Self-Supervised Enhancement for Depth from a Lightweight ToF Sensor with Monocular Images
This addresses the cost-effective depth enhancement problem for applications using lightweight sensors, but it is incremental as it builds on existing self-supervised depth estimation methods.
The paper tackles the problem of enhancing low-resolution depth maps from lightweight ToF sensors using paired RGB images without groundtruth depth supervision, achieving a large performance boost as verified on NYU and ScanNet datasets.
Depth map enhancement using paired high-resolution RGB images offers a cost-effective solution for improving low-resolution depth data from lightweight ToF sensors. Nevertheless, naively adopting a depth estimation pipeline to fuse the two modalities requires groundtruth depth maps for supervision. To address this, we propose a self-supervised learning framework, SelfToF, which generates detailed and scale-aware depth maps. Starting from an image-based self-supervised depth estimation pipeline, we add low-resolution depth as inputs, design a new depth consistency loss, propose a scale-recovery module, and finally obtain a large performance boost. Furthermore, since the ToF signal sparsity varies in real-world applications, we upgrade SelfToF to SelfToF* with submanifold convolution and guided feature fusion. Consequently, SelfToF* maintain robust performance across varying sparsity levels in ToF data. Overall, our proposed method is both efficient and effective, as verified by extensive experiments on the NYU and ScanNet datasets. The code is available at \href{https://github.com/denyingmxd/selftof}{https://github.com/denyingmxd/selftof}.