Code to accompany our paper "How to Train a CAT: Learning Canonical Appearance Transformations for Direct Visual Localization Under Illumination Change".

• numpy
• matpotlib
• pytorch + torchvision (1.2)
• Pillow
• progress (for progress bars in train/val/test loops)
• tensorboard + tensorboardX (for visualization)
• pyslam + liegroups (optional, for running odometry/localization experiments)
• OpenCV (optional, for running odometry/localization experiments)

1. Download the ETHL dataset from here or the Virtual KITTI dataset from here
   1. ETHL only: rename ethl1/2 to ethl1/2_static.
   2. ETHL only: Update the local paths in tools/make_ethl_real_sync.py and run python3 tools/make_ethl_real_sync.py to generate a synchronized copy of the real sequences.
2. Update the local paths in run_cat_ethl/vkitti.py and run python3 run_cat_ethl/vkitti.py to start training.
3. In another terminal run tensorboard --port [port] --logdir [path] to start the visualization server, where [port] should be replaced by a numeric value (e.g., 60006) and [path] should be replaced by your local results directory.
4. Tune in to localhost:[port] and watch the action.

1. Ensure the pyslam and liegroups packages are installed.
2. Update the local paths in make_localization_data.py and run python3 make_localization_data.py [dataset] to compile the model outputs into a localization_data directory.
3. Update the local paths in run_localization_[dataset].py and run python3 run_localization_[dataset].py [rgb,cat] to compute VO and localization results using either the original RGB or CAT-transformed images.
4. You can compute localization errors against ground truth using the compute_localization_errors.py script, which generates CSV files and several plots. Update the local paths and run python3 compute_localization_errors.py [dataset].

If you use this code in your research, please cite:

@article{2018_Clement_Learning,
  author = {Lee Clement and Jonathan Kelly},
  journal = {{IEEE} Robotics and Automation Letters},
  link = {https://arxiv.org/abs/1709.03009},
  title = {How to Train a {CAT}: Learning Canonical Appearance Transformations for Direct Visual Localization Under Illumination Change},
  year = {2018}
}