Tadmor Y, Tolhurst D J
Physiological Laboratory, University of Cambridge, England.
Vision Res. 1994 Feb;34(4):541-54. doi: 10.1016/0042-6989(94)90167-8.
It has been suggested that the second-order statistics of different natural images are all remarkably similar and that neurones and channels in the visual system may exploit this similarity. We have measured the ability of human observers to discriminate changes in these statistics using different natural and synthetic stimulus images and have found that the dependence of their discrimination thresholds upon the reference second-order statistics is similar in form, for both kinds of stimuli. However, there is some variety in the magnitudes of the thresholds for the natural stimulus images; in fact, the second-order statistics of different natural images are more diverse than previously suggested. The discrimination task can be modelled as the discrimination of changes in local contrast within restricted spatial frequency bands and is similar to the discrimination of blur.
有人提出，不同自然图像的二阶统计量都非常相似，并且视觉系统中的神经元和通道可能会利用这种相似性。我们使用不同的自然和合成刺激图像测量了人类观察者辨别这些统计量变化的能力，发现对于这两种刺激，他们的辨别阈值对参考二阶统计量的依赖性在形式上是相似的。然而，自然刺激图像的阈值大小存在一定差异；事实上，不同自然图像的二阶统计量比之前认为的更加多样。辨别任务可以建模为对受限空间频率带内局部对比度变化的辨别，并且类似于模糊辨别。
