Rotation equivariance has recently become a strongly desired property in the 3D deep learning community. Yet most existing methods focus on equivariance regarding a global input rotation while ignoring the fact that rotation symmetry has its own spatial support. Specifically, we consider the object detection problem in 3D scenes, where an object bounding box should be equivariant regarding the object pose, independent of the scene motion. This suggests a new desired property we call object-level rotation equivariance. To incorporate object-level rotation equivariance into 3D object detectors, we need a mechanism to extract equivariant features with local object-level spatial support while being able to model cross-object context information. To this end, we propose Equivariant Object detection Network (EON) with a rotation equivariance suspension design to achieve object-level equivariance. EON can be applied to modern point cloud object detectors, such as VoteNet and PointRCNN, enabling them to exploit object rotation symmetry in scene-scale inputs. Our experiments on both indoor scene and autonomous driving datasets show that significant improvements are obtained by plugging our EON design into existing state-of-the-art 3D object detectors.

提出了一种具有对象级旋转等变性的3D物体检测器，EON，其通过旋转等变性悬挂设计来提取具有局部对象级空间支持并能够建模交叉对象上下文信息的等变特征，可应用于现代点云物体检测器，如VoteNet和PointRCNN，以利用场景尺度下的物体旋转对称性，能够显著提高现有最先进3D物体检测器的表现。

3D物体检测的旋转等变性