Luminance texture boundaries and luminance step boundaries are segmented using different mechanisms.
Luminance texture boundaries and luminance step boundaries are segmented using different mechanisms.
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DOI：
10.1016/j.visres.2021.107968
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发表时间：
2022-01
期刊：
影响因子：
1.8
通讯作者：
DiMattina C
中科院分区：
文献类型：
--
作者：
DiMattina C
在自然场景中，两个相邻表面的平均亮度可能不同，而在它们的边界处的亮度没有任何急剧变化，而是由于每个表面内的亮区和暗区的相对比例不同。我们将这种边界称为亮度纹理边界（LTB），在这项研究中，我们研究LTB是否使用不同的机制比亮度阶跃边界（LSB）进行分割。我们开发了一种新的方法来生成亮度纹理边界从自然均匀的纹理，并使用这些自然的LTB刺激的边界分割任务，我们发现，观察者更敏感的相同的亮度差异定义的纹理（LTB）比均匀的亮度步骤（LSB），符合不同的机制的可能性。在第二和第三组实验中，我们表征观察员的性能分割自然LTB的存在下，掩蔽LSB的观察员被指示忽略。我们发现，有很小的影响LTB分割性能的掩蔽LSB。此外，我们发现的任何掩蔽效应都远小于在掩蔽物和目标都是LSB的对照实验中观察到的掩蔽效应，并且远小于假设相同机制的模型预测的掩蔽效应。最后，我们进行第四组边界分割实验，使用人工LTB刺激组成的不同比例的白色和黑色点的边界的相对两侧。我们发现，这些刺激也是非常强大的掩蔽阈上LSB，与我们的结果使用自然刺激，并与我们早期的研究使用类似的刺激。作为一个整体，这些结果表明，视觉系统包含的机制非常适合于检测表面边界，是鲁棒的亮度产生的亮度台阶像那些由阴影形成的亮度差异的干扰。
In natural scenes, two adjacent surfaces may differ in mean luminance without any sharp change in luminance at their boundary, but rather due to different relative proportions of light and dark regions within each surface. We refer to such boundaries as luminance texture boundaries (LTBs), and in this study we investigate whether LTBs are segmented using different mechanisms than luminance step boundaries (LSBs). We develop a novel method to generate luminance texture boundaries from natural uniform textures, and using these natural LTB stimuli in a boundary segmentation task, we find that observers are much more sensitive to identical luminance differences which are defined by textures (LTBs) than by uniform luminance steps (LSBs), consistent with the possibility of different mechanisms. In a second and third set of experiments, we characterize observer performance segmenting natural LTBs in the presence of masking LSBs which observers are instructed to ignore. We show that there is very little effect of masking LSBs on LTB segmentation performance. Furthermore, any masking effects we find are far less than those observed in a control experiment where both the masker and target are LSBs, and far less than those predicted by a model assuming identical mechanisms. Finally, we perform a fourth set of boundary segmentation experiments using artificial LTB stimuli comprised of differing proportions of white and black dots on opposite sides of the boundary. We find that these stimuli are also highly robust to masking by supra-threshold LSBs, consistent with our results using natural stimuli, and with our earlier studies using similar stimuli. Taken as a whole, these results suggest that the visual system contains mechanisms well suited to detecting surface boundaries that are robust to interference from luminance differences arising from luminance steps like those formed by cast shadows.
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DOI：
10.1364/josaa.11.002350
发表时间：
1994-09-01
影响因子：
1.9
作者：
CHUBB, C;ECONOPOULY, J;LANDY, MS
通讯作者：
LANDY, MS
影响因子：
1.8
作者：
Elder, JH;Sachs, AJ
通讯作者：
Sachs, AJ
影响因子：
1.8
作者：
Kingdom, Frederick A. A.;Baldwin, Alex S.;Schmidtmann, Gunnar
通讯作者：
Schmidtmann, Gunnar
影响因子：
1.8
作者：
Arsenault, Elizabeth;Yoonessi, Ahmad;Baker, Curtis, Jr.
通讯作者：
Baker, Curtis, Jr.
影响因子：
4.6
作者：
DiMattina C;Baker CL Jr
通讯作者：
Baker CL Jr