Affine invariant feature matching of oblique images based on multi-branch network

The available wide-baseline image matching algorithms have been prone to failure or only producing few matches, due to the complex affine deformation and perspective distortion. On this basis, we proposed a novel affine invariant feature matching algorithm for oblique stereo images based on multivariate network. In our method, we applied the Hessian algorithm to extract initial feature regions, then we constructed triplet network (TN) model, and obtained affine invariant feature regions through deep learning. To improve the matching performance of similar features, we proposed multilateral constraint loss function to train multi-branch descriptor network (MDN) model, and then generated deep learning descriptors with higher discrimination for image features. Afterwards, the conjugate features were produced by the matching metric of nearest/next distance ratio (NNDR), and eliminated possible mismatch points through random sampling consistency (RANSAC) algorithm. Finally, experiments on oblique stereo images acquired by unmanned aerial vehicle verified the effectiveness of the proposed approach.