This is the Pytorch implementation of our work "Multi-Domain Incremental Learning for Semantic Segmentation", accepted at WACV 2022 (Algorithms Track)

Full paper: http://arxiv.org/abs/2110.12205

[New] Model checkpoints and evaluation notebook now out for easy reproducibility!

• Python 3.6
• Pytorch: Make sure to install the Pytorch version for Python 3.6 with CUDA support (This code has been run with CUDA 10.2)
• Models can take upto 40 hours on 2 Nvidia GeForce GTX 1080 Ti GPUs for Step 2; and upto 90 hours on 4 Nvidia GeForce GTX 1080 Ti GPUs for Step 3.

• Cityscapes: https://www.cityscapes-dataset.com/
• BDD100k: https://www.bdd100k.com/
• IDD: Download IDD Part 1 from https://idd.insaan.iiit.ac.in/

Preprocessing IDD: convert polygon labels to segmentation masks:

1. Clone public-code
2. export PYTHONPATH='../public-code/helpers/'
3. python ../public-code/preperation/createLabels.py --datadir <datadir> --id-type level3Id

Training occurs in incremental steps. Model at each subsequent step is initialized from the previous step model. Hence, training in steps 2 and 3 are dependent on previous checkpoints.

Sample commands for the incremental domain sequence Cityscapes (CS) -> BDD -> IDD:

Step 1: Learn model on CS
python train_RAPFT_step1.py --savedir <savedir> --num-epochs 150 --batch-size 6 --state "trained_models/erfnet_encoder_pretrained.pth.tar" --num-classes 20 --current_task=0 --dataset='cityscapes'

Step 2: Learn CS model on BDD
python train_new_task_step2.py --savedir <savedir> --num-epochs 150 --model-name-suffix='ours-CS1-BDD2' --batch-size 6 --state <path_to_Step1_model> --dataset='BDD' --dataset_old='cityscapes' --num-classes 20 20 --current_task=1 --nb_tasks=2 --num-classes-old 20

Step 3: Learn CS|BDD model on IDD
python train_new_task_step3.py --savedir <savedir> --num-epochs 150 --model-name-suffix='OURS-CS1-BDD2-IDD3' --batch-size 6 --state "path_to_Step2_model" --dataset-new='IDD' --datasets 'cityscapes' 'BDD' 'IDD' --num-classes 20 20 27 --num-classes-old 20 20 --current_task=2 --nb_tasks=3 --lambdac=0.1

Training commands for the Fine-tuning model, Multi-task (joint, offline) model and Single-task (independent models) can be found in the bash scripts inside trainer_files directory. Other ablation experiment files can be requested.

Our checkpoints for (1) Proposed model, (2) Fine-tuning, and (3) Single-Task baselines on ERFNet for CS, BDD and IDD can be found here. Checkpoints for other settings (like BDD->CS or IDD->BDD) can be released if required.

Refer to jupyter notebook Evaluation_Notebook.ipynb for evaluation of our models. Make sure to set suitable paths for dataset, models and checkpoints.

Refer to file Plot_Tsne_Notebook.ipynb for T-sne plots. We plot the output of the encoder before and after step 2. We compare finetuning versus our method.

@inproceedings{garg2022multi, title={Multi-Domain Incremental Learning for Semantic Segmentation}, author={Garg, Prachi and Saluja, Rohit and Balasubramanian, Vineeth N and Arora, Chetan and Subramanian, Anbumani and Jawahar, CV}, booktitle={Proceedings of the IEEE/CVF Winter Conference on Applications of Computer Vision}, pages={761--771}, year={2022} }

• Code was originally borrowed from the ERFNet Pytorch implementation: https://github.com/Eromera/erfnet_pytorch
• Implementation of the residual adapters has been inspired from:
  • https://github.com/menelaoskanakis/RCM
  • https://github.com/srebuffi/residual_adapters