I am trying to test the camera calibration app with some images. One image failed point detection because the APP should detect the 9x6 points at the center area but obviously the points on the very left and on the bottom are also detected. I have attached the image. Checkboard square is 50mm x 50mm. Please help me understand why this image fails. Thanks in advance.
Unfortunately, sometimes the checkerboard detetction algorithm fails. In this particular case, you can avoid this problem by using a checker board with wide white margins, or by placing it on light background.