Cannon M W
Vision Res. 1984;24(9):1049-55. doi: 10.1016/0042-6989(84)90082-8.
The exponents of perceived contrast functions determined for sine wave gratings varied from 1.1, when perceived contrasts were estimated over a 0.6 log unit range of stimulus contrast, to 0.56 when perceived contrasts were estimated over a 1.9 log unit range of stimulus contrast. Intermediate stimulus contrast ranges produced intermediate exponents. This contrast range effect appears to account for the different exponents reported in previous magnitude estimation studies and for the fact that some studies show an exponent increasing with increasing spatial frequency while others do not.
针对正弦波光栅确定的感知对比度函数的指数有所不同，当在0.6对数单位的刺激对比度范围内估计感知对比度时，指数为1.1；而当在1.9对数单位的刺激对比度范围内估计感知对比度时，指数为0.56。中间的刺激对比度范围产生中间的指数。这种对比度范围效应似乎可以解释先前大小估计研究中报告的不同指数，以及一些研究显示指数随空间频率增加而增加而另一些研究则不然这一事实。
