Feature Space Augmentation for Long Tailed Data

Unofficial implementation for ECCV 2020 paper "Feature Space Augmentation for Long-Tailed Data".

Getting Started

Setup Environment

Installation Requirements

• Python >= 3.6
• PyTorch >= 1.2

Install python packages in requirements.txt.

Phase-I: Initial Feature Learning

Modify configuration file in /configs/phase_i, and run phase_i_train_or_test.py :

python phase_i_train_or_test.py --config config_name --device GPU_id

Phase-II: Determining Confusing Classes & Calculating Features for Offline Augmentation

Modify configuration file in /configs/phase_ii, and run phase_ii_extract_feature.py :

python phase_ii_extract_feature.py --config config_name --device GPU_id

Phase-III (a.k.a. Phase II in Paper): Fine Tuning with Feature Space Augmentation

Modify configuration file in /configs/phase_iii, and run phase_iii_online_train_or_test.py :

python phase_iii_online_train_or_test.py --config config_name --device GPU_id

We also implement offline feature augmentation algorithm, which calculates all training feature vectors in Phase-II and trains in phase-III without updating training samples. Run phase_iii_offline_train_or_test.py :

python phase_iii_offline_train_or_test.py --config config_name --device GPU_id

The offline version overfits quickly and does not improve over phase-I baseline.

Grad-CAM Visualization

To visualize the Grad-CAM heatmap over input images, modify configuration file in /configs/phase_ii, and run visualize.py :

python visualize.py --config config_name --device GPU_id

Here is some examples of tail classes from ImageNet-LT:

Code Structure

./
├── configs/                            # store experiment configs
│   ├── phase_i/                        # phase-I configurations
│   │   ├── example.yaml    
│   │   └── ... 
│   ├── phase_ii/                       # phase-II configurations
│   │   ├── example.yaml    
│   │   └── ... 
│   └── phase_iii/                      # phase-III configurations
│   │   ├── example.yaml    
│   │   └── ... 
├── datasets/                           # all datasets
│   ├── __init__.py                     # include get_dataset()
│   ├── finetune_dataset.py             # online augmentation dataset for phase-III
│   ├── feature_dataset.py              # offline augmentation dataset for phase-III
│   ├── example.py
│   ├── cifar_lt.py
│   └── imagenet_lt.py
├── models/                             # all models
│   ├── __init__.py                     # include get_model()
│   ├── resnet.py
│   └── resnet_cifar.py
├── utils/                              # Tools and utilities
├── checkpoints/                        # save model checkpoints
│   ├── phase_i/
│   │   ├── cifar10-LT_resnet18/        # same as current config filename
│   │   │   ├── note_1/                 # pass to argparser to identify different experiment setting
│   │   │   │   ├── best_model.pt       # checkpoint with best test acc
│   │   │   │   ├── model_epoch_0020.pt # checkpoint at epoch 20
│   │   │   │   └── ... 
│   │   │   ├── note_2/
│   │   │   └── ...
│   │   └── ...
│   └── phase_iii/
├── log/                                # logging files and backup configs, same structure as 
├── phase_i_train_or_test.py            # phase-I training & test script
├── phase_ii_extract_feature.py         # phase-II script
├── phase_iii_online_train_or_test.py   # phase-III online training & test script
├── phase_iii_offline_train_or_test.py  # phase-III offline training & test script
├── run_summary/                        # tensorboard summary, same structure as ./checkpoints
├── .gitignore                          
├── LICENSE
├── requirements.txt                   
└── README.md