Information-Theoretic Estimates of Surface-Colour Coding in Natural Scenes

颜色视觉有几个功能，但最重要的一个是帮助我们识别周围世界的物体，即使照明条件可能因场合而异。然而，由于眼睛中只有三类锥体光感受器，眼睛不可能唯一地估计表面的光反射特性。因此，判断有时是错误的。由于这种物理性能的限制和其他感官和知觉的不确定性的影响，预测表面颜色判断的准确性，即观察者的颜色恒定性的程度，是困难的，特别是当表面是复杂的自然场景的一部分。在处理这一问题和相关问题时，我们利用了基于香农信息理论的分析方法，该理论提供了一种客观、定量、面向操作的方式来表示和评估绩效。本建议的总目标是验证这一方法，并将其应用于分析中产生的一些具体问题。这些问题涉及的程度上的差异，在不同的照明下观看自然场景的非彩色和彩色途径，这两个途径上的信息承载能力的不同的空间分辨率的影响，和特性的彩色编码的彩色途径，是最佳的这项任务。

Colour vision has several functions, but one of the most important is in helping us to identify objects in the world around us, even though the lighting conditions may vary from occasion to occasion. With just three classes of cone photoreceptors in the eye, however, it is impossible for the eye to estimate uniquely the light-reflecting properties of surfaces. Judgements will therefore sometimes be wrong. Because of this physical limit on performance and the effects of other sensory and perceptual uncertainties, predicting the accuracy of surface-colour judgments, that is, the degree of observers' colour constancy , is difficult, especially when the surfaces are part of complex natural scenes. In working on this and related issues, we have taken advantage of methods of analysis based on Shannon's information theory, which provides an objective, quantitative, operationally oriented way to represent and assess performance. The general aim of this proposal is to validate this approach and to apply it to some specific questions arising from this analysis. These questions concern the extent of differences in the amount of information carried by achromatic and chromatic pathways in viewing natural scenes under different illuminations, the effects of the different spatial resolutions of these two pathways on information-carrying capacity, and the characteristics of opponent-colour coding in the chromatic pathway that are optimal for this task.