Kumar T, Glaser D A
Department of Molecular and Cell Biology, University of California, Berkeley 94720.
Vision Res. 1995 Mar;35(5):657-66. doi: 10.1016/0042-6989(94)00149-g.
Observers usually cannot discriminate the relative depth of a crowded feature with respect to crowding features about 2 arc min distant if all the features have the same luminance. However, stereo thresholds significantly less than 20 arc sec are obtained when the crowded feature is about twice as luminant as the features crowding it. The thresholds depend only upon the ratio of the luminance of the target feature to the luminance of the crowding features and are independent of the absolute luminance of the features. With further increase in the relative luminance of the target feature, the performance eventually deteriorates and this deterioration is not due to difficulty in seeing the features which were individually clearly visible for all the luminances tested. The closest spacing of local crowded features that still allows good stereo discrimination is about the same as the spatial resolution attainable for many luminance-based non-stereo tasks.
如果所有特征具有相同的亮度，观察者通常无法辨别拥挤特征相对于约2角分距离处的拥挤特征的相对深度。然而，当拥挤特征的亮度约为其周围拥挤特征亮度的两倍时，立体视觉阈值会显著小于20角秒。这些阈值仅取决于目标特征的亮度与拥挤特征亮度的比值，而与特征的绝对亮度无关。随着目标特征相对亮度的进一步增加，性能最终会下降，而这种下降并非由于难以看清在所有测试亮度下单独都清晰可见的特征所致。仍然能够实现良好立体视觉辨别的局部拥挤特征的最小间距，与许多基于亮度的非立体视觉任务可达到的空间分辨率大致相同。
