论文标题

宣言:隐式代表歧管,并以归一流的流量

ManiFlow: Implicitly Representing Manifolds with Normalizing Flows

论文作者

Postels, Janis, Danelljan, Martin, Van Gool, Luc, Tombari, Federico

论文摘要

标准化流(NFS)是灵活的显式生成模型,已被证明可以准确地对复杂的现实世界数据分布进行建模。但是,它们的可逆性限制对存在于嵌入较高维空间的较低维流形的数据分布对数据分布施加限制。实际上,这种缺点通常通过在影响生成样品质量的数据中添加噪声来绕过。与先前的工作相反,我们通过从原始数据分布中生成样本来解决此问题,并有有关扰动分布和噪声模型的全部知识。为此,我们确定对受扰动数据训练的NFS隐式代表了最大似然区域中的歧管。然后,我们提出了一个优化目标,该目标从扰动分布中恢复了歧管上最有可能的点。最后,我们专注于我们利用NF的明确性质的3D点云,即从log-ofikelihood的梯度和对数类样本本身中提取的表面正态,将泊松表面重建应用于精炼生成的点集。

Normalizing Flows (NFs) are flexible explicit generative models that have been shown to accurately model complex real-world data distributions. However, their invertibility constraint imposes limitations on data distributions that reside on lower dimensional manifolds embedded in higher dimensional space. Practically, this shortcoming is often bypassed by adding noise to the data which impacts the quality of the generated samples. In contrast to prior work, we approach this problem by generating samples from the original data distribution given full knowledge about the perturbed distribution and the noise model. To this end, we establish that NFs trained on perturbed data implicitly represent the manifold in regions of maximum likelihood. Then, we propose an optimization objective that recovers the most likely point on the manifold given a sample from the perturbed distribution. Finally, we focus on 3D point clouds for which we utilize the explicit nature of NFs, i.e. surface normals extracted from the gradient of the log-likelihood and the log-likelihood itself, to apply Poisson surface reconstruction to refine generated point sets.

扫码加入交流群

加入微信交流群

微信交流群二维码

扫码加入学术交流群,获取更多资源