera with a position error of less than 100 mm.

Free viewpoint video technology, which provides a high sense of presence and immersion by allowing users to view live video from any viewpoint, is increasingly demanded mainly in the entertainment field, as an application that provides new experiences for users. Although there have been many studies on free viewpoint video generation for large-scale spaces, they have focused on generating video for the entire wide-area space. For this reason, challenges still remain in terms of reproduction of object details and real-time video performance of image generation. In this study, for the purpose of developing a system which enables immersion into a moving miniature world, a method to generate high-definition free viewpoint video for small-scale spaces in real time was realized and evaluated. It can generate high-definition free viewpoint images by combining free viewpoint depth images applying noise reduction processing and the corresponding color images considering occlusion and the normal direction of the object's surface. The free viewpoint images generated by the proposed system was evaluated. The results confirmed that consideration of occlusion and the normal direction of the object's surface improved the quality of the generated images. In addition, the realized methods were able to generate clear free viewpoint images even when the free viewpoint approached the object.

With the advent of the information society in recent years, ideas are becoming more and more valuable, and divergent thinking is becoming more and more important. Although there are methods to present visual stimuli to improve divergent thinking, these methods mainly present visual stimuli to the central visual field. The purpose of this study is to test hypotheses about changes in the number and variety of divergent thinking ideas under conditions in which visual stimuli, called geometric Figure animations, are presented in the peripheral visual field. The evaluation experiment was conducted with the participation of 32 university students. We asked them to perform the Alternative Uses Test (AUT) under two conditions: presenting and non-presenting geometric Figure animations in the peripheral visual field. The performance of divergent thinking was evaluated by measuring the number of responses, fluency, and flexibility of the AUT. The scores were standardized because the AUT differed in difficulty depending on each AUT topic. The results showed that all scores were higher in the presenting condition than in the non-presenting condition, and the effect size of the mean difference in flexibility was moderate. On the other hand, according to the results of the questionnaire, most of the participants did not feel that the geometric Figure animations provided any cues for divergent thinking. This suggests that the flexibility of divergent thinking might be improved unconsciously by geometric Figure animations presented in the peripheral visual field.

3D reconstruction from images obtained by RGB-D camera provides a 3D model that reflects the current conditions of nuclear power plants (NPPs), and it is useful for field work support in NPPs. However, machinery equipment and pipes are intricately connected in NPPs and a lot of areas are not photographed because they are occluded by peripheral machines or pipes. It is feasible, but still challenging photographing those areas with RGB-D camera-mounted drones, due to the battery capability and the weight of drones.In this study, 3D reconstruction in cooperation with a lightweight mirror-mounted autonomous drone has been proposed and a novel method for determining drone’s flight path to scan those areas with a mirror has been developed. In this method, suitable locations for scanning the occluded areas with a mirror are detected and connected using multiple paths that are verified as safe to fly.The developed method was evaluated in the simulation environment. The results suggested that the developed method could obtain more points and photograph more occluded areas than the method of repeating random movements and the method to locally search for the optimal direction.

Recently, digital signages are widely utilized to provide information for tourists in plural languages, but it takes longer time to offer information in each language separately. Although simultaneous multilingual display is expected to reduce the time for presentation, there is no guideline for simultaneous multilingual display to keep its legibility. In order to estimate the effect of layout on legibility, the authors prepared contents which have different layout factors and conducted evaluated the legibility of contents with Thurstone’s pairwise comparison. Since the number of combinations in layout factors increases exponentially, the number of stimuli was reduced using an orthogonal table. As a result, significant differences were found in some layout factors and it was found that horizontal arrangement of images and sentences, left alignment in sentences, middle margin from screen edge and medium-sized images made contents more legible.

Pairwise comparison has been widely employed as an easy method for subjective evaluation of several candidates to develop new products or to improve service. In this paper, a method using response time was proposed to improve the accuracy of pairwise comparison. Firstly, a pairwise comparison experiment was conducted to investigate the relationship between response time and difficulty of judgement. Then, a method to improve the accuracy of calculated scales of the objects was proposed where the answer of the pairwise comparison was modified by using the response time and correction function. In this study, three correction functions were compared to find the difference of the accuracy improvement, and two of them showed significant improvement.

As the number of international tourist has been rapidly increasing recently, they have more opportunities to experience different cultures. With the upcoming Olympic game in Tokyo, Japan 2020, digital signage is expected to be utilized for an effective information presentation device for them. This study focuses on the information presentation with four-frame comic for foreign tourists to improve cross-cultural understanding. A subject experiment was conducted to compare four information presentation methods including the four-frame comic from the viewpoint of attractiveness and easy memorization. Participants from various countries watched Japanese food tradition information with four information presentation methods (four-frame comic, photograph, illustration and video) and evaluated their impressions. As a result, it was found that four-frame comic was easy to memorize although its attractiveness was different depending on the participants. However, as the experiment was conducted in a controlled laboratory, it is necessary to conduct a field study using a digital signage in the city to investigate the effective information method.

The energy consumption of commercial and business sector has rapidly increased and saving energy in office building has been encouraged. However, it may not only affect comfort of office workers but also give negative effect on their intellectual productivity. So it is important to evaluate and keep or improve intellectual productivity and authors have been developed the quantitative and objective index of intellectual productivity. In this study, a new working state model including the idea of concentration depth and new index MCTR and CDI were developed from the proposed model. These new index were confirmed by the experiment of varied motivation and data analysis of the past experiment.