1st of all, thank you very much for sharing this awesome software to us.
I have several questions regarding the use of PIVlab as below.
1. The pictures that I am using for processing were taken by a camera which was installed quite close to the observed plane. This results in significant effect of the focal plane. In other word, the captured pictures had torsions which are not present in the real observed plane. Is there any suggestion to eliminate the issue of focal plane?
2. Calibration: PIVlab offers the calibration function to convert from px to mm which is cool. However, the way the program allows the user to pick reference points is somehow not really precise. Is there any way/suggestion to improve the accuracy of picking the reference points?
I think there are toolboxes for Matlab that allow to undistort images (camera calibration toolbox or something like that...?)
Concerning you second remark: Why do you feel that this is not precise? When you take a good calibration image with markers close to the borders of the image, you can select a distance with subpixel precision. That should give very little error. Or am I missing something?