Three-stage generative network for single-view point cloud completion

3D shape completion from single-view scan is an important task for follow-up applications such as recognition and segmentation, but it is challenging due to the critical sparsity and structural incompleteness of single-view point clouds. In this paper, a three-stage generative network (TSGN) is proposed for single-view point cloud completion, which generates fine-grained dense point clouds step by step and effectively overcomes the ubiquitous problem-the imbalance between general and individual characteristics. In the first stage, an encoder-decoder network consumes a partial point cloud and generates a rough sparse point cloud inferring the complete geometric shape. Then, a bi-channel residual network is designed to refine the preliminary result with assistance of the original partial input. A local-based folding network is introduced in the last stage to extract local context information from the revised result and build a dense point cloud with finer-grained details. Experiments on ShapeNet dataset and KITTI dataset validate the effectiveness of TSGN. The results on ShapeNet demonstrate the competitive performance on both CD and EMD.