How to choose a target
Six target families ship here, and the differences that matter are not subtle. This page is the decision, not the tour — each row links to the reference page for the family.
The short version
Calibrating one camera, board fully visible, no other constraints? Use a chessboard. It is the simplest thing that works and there is nothing to configure.
Need pose from any direction, or from a target that cannot be kept facing the camera? Use a PuzzlePole — it is the only family here that is not flat.
Anything else? Read the table.
The table
| Family | Corner IDs | Partial views | Needs | Reference |
|---|---|---|---|---|
| Chessboard | none | ✗ whole board | nothing | pipeline |
| ChArUco | absolute | ✓ | an ArUco dictionary | pipeline |
| PuzzleBoard | absolute | ✓ down to a small fragment | nothing | pipeline |
| Marker board | absolute | ✓ | a custom circle layout | pipeline |
| PuzzlePole | absolute, 3-D | ✓ from any azimuth | a tube to wrap it on | how-to |
| Regular grid | none | ✗ | nothing | pipeline |
Corner IDs is the property that decides most cases. Without them a detection is a set of corners in some order, so the board has to be fully visible for its corners to mean anything. With them every corner carries an absolute identity, so a partial view is still useful and the board’s orientation is never ambiguous.
Choosing between the identified families
They differ in how the identity is encoded, which is what drives the resolution each one needs.
ChArUco puts an ArUco marker inside every white square. Each marker is a self-contained code, so a single readable marker locates the board — but a marker needs enough pixels to resolve its bit grid, so ChArUco wants the most resolution of the three. Pick it when you already have ArUco in the stack, or when you want a format other tools recognise.
PuzzleBoard distributes the code across neighbouring cells: one bit per edge, read as is the dot between these two corners black or white. A bit therefore costs one dot rather than a whole marker grid, which is why it stays decodable at markedly lower resolution and from smaller fragments. Pick it when the board will be small in frame, partly occluded, or oblique. It is the best-covered family in this book — see the decode and the code maps.
PuzzlePole is the PuzzleBoard pattern wrapped round a cylinder, so it is the same code read the same way — but on a surface with no back. Every other family here degrades as it turns away from the camera and stops working altogether near edge-on; a pole presents the same face at every azimuth, and its corners come with 3-D object points instead of points on a plane. Pick it when the target must be viewed from several directions at once, when it cannot be aimed at the camera, or when you want a single-view pose without a rig. The cost is that it must be wrapped accurately on a tube of the right diameter, and that only seven circumferences wrap seamlessly.
Marker board is a plain checkerboard with three circular markers placed to break its symmetry. It carries far less information than the others — just enough to fix the frame — but it prints as an ordinary chessboard with three dots, which suits setups where the full pattern is impractical.
Then choose the size
Two independent numbers, and both are constrained by the camera rather than by taste:
- Square size. Big enough that a square spans a comfortable number of pixels at your working distance. If corners come out noisy, this is usually the reason before any parameter is.
- Board extent. Big enough to fill a useful fraction of the frame across the poses you intend to shoot. A board that only ever covers the middle third constrains the lens model poorly no matter how clean its corners are.
Printing them covers the mechanics — page size, DPI, and why scale-to-fit is the single most common way to invalidate a calibration.