2004 Volume 88 Issue 5 Pages 274-280
We have proposed a new estimation method for a perceived brightness of a room based on the concept of the recognized visual space of illumination, or RVSI. We use the term ‘brightness size’ of RVSI to express an observer’s perception of the intensity of illumination. We define the border luminance between surface color and unnatural surface color modes as the brightness size of RVSI. Our previous work1) showed that the border luminance was proportional to the illuminance of a room and that was equal to the luminance of the brightest object in the room. We measured the border luminance in two differently decorated rooms to test the effect of the highest lightness of object. One room was furnished with white walls and various lightness objects from black to white (environment N). The other was furnished with black walls and objects whose Munsell Value were 5 or less (environment L). Although the illuminances of two rooms was the same, the border luminance in environment L was a half of that in environment N. Contrary to our previous result, the border luminance in environment L was higher than the luminance of the brightest object. We also compared the border luminance among three different positions where the local contrast and the local illuminance were different. The border luminance was almost constant regardless of the measuring position, suggesting that the local environments have little effect on the perceived brightness of a room.
