Non-linearities in texture segregation.
Non-linearities in texture segregation.
复制标题
纹理分离的非线性。
DOI：
10.1002/9780470514610.ch16
复制
发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Graham,N
中科院分区：
文献类型：
--
作者：
Graham,N
复杂(非傅立叶，二阶)通道的存在是由视觉纹理区分的区域之间的一些分离特征所提示的。这些复杂的通道由两个由整流型非线性隔开的线性滤波级组成。我们研究了(I)第一级滤波器的空间频率选择性和取向选择性；(Ii)第一级和第二级滤波器的取向优先值与空间频率之间的关系；(Iii)空间合并及其对复杂通道中间的非线性的影响；以及(Iv)复杂和简单线性通道的动力学。一个强烈的非线性也是必要的，以解释感知的区域隔离。这种强烈的非线性可能源于通道之前的早期局部非线性(可能是视网膜光适应)或通道之间的正常化(可能是由于皮质内抑制)。在这两位候选人之间做出决定比我们希望的要困难得多。看来：(I)这种强烈的非线性对简单和复杂通道都有效；(Ii)平均亮度或空间尺度的改变对其的影响可以由灵敏度参数来解释；(Iii)即使在高平均亮度和大尺度的对比度小于25%的情况下，其也可以是显著压缩的；以及(Iv)在更低的对比度中，存在在复杂通道的第二滤波之前起作用的加速非线性。
The existence of complex (non‐Fourier, second‐order) channels is suggested by some characteristics of segregation perceived between regions distinguished by visual texture. These complex channels consist of two linear‐filtering stages separated by a rectification‐type non‐linearity. We have investigated (i) the spatial frequency selectivity and orientation selectivity of their first‐stage filters; (ii) the relationship between the preferred values of orientation and spatial frequency at the first and second filters; (iii) spatial pooling and its implications for the non‐linearity at the middle of the complex channel; and (iv) the dynamics of complex and simple linear channels. An intensive non‐linearity is also necessary to explain perceived region segregation. This intensive non‐linearity might arise from anearly local non‐linearitypreceding the channels (perhaps retinal light adaptation) or fromnormalizationamong the channels themselves (perhaps due to intracortical inhibition). Deciding between these two candidates has been more difficult than we had hoped. It appears that: (i) this intensive non‐linearity operates for both simple and complex channels; (ii) the effects on it of changing mean luminance or spatial scale may be accounted for by a sensitivity parameter; (iii) it can be dramatically compressive even at contrasts less than 25% for high mean luminances and large scales; and (iv) at even lower contrasts there is an accelerating non‐linearity that acts before the second filter of the complex channels.
登录
查看更多内容
影响因子：
1.8
作者：
EJIMA, Y;TAKAHASHI, S
通讯作者：
TAKAHASHI, S
DOI：
10.1364/josaa.8.001330
发表时间：
1991-08-01
影响因子：
1.9
作者：
ANDERSON, SJ;BURR, DC
通讯作者：
BURR, DC
影响因子：
1.8
作者：
P. Werkhoven;G. Sperling;C. Chubb
通讯作者：
P. Werkhoven;G. Sperling;C. Chubb
DOI：
10.1364/josaa.9.001653
发表时间：
1992
期刊：
Journal of the Optical Society of America. A, Optics and image science
影响因子：
--
作者：
Wilson,HR;Richards,WA
通讯作者：
Richards,WA
DOI：
10.1364/josaa.8.001340
发表时间：
1991-08-01
影响因子：
1.9
作者：
ANDERSON, SJ;BURR, DC;MORRONE, MC
通讯作者：
MORRONE, MC