Higher order texture statistics impair contrast boundary segmentation
Higher order texture statistics impair contrast boundary segmentation
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DOI：
10.1167/11.10.14
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发表时间：
2011-01-01
影响因子：
1.8
通讯作者：
Baker, Curtis, Jr.
中科院分区：
文献类型：
--
作者：
Arsenault, Elizabeth;Yoonessi, Ahmad;Baker, Curtis, Jr.
纹理边界分割通常被认为是由傅里叶能量的全局差异介导的，即低阶纹理统计量。在这里，我们研究了纹理的高阶统计结构在一个简单的二阶分割任务中的重要性。我们测量了从自然场景照片中提取的纹理样本上施加的对比度边界的调制深度阈值，使用边界方向（左与右倾斜）的强制选择判断。我们比较了组成纹理完整或相位混乱的对比度边界的分割阈值。在完整条件下，所有纹理统计量被保留，而在相位置乱条件下，相同纹理的高阶统计量被随机化，但低阶统计量不变。我们发现(1)高阶统计量的存在削弱了对比度边界分割；(2)每一种纹理都有损伤，但有些纹理明显比其他纹理多；(3)我们的发现与扰频引起的可探测性变化无关。单个纹理的相位置乱效应的大小与其振幅谱的变化无关，但我们认为它可能与局部边缘结构或稀疏度的差异有关。
Texture boundary segmentation is conventionally thought to be mediated by global differences in Fourier energy, i.e., low-order texture statistics. Here, we have examined the importance of higher order statistical structure of textures in a simple second-order segmentation task. We measured modulation depth thresholds for contrast boundaries imposed on texture samples extracted from natural scene photographs, using forced-choice judgments of boundary orientation (left vs. right oblique). We compared segmentation thresholds for contrast boundaries whose constituent textures were either intact or phase scrambled. In the intact condition, all the texture statistics were preserved, while in the phase-scrambled condition the higher order statistics of the same texture were randomized, but the lower order statistics were unchanged. We found that (1) contrast boundary segmentation is impaired by the presence of higher order statistics; (2) every texture shows impairment but some substantially more than others; and (3) our findings are not related to scrambling-induced changes in detectability. The magnitude of phase-scrambling effect for individual textures was uncorrelated with variations in their amplitude spectra, but instead we suggest that it might be related to differences in local edge structure or sparseness.