Multimodal Scale Consistency and Awareness for Monocular Self-Supervised Depth Estimation
This addresses scale inconsistency in depth estimation for autonomous driving systems, representing an incremental improvement over existing self-supervised methods.
The paper tackles the problem of scale inconsistency in monocular self-supervised depth estimation for autonomous driving by using GPS data during training to provide a scale signal, resulting in improved scale-consistent depth estimation with performance gains even with low-frequency GPS data.
Dense depth estimation is essential to scene-understanding for autonomous driving. However, recent self-supervised approaches on monocular videos suffer from scale-inconsistency across long sequences. Utilizing data from the ubiquitously copresent global positioning systems (GPS), we tackle this challenge by proposing a dynamically-weighted GPS-to-Scale (g2s) loss to complement the appearance-based losses. We emphasize that the GPS is needed only during the multimodal training, and not at inference. The relative distance between frames captured through the GPS provides a scale signal that is independent of the camera setup and scene distribution, resulting in richer learned feature representations. Through extensive evaluation on multiple datasets, we demonstrate scale-consistent and -aware depth estimation during inference, improving the performance even when training with low-frequency GPS data.