AprilTag Detector

Sean M. Messenger

About this app

This app provides core apriltag detection functionality directly from APRIL Robotics Lab alumni. Supports all apriltag2 tag families. Tunable settings for decimation, hamming error, etc available. Detected valid tags will be outlined in the preview window.

Supported tag families include:
- 36h11 (recommended)
- 36h10
- 25h9
- 25h7
- 16h5 (used by FIRST Robotics Competition in 2023)

Performance is based on user settings and devices, if you're running into slow detections, consider increasing the decimation factor or number of threads used.

The app is open source and available here: https://github.com/johnjwang/apriltag-android

The core tag detection is from University of Michigan's APRIL Robotics Lab, which is distributed with the BSD 2-Clause License and is available here: https://github.com/AprilRobotics/apriltag

Ratings and reviews

Not compatible with 41h12 tags. (The ones i need to detect) Otherwise good. Works with frc apriltags

App claims to do one thing (detect April tags). App does that thing, does it well, and doesn't do other things it didn't advertise. The ideal single utility app.

Works fine... Picks up the tags quickly (about 15fps on my Galaxy S20) and reliably. Thanks for creating and sharing the app!

What’s new

3x improvement in detection speed, 10 Hz easily feasible for most reasonable settings/phones.
Decoupled camera, detections, and tag rendering.
Improved rendering for detections: shades region, more visible axes, and tag ID is rendered.
Add max hamming error parameter, defaults to 0 instead of the previous fixed 2. Reduces false positives on 16h5 particularly.
Increase default decimation to 8, add higher options.
Increase default nthreads to 4.
Add diagnostics options.
Misc. bug fixes.