Variance of high contrast textures is sensed using negative half-wave rectification
Variance of high contrast textures is sensed using negative half-wave rectification
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DOI：
10.1016/s0042-6989(00)00007-9
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发表时间：
2000-01-01
期刊：
影响因子：
1.8
通讯作者：
Nam, JH
中科院分区：
文献类型：
--
作者：
Chubb, C;Nam, JH
需要一个校正变换来感知纹理对比度的变化。各种理论和实践的考虑倾向于研究人员假设这种整流是全波，而不是半波。在这里报道的研究中，观察者被要求判断两个纹理补丁中哪一个具有更高的纹理方差。纹理由小方块组成，每个方块都涂有九种不同亮度中的一种。不同的纹理方差是通过操纵的纹理补丁的直方图进行比较。当9个亮度线性范围从0到160 cd/m（2）时，对纹理方差判断的转换中介采用负半波整流器的形式：纹理方差判断仅由被比较纹理中低于平均亮度的亮度的频率确定。然而，当9个亮度的线性范围从60到100 cd/m（2）时，三个观察者中有两个使用全波整流变换进行纹理方差判断;第三个观察者继续使用负半波整流器。低亮度与高亮度在纹理方差判断中所起的出乎意料的不对称作用表明，偏心系统可能在人类感知纹理对比度中起主导作用。(C)2000爱思唯尔科技有限公司版权所有。
A rectifying transformation is required to sense variations in texture contrast. Various theoretical and practical considerations have inclined researchers to suppose that this rectification is full-wave, rather than half-wave. In the studies reported here, observers are asked to judge which of two texture patches has higher texture variance. Textures are composed of small squares, with each square being painted with one of nine different luminances. Different texture variances are achieved by manipulating the histograms of the texture patches to be compared. When the nine luminances range linearly from 0 to 160 cd/m(2), the transformation mediating judgments of texture variance takes the form of a negative half-wave rectifier: texture Variance judgments are determined exclusively by the frequencies of luminances below mean luminance in the textures being compared. However, when the nine luminances range linearly from 60 to 100 cd/m(2), two of three observers use a full-wave rectifying transformation in making texture variance judgments; the third observer continued to use a negative half-wave rectifier. The unexpectedly asymmetric roles played by low versus high luminances in texture variance judgments suggest that the off-center system may play a dominant role in human perception of texture contrast. (C) 2000 Elsevier Science Ltd. All rights reserved.