Multiview supervision by registration

This paper presents a semi-supervised learning framework to train a keypoint detector using multiview image streams given the limited number of labeled instances (typically <4%). We leverage three self-supervisionary signals in multiview tracking to utilize the unlabeled data: (1) a keypoint in one view can be supervised by other views via epipolar geometry; (2) a keypoint detection must be consistent across time; (3) a visible keypoint in one view is likely to be visible in the adjacent view. We design a new end-to-end network that can propagate these self-supervisionary signals across the unlabeled data from the labeled data in a differentiable manner. We show that our approach outperforms existing detectors including DeepLabCut tailored to the keypoint detection of non-human species such as monkeys, dogs, and mice.