Occlusion Boundary and Depth: Mutual Enhancement via Multi-Task Learning

Occlusion Boundary Estimation (OBE) identifies boundaries arising from both inter-object occlusions and self-occlusion within individual objects, distinguishing them from ordinary edges and semantic contours to support more accurate scene understanding.This task is closely related to Monocular Depth Estimation (MDE), which infers depth from a single image, as Occlusion Boundaries (OBs) provide critical geometric cues for resolving depth ambiguities, while depth can conversely refine occlusion reasoning. In this paper, we propose MoDOT, a novel method that jointly estimates depth and OBs from a single image for the first time. MoDOT incorporates a new module, CASM, which combines cross-attention and multi-scale strip convolutions to leverage mid-level OB features for improved depth prediction. It also includes an occlusion-aware loss, OBDCL, which encourages more accurate boundaries in the predicted depth map.Extensive experiments demonstrate the mutual benefits of jointly estimating depth and OBs, and validate the effectiveness of MoDOT's design. Our method achieves state-of-the-art (SOTA) performance on two synthetic datasets and the widely used NYUD-v2 real-world dataset, significantly outperforming multi-task baselines. Furthermore, the cross-domain results of MoDOT on real-world depth prediction—trained solely on our synthetic dataset—yield promising results, preserving sharp OBs in the predicted depth maps and demonstrating improved geometric fidelity compared to competitors. We will release our code, pre-trained models, and dataset at [link].