opencv - generation of huge calibration pattern

Question

We need a calibration pattern with outer dimensions of around 600 mm x 600 mm.

I tried to use the python script which can be found in the docs folder of the OpenCV distribution but it does not generate an svg of this size. It stops without an error message and does not write an svg file.

So I want to create the pattern on my own and want to understand the "rules":

• is it better to use a different count of rows and columns?
• how many circles do I need for a good calibration pattern?
• which radius should I use in relation to the outer dimensions?
• which spacing is needed between the circles?
• which spacing is needed between the outer circles and the border of the whole pattern?

Because I can not print a pattern of this size and have to pay for the printing, I need to know the rules and can not try many different things.

Thanks!

Answer 1

Two links that may give some ideas. One is from Carnegie Mellon University website and the other is a paper from Janne Heikkila (see p7)

Disclaimer: I don't know about these patterns being optimized or not. I am also interested in learning more about this.

Edit: one more hint from opencv findCirclesGrid documentation: The function requires white space (like a square-thick border, the wider the better) around the board to make the detection more robust in various environments.