In this work, we propose to leverage global instances, which are robust to illumination and season changes for both coarse and fine localization. For coarse localization, instead of performing global reference search directly, we search for reference images from recognized global instances progressively. The recognized instances are further utilized for instance-wise feature detection and matching to enhance the localization accuracy.

• Full paper PDF: SFD2: Semantic-guided Feature Detection and Description.

• Authors: Fei Xue, Ignas Budvytis, Roberto Cipolla

• Website: SFD2 for videos and slides.

• Python 3 >= 3.6
• PyTorch >= 1.8
• OpenCV >= 3.4
• NumPy >= 1.18
• segmentation-models-pytorch = 0.1.3
• colmap
• pycolmap = 0.0.1

• training data. We use the same training dataset as R2D2. Please download the training dataset following the instructions provided by R2D2.
• segmentation model. ConvXt is used to provide semantic labels and semantic-aware features for stability learning in the training process.
• local feature model. SuperPoint is used to provide local reliability in the training process.

Pretrained weight of SFD2 is in the weights directory. If you want to retrain the model, please also download the weights of ConvXt and SuperPoint from here and put them nto the weights directory.

Please download datasets e.g. Aachen_v1.1, RobotCar-Seasons v2, and Extended-CMU-Seasons from the visualization benchmark for evaluation.

• localization on Aachen_v1.1

./test_aachenv_1_1

you will get results like this:

• localization on RobotCar-Seasons

./test_robotcar

you will get results like this:

• localization on Extended CMU-Seasons

./test_ecmu

you will get results like this:

./train.sh

If you use any ideas from the paper or code from this repo, please consider citing:

@inproceedings{xue2023sfd2,
  author    = {Fei Xue and Ignas Budvytis and Roberto Cipolla},
  title     = {SFD2: Semantic-guided Feature Detection and Description},
  booktitle = {CVPR},
  year      = {2023}
}

Part of the code is from previous excellent works including SuperPoint, R2D2 , HLoc, ConvXt, LBR. You can find more details from their released repositories if you are interested in their works.