PerLDiff: Controllable Street View Synthesis Using Perspective-Layout Diffusion ModelsJinhua Zhang, Hualian Sheng, Sijia Cai et al.
Controllable generation is considered a potentially vital approach to address the challenge of annotating 3D data, and the precision of such controllable generation becomes particularly imperative in the context of data production for autonomous driving. Existing methods focus on the integration of diverse generative information into controlling inputs, utilizing frameworks such as GLIGEN or ControlNet, to produce commendable outcomes in controllable generation. However, such approaches intrinsically restrict generation performance to the learning capacities of predefined network architectures. In this paper, we explore the innovative integration of controlling information and introduce PerLDiff (\textbf{Per}spective-\textbf{L}ayout \textbf{Diff}usion Models), a novel method for effective street view image generation that fully leverages perspective 3D geometric information. Our PerLDiff employs 3D geometric priors to guide the generation of street view images with precise object-level control within the network learning process, resulting in a more robust and controllable output. Moreover, it demonstrates superior controllability compared to alternative layout control methods. Empirical results justify that our PerLDiff markedly enhances the precision of controllable generation on the NuScenes and KITTI datasets.
CascadeV-Det: Cascade Point Voting for 3D Object DetectionYingping Liang, Ying Fu
Anchor-free object detectors are highly efficient in performing point-based prediction without the need for extra post-processing of anchors. However, different from the 2D grids, the 3D points used in these detectors are often far from the ground truth center, making it challenging to accurately regress the bounding boxes. To address this issue, we propose a Cascade Voting (CascadeV) strategy that provides high-quality 3D object detection with point-based prediction. Specifically, CascadeV performs cascade detection using a novel Cascade Voting decoder that combines two new components: Instance Aware Voting (IA-Voting) and a Cascade Point Assignment (CPA) module. The IA-Voting module updates the object features of updated proposal points within the bounding box using conditional inverse distance weighting. This approach prevents features from being aggregated outside the instance and helps improve the accuracy of object detection. Additionally, since model training can suffer from a lack of proposal points with high centerness, we have developed the CPA module to narrow down the positive assignment threshold with cascade stages. This approach relaxes the dependence on proposal centerness in the early stages while ensuring an ample quantity of positives with high centerness in the later stages. Experiments show that FCAF3D with our CascadeV achieves state-of-the-art 3D object detection results with 70.4\% mAP@0.25 and 51.6\% mAP@0.5 on SUN RGB-D and competitive results on ScanNet. Code will be released at https://github.com/Sharpiless/CascadeV-Det