Define a calibration board
Configure the board realtime-calib will detect, download it to print, then enter its measured size. ChArUco is recommended (robust detection plus checkerboard-corner accuracy).
Scaffold page — to be expanded with screenshots of the board configuration UI.
Board types
The supported targets are ChArUco and ArUco. Detection uses OpenCV's ArUco / ChArUco detectors (OpenCV ≥ 4.8).
Geometry (renders the printable PNG)
The geometry defines what gets rendered and printed:
- Type — ChArUco (a grid) or ArUco (a single marker).
- Dictionary — an OpenCV predefined ArUco dictionary (e.g.
DICT_5X5_100). - Columns × rows — the ChArUco grid size.
- Marker ratio — the marker/square size ratio (render-only).
A live preview updates as you edit, and you Download the PNG to print it. The preview and the download come from the same server-side render engine.
Metric scale (measured after printing)
The physical scale does not come from the render — it comes from measuring your printed board. After printing, measure a printed square (ChArUco) or the marker side (ArUco) with a caliper and enter that value in millimetres. That measurement is what puts extrinsic translations into real-world units.
One board or two
By default the same board is used for intrinsics and extrinsics. A "use a different board for extrinsic" option lets you define a second, distinct board for the extrinsic step.
→ See also: Calibration best practices — board type, dictionary and geometry.