Hi, the findCirclesGrid() can detect the circle center points with symmetrical patternSize of 16 * 8, which is shown as follow:
However, I fail to use this function to deal with the symmetrical patternSize of 4 * 3, which is shown as follow:
Could someone tell me how to detect the circle points in patternSize of 4 * 3 ? Thanks!
Hi,
I can reproduce your problem and indeed the second grid is not detected with the default method. You can use the second available method as a workaround. The code becomes like this:
findCirclesGrid(image, patternSize, centers, CALIB_CB_SYMMETRIC_GRID + CALIB_CB_CLUSTERING)
The 4x3 grid was detected in this case.
P.S. It seems to be a bug that the grid was not detected initially so please fill in a bug report at http://code.opencv.org.
Thank you very much for your kind help! With the method you suggested I succeed to detect the 4x3 grid.
By debugging for a lot of times, I find the ‘minDensity’, a member variable defined in class ‘CirclesGridFinderParameters’, has a default initial value of 10, which is a little big for my case of 4x3 grid. I reset this value to 5, and the default method of ‘findCirclesGrid()’ detected the 4x3 grid of circle successfully.
Therefore, the main reason for the problem is that I have not set a reasonable value for some parameter defined in class ‘CirclesGridFinderParameters’, and it has nothing to do with the ‘findCirclesGrid()’.
Thanks again!
Asked: 2012-12-12 20:34:52 -0600
Seen: 5,292 times
Last updated: Dec 13 '12
