Guan Phillip, Banks Martin S
UC Berkeley-UCSF Graduate Program in Bioengineering, Berkeley and San Francisco, CA 94720, USA.
UC Berkeley-UCSF Graduate Program in Bioengineering, Berkeley and San Francisco, CA 94720, USA School of Optometry, Vision Science Program, UC Berkeley, Berkeley, CA 94720, USA
Philos Trans R Soc Lond B Biol Sci. 2016 Jun 19;371(1697). doi: 10.1098/rstb.2015.0253.
Depth constancy is the ability to perceive a fixed depth interval in the world as constant despite changes in viewing distance and the spatial scale of depth variation. It is well known that the spatial frequency of depth variation has a large effect on threshold. In the first experiment, we determined that the visual system compensates for this differential sensitivity when the change in disparity is suprathreshold, thereby attaining constancy similar to contrast constancy in the luminance domain. In a second experiment, we examined the ability to perceive constant depth when the spatial frequency and viewing distance both changed. To attain constancy in this situation, the visual system has to estimate distance. We investigated this ability when vergence, accommodation and vertical disparity are all presented accurately and therefore provided veridical information about viewing distance. We found that constancy is nearly complete across changes in viewing distance. Depth constancy is most complete when the scale of the depth relief is constant in the world rather than when it is constant in angular units at the retina. These results bear on the efficacy of algorithms for creating stereo content.This article is part of the themed issue 'Vision in our three-dimensional world'.
深度恒常性是指尽管观察距离和深度变化的空间尺度发生了改变，仍能将世界中固定的深度间隔感知为恒定的能力。众所周知，深度变化的空间频率对阈值有很大影响。在第一个实验中，我们确定当视差变化超过阈值时，视觉系统会补偿这种差异敏感性，从而实现类似于亮度领域中对比度恒常性的恒常性。在第二个实验中，我们研究了空间频率和观察距离都发生变化时感知恒定深度的能力。为了在这种情况下实现恒常性，视觉系统必须估计距离。我们在准确呈现辐辏、调节和垂直视差并因此提供有关观察距离的真实信息时研究了这种能力。我们发现，观察距离变化时恒常性几乎是完整的。当深度浮雕的尺度在世界中保持恒定时，而不是在视网膜上以角度单位保持恒定时，深度恒常性最为完整。这些结果与创建立体内容的算法的有效性相关。本文是主题为“我们三维世界中的视觉”特刊的一部分。
