NeRF-DetS: Enhancing Multi-View 3D Object Detection with Sampling-adaptive Network of Continuous NeRF-based Representation

As a preliminary work, NeRF-Det unifies the tasks of novel view synthesis and 3D perception, demonstrating that perceptual tasks can benefit from novel view synthesis methods like NeRF, significantly improving the performance of indoor multi-view 3D object detection. Using the geometry MLP of NeRF to direct the attention of detection head to crucial parts and incorporating self-supervised loss from novel view rendering contribute to the achieved improvement. To better leverage the notable advantages of the continuous representation through neural rendering in space, we introduce a novel 3D perception network structure, NeRF-DetS. The key component of NeRF-DetS is the Multi-level Sampling-Adaptive Network, making the sampling process adaptively from coarse to fine. Also, we propose a superior multi-view information fusion method, known as Multi-head Weighted Fusion. This fusion approach efficiently addresses the challenge of losing multi-view information when using arithmetic mean, while keeping low computational costs. NeRF-DetS outperforms competitive NeRF-Det on the ScanNetV2 dataset, by achieving +5.02% and +5.92% improvement in mAP@.25 and mAP@.50, respectively.