Papers › Learning 3D Representations from 2D Pre-trained Models via Image-to-Point Masked Autoencoders

Learning 3D Representations from 2D Pre-trained Models via Image-to-Point Masked Autoencoders

13 Dec 2022CVPR 2023 1arXiv:2212.06785archive 2025-07-28

Renrui Zhang, Liuhui Wang, Yu Qiao, Peng Gao, Hongsheng Li

Pre-training by numerous image data has become de-facto for robust 2D representations. In contrast, due to the expensive data acquisition and annotation, a paucity of large-scale 3D datasets severely hinders the learning for high-quality 3D features. In this paper, we propose an alternative to obtain superior 3D representations from 2D pre-trained models via Image-to-Point Masked Autoencoders, named as I2P-MAE. By self-supervised pre-training, we leverage the well learned 2D knowledge to guide 3D masked autoencoding, which reconstructs the masked point tokens with an encoder-decoder architecture. Specifically, we first utilize off-the-shelf 2D models to extract the multi-view visual features of the input point cloud, and then conduct two types of image-to-point learning schemes on top. For one, we introduce a 2D-guided masking strategy that maintains semantically important point tokens to be visible for the encoder. Compared to random masking, the network can better concentrate on significant 3D structures and recover the masked tokens from key spatial cues. For another, we enforce these visible tokens to reconstruct the corresponding multi-view 2D features after the decoder. This enables the network to effectively inherit high-level 2D semantics learned from rich image data for discriminative 3D modeling. Aided by our image-to-point pre-training, the frozen I2P-MAE, without any fine-tuning, achieves 93.4% accuracy for linear SVM on ModelNet40, competitive to the fully trained results of existing methods. By further fine-tuning on on ScanObjectNN's hardest split, I2P-MAE attains the state-of-the-art 90.11% accuracy, +3.68% to the second-best, demonstrating superior transferable capacity. Code will be available at https://github.com/ZrrSkywalker/I2P-MAE.

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zrrskywalker/i2p-mae officialmentioned in papermentioned on GitHubpytorch report
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index_points zrrskywalker/point-m2ae/models/modules.py community (archive-listed) ran · fixture could not drive it MIT (permissive) · 449a0265144f6530 · report
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timeit zrrskywalker/point-m2ae/segmentation/pointnet2_utils.py community (archive-listed) unverified MIT (permissive) · b1227ddb721e2999 · report

Tasks

3D Point Cloud Classification3D Point Cloud Linear ClassificationDecoderFew-Shot 3D Point Cloud Classification

Results from the paper archive 2025-07-28

TaskDatasetModelMetricValueRank at snapshotLeaderboardReport
3D Point Cloud Classification ScanObjectNN I2P-MAE (no voting) OBJ-BG (OA) 94.15 #21 of 77 Archive leaderboard report
3D Point Cloud Classification ScanObjectNN I2P-MAE (no voting) OBJ-ONLY (OA) 91.57 #21 of 77 Archive leaderboard report
3D Point Cloud Classification ScanObjectNN I2P-MAE (no voting) Overall Accuracy 90.11 #21 of 77 Archive leaderboard report
3D Point Cloud Linear Classification ModelNet40 I2P-MAE Overall Accuracy 93.4 #3 of 20 Archive leaderboard report
Few-Shot 3D Point Cloud Classification ModelNet40 10-way (10-shot) I2P-MAE Overall Accuracy 92.6 #15 of 31 Archive leaderboard report
Few-Shot 3D Point Cloud Classification ModelNet40 10-way (10-shot) I2P-MAE Standard Deviation 5.0 #15 of 31 Archive leaderboard report
Few-Shot 3D Point Cloud Classification ModelNet40 10-way (20-shot) I2P-MAE Overall Accuracy 95.5 #12 of 31 Archive leaderboard report
Few-Shot 3D Point Cloud Classification ModelNet40 10-way (20-shot) I2P-MAE Standard Deviation 3.0 #12 of 31 Archive leaderboard report
Few-Shot 3D Point Cloud Classification ModelNet40 5-way (10-shot) I2P-MAE Overall Accuracy 97.0 #11 of 30 Archive leaderboard report
Few-Shot 3D Point Cloud Classification ModelNet40 5-way (10-shot) I2P-MAE Standard Deviation 1.8 #11 of 30 Archive leaderboard report
Few-Shot 3D Point Cloud Classification ModelNet40 5-way (20-shot) I2P-MAE Overall Accuracy 98.3 #10 of 30 Archive leaderboard report
Few-Shot 3D Point Cloud Classification ModelNet40 5-way (20-shot) I2P-MAE Standard Deviation 1.3 #10 of 30 Archive leaderboard report

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Methods

SVM

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