Few-Shot Learning of Part-Specific Probability Space for 3D Shape Segmentation
Lingjing Wang,  Xiang Li,  Yi Fang

Recently, deep neural networks are introduced as supervised discriminative models for the learning of 3D point cloud segmentation. Most previous supervised methods require a large number of training data with human annotation part labels to guide the training process to ensure the model's generalization abilities on test data. In comparison, we propose a novel 3D shape segmentation method that requires few labeled data for training. Given an input 3D shape, the training of our model starts with identifying a similar 3D shape with part annotations from a mini-pool of shape templates (e.g. 10 shapes). With the selected template shape, a novel Coherent Point Transformer is proposed to fully leverage the power of a deep neural network to smoothly morph the template shape towards the input shape. Then, based on the transformed template shapes with part labels, a newly proposed Part-specific Density Estimator is developed to learn a continuous part-specific probability distribution function on the entire 3D space with a batch consistency regularization term. With the learned part-specific probability distribution, our model is able to predict the part labels of a new input 3D shape in an end-to-end manner. We demonstrate that our proposed method can achieve remarkable segmentation results on the ShapeNet dataset with few shots, compared to previous supervised learning approaches.