type and size of calibration pattern for most accurate results
Hi!
I want to use OpenCV for accurate measuring - so the first step should be the best camera calibration possible.
There are three types of camera calibration patterns:
- chessboard
- symmetric circles
- asymmetric circles
Does anyone have some experience which type is the most accurate?
What is the advantage of sym and asym. circle pattern, if any?
Another important parameter is the relative size of the pattern in the camera image.
Are there any rules for the minimum size? For example the pattern should cover 25% of the image or something like that?
Is there any minimum radius in pixels for the circles/width of the squares in the resulting image?
Thanks!
The guys that wrote those calibration algorithms say that circles are far more accurate. But I cannot remember where they wrote that - I think in the Weekly Meeting Notes.
And did they mention which relative size the pattern should have in the final image? I guess if it's too small the calibration is only valid for small parts of the image and not for the whole covered area?