Donate Arturo, Liu Xiuwen, Collins Emmanuel G
Department of Computer Science, Florida State University, Tallahassee, FL 32306, USA.
IEEE Trans Syst Man Cybern B Cybern. 2011 Feb;41(1):183-95. doi: 10.1109/TSMCB.2010.2049839. Epub 2010 Jun 21.
This paper presents an efficient algorithm to achieve accurate subpixel matchings for calculating correspondences between stereo images based on a path-based matching algorithm. Compared with point-by-point stereo-matching algorithms, path-based algorithms resolve local ambiguities by maximizing the cross correlation (or other measurements) along a path, which can be implemented efficiently using dynamic programming. An effect of the global matching criterion is that cross correlations at all pixels contribute to the criterion; since cross correlation can change significantly even with subpixel changes, to achieve subpixel accuracy, it is no longer sufficient to first find the path that maximizes the criterion at integer pixel locations and then refine to subpixel accuracy. In this paper, by writing bilinear interpolation using integral images, we show that cross correlations at all subpixel locations can be computed efficiently and, thus, lead to a subpixel accuracy path-based matching algorithm. Our results show the feasibility of the method and illustrate significant improvement over existing path-based matching methods.
本文提出了一种高效算法，用于基于基于路径的匹配算法实现精确的亚像素匹配，以计算立体图像之间的对应关系。与逐点立体匹配算法相比，基于路径的算法通过沿路径最大化互相关（或其他度量）来解决局部模糊性，这可以使用动态规划有效地实现。全局匹配准则的一个效果是所有像素处的互相关都对该准则有贡献；由于即使是亚像素变化，互相关也可能发生显著变化，为了实现亚像素精度，先在整数像素位置找到使准则最大化的路径，然后再细化到亚像素精度已不再足够。在本文中，通过使用积分图像编写双线性插值，我们表明可以有效地计算所有亚像素位置的互相关，从而得到一种基于路径的亚像素精度匹配算法。我们的结果表明了该方法的可行性，并说明了与现有的基于路径的匹配方法相比有显著改进。
