3D Recurrent Neural Networks with Context
Fusion for Point Cloud Semantic Segmentation
Abstract. Semantic segmentation of 3D unstructured point clouds remains an open research problem. Recent works predict semantic labels of 3D points by virtue of neural networks but take limited context
knowledge into consideration. In this paper, a novel end-to-end approach
for unstructured point cloud semantic segmentation, named 3P-RNN,
is proposed to exploit the inherent contextual features. First the effi-
cient pointwise pyramid pooling module is investigated to capture local
structures at various densities by taking multi-scale neighborhood into
account. Then the two-direction hierarchical recurrent neural networks
(RNNs) are utilized to explore long-range spatial dependencies. Each recurrent layer takes as input the local features derived from unrolled cells
and sweeps the 3D space along two directions successively to integrate
structure knowledge. On challenging indoor and outdoor 3D datasets,
the proposed framework demonstrates robust performance superior to
state-of-the-arts