Howe Piers D L
Harvard Medical School, 220 Longwood Avenue WAB 232, Boston, MA 02115, USA.
Perception. 2006;35(3):291-301. doi: 10.1068/p5461.
What determines an object's lightness remains unclear, but it is generally thought that the ratios of its luminance to the luminance of other objects in a scene play a crucial role because these ratios allow the relative reflectance of each object to be estimated, providing all the objects are under the same illumination. Because objects that lie in the same plane are typically illuminated equally, it has been suggested that it is the luminance ratios between coplanar objects that primarily determine lightness (Gilchrist, 1977 Science 195 185-187; Gilchrist et al, 1999 Psychological Review 106 795-834). An alternative hypothesis is that perceived illumination differences can affect lightness directly. As the studies that provided evidence for the coplanar ratio hypothesis always varied the illumination and the coplanar relationships simultaneously, it is unclear which hypothesis is correct. I measured the influence of each factor separately and found that the perceived illumination differences have a greater effect on lightness.
是什么决定了物体的明度仍不清楚，但一般认为，在一个场景中，该物体的亮度与其他物体亮度的比率起着关键作用，因为只要所有物体处于相同照明条件下，这些比率就能让人们估算出每个物体的相对反射率。由于位于同一平面的物体通常受到同等照明，因此有人提出，主要是共面物体之间的亮度比率决定了明度（吉尔克里斯特，1977年，《科学》杂志第195卷，第185 - 187页；吉尔克里斯特等人，1999年，《心理学评论》第106卷，第795 - 834页）。另一种假设是，感知到的照明差异会直接影响明度。由于为共面比率假设提供证据的研究总是同时改变照明条件和共面关系，所以不清楚哪种假设是正确的。我分别测量了每个因素的影响，发现感知到的照明差异对明度的影响更大。
