Aprilgrid

Pure python version of aprilgrid

Inspired by Apriltag and Kalibr. There are lots of existing python binding of Apriltag. But as everyone knows, python binding causes a lot of issues. So I rewrite a pure python version of Apriltag, and it's also able to detect Aprilgrid.

Install from PyPI

pip install aprilgrid

Usage

Some examples of usage can be seen in the example/main.py file.

from aprilgrid import Detector

detector = Detector("t36h11")

detector.detect(img)

Kalibr uses 2 bit black border while apriltag3 uses 1 bit black border for each tag. The default of aprilgrid follows Kalibr. Please use t36h11b1 if you're using tags with 1 bit black border.

Development

git clone https://github.com/powei-lin/aprilgrid.git
cd aprilgrid
pip install -e .

TODO

• [ ] Add output for opencv calibrate camera.
• [ ] Provide pregenerated pdf and easy way to customize.
• [ ] Support all tag families.
• [ ] Accelerate and multi-threading.
• [ ] Robustness.

Reference

• https://github.com/AprilRobotics/apriltag
• https://github.com/ethz-asl/kalibr