论文标题
单视对象点云的分类
Classification of Single-View Object Point Clouds
论文作者
论文摘要
自从释放基准数据集(例如ModelNet和Shapenet)以来,对象点云分类引起了极大的研究关注。这些基准测试假设涵盖对象实例的完整表面的点云,为此开发了许多高性能方法。但是,它们的设置偏离了经常在实践中相遇的设置,在这种情况下,由于(自我)阻塞,从任意视图捕获了对象的部分云覆盖物体的部分表面。我们在本文中表明,现有的点云分类器的性能在被考虑的单视图,部分设置下急剧下降。该现象与观察结果一致,即只有在明确指定其在整个表面上的分布时,部分对象表面的语义类别就不太模棱两可。为此,我们主张一个单视图,部分设置,其中监督对象姿势估计的学习应伴随分类。从技术上讲,我们提出了一种基线方法的姿势companied点云分类网络(Papnet);基于SE(3) - 等级卷积,纸页学习了在矢量字段上定义的均值特征的中间姿势转换,这使得随后的分类在类别级别的规范,规范姿势中更加容易(理想情况下)。通过将现有的ModelNet40和Scannet数据集调整为单视图,部分设置可以验证对象姿势估计的必要性和纸巾对现有分类器的优势。
Object point cloud classification has drawn great research attention since the release of benchmarking datasets, such as the ModelNet and the ShapeNet. These benchmarks assume point clouds covering complete surfaces of object instances, for which plenty of high-performing methods have been developed. However, their settings deviate from those often met in practice, where, due to (self-)occlusion, a point cloud covering partial surface of an object is captured from an arbitrary view. We show in this paper that performance of existing point cloud classifiers drops drastically under the considered single-view, partial setting; the phenomenon is consistent with the observation that semantic category of a partial object surface is less ambiguous only when its distribution on the whole surface is clearly specified. To this end, we argue for a single-view, partial setting where supervised learning of object pose estimation should be accompanied with classification. Technically, we propose a baseline method of Pose-Accompanied Point cloud classification Network (PAPNet); built upon SE(3)-equivariant convolutions, the PAPNet learns intermediate pose transformations for equivariant features defined on vector fields, which makes the subsequent classification easier (ideally) in the category-level, canonical pose. By adapting existing ModelNet40 and ScanNet datasets to the single-view, partial setting, experiment results can verify the necessity of object pose estimation and superiority of our PAPNet to existing classifiers.