Hello,
I have a problem with the following image acquired from a high resolution camera:
You can see that the upper and lower edges of the table are not parallel but slightly curved outwards. It is obvious when watching the line that is drawn between the corner circles that do not go through the centers of the upper and lower middle circles. I could use a piece of advice: what kind of distortion is this? At first I thought it is a perspective issue, since the small edges of the table are far away from the camera, but now I'm not so sure, it looks more like a fish-eye effect.
Also, what is the best option to correct this aberration? The tricky part is that I need the correction to be as accurate as possible (an item placed on the table should be detected as the same number of pixels anywhere on the table). Can I make use of the circles placed on the table (I can assume they are perfectly aligned) or do I need a chessboard? The the chessboard calibration technique precise enough to cover this case?
Thanks