Abstract
The visual system has an ability to segregate a figure in a multi-colored texture by grouping similar colors. Chromatic properties of this figure segregation, however, have not been fully investigated as compared with the luminance-based figure segregation.
The present study aims to reveal chromatic mechanisms underling chromatic figure segregation.
We used a multi-colored texture as a stimulus. It was divided into two regions, test and background regions, having different color distributions. The DKL opponent color space was utilized to define the stimulus. The stimulus color distribution was obtained on an isoluminant azimuth line from the origin of the DKL space. We measured the threshold of angle between the test and the background azimuth lines to segregate the test figure from the background. We also measured the thresholds in color discrimination between the test and the background color distributions.
It was found that the mean threshold in figure segregation was about three times as high as that in color discrimination, which means that chromatic figure segregation could not be achieved by small color difference even above color discrimination threshold. The thresholds in the figure segregation and in the color discrimination differently depended on the azimuth line of the background distribution in the DKL space. These results suggest that the chromatic mechanism responsible for figure segregation would not be the same as that for color discrimination, and the chromatic figure segregation might be characterized in the opponent-color mechanism.