How to Rethink Visual Geo-localization for Large-Scale Applications

Aug 31, 2023 | Data Science

Welcome to our detailed guide on rethinking visual geo-localization for large-scale applications. Here, we’ll break down the process in a user-friendly manner while providing troubleshooting tips to ensure a smooth experience.

Understanding the Basics

The paper “Rethinking Visual Geo-localization for Large-Scale Applications” introduces a novel dataset called the San Francisco eXtra Large (SF-XL) and a new training method known as CosPlace. This methodology not only allows for more scalable training approaches but also improves the performance achieved with compact descriptors.

Setting Up Your Environment

  1. First, download the SF-XL dataset. You can follow the link here.
  2. Ensure you have Python installed along with PyTorch.

Training Your Model

Once you have downloaded the data, training can be initiated with the following command:

$ python3 train.py --train_set_folder path/to/sf_xl/raw/train/database --val_set_folder path/to/sf_xl/processed/val --test_set_folder path/to/sf_xl/processed/test

The process automatically splits the dataset into CosPlace Groups and saves the resulting object in a cache folder. By default, it utilizes a ResNet-18 architecture with a descriptor size of 512, which is manageable under 4GB of VRAM.

An Analogy to Simplify the Concept

Imagine you’re organizing a massive library. The SF-XL dataset serves as your library’s collection of books, and the CosPlace training method acts like a librarian efficiently categorizing and shelving those books. Just like a librarian sorts books based on genres and topics, CosPlace groups images in a way that maximizes efficiency when searching or referencing them later. This effective organization helps you locate the right book (or image) in no time!

Customizing Your Training

You can customize your training parameters with the following command:

$ python3 train.py --backbone ResNet50 --fc_output_dim 128

If you need to speed up the training, consider using Automatic Mixed Precision (AMP) by running:

$ python3 train.py --use_amp16

For a complete list of hyperparameters, use:

$ python3 train.py -h

Troubleshooting Tips

  • If you experience memory issues, reduce the descriptor dimensionality or switch to a smaller backbone.
  • In case of running into errors related to the dataset, make sure the file paths are correctly specified.
  • If you have any queries regarding the code or dataset, feel free to open an issue or email berton.gabri@gmail.com.
  • For more insights, updates, or to collaborate on AI development projects, stay connected with fxis.ai.

Visualization of Predictions

You can visualize your predictions by running the following:

python3 eval.py --backbone ResNet50 --fc_output_dim 512 --resume_model path/to/best_model.pth --num_preds_to_save=3 --exp_name=cosplace_on_stlucia

This will create a directory of prediction images for your review.

Accessing Pre-Trained Models

You can utilize various pre-trained models directly from PyTorch Hub like so:

import torch
model = torch.hub.load('gmberton/cosplace', 'get_trained_model', backbone='ResNet50', fc_output_dim=2048)

This simplifies your workflow and helps you integrate the models seamlessly into your projects.

Conclusion

At fxis.ai, we believe that such advancements are crucial for the future of AI, as they enable more comprehensive and effective solutions. Our team is continually exploring new methodologies to push the envelope in artificial intelligence, ensuring that our clients benefit from the latest technological innovations.

Stay Informed with the Newest F(x) Insights and Blogs

Tech News and Blog Highlights, Straight to Your Inbox