IS EDGE INFORMATION FOR STEREOACUITY SPATIALLY CHANNELED
IS EDGE INFORMATION FOR STEREOACUITY SPATIALLY CHANNELED
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DOI：
10.1016/0042-6989(89)90045-x
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发表时间：
1989-01-01
期刊：
影响因子：
1.8
通讯作者：
SCHOR, CM
中科院分区：
文献类型：
--
作者：
HECKMANN, T;SCHOR, CM
立体视觉模型通常假设双眼对应是通过两只眼睛的亮度边缘对齐来实现的。然而，构成立体视觉边缘信息的刺激特性尚未定义。三个实验探讨了这些刺激特性的本质。前两个实验测试了局部亮度梯度和空间分量的相对相位是否提供了影响立体灵敏度的边缘位置信息。在实验 1 中，立体阈值随着正弦亮度光栅的空间频率或对比度的增加而降低，但没有发现目标亮度梯度和立体灵敏度之间的简单关系。在实验 2 中，立体阈值对于具有相同空间频率分量的目标是等效的，但最大亮度梯度和其分量的相对空间相位不同。此外，在具有相等最大亮度梯度的不等对比度目标对中，具有较高对比度的目标的立体阈值较低。这些结果表明，亮度梯度和相对空间相位的特性不会独立于空间频率和对比度影响立体灵敏度。实验3直接检验立体敏感性是否依赖于在不同空间尺度上独立检测视差的边缘信息。发现 1F + 5F 复合目标的立体阈值相当于用两个组分中较敏感的组分单独获得的阈值。结合其他人（Halpern 和 Blake，1989；Legge 和 Gu，1989）获得并在实验 1 中复制的对比度和立体阈值之间关系的压缩非线性，实验 3 的结果表明，无论视差检测中使用的亮度不连续性信息的确切性质如何，它都会在不同的空间尺度上独立处理。
Models of stereopsis generally assume that binocular correspondence is achieved through alignment of luminance edges in the two eyes. Yet the stimulus properties which constitute edge information for stereopsis have not been defined. Three experiments explored the nature of these stimulus properties. The first two experiments tested whether local luminance gradient and the relative phase of spatial components supply information about the position of edges which influences stereosensitivity. In Expt 1, stereothresholds were reduced with increased spatial frequency or contrast of sinusoidal luminance gratings, but no simple relationship between target luminance gradient and stereosensitivity was found. In Expt 2, stereothresholds were equivalent for targets having identical spatial frequency components, but differing in maximum luminance gradient and the relative spatial phase of their components. In addition, stereothresholds were lower for the target having the higher contrast in pairs of unequal-contrast targets having equal maximum luminance gradients. These results suggest that the properties of luminance gradient and relative spatial phase do not influence stereosensitivity independently of spatial frequency and contrast. Experiment 3 directly whether stereosensitivity depends on edge information whose disparity is detected independently at different spatial scales. Stereothresholds for 1F + 5F compound targets were found to be equivalent to thresholds obtained separately with the more sensitive of the two components. Taken together with a compressive nonlinearity in the relationship between contrast and stereothreshold obtained by others (Halpern and Blake, 1989; Legge and Gu, 1989) and replicated in Expt 1, the results of Expt 3 indicate that, whatever the exact nature of the luminance discontinuity information utilized in disparity detection, it is processed independently at different spatial scales.