MaskClustering: View Consensus based Mask Graph Clustering for Open-Vocabulary 3D Instance Segmentation
Authors: Mi Yan, Jiazhao Zhang, Yan Zhu, He Wang

Open-vocabulary 3D instance segmentation is cutting-edge for its ability to segment 3D instances without predefined categories. However progress in 3D lags behind its 2D counterpart due to limited annotated 3D data. To address this recent works first generate 2D open-vocabulary masks through 2D models and then merge them into 3D instances based on metrics calculated between two neighboring frames. In contrast to these local metrics we propose a novel metric view consensus rate to enhance the utilization of multi-view observations. The key insight is that two 2D masks should be deemed part of the same 3D instance if a significant number of other 2D masks from different views contain both these two masks. Using this metric as edge weight we construct a global mask graph where each mask is a node. Through iterative clustering of masks showing high view consensus we generate a series of clusters each representing a distinct 3D instance. Notably our model is training-free. Through extensive experiments on publicly available datasets including ScanNet++ ScanNet200 and MatterPort3D we demonstrate that our method achieves state-of-the-art performance in open-vocabulary 3D instance segmentation. Our project page is at \href https://pku-epic.github.io/MaskClustering/  https://pku-epic.github.io/MaskClustering .