Linear mechanisms can produce motion sharpening
Linear mechanisms can produce motion sharpening
复制标题
线性机构可以产生运动锐化
DOI：
10.1016/s0042-6989(01)00170-5
复制
发表时间：
2001
期刊：
影响因子：
1.8
通讯作者：
M. Morgan
中科院分区：
文献类型：
--
作者：
A. Pääkkönen;M. Morgan
人类观察者通常不会意识到来自移动物体的模糊[Nature 284（1980）164]。最近的几份报告甚至表明，模糊的图像在漂移时比静止时更清晰，并提出了不同的非线性机制来解释这种现象[Vision Res.36（1996）2729; Vision Res.38（1998）2099]。我们在这里证明，即使漂移窄带正弦波光栅的失真不能解释的线性机制，这些机制可能有一个重要的作用，在锐化移动边缘。我们首先表明，由一个简单的差分高斯空间滤波器和典型的双相时间脉冲响应函数形成的移动对象的有效空间滤波器可以近似由高斯滤波器的组合。当这个过滤器被应用到移动，高斯模糊的边缘，模糊和锐化的区域被发现在相同的范围内的模糊宽度和速度，最近的实验结果表明，它们存在。一般来说，这意味着滤波器的输出会响应于较小的模糊宽度而显示模糊，并响应于较大的模糊宽度而显示锐化。
Human observers are not normally conscious of blur from moving objects [Nature 284 (1980) 164]. Several recent reports have even shown that blurred images appear sharper when drifting than when stationary and have suggested different non-linear mechanisms to explain this phenomenon [Vision Res. 36 (1996) 2729; Vision Res. 38 (1998) 2099]. We demonstrate here that even though distortions of drifting narrow-band sine-wave gratings cannot be explained by linear mechanisms, these mechanisms may have an important role in sharpening of moving edges. We show first that the effective spatial filter for a moving object that is formed by a simple difference-of-Gaussians spatial filter and the typical biphasic temporal impulse response function can be approximated by a combination of Gaussian filters only. When this filter is applied to moving, Gaussian-blurred edges, regions of blurring and sharpening are found over the same ranges of blur widths and velocities where recent experimental findings have shown them to exist. In general, that means that the output of the filter shows blurring in response to small blur widths and sharpening in response to larger blur widths.