Detection of light transformations and concomitant changes in surface albedo
Detection of light transformations and concomitant changes in surface albedo
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DOI：
10.1167/10.9.1
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发表时间：
2010-01-01
影响因子：
1.8
通讯作者：
Maloney, Laurence T.
中科院分区：
文献类型：
--
作者：
Gerhard, Holly E.;Maloney, Laurence T.
我们报告了两个实验，证明（1）观察者对局部场景统计未捕获的光场变化信息敏感，（2）他们可以使用这些信息来增强对表面反射变化的检测。观察者观看由准直光源照射的多个方向的磨砂表面组成的场景。所有表面都是无色的，所有灯光都是中性的。在第一个实验中，观察者试图区分准直光源方向的微小变化（光变换）与所有表面的反射率的匹配变化（非光变换）。光变化和非光变化共享相同的局部场景统计和边缘比率，但后者与准直源方向的任何变化不一致。我们发现观察者可以分辨小到5度的光变化，灵敏度d' > 1，并准确判断变化的方向。在第二个实验中，我们测量观察者的能力，以检测在一个孤立的表面补丁的表面反射率的变化，无论是在光的变化或表面的变化。观察员更准确地检测孤立的光的变化过程中的变化。灵敏度d'的测量值是两倍多。
We report two experiments demonstrating that (1) observers are sensitive to information about changes in the light field not captured by local scene statistics and that (2) they can use this information to enhance detection of changes in surface albedo. Observers viewed scenes consisting of matte surfaces at many orientations illuminated by a collimated light source. All surfaces were achromatic, all lights neutral. In the first experiment, observers attempted to discriminate small changes in direction of the collimated light source (light transformations) from matched changes in the albedos of all surfaces (non-light transformations). Light changes and non-light changes shared the same local scene statistics and edge ratios, but the latter were not consistent with any change in direction to the collimated source. We found that observers could discriminate light changes as small as 5 degrees with sensitivity d' > 1 and accurately judge the direction of change. In a second experiment, we measured observers' ability to detect a change in the surface albedo of an isolated surface patch during either a light change or a surface change. Observers were more accurate in detecting isolated albedo changes during light changes. Measures of sensitivity d' were more than twice as great.