Edge-aware Correlation Learning for Unsupervised Progressive Homography Estimation

Homography estimation aligns image pairs in cross-views, which is a crucial and fundamental computer vision problem. Existing methods only consider correspondences of texture features for homography estimation, leading to unpleasant artifacts and misalignments introduced by mismatches, especially for low-texture image pairs. In contrast to others, we introduce intuitive structural information as an additional clue that is more sensitive to human vision and low-texture scenarios. In this paper, we propose an edge-aware unsupervised progressive network that couples texture and edge correlation to comprehensively explore potential matching features for homography estimation. To explore robust edge and texture features, we employ a multiscale network to capture feature pyramids with different receptive fields. Then, we design an edge-aware correlation module tailored for homography regression, which plugs in multiscale features to capture accurate correlation maps. Specifically, the edge-aware correlation module leverages the feature-selecting strategy for edge features to capture discriminative matching edges and further guides the texture correlation unit to focus on correctly matched textures. Finally, we leverage multiscale edge-aware correlation maps to predict homography progressively from coarse to fine. Experimental results demonstrate that our proposed method improves PSNR by 11.09% on the real large parallax dataset and reduces matching error by 32.04% on the synthetic COCO dataset, yielding more accurate alignment results than previous state-of-the-art methods.