We present an unsupervised learning framework for simultaneously training single-view depth prediction and optical flow estimation models using unlabeled video sequences. Existing unsupervised methods often exploit brightness constancy and spatial smoothness priors to train depth or flow models. In this paper, we propose to leverage geometric consistency as additional supervisory signals. Our core idea is that for rigid regions we can use the predicted scene depth and camera motion to synthesize 2D optical flow by backprojecting the induced 3D scene flow. The discrepancy between the rigid flow (from depth prediction and camera motion) and the estimated flow (from optical flow model) allows us to impose a cross-task consistency loss. While all the networks are jointly optimized during training, they can be applied independently at test time. Extensive experiments demonstrate that our depth and flow models compare favorably with state-of-the-art unsupervised methods.

这篇论文提出了一种利用几何一致性作为监督信号的无监督学习框架，可以同时训练单视角深度预测和光流估计模型，在训练过程中，所有网络均进行联合优化，在测试时可以单独应用，实验证明该方法与现有的无监督方法相比具有竞争优势。

DF-Net: 无监督联合学习深度和光流，使用交任务一致性