This study defines scene illumination as lighting that illuminates an achromatic object and analyzes the effects of changes in the color temperature and illuminance of the scene illumination on the perception of glossiness and hardness in an image. Charts made of characteristic materials were photographed under nine different lighting environments combining three color temperatures (3000 K, 4000 K, and 5000 K) and three illuminations (500 lx, 750 lx, and 1000 lx). The photographed images were used for psychological experiments to analyze the effects of scene illumination on the perception of glossiness and hardness. Results suggested that the illuminance of the scene affected the perception of glossiness independent of the color temperature and that color temperature affected the perception of hardness independent of the illuminance. The relationship between the obtained subjective evaluation values and image features calculated from the images was constructed using regression analysis. Results showed that both glossiness and hardness can be modeled with high accuracy and that the model for hardness is particularly robust against estimation errors in color temperature.

  Several studies have explored the effects of ipRGCs on visual perception. In our previous study, we analyzed the impacts of ipRGCs on color discrimination in central vision through visual experiments using a multispectral projector. We showed that the greater the difference in the amount of stimulus given to ipRGCs, the more the ipRGCs affected color discrimination in central vision. However, previous studies have shown that ipRGCs are located a short distance from the central fossa, and verification in the peripheral vision environment is required to eliminate the influence of macular pigment and other factors. This study examines the influence of ipRGCs on peripheral color discrimination by conducting evaluation experiments using metameric stimulus pairs in the periphery. We selected observers showing less deviation from the sensitivity of standard observers by using "pentamic-metamer pair stimuli." Then, we conducted a color discrimination evaluation experiment using "metameric ipRGC pair stimuli." The results showed that some observers had an increased discrimination rate when the number of ipRGC stimuli increased and the cone and rod stimuli were kept constant. However, some observers attributed the difference in vision to brightness, while others attributed it to color, making it difficult to identify a cue for discrimination.

  In Japan, color education in art classes of schools is based on the trichromacy of color vision so color-deficient pupils and students often struggle and feel inferior to using colors. The purpose of this study was to identify the subjects to investigate with promoting color education in art classes that are based on color vision diversity by assessing the actual situation and clarifying the issues. As a method, we had a questionnaire survey to the schoolteachers of art and got answers from 210 teachers. As a result, we found 4 subjects for future investigations: 1) the guarantee for teacher’s education to learn color vision, color deficient and color vision diversity, 2) the creation of the guidelines for color education based on color vision diversity in art class, 3) development of the criteria for evaluation of the artworks created by pupils and students with diverse color visions, and 4) development of the education program even elementary school kids can learn color vision diversity through their experiences. We will promote the studies based on the 4 subjects.

  The differences in color discrimination ability between dominant and non-dominant eyes in humans and their effects on color discrimination in both eyes are unclear. In this study, we examined the effects of dominant and non-dominant eyes on the color discrimination ability of both eyes. In this study, the color discrimination abilities of both eyes, the right eye and the left eye, were measured using the Famsworth-Munsell (FM) 100 hue test on 30 normal color vision subjects. The dominant eye was also determined by the Miles method. The results of the FM 100 hue test showed no statistically significant differences between the dominant and non-dominant eyes. On the other hand, multiple regression analysis showed that unlike the dominant eye, the non-dominant eye had a significant influence on the color discrimination ability of both eyes in all the analyzed items of the FM 100 hue test (p<0.01 respectively). The present study revealed that the color discrimination abilities of the dominant and non-dominant eyes were similar. Moreover, it was suggested that the non-dominant eye may be more influential to both eyes in color discrimination.

  Gourmet websites featuring user-generated media host a blend of photos from restaurants and users. The impression derived from each photo varies. However, simultaneous images portraying favorable and unfavorable aspects of the same restaurant often lead to an unclear overall impression for users. Previous studies analyzing the overall impression formed by combining elements with different impressions have solely focused on assessing the influence of each element on the overall impression. Further, previous studies have overlooked the impact of the overall color characteristics resulting from combining images. Therefore, this study aims to elucidate the overall impression of combined images by examining the color similarity among the images and the impression conveyed by each image. The results indicate that when the average impression of luxury for each combined image is high, color similarity among images becomes more important. Conversely, when the average impression of luxury is moderate, the influence of the image with the highest impression of luxury becomes more pronounced. This study addresses a common yet previously unexplored scenario where multiple images are simultaneously presented. Additionally, it provides a quantitative analysis of the factors influencing impressions, enhancing understanding in this area.