zwwwayne/switchable-normalization

Switchable Normalization

Switchable Normalization is a normalization technique that is able to learn different normalization operations for different normalization layers in a deep neural network in an end-to-end manner.

Update

• 2018/7/9: We would like to explain the merit behind SN. See html preview or this blog (in Chinese). More trained models and the code of object detection will be released soon!
• 2018/7/4: Model zoo updated!
• 2018/7/2: The code of image classification and a pretrained model on ImageNet are released.

Introduction

This repository provides imagenet classification and object detection results and models trained with Switchable Normalization:

@article{SwitchableNorm,
  title={Differentiable Learning-to-Normalize via Switchable Normalization},
  author={Ping Luo and Jiamin Ren and Zhanglin Peng},
  journal={arXiv:1806.10779},
  year={2018}
}

Overview of Results

Image Classification in ImageNet

Comparisons of top-1 accuracies on the validation set of ImageNet, by using ResNet50 trained with SN, BN, and GN in different batch size settings. The bracket (·, ·) denotes (#GPUs,#samples per GPU). In the bottom part, “GN-BN” indicates the difference between the accuracies of GN and BN. The “-” in (8, 1) of BN indicates it does not converge.

	(8,32)	(8,16)	(8,8)	(8,4)	(8,2)	(1,16)	(1,32)	(8,1)	(1,8)
BN	76.4	76.3	75.2	72.7	65.3	76.2	76.5	–	75.4
GN	75.9	75.8	76.0	75.8	75.9	75.9	75.8	75.5	75.5
SN	76.9	76.7	76.7	75.9	75.6	76.3	76.6	75.0*	75.9
GN−BN	-0.5	-0.5	0.8	3.1	10.6	-0.3	-0.7	–	0.1
SN−BN	0.5	0.4	1.5	3.2	10.3	0.1	0.1	–	0.5
SN−GN	1.0	0.9	0.7	0.1	-0.3	0.4	0.8	-0.5	0.4

*For (8,1), SN contains IN and SN without BN, as BN is the same as IN in training.

Getting Started

• Install PyTorch
• Clone the repo:

  git clone https://github.com/switchablenorms/Switchable-Normalization.git
  

Requirements

• python packages
  • pytorch>=0.4.0
  • torchvision>=0.2.1
  • tensorboardX
  • pyyaml

Data Preparation

• Download the ImageNet dataset and put them into the {repo_root}/data/imagenet.
  • move validation images to labeled subfolders
    • To do this, you can use the following script: https://raw.githubusercontent.com/soumith/imagenetloader.torch/master/valprep.sh

Training a model from scratch

./train_val.sh configs/config_resnetv1sn50_cosine.yaml

Evaluating performance of a model

Download the pretrained models from Model Zoo and put them into the {repo_root}/data/pretrained_model

./test.sh configs/config_resnetv1sn50_cosine.yaml

Model Zoo

We provide models pretrained with SN on ImageNet, and compare to those pretrained with BN as reference. If you use these models in research, please cite the SN paper.

Model	Top-1*	Top-5*	Epochs	LR Scheduler	Weight Decay	Download
ResNet50v1+SN (8,32)	77.49%	93.32%	120	warmup + cosine lr	1e-4	[Google Drive] [Baidu Pan]
ResNet50v1+SN (8,32)	76.92%	93.26%	100	Initial lr=0.1 decay=0.1 steps[30,60,90,10]	1e-4	[Google Drive] [Baidu Pan]
ResNet50v1+BN	75.20%	92.20%	--	stepwise decay	--	[TensorFlow models]
ResNet50v1+BN	76.00%	92.98%	--	stepwise decay	--	[PyTorch Vision]
ResNet50v1+BN	75.30%	92.20%	--	stepwise decay	--	[MSRA]
ResNet50v1+BN	75.99%	92.98%	--	stepwise decay	--	[FB Torch]

*single-crop validation accuracy on ImageNet (a 224x224 center crop from resized image with shorter side=256)

When evaluation, download them and put them into the {repo_root}/data/pretrained_model.

License

All materials in this repository are released under the CC-BY-NC 4.0 LICENSE.