MoPro: Webly Supervised Learning with Momentum Prototypes

ICLR 2021  ·  Junnan Li, Caiming Xiong, Steven C. H. Hoi ·

We propose a webly-supervised representation learning method that does not suffer from the annotation unscalability of supervised learning, nor the computation unscalability of self-supervised learning. Most existing works on webly-supervised representation learning adopt a vanilla supervised learning method without accounting for the prevalent noise in the training data, whereas most prior methods in learning with label noise are less effective for real-world large-scale noisy data. We propose momentum prototypes (MoPro), a simple contrastive learning method that achieves online label noise correction, out-of-distribution sample removal, and representation learning. MoPro achieves state-of-the-art performance on WebVision, a weakly-labeled noisy dataset. MoPro also shows superior performance when the pretrained model is transferred to down-stream image classification and detection tasks. It outperforms the ImageNet supervised pretrained model by +10.5 on 1-shot classification on VOC, and outperforms the best self-supervised pretrained model by +17.3 when finetuned on 1\% of ImageNet labeled samples. Furthermore, MoPro is more robust to distribution shifts. Code and pretrained models are available at

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Task Dataset Model Metric Name Metric Value Global Rank Uses Extra
Training Data
Result Benchmark
Image Classification OmniBenchmark MoPro-V2 Average Top-1 Accuracy 36.1 # 13
Image Classification WebVision-1000 MoPro (ResNet-50) Top-1 Accuracy 73.9% # 12
Top-5 Accuracy 90.0% # 10
ImageNet Top-1 Accuracy 67.8% # 4
ImageNet Top-5 Accuracy 87.0% # 4