• Zen-NAS: A Zero-Shot NAS for High-Performance Deep Image Recognition
  • How Fast
  • Compare to Other Zero-Shot NAS Proxies on CIFAR-10/100
  • Pre-trained Models
    • ImageNet Models
    • CIFAR-10/CIFAR-100 Models
  • Reproduce Paper Experiments
    • System Requirements
    • Evaluate pre-trained models on ImageNet and CIFAR-10/100
    • Searching on CIFAR-10/100
    • Searching on ImageNet
  • Customize Your Own Search Space and Zero-Shot Proxy
  • FAQ
  • Major Contributors
  • How to Cite This Work
  • Open Source
  • Copyright

Zen-NAS is a lightning fast, training-free Neural Architecture Searching (NAS) algorithm for automatically designing deep neural networks with high prediction accuracy and high inference speed on GPU and mobile device.

This repository contains pre-trained models, a mini framework for zero-shot NAS searching, and scripts to reproduce our results. You can even customize your own search space and develop a new zero-shot NAS proxy using our pipeline. Contributions are welcomed.

The arXiv version of our paper is available from here. To appear in ICCV 2021. bibtex

Using 1 GPU searching for 12 hours, ZenNAS is able to design networks of ImageNet top-1 accuracy comparable to EfficientNet-B5 (~83.6%) while inference speed 4.9x times faster on V100, 10x times faster on NVIDIA T4, 1.6x times faster on Google Pixel2.

We use the ResNet-like search space and search for models within parameter budget 1M. All models are searched by the same evolutionary strategy, trained on CIFAR-10/100 for 1440 epochs with auto-augmentation, cosine learning rate decay, weight decay 5e-4. We report the top-1 accuracies in the following table:

Please check our paper for more details.

We provided pre-trained models on ImageNet and CIFAR-10/CIFAR-100.

• 'V100' is the inference latency on NVIDIA V100 in milliseconds, benchmarked at batch size 64, float16.
• 'T4' is the inference latency on NVIDIA T4 in milliseconds, benchmarked at batch size 64, TensorRT INT8.
• 'Pixel2' is the inference latency on Google Pixel2 in milliseconds, benchmarked at single image.

• PyTorch >= 1.5, Python >= 3.7
• By default, ImageNet dataset is stored under ~/data/imagenet; CIFAR-10/CIFAR-100 is stored under ~/data/pytorch_cifar10 or ~/data/pytorch_cifar100
• Pre-trained parameters are cached under ~/.cache/pytorch/checkpoints/zennet_pretrained

To evaluate the pre-trained model on ImageNet using GPU 0:

python val.py --fp16 --gpu 0 --arch ${zennet_model_name}

where ${zennet_model_name} should be replaced by a valid ZenNet model name. The complete list of model names can be found in 'Pre-trained Models' section.

To evaluate the pre-trained model on CIFAR-10 or CIFAR-100 using GPU 0:

python val_cifar.py --dataset cifar10 --gpu 0 --arch ${zennet_model_name}

To create a ZenNet in your python code:

gpu=0
model = ZenNet.get_ZenNet(opt.arch, pretrained=True)
torch.cuda.set_device(gpu)
torch.backends.cudnn.benchmark = True
model = model.cuda(gpu)
model = model.half()
model.eval()

Searching for CIFAR-10/100 models with budget params < 1M , using different zero-shot proxies:

'''bash scripts/Flops_NAS_cifar_params1M.sh scripts/GradNorm_NAS_cifar_params1M.sh scripts/NASWOT_NAS_cifar_params1M.sh scripts/Params_NAS_cifar_params1M.sh scripts/Random_NAS_cifar_params1M.sh scripts/Syncflow_NAS_cifar_params1M.sh scripts/TE_NAS_cifar_params1M.sh scripts/Zen_NAS_cifar_params1M.sh '''

Searching for ImageNet models, with latency budget on NVIDIA V100 from 0.1 ms/image to 1.2 ms/image at batch size 64 FP16:

scripts/Zen_NAS_ImageNet_latency0.1ms.sh
scripts/Zen_NAS_ImageNet_latency0.2ms.sh
scripts/Zen_NAS_ImageNet_latency0.3ms.sh
scripts/Zen_NAS_ImageNet_latency0.5ms.sh
scripts/Zen_NAS_ImageNet_latency0.8ms.sh
scripts/Zen_NAS_ImageNet_latency1.2ms.sh

Searching for ImageNet models, with FLOPs budget from 400M to 800M:

scripts/Zen_NAS_ImageNet_flops400M.sh
scripts/Zen_NAS_ImageNet_flops600M.sh
scripts/Zen_NAS_ImageNet_flops800M.sh

The masternet definition is stored in "Masternet.py". The masternet takes in a structure string and parses it into a PyTorch nn.Module object. The structure string defines the layer structure which is implemented in "PlainNet/*.py" files. For example, in "PlainNet/SuperResK1KXK1.py", we defined SuperResK1K3K1 block, which consists of multiple layers of ResNet blocks. To define your own block, e.g. ABC_Block, first implement "PlainNet/ABC_Block.py". Then in "PlainNet/__init__.py", after the last line, append the following lines to register the new block definition:

from PlainNet import ABC_Block
_all_netblocks_dict_ = ABC_Block.register_netblocks_dict(_all_netblocks_dict_)

After the above registration call, the PlainNet module is able to parse your customized block from structure string.

The search space definitions are stored in SearchSpace/*.py. The important function is

gen_search_space(block_list, block_id)

block_list is a list of super-blocks parsed by the masternet. block_id is the index of the block in block_list which will be replaced later by a mutated block This function must return a list of mutated blocks.

The zero-shot proxies are implemented in "ZeroShotProxy/*.py". The evolutionary algorithm is implemented in "evolution_search.py". "analyze_model.py" prints the FLOPs and model size of the given network. "benchmark_network_latency.py" measures the network inference latency. "train_image_classification.py" implements SGD gradient training and "ts_train_image_classification.py" implements teacher-student distillation.

Q: Why it is so slow when searching with latency constraints? A: Most of the time is spent in benchmarking the network latency. We use a latency predictor in our paper, which is not released.

• Ming Lin (Home Page, linming04@gmail.com, ming.l@alibaba-inc.com)
• Pichao Wang (pichao.wang@alibaba-inc.com)
• Zhenhong Sun (zhenhong.szh@alibaba-inc.com)
• Hesen Chen (hesen.chs@alibaba-inc.com)

Ming Lin, Pichao Wang, Zhenhong Sun, Hesen Chen, Xiuyu Sun, Qi Qian, Hao Li, Rong Jin. Zen-NAS: A Zero-Shot NAS for High-Performance Deep Image Recognition. 2021 IEEE/CVF International Conference on Computer Vision (ICCV 2021).

@inproceedings{ming_zennas_iccv2021,
  author    = {Ming Lin and Pichao Wang and Zhenhong Sun and Hesen Chen and Xiuyu Sun and Qi Qian and Hao Li and Rong Jin},
  title     = {Zen-NAS: A Zero-Shot NAS for High-Performance Deep Image Recognition},
  booktitle = {2021 IEEE/CVF International Conference on Computer Vision, {ICCV} 2021},  
  year      = {2021},
}

A few files in this repository are modified from the following open-source implementations:

https://github.com/DeepVoltaire/AutoAugment/blob/master/autoaugment.py
https://github.com/VITA-Group/TENAS
https://github.com/SamsungLabs/zero-cost-nas
https://github.com/BayesWatch/nas-without-training
https://github.com/rwightman/gen-efficientnet-pytorch
https://pytorch.org/vision/0.8/_modules/torchvision/models/resnet.html

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