Improving Semantic Correspondence with Viewpoint-Guided Spherical Maps
Authors: Octave Mariotti, Oisin Mac Aodha, Hakan Bilen

Recent self-supervised models produce visual features that are not only effective at encoding image-level but also pixel-level semantics. They have been reported to obtain impressive results for dense visual semantic correspondence estimation even outperforming fully-supervised methods. Nevertheless these models still fail in the presence of challenging image characteristics such as symmetries and repeated parts. To address these limitations we propose a new semantic correspondence estimation method that supplements state-of-the-art self-supervised features with 3D understanding via a weak geometric spherical prior. Compared to more involved 3D pipelines our model provides a simple and effective way of injecting informative geometric priors into the learned representation while requiring only weak viewpoint information. We also propose a new evaluation metric that better accounts for repeated part and symmetry-induced mistakes. We show that our method succeeds in distinguishing between symmetric views and repeated parts across many object categories in the challenging SPair-71k dataset and also in generalizing to previously unseen classes in the AwA dataset.