de Almeida Vasco M N, Fiadeiro Paulo T, Nascimento Sérgio M C
Remote Sensing Unit/Department of Physics, University of Beira Interior, 6201-001 Covilhã, Portugal.
Vis Neurosci. 2004 May-Jun;21(3):341-5. doi: 10.1017/s0952523804213074.
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.
一般来说，颜色匹配实验所使用的刺激物并不能很好地呈现自然世界。这项工作的目的是使用一种新的匹配技术来比较一系列光源对的颜色恒常程度，该技术同时使用真实物体和三维（3-D）真实场景。在实验中，观察者通过一个大型分光镜观察一个三维真实场景，分光镜将一个三维物体的虚拟图像投射到场景的右侧（匹配场景），使其看起来像是场景的一部分。在场景的左侧（测试场景），观察者观察一个对称场景，其中包含一个与匹配物体相同的测试物体。测试物体和匹配物体都被相同反射率且空间排列相同的物体包围。测试场景中的光源相关色温始终为25000K。匹配场景中的光源可以是七种不同光源中的任何一种，其相关色温范围在25000K至4000K之间。在每次试验中，被指示进行表面颜色匹配的观察者会调整匹配物体上的光源。恒常指数非常高（0.81 - 0.93），随匹配物体的颜色而变化，并随着光源变化程度的增加而增加。然而，观察者的不匹配与光源变化的程度无关。
