pengboxiangshang / mobilenetv3_pytorch

MobileNetV3, PyTorch, pretrained model, on ImageNet 1K, detailed training processing.

MobileNetV3_PyTorch_pretrained_model

This is an unofficial PyTorch implementation for MobileNetV3. Multi-GPUs training is supported. We trained it on ImageNet-1K and released the model parameters.

This project is designed with these goals:

• Train MobileNetV3-Small 1.0 on ImageNet-1K dataset.
• Train MobileNetV3-Small 0.75 on ImageNet-1K dataset.
• Train MobileNetV3-Large 1.0 on ImageNet-1K dataset.
• Train MobileNetV3-Large 0.75 on ImageNet-1K dataset.

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Requirements

Ubuntu 14.04

Python 2.7

PyTorch 0.4.0

Our Hardware Environment

Our server details: 2 Intel(R) Xeon(R) CPUs (E5-2620 v3 @ 2.40GHz), 128 GB RAM, 4 GTX 1080 Ti GPUs.

For fast IO, ImageNet-1K dataset is stored in our SSD.

Experimental Results

We report the performance (Top-1 accuracy) on ImageNet-1K validation set.

Network	Top-1 Accuracy	Pretrained Model
MobileNetV3-Small 1.0 (Official Implementation)	67.4%
MobileNetV3-Small 1.0 (Our Implementation)	63.37% 64.27%	Google Drive; BaiduYun Disk (password:j2nh); 12MB，MD5：82c676590a9ad63674b49e897937547c

Detailed Processings of Our Training

Data Preprocessings:

transform_train = transforms.Compose([
    transforms.RandomResizedCrop(224),
    transforms.RandomHorizontalFlip(),
    transforms.ToTensor(),
    transforms.Normalize(mean=[0.485, 0.456, 0.406], std=[0.229, 0.224, 0.225])
])

transform_val = transforms.Compose([
    transforms.Resize(256),
    transforms.CenterCrop(224),
    transforms.ToTensor(),
    transforms.Normalize(mean=[0.485, 0.456, 0.406], std=[0.229, 0.224, 0.225])
])

Optimizer： SGD

optimizer = torch.optim.SGD(net.parameters(
), lr=basic_configs['learning_rate'], momentum=0.9, weight_decay=1e-5)

Learning rate： 1e-1 (105 epoches) ==> 1e-2 (20 epoches) ==> 1e-3 (10 epoches) ==> 1e-4 (10 epoches) ==> 1e-5 (10 epoches)

Batch Size = 1700

Please see more details in our training file train.py.

Running costs are summarized in following table.

GPU RAM	RAM	Running Time
30 GB	100 GB	approximatively 48 hours

Please see more details in our training file train.py.

Loss curve:

How to Use

from MobileNetV3 import *

net = MobileNetV3()
state_dict = torch.load('MobileNetV3_Small_1.0.pth')
net.load_state_dict(state_dict)

Discussion about "dropout 0.8"

In the original paper, the authors said "We use dropout of 0.8". This statement is ambiguous. Therefore, our current pretrained model has no dropout operations during training. We guess the dropout should be inserted before the final 1000-way logits layer. Please see details in our MobileNetV3_dropout.py. Our "MobileNetV3_dropout.py" is implemented based on the "mobilenetv3.py" of kuan Wang. Thanks to Wang Kuan.

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This work was implemented by Peng Xu, and Jin Feng.