COLOR APPEARANCE - NEUTRAL SURROUNDS AND SPATIAL CONTRAST

The experimental data in this paper show that chromatic bars presented in alternation with equiluminant neutral-appearing bars are seen as m ore saturated than the same chromaticity presented as a uniform rectan gle. This effect was diminished but not eliminated when test and match stimuli were presented within a slightly dimmer neutral surround. The test stimulus was a 2 x 5 degrees rectangle with a 0.7 cpd square wav e grating composed of alternating equiluminant chromatic test bars and neutral bars. Asymmetric matching was used to match the test bar appe arance to a uniform 2 x 5 degrees comparison rectangle. Test and compa rison stimuli were presented to separate eyes in a haploscope and appe ared flanking a central fixation target. Data were collected with test and inducing stimuli on the cardinal axes of color space. Test bars s eparated by neutral bars appeared more saturated than the comparison r ectangle for both the l- and s-axis directions. Manipulation of excita tion on one cardinal axis did not affect the appearance matches made f or the other cardinal axis. (C) 1998 Elsevier Science Ltd. All rights reserved.