Detecting animals in natural surroundings: The role of color distributions
Detecting animals in natural surroundings: The role of color distributions
复制标题
检测自然环境中的动物：颜色分布的作用
DOI：
10.1167/11.11.360
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发表时间：
2011
影响因子：
1.8
通讯作者：
Giesel
中科院分区：
文献类型：
--
作者：
Jansen;Giesel
颜色和图案被认为在隐藏中起着躲避捕食者的作用，在展示中起着吸引配偶或警告敌人的作用。动物的颜色和它们的自然环境形成在光谱反射率和照明光谱之间拉长的分布。我们调查颜色分布是否有助于伪装和显示独立的空间信息。我们获得了30张在自然环境中清晰可见的动物图像，以及29张在其背景下隐藏的动物图像。从动物图像中的每个像素以及与动物大致相同宽度的周围环中的每个像素中提取颜色。环绕颜色随机放置在8度正方形的像素中，动物颜色随机放置在1.5× 6度矩形中。随机掩模作为所有图像的平均值。通过在正方形中心随机呈现水平或垂直的矩形，然后用掩模，在持续时间为8.5至100 msec的恒定刺激的2AFC方法中，测量用于区分每种动物颜色分布与其背景分布的持续时间阈值。除了原始的分布，实验还使用了随机显示的等亮度和消色差版本。根据每种条件和每名观察者的每幅图像拟合的心理测量曲线确定阈值。将等亮度阈值与原始分布的阈值进行比较，揭示了仅基于彩色信息是否可以可靠地检测动物分布。将非彩色阈值与原始分布的阈值进行比较，揭示了添加彩色信息是否增强了动物分布的检测。一般来说，两种测试都将图像分为相同的组，可以使用彩色信号检测的动物和不能检测的动物。我们将证明彩色信号的有用性与颜色分布之间的角度差有关。
Coloration and pattern are thought to play roles in crypsis for evading predators, and display for attracting mates or warning enemies. Colors of animals and their natural surroundings form distributions elongated between spectral reflectances and illumination spectra. We investigate whether color distributions contribute to camouflage and display independent of spatial information. We obtained 30 images of animals distinctly visible on the natural surround, and 29 images of animals camouflaged against their background. Colors were extracted from each pixel in the animal's image, and each pixel in the surrounding annulus of roughly the same width as the animal. The surround colors were randomly placed in the pixels of an 8 deg square, and the animal colors randomly in a 1.5× 6 deg rectangle. Random masks were made as averages of all the images. Duration thresholds for discrimination of each animal color distribution from its background distribution, were measured by presenting rectangles randomly as horizontal or vertical in the center of the square, followed by a mask, in a 2AFC method of constant stimuli for durations from 8.5 to 100 msec. Besides the original distributions, the experiment also used isoluminant and achromatic versions of the random displays. Thresholds were determined from psychometric curves fitted to each image for each condition and for each observer. Comparing isoluminant thresholds to thresholds for the original distributions, reveals whether an animal distribution can be reliably detected on the basis of chromatic information alone. Comparing achromatic thresholds to thresholds for the original distributions reveals whether the addition of chromatic information enhances detection of an animal distribution. In general, both tests separated the images into the same groups, animals that could be detected using chromatic signals, and animals that could not. We will show that the usefulness of chromatic signals is related to the angular difference between color distributions.