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Semi-Supervised and Semi-Weakly Supervised ImageNet Models

This project includes the semi-supervised and semi-weakly supervised ImageNet models introduced in "Billion-scale Semi-Supervised Learning for Image Classification"

"Semi-supervised" (SSL) ImageNet models are pre-trained on a subset of unlabeled YFCC100M public image dataset and fine-tuned with the ImageNet1K training dataset, as described by the semi-supervised training framework in the paper mentioned above. In this case, the high capacity teacher model was trained only with labeled examples.

"Semi-weakly" supervised (SWSL) ImageNet models are pre-trained on 940 million public images with 1.5K hashtags matching with 1000 ImageNet1K synsets, followed by fine-tuning on ImageNet1K dataset. In this case, the associated hashtags are only used for building a better teacher model. During training the student model, those hashtags are ingored and the student model is pretrained with a subset of 64M images selected by the teacher model from the same 940 million public image dataset.

We are providing the following semi-supervised and semi-weakly supervised ImageNet models. The teacher models used for training these models have the ResNet-101-32x48 model architecture.

Semi-weakly supervised ResNet and ResNext models provided in the table below significantly improve the top-1 accuracy on the ImageNet validation set compared to training from scratch or other training mechanisms introduced in the literature as of September 2019. For example, We achieve state-of-the-art accuracy of 81.2% on ImageNet for the widely used/adopted ResNet-50 model architecture.

Architecture Supervision #Parameters FLOPS Top-1 Acc. Top-5 Acc.
ResNet-18 semi-supervised 14M 2B 72.8 91.5
ResNet-50 semi-supervised 25M 4B 79.3 94.9
ResNeXt-50 32x4d semi-supervised 25M 4B 80.3 95.4
ResNeXt-101 32x4d semi-supervised 42M 8B 81.0 95.7
ResNeXt-101 32x8d semi-supervised 88M 16B 81.7 96.1
ResNeXt-101 32x16d semi-supervised 193M 36B 81.9 96.2
ResNet-18 semi-weakly supervised 14M 2B 73.4 91.9
ResNet-50 semi-weakly supervised 25M 4B 81.2 96.0
ResNeXt-50 32x4d semi-weakly supervised 25M 4B 82.2 96.3
ResNeXt-101 32x4d semi-weakly supervised 42M 8B 83.4 96.8
ResNeXt-101 32x8d semi-weakly supervised 88M 16B 84.3 97.2
ResNeXt-101 32x16d semi-weakly supervised 193M 36B 84.8 97.4

Loading models with torch.hub

The models are available with torch.hub. As an example, to load the semi-weakly trained ResNet-50 model, simply run:

model = torch.hub.load('facebookresearch/semi-supervised-ImageNet1K-models', 'resnet50_swsl')

Please refer to torch.hub to see a full example of using the model to classify an image.


If you use the models released in this repository, please cite the following publication.

    title={Billion-scale semi-supervised learning for image classification},
    author={I. Zeki Yalniz and Hervé Jégou and Kan Chen and Manohar Paluri and Dhruv Mahajan},


The models in this repository are released under the CC-BY-NC 4.0 license. See LICENSE for additional details.


Semi-supervised ImageNet1K models



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