Spatial Filtering Requirements for Gradient-Based Optical Flow Measurement
Spatial Filtering Requirements for Gradient-Based Optical Flow Measurement
复制标题
基于梯度的光流测量的空间滤波要求
DOI：
10.5244/c.12.19
复制
发表时间：
1998
影响因子：
19.5
通讯作者：
W. Christmas
中科院分区：
文献类型：
--
作者：
W. Christmas
当使用基于梯度的方法来确定图像序列的光流场时，通常需要对图像进行一些空间预滤波，特别是对于大的运动值。然而，一般没有给出滤波器的特性。本文从采样理论的角度对运动测量进行了分析。我们展示了在时域中由于采样不足而产生的混叠问题，以及如何通过适当的采样后空间滤波来缓解这个问题。我们还演示了这种滤波和用于生成空间和时间图像强度梯度的方法之间的联系。
When using a gradient-based method to determine the optical flow field for an image sequence, it is generally appreciated that some spatial pre-filtering of the images is usually needed, particularly for large motion values. However the characteristics of the filter are not generally given. In this paper we analyse the motion measurement from the point of view of sampling theory. We show how an aliasing problem can arise due to undersampling in the temporal domain, and how this problem can be alleviated by appropriate post-sampling spatial filtering. We also demonstrate a connection between this filtering and the methods used to generate the spatial and temporal image intensity gradients.