ILLUMINATION CONDITION TO PERCEIVE EXACT COLOR IN PICTURES
Grant-in-Aid for Scientific Research (C)
|Allocation Type||Single-year Grants|
Applied optics/Quantum optical engineering
|Research Institution||Ritsumeikan University|
IKEDA Mitsuo Ritsumeikan Univ.Faculty of Sci. and Eng..,Professor, 理工学部, 教授 (30016604)
|Project Period (FY)
1998 – 1999
Completed(Fiscal Year 1999)
|Budget Amount *help
¥1,100,000 (Direct Cost : ¥1,100,000)
Fiscal Year 1999 : ¥1,100,000 (Direct Cost : ¥1,100,000)
|Keywords||color reproduction / color perception / photography / picture taking / observation / color constancy / recognized visual space / illumination / 撮影 / 観測 / 証明認識視空間 / 色画像 / 色順応|
A photographic picture taken under daylight illumination may be observed in a room illuminated by a tungsten lamp. Does an observer sees the color in the picture that was experienced by the photographer? The concept of the recognized visual space of illumination RVSI predicts that it is not so and the picture must be modified for the intended color perception. We obtained the quantity how much modification is needed in the present research, It is composed of three experiments.
Experiment 1 : Shift of recognition axis in RVSI.
A simple stimulus of uniform white was employed and its color was judged under illumination of 12 different colors. The color approximately opponent to the color of illumination was observed in the stimulus to imply the shift of the recognition axis in the RVSI toward the illumination color.
Experiment 2 : Color perception by aged and the color display for young observers.
The color perception changes when people get older due to the yellowing crystalline lenses. Appr
opriate color of the illumination in the observing room was obtained for young observes to experience the exact color perceived by the aged. The experimental principle, method and results are similar to Experiment 3 and the explanation is omitted here.
Experiment 3 : Illumination condition to perceive exact color in pictures.
The amount of modification in color for a picture was obtained in order that the exact color experienced for the scene is to be perceived when the illumination condition was different for the scene and for the observing room. A subject saw inside a room illuminated by L light source for three minutes in the learning phase and he/she moved to another room illuminated with O light source, which is different from L. There slides are projected one by one. The slide pictures were made beforehand for the learning room illuminated by lamp of twenty different color temperature respectively. The subject's task was to choose a slide that gave him/her the color appearance of the learning room. The results showed that the color of the slide chosen is a picture taken under the illumination of which color is just between L and O in the xy chromaticity diagram. The result implies that when one uses a color picture to demonstrate the color of a scene to an observer, the photographer should prepare the picture as if it was taken under the illumination of which color is in the midst between the color of illumination that the photographer experienced and the color of illumination for the observation. Less
Research Output (3results)