2

I am using OpenCV3.0 and VS2013 to do fisheye wide-angle(185 deg) camera calibration. There are some pictures that can work well, e.g:

Chessboard to be detected-- fish-eye

and the correction result is satisfying as:

![corrected image -- fish-eye][2]

The result looks good, but I use a similar image to do calibration instead, it cannot find any chessboard corners!! The image is like this:

another chessboard image

The results are very confusing to me since I try many many similar images( same distance different angel, same angel different distance ) for about 60 images, and small part of them can be detected. I use 2592x1944 resolution BMP files, and I accurately put the chessboard center in the center of camera, but the result is no good than the casually captured images, some even cannot find corners. I use this code to detect:

bool patternfound = findChessboardCorners(imageGray, board_size, corners,CALIB_CB_ADAPTIVE_THRESH + CALIB_CB_NORMALIZE_IMAGE+ 
        CALIB_CB_FAST_CHECK );
techraf
  • 64,883
  • 27
  • 193
  • 198
tzz
  • 21
  • 3
  • I doubt it is supposed to work with fish-eye at all – Andrey Kamaev Oct 13 '16 at 20:49
  • @AndreyKamaev, thanks for reply! You mean the function findChessBoardCorner doesn't meant to work with fish-eye images? But small part of my images can work well, they can be calibrated well and make good correction results. I am sorry i cannot upload many images. – tzz Oct 14 '16 at 02:53
  • 1
    Have you seen this http://abarry.org/wide-angle-lens-stereo-calibration-with-opencv/ ? – Andrey Kamaev Oct 14 '16 at 20:47
  • The link to your second image is missing. – techraf Oct 16 '16 at 03:01
  • @techraf, sorry, i cannot upload more than 2 images, the second image is well defished, just like the normal pinhole image taken from ordinary camera or phone. – tzz Oct 16 '16 at 06:31
  • @AndreyKamaev, i have seen this website, and it doesn't work. Do you have any other points? Thanks! – tzz Oct 16 '16 at 06:32

1 Answers1

1

Turn off CALIB_CB_FAST_CHECK , when testing fisheye image.

bwlim
  • 11
  • 1