Párraga C A, Troscianko T, Tolhurst D J
Department of Experimental Psychology, University of Bristol, United Kingdom.
Curr Biol. 2002 Mar 19;12(6):483-7. doi: 10.1016/s0960-9822(02)00718-2.
The human visual system shows a relatively greater response to low spatial frequencies of chromatic spatial modulation than to luminance spatial modulation. However, previous work has shown that this differential sensitivity to low spatial frequencies is not reflected in any differential luminance and chromatic content of general natural scenes. This is contrary to the prevailing assumption that the spatial properties of human vision ought to reflect the structure of natural scenes. Now, colorimetric measures of scenes suggest that red-green (and perhaps blue-yellow) color discrimination in primates is particularly suited to the encoding of specific scenes: reddish or yellowish objects on a background of leaves. We therefore ask whether the spatial, as well as chromatic, properties of such scenes are matched to the different spatial-encoding properties of color and luminance modulation in human vision. We show that the spatiochromatic properties of a wide class of scenes, which contain reddish objects (e.g., fruit) on a background of leaves, correspond well to the properties of the red-green (but not blue-yellow) systems in human vision, at viewing distances commensurate with typical grasping distance. This implies that the red-green system is particularly suited to encoding both the spatial and the chromatic structure of such scenes.
人类视觉系统对彩色空间调制的低空间频率的反应比对亮度空间调制的反应相对更大。然而，先前的研究表明，这种对低空间频率的差异敏感性并未体现在一般自然场景的任何亮度和色彩差异内容中。这与普遍的假设相反，即人类视觉的空间特性应该反映自然场景的结构。现在，场景的色度测量表明，灵长类动物的红绿色（也许还有蓝黄色）颜色辨别特别适合于对特定场景进行编码：树叶背景上的红色或黄色物体。因此，我们要问，此类场景的空间以及色彩特性是否与人类视觉中颜色和亮度调制的不同空间编码特性相匹配。我们表明，在与典型抓握距离相称的观察距离下，一类包含树叶背景上红色物体（如水果）的广泛场景的空间色彩特性与人类视觉中红绿色（而非蓝黄色）系统的特性非常吻合。这意味着红绿色系统特别适合于编码此类场景的空间和色彩结构。
