LDMLR

The Pytorch implementation for the following paper (accpeted by L3D-IVU CVPR2024):
"Latent-based Diffusion Model for Long-tailed Recognition"

Paper and Citation

If you find our paper/code is useful, please cite:

@inproceedings{han2024latent,
  title={Latent-based Diffusion Model for Long-tailed Recognition},
  author={Han, Pengxiao and Ye, Changkun and Zhou, Jieming and Zhang, Jing and Hong, Jie and Li, Xuesong},
  booktitle={Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition},
  pages={2639--2648},
  year={2024}
}

Framework

Overview of the proposed framework, LDMLR. The figure describes the training of the framework: (a) obtain encoded features by a pre-training convolutional neural network on the long-tailed training set, (b) Generate pseudo-features by the diffusion model using encoded features, and (c) Train the fully connected layers using encoded and pseudo-features. The encoder from (a) and the classifier from (c) are used to predict long-tailed data in the evaluation stage.

Installation

• Install Python >= 3.8 PyTorch >= 1.12.
• (Optional, Recommended) Create a virtual environment as follows:

git clone https://github.com/AlvinHan123/LDMLR
cd LDMLR

conda create -n LDMLR python=3.9
conda activate LDMLR

# install pytorch
pip3 install torch torchvision torchaudio --index-url https://download.pytorch.org/whl/cu118

# install dependencies
pip install -r requirements.txt

Usage

Dataset

Arrange files as following:

data
    imagenet
        imagenet_lt_test.txt
        imagenet_lt_train.txt
        imagenet_lt_val.txt
        ImageNet_val_preprocess.py
        imagenet_lt_test.txt
        train
            n01440764
            ....
        val
            ILSVRC2012_val_0000000001.JPEG
            ...
    CIFAR10_LT01
        airplane
            ariplane1.png
            ...
    CIFAR10_test
        airplane
            ariplane1.png
            ...

CE and Label shift

# Train
python main.py --datapath your_datapath --model_fixed your_pretrained_resnet32_on_long_tailed
# Test
python main.py --datapath your_datapath --model_fixed your_pretrained_resnet32_on_long_tailed --eval your_pretrained_LDMLR

# Example (CIFAR-10-LT, Long-tailed ratio:0.01, ResNet-32)
python main.py --datapath ./data/CIFAR10_LT001 --model_fixed ./pretrained_models/resnet32_cifar10_lt001.checkpoint
python main.py --datapath ./data/CIFAR10_LT001 --model_fixed ./pretrained_models/resnet32_cifar10_lt001.checkpoint --eval ./saved_models/ckpt_best_ce.checkpoint

WCDAS

# Train
python ./WCDAS_code/main_train.py --dataset cifar10lt --model_file ./WCDAS_code/pretrained_models/cifar10lt_loss_WCDAS_CIFARLT_ResNet32Feature_lr_0.2_ir_100_model/model_best.pth.tar --net-config ResNet32Feature
python ./WCDAS_code/main_finetune.py --dataset cifar10lt --model-file ./WCDAS_code/results/cifar10lt_loss_WCDAS_CIFARLT_ResNet32Feature_lr_0.2_ir_100_gener_0.2_DMepoch_201_model_new/ --is_diffusion_pretrained ./WCDAS_code/pretrained_models/diffusion_model_ResNet32Feature_cifar10lt_0.01_epoch_200.pt

Results

CIFAR-LT. The encoder is ResNet-32. Classification accuracies in percentages are provided. "↑" indicates improvements over the baseline. The best numbers are in bold. The results of CE, Label Shift, and WCDAS are obtained by self-implemented networks.

Method	CIFAR-10-LT (IF=10)	CIFAR-10-LT (IF=100)	CIFAR-100-LT (IF=10)	CIFAR-100-LT (IF=100)
CE	88.22	72.46	58.70	41.28
Label shift	89.46	80.88	61.81	48.58
WCDAS	92.48	84.67	65.92	50.95
CE+LDMLR	89.13 (↑0.91)	76.26 (↑3.80)	60.10 (↑1.40)	43.34 (↑2.06)
Label shift+LDMLR	89.70 (↑0.24)	82.77 (↑1.89)	62.67 (↑0.86)	49.76 (↑1.18)
WCDAS+LDMLR	92.58 (↑0.10)	86.29 (↑1.62)	66.32 (↑0.40)	51.92 (↑0.97)

ImageNet-LT. The encoder is ResNet-10. The classification accuracies in percentages are provided. "↑" indicates the improvements over the baseline. The best numbers are in bold.

Method	Many	Medium	Few	All
CE	57.7	26.6	4.4	35.8
Label shift	52.0	39.3	20.3	41.7
WCDAS	57.1	40.9	23.3	44.6
CE+LDMLR	57.2	29.2	7.3	37.2 (↑1.4)
Label shift+LDMLR	50.9	39.4	23.7	42.2 (↑0.5)
WCDAS+LDMLR	57.0	41.2	23.4	44.8 (↑0.2)

Code references:
WCDAS, LT-baseline, denoising-diffusion-pytorch.