The Normalized Eight-Point algorithm has been widely viewed as the cornerstone in two-view geometry computation, where the seminal Hartley's normalization greatly improves the performance of the direct linear transformation (DLT) algorithm. A natural question is, whether there exists and how to find other normalization methods that may further improve the performance as per each input sample. In this paper, we provide a novel perspective and make two contributions towards this fundamental problem: 1) We revisit the normalized eight-point algorithm and make a theoretical contribution by showing the existence of different and better normalization algorithms; 2) We present a deep convolutional neural network with a self-supervised learning strategy to the normalization. Given eight pairs of correspondences, our network directly predicts the normalization matrices, thus learning to normalize each input sample. Our learning-based normalization module could be integrated with both traditional (e.g., RANSAC) and deep learning framework (affording good interpretability) with minimal efforts. Extensive experiments on both synthetic and real images show the effectiveness of our proposed approach.
翻译:标准化八点算法被广泛视为计算两个视图几何关系的基石, 其中经典的Hartley标准化极大地改善了直接线性变换算法的性能。一个自然的问题是,是否存在且如何找到其他规范化方法以按每个输入样本进一步提高性能。在本文中, 我们提供了一个新的视角,并作出了两种贡献:
1) 我们重新审视了标准化八点算法,并通过展示不同且更好的标准化算法的存在而做出了理论上的贡献;
2) 我们提出了一种带有自监督学习策略的深度卷积神经网络。给定八对对应关系,我们的网络直接预测规范化矩阵,从而学习规范化每个输入样本。我们的基于学习的规范化模块可以与传统方法(例如RANSAC)和深度学习框架(具有良好的可解释性)结合使用,代价极小。大量的实验在合成和真实图像上验证了我们所提出的算法的有效性。