Abstract:We introduce MV-DeepSimNets, a comprehensive suite of deep neural networks designed for multi-view similarity learning, leveraging epipolar geometry for training. Our approach incorporates an online geometry prior to characterize pixel relationships, either along the epipolar line or through homography rectification. This enables the generation of geometry-aware features from native images, which are then projected across candidate depth hypotheses using plane sweeping. Our method geometric preconditioning effectively adapts epipolar-based features for enhanced multi-view reconstruction, without requiring the laborious multi-view training dataset creation. By aggregating learned similarities, we construct and regularize the cost volume, leading to improved multi-view surface reconstruction over traditional dense matching approaches. MV-DeepSimNets demonstrates superior performance against leading similarity learning networks and end-to-end regression models, especially in terms of generalization capabilities across both aerial and satellite imagery with varied ground sampling distances. Our pipeline is integrated into MicMac software and can be readily adopted in standard multi-resolution image matching pipelines.
Abstract:We present three multi-scale similarity learning architectures, or DeepSim networks. These models learn pixel-level matching with a contrastive loss and are agnostic to the geometry of the considered scene. We establish a middle ground between hybrid and end-to-end approaches by learning to densely allocate all corresponding pixels of an epipolar pair at once. Our features are learnt on large image tiles to be expressive and capture the scene's wider context. We also demonstrate that curated sample mining can enhance the overall robustness of the predicted similarities and improve the performance on radiometrically homogeneous areas. We run experiments on aerial and satellite datasets. Our DeepSim-Nets outperform the baseline hybrid approaches and generalize better to unseen scene geometries than end-to-end methods. Our flexible architecture can be readily adopted in standard multi-resolution image matching pipelines.