title: Color constancy by asymmetric color matching with real objects in three-dimensional scenes.
abstract: Color matching experiments use, in general, stimuli that are poor representations of the natural world. The aim of this work was to compare the degree of color constancy for a range of illuminant pairs using a new matching technique that uses both real objects and three-dimensional (3-D) real scenes. In the experiment, observers viewed a 3-D real scene through a large beamsplitter that projects on the right-hand side of the scene (match scene), the virtual image of a 3-D object (match object) such it appeared part of the scene. On the left-hand side of the scene (test scene), observers viewed a symmetrical scene containing a test object identical to the match object. Test and match objects were both surrounded by the same reflectances with identical spatial arrangement. The illuminant on the test scene had always a correlated color temperature of 25,000 K. The illuminant on the match scene could be any of seven different illuminants with correlated color temperatures in the range 25,000 K-4000 K. In each trial, the observers, who were instructed to perform surface color matches, adjusted the illuminant on the match object. Constancy indices were very high (0.81-0.93), varied with the color of the match object, and increased with the extent of the illuminant change. Observer's mismatches, however, were independent of the extent of the illuminant change.
authors.affiliation: Remote Sensing Unit/Department of Physics, University of Beira Interior, 6201-001 Covilhã, Portugal. vasco@dfisica.ubi.pt
authors.forename: Vasco M N
authors.initials: VM
authors.lastname: de Almeida
authors.forename: Paulo T
authors.initials: PT
authors.lastname: Fiadeiro
authors.forename: Sérgio M C
authors.initials: SM
authors.lastname: Nascimento
mesh_terms: D003118:Color Perception / Q000502:physiology*; D003867:Depth Perception / Q000502:physiology*; D006801:Humans; D008029:Lighting; D010364:Pattern Recognition, Visual; D012016:Reference Values