This repository contains the implementation of the paper: SOLD² : Self-supervised Occlusion-aware Line Description and Detection, J-T. Lin*, R. Pautrat*, V. Larsson, M. Oswald and M. Pollefeys (Oral at CVPR 2021).

SOLD² is a deep line segment detector and descriptor that can be trained without hand-labelled line segments and that can robustly match lines even in the presence of occlusion.

Matching in the presence of occlusion:

Matching with a moving camera:

We recommend using this code in a Python environment (e.g. venv or conda). The following script installs the necessary requirements with pip:

pip install -r requirements.txt

Set your dataset and experiment paths (where you will store your datasets and checkpoints of your experiments) by modifying the file config/project_config.py. Both variables DATASET_ROOT and EXP_PATH have to be set.

Install the Python package:

pip install -e .

You can download the version of the Wireframe dataset that we used during our training and testing here. This repository also includes some files to train on the Holicity dataset to add more outdoor images, but note that we did not extensively test this dataset and the original paper was based on the Wireframe dataset only.

All training parameters are located in configuration files in the folder config. Training SOLD² from scratch requires several steps, some of which taking several days, depending on the size of your dataset.

python -m sold2.experiment --mode train --dataset_config sold2/config/synthetic_dataset.yaml --model_config sold2/config/train_detector.yaml --exp_name sold2_synth

python -m sold2.experiment --exp_name wireframe_train --mode export --resume_path <path to your previously trained sold2_synth> --model_config sold2/config/train_detector.yaml --dataset_config sold2/config/wireframe_dataset.yaml --checkpoint_name <name of the best checkpoint> --export_dataset_mode train --export_batch_size 4

python -m sold2.experiment --exp_name wireframe_test --mode export --resume_path <path to your previously trained sold2_synth> --model_config sold2/config/train_detector.yaml --dataset_config sold2/config/wireframe_dataset.yaml --checkpoint_name <name of the best checkpoint> --export_dataset_mode test --export_batch_size 4

python -m sold2.postprocess.convert_homography_results <name of the previously exported file (e.g. "wireframe_train.h5")> <name of the new data with extracted line segments (e.g. "wireframe_train_gt.h5")> sold2/config/export_line_features.yaml

python -m sold2.experiment --mode train --dataset_config sold2/config/wireframe_dataset.yaml --model_config sold2/config/train_detector.yaml --exp_name sold2_wireframe

python -m sold2.experiment --mode train --dataset_config sold2/config/wireframe_dataset.yaml --model_config sold2/config/train_detector.yaml --exp_name sold2_wireframe --pretrained --pretrained_path <path ot the pre-trained sold2_synth> --checkpoint_name <name of the best checkpoint>

python -m sold2.experiment --mode train --dataset_config sold2/config/wireframe_dataset.yaml --model_config sold2/config/train_detector.yaml --exp_name sold2_wireframe --resume --resume_path <path to the  model to resume> --checkpoint_name <name of the last checkpoint>

python -m sold2.experiment --mode train --dataset_config sold2/config/wireframe_dataset.yaml --model_config sold2/config/train_full_pipeline.yaml --exp_name sold2_full_wireframe --pretrained --pretrained_path <path ot the pre-trained sold2_wireframe> --checkpoint_name <name of the best checkpoint>

We provide the checkpoints of two pretrained models:

• sold2_synthetic.tar: SOLD² detector trained on the synthetic dataset only.
• sold2_wireframe.tar: full version of SOLD² trained on the Wireframe dataset.

Note that you do not need to untar the models, you can directly used them as they are.

We provide a notebook showing how to use the trained model of SOLD². Additionally, you can use the model to export line features (segments and descriptor maps) as follows:

python -m sold2.export_line_features --img_list <list to a txt file containing the path to all the images> --output_folder <path to the output folder> --checkpoint_path <path to your best checkpoint,>

You can tune some of the line detection parameters in config/export_line_features.yaml, in particular the 'detect_thresh' and 'inlier_thresh' to adapt them to your trained model and type of images. As the line detection can be sensitive to the image resolution, we recommend using it with images in the range 300~800 px per side.

Comparison of repeatability and localization error to the state of the art on the Wireframe dataset for an error threshold of 5 pixels in structural and orthogonal distances:

Matching precision-recall curves on the Wireframe and ETH3D datasets:

If you use this code in your project, please consider citing the following paper:

@InProceedings{Pautrat_Lin_2021_CVPR,
    author = {Pautrat*, Rémi and Lin*, Juan-Ting and Larsson, Viktor and Oswald, Martin R. and Pollefeys, Marc},
    title = {SOLD2: Self-supervised Occlusion-aware Line Description and Detection},
    booktitle = {Computer Vision and Pattern Recognition (CVPR)},
    year = {2021},
}