V2PNet: A Voxel-to-Point Network Framework for Task-Oriented Point Cloud Sampling

Task-oriented point cloud sampling is a fundamental technique in 3D computer vision and has become a crucial step in numerous 3D applications. However, most state-of-the-art task-oriented sampling methods adopt a point-wise analysis strategy, making them susceptible to data redundancy. Taking inspiration from the abstract-to-detailed recognition process of the human visual system, we propose a novel voxel-to-point network framework called V2PNet for task-oriented point cloud sampling. Specifically, we first design a lightweight coarse-grained sampling module named Important Voxel Prediction (IMVP). This module adaptively outputs points from significant regions of the point cloud by explicitly modeling inter-region relationships, thereby reducing interference from redundant points. Then, the V2PNet framework seamlessly integrates the IMVP module with existing point-wise and task-oriented sampling networks, enabling joint training with downstream tasks. This creates a task-oriented coarse-to-fine-grained sampling pipeline that effectively samples representative and informative points from significant regions to represent the original point cloud. Moreover, to mitigate disturbances across similar regions, we introduce a voxel simplification loss function to enhance the discriminative voxel prediction. Extensive experiments demonstrate that V2PNet improves the performance of existing state-of-the-art task-oriented sampling models.