CONTRAST CONSTANCY - DEBLURRING IN HUMAN VISION BY SPATIAL FREQUENCY CHANNELS
CONTRAST CONSTANCY - DEBLURRING IN HUMAN VISION BY SPATIAL FREQUENCY CHANNELS
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DOI：
10.1113/jphysiol.1975.sp011162
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发表时间：
1975-01-01
影响因子：
5.5
通讯作者：
SULLIVAN, GD
中科院分区：
文献类型：
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作者：
GEORGESON, MA;SULLIVAN, GD
人类对对比度的感知是通过主观对比度匹配技术来测量的，并与阈值测量定义的对比敏感度进行比较。 2. 尽管光学和神经因素的衰减导致对比度阈值存在较大差异，但不同空间频率之间的对比度匹配仍然正确执行（特别是在高于 5 c/deg 的频率下）。 3.不同宽度的单线之间的对比度匹配也是真实的，并且不受阈值处存在的空间整合（里科定律）的限制。对光栅的适应改变了线条的外观，这可以用傅里叶术语来最好地理解。 4. 这些结果的一般性是通过匹配经过滤波的图像对比度来显示的，每个图像都包含一个倍频程的空间频率。 5. 在阈值和分辨率的限制内，对比度匹配在很大程度上与视网膜上的亮度和位置无关。 6. 十一名散光观察者中有六人对其对比敏感度方面的方向特异性神经缺陷表现出相当大的阈上补偿。 7. 这些结果定义了视觉的一个新特性：对比度恒定性。有人认为，视觉皮层中的空间频率通道的组织是为了补偿早期的衰减。这实现了图像的戏剧性“去模糊”，并优化了视觉清晰度。
The perception of contrast was measured in humans by a technique of subjective contrast‐matching, and was compared with contrast sensitivity as defined by threshold measures. 2. Contrast‐matching between different spatial frequencies was performed correctly (especially at frequencies above 5 c/deg) despite the attenuation by optical and neural factors which cause large differences in contrast thresholds. 3. Contrast‐matching between single lines of different widths was also veridical, and was not limited by the spatial integration (Ricco's Law) present at threshold. Adaptation to gratings altered the appearance of lines, and this could be best understood in Fourier terms. 4. The generality of these results was shown by matching the contrast of pictures which had been filtered so that each contained a one octave band of spatial frequencies. 5. Within the limits imposed by threshold and resolution, contrast‐matching was largely independent of luminance and position on the retina. 6. Six out of eleven astigmatic observers showed considerable suprathreshold compensation for their orientation‐specific neural deficit in contrast sensitivity. 7. These results define a new property of vision: contrast constancy. It is argued that spatial frequency channels in the visual cortex are organized to compensate for earlier attenuation. This achieves a dramatic 'deblurring' of the image, and optimizes the clarity of vision.