Time-lapse ratios of cone excitations in natural scenes
Time-lapse ratios of cone excitations in natural scenes
复制标题
DOI：
10.1016/j.visres.2015.03.012
复制
发表时间：
2016-03-01
期刊：
影响因子：
1.8
通讯作者：
Nascimento, Sergio M. C.
中科院分区：
文献类型：
--
作者：
Foster, David H.;Amano, Kinjiro;Nascimento, Sergio M. C.
自然环境中的光照在一天中是不同的。关于表面颜色的稳定推断可能是由反射光的锥激发的空间比支持的，但它们的不变性仅被量化为照明光谱的全局变化。这里的目的是测试它们在光照光谱和几何形状的自然变化下的不变性，特别是在阴影分布方面。获取5个室外植被和非植被场景的时移高光谱辐射图像。从每个场景中随机抽取10,000对点，并测量其随时间变化的比例。比率的平均相对偏差通常很大，但当采样限于短距离或中等时间间隔时，它们低于检测违反比率不变性的水平。当不考虑几何形状不均匀引起的光照变化时，它们进一步下降，达到仅在全局光照光谱变化时获得的水平。在采样约束下，尽管场景照明的光谱和几何变化，锥体激发的比率以及对手颜色组合为稳定的表面颜色推断提供了近似不变的信号。(C) 2015年作者。Elsevier Ltd.出版。
The illumination in natural environments varies through the day. Stable inferences about surface color might be supported by spatial ratios of cone excitations from the reflected light, but their invariance has been quantified only for global changes in illuminant spectrum. The aim here was to test their invariance under natural changes in both illumination spectrum and geometry, especially in the distribution of shadows. Time-lapse hyperspectral radiance images were acquired from five outdoor vegetated and non vegetated scenes. From each scene, 10,000 pairs of points were sampled randomly and ratios measured across time. Mean relative deviations in ratios were generally large, but when sampling was limited to short distances or moderate time intervals, they fell below the level for detecting violations in ratio invariance. When illumination changes with uneven geometry were excluded, they fell further, to levels obtained with global changes in illuminant spectrum alone. Within sampling constraints, ratios of cone excitations, and also of opponent-color combinations, provide an approximately invariant signal for stable surface-color inferences, despite spectral and geometric variations in scene illumination. (C) 2015 The Authors. Published by Elsevier Ltd.