Effect of the apparent brightness of a space on lightness and saturation perception
56.412, Tuesday, May 14, 2:45 - 6:45 pm, Orchid Ballroom
Yoko Mizokami1, Haruka Maruyama1, Hirohisa Yaguchi1; 1Graduate School of Advanced Integration Science, Chiba University
It is known that color perception of an object is affected by its surround in each attribute, such as the simultaneous contrast effect on hue and lightness and the gamut expansion effect on saturation. Although the effects on a two-dimensional plane have been extensively investigated, those in a three-dimensional space are not well understood. It was reported that the lightness configuration of a room changes the apparent brightness of the space and affects the lightness perception of an object in the room. However, it is not clear if it would also affect to saturation perception. Here, we investigate how lightness and saturation perception are influenced by the brightness perception of surrounding environments. We examined the appearance of a color patch in the miniature room composed of achromatic colors, by color matching with a Munsell color chart. While the illuminance of the rooms was kept the same, the apparent brightness of the room was controlled by changing lightness configurations and surface materials. Five chromatic colors (5R5/6, 5Y5/6, 5G5/6, 5B5/6, 5P5/6) and N5 were used for test patches. We tested conditions with a two-dimensional plane for comparison. Each observer also evaluated the brightness of the rooms by magnitude estimation in a separate session. Results showed that the test patch in the room with low lightness appeared higher in chroma as well as in value, and vice vasa. On the other hand, the difference in the chroma perception of the test patch on planes with lower and higher lightness was smaller than those in the room. It was suggested that the difference in the overall brightness perception of the room affected lightness perception of patches, but did not change their apparent xy chromaticities, resulting in the change of saturation perception.