Abstract
The costly and time-consuming annotation process to produce large training sets for modelling semantic LiDAR segmentation methods has motivated the development of semi-supervised learning (SSL) methods. However, such SSL approaches often concentrate on employing consistency learning only for individual LiDAR representations. This narrow focus results in limited perturbations that generally fail to enable effective consistency learning. Additionally, these SSL approaches employ contrastive learning based on the sampling from a limited set of positive and negative embedding samples. This paper introduces a novel semi-supervised LiDAR semantic segmentation framework called ItTakesTwo (IT2). IT2 is designed to ensure consistent predictions from peer LiDAR representations, thereby improving the perturbation effectiveness in consistency learning. Furthermore, our contrastive learning employs informative samples drawn from a distribution of positive and negative embeddings learned from the entire training set. Results on public benchmarks show that our approach achieves remarkable improvements over the previous state-of-the-art (SOTA) methods in the field. https://github.com/yyliu01/IT2.
Y. Liu and Y. Chen—Denotes equal contribution.
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Notes
- 1.
Cluster hypothesis (or assumption) [42]: the data of various forms that behave similarly with respect to information relevance should be clustered together.
- 2.
Range-to-point projection can lead to information loss [45], which is typically mitigated by post-processing with K-Nearest Neighbors (KNN). In pursuit of efficiency, our IT2 does not use any post-processing during training.
- 3.
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The project is supported by the Australian Research Council (ARC) through grant FT190100525.
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Liu, Y., Chen, Y., Wang, H., Belagiannis, V., Reid, I., Carneiro, G. (2025). ItTakesTwo: Leveraging Peer Representations for Semi-supervised LiDAR Semantic Segmentation. In: Leonardis, A., Ricci, E., Roth, S., Russakovsky, O., Sattler, T., Varol, G. (eds) Computer Vision – ECCV 2024. ECCV 2024. Lecture Notes in Computer Science, vol 15059. Springer, Cham. https://doi.org/10.1007/978-3-031-73232-4_5
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