Poirson A B, Wandell B A
Department of Psychology, Stanford University, California 94305.
J Opt Soc Am A Opt Image Sci Vis. 1993 Dec;10(12):2458-70. doi: 10.1364/josaa.10.002458.
We have measured how color appearance of square-wave bars varies with stimulus strength and spatial frequency. Observers adjusted the color of a uniform patch to match the color appearance of the bars in square-wave patterns. We used low-to-moderate square-wave patterns, from 1 to 8 cycles per degree (c/deg). The matches are not photoreceptor matches but rather are established at more central neural sites. The signals at the putative central sites obey several simple regularities. The cone contrast of the uniform patch is proportional to square-wave stimulus strength (color homogeneity) and additive with respect to the superposition of equal-frequency square waves containing different colors (color superposition). We use the asymmetric matches to derive, from first principles, three pattern-color-separable appearance pathways. The matches are explained by two spectrally opponent, spatially low-pass mechanisms and one spectrally positive, spatially bandpass mechanism. The spectral mechanisms that we derive are similar to luminance and opponent mechanisms that are derived with entirely different experimental methods.
我们测量了方波条纹的颜色外观如何随刺激强度和空间频率而变化。观察者调整均匀色块的颜色，使其与方波图案中条纹的颜色外观相匹配。我们使用了每度1至8个周期（c/deg）的低到中等方波图案。这些匹配并非光感受器匹配，而是在更中枢的神经部位建立的。假定中枢部位的信号遵循几个简单的规律。均匀色块的锥体对比度与方波刺激强度（颜色均匀性）成正比，并且对于包含不同颜色的等频率方波的叠加是可加性的（颜色叠加）。我们利用不对称匹配，从第一原理出发，推导了三条图案 - 颜色可分离的外观通路。这些匹配由两个光谱对立、空间低通机制和一个光谱正性、空间带通机制来解释。我们推导的光谱机制类似于通过完全不同的实验方法推导出来的亮度和对立机制。
