Valberg A, Lange-Malecki B
Department of Physics, University of Oslo, Norway.
Vision Res. 1990;30(3):371-80. doi: 10.1016/0042-6989(90)90079-z.
Edwin Land's Mondrian demonstrations (Land 1977, 1983, 1986a) are striking examples that the perceived colours of objects are largely independent of the chromaticity of the light incident upon them. Attempts to implement this independence in artificial vision systems have renewed interest in colour constancy and contrast, and the explanation of these phenomena in the Retinex theory. We use colour matches to demonstrate that departures from "colour constancy" are large and that it is possible to obtain the same colour shifts when the complex Mondrian pattern is replaced by a homogeneous grey field surrounding a test patch. A given patch has the same colour when surrounded by the Mondrian as when set in a grey background, provided that the grey represents the spatially weighted average of the Mondrian. Neither the colour shifts nor the equivalence of this neutral surround are correctly predicted by the Retinex theory. The phenomenon of partial cancellation of physical chromaticity shifts with changes of illuminant thus reduces to one of simultaneous contrast and adaptation where a spatio-chromatic and luminance average over a Mondrian pattern is the same as for a grey surround. Experiments with simultaneous contrast demonstrate that spatial weighting factors need to be applied in computations of the effect of the separate areas of a complex Mondrian pattern.
埃德温·兰德的蒙德里安演示实验（兰德，1977年、1983年、1986a）是引人注目的例子，表明物体的感知颜色在很大程度上独立于入射光的色度。在人工视觉系统中实现这种独立性的尝试，重新引发了人们对颜色恒常性和对比度以及视网膜皮层理论中对这些现象解释的兴趣。我们通过颜色匹配来证明，与“颜色恒常性”的偏差很大，并且当复杂的蒙德里安图案被围绕测试色块的均匀灰色场取代时，有可能获得相同的颜色偏移。如果灰色代表蒙德里安图案的空间加权平均值，那么给定的色块在被蒙德里安图案包围时与设置在灰色背景中时具有相同的颜色。视网膜皮层理论既没有正确预测颜色偏移，也没有正确预测这种中性背景的等效性。因此，随着光源变化物理色度偏移的部分抵消现象，简化为同时对比和适应现象之一，即蒙德里安图案上空间色度和亮度平均值与灰色背景相同。同时对比实验表明，在计算复杂蒙德里安图案各区域的效果时需要应用空间加权因子。
