5

So I did a camera calibration using the checkerboard and the matlab camera calibration toolbox. So the Intrinsic Matrix that I obtained for that particular session is as follows:

Intrinsic Matrix: [349.3601,0,0;0,349.7267,0;258.0883,210.5905,1]

I have been trying to search the meaning of those values in the matrix but has been unsuccessful so far.

Can anyone help me?

Thanks

enter image description here

Ali P
  • 519
  • 6
  • 21
  • @HighPerformanceMark Thank you for your reply. Okay so in the screenshot above (see edits) you can see there is the Intrinsic matrix. I am trying to get the focal length of the camera and its exact mid point. So from this intrinsic matrix, which one is it? – Ali P Sep 16 '14 at 17:49

1 Answers1

6

According to the official MATLAB documentation, the intrinsic matrix is defined as follows:

enter image description here

where fx = F*sx, fy = F*sy, F is the focal length in world units, typically expressed in millimeters and [sx, sy] are the number of pixels per world unit in the x and y direction respectively. fx and fyare expressed in pixels.

Dan
  • 1,466
  • 1
  • 13
  • 27
  • thank you for pointing this out. okay so from the above, how can I obtain F, the focal length? I cannot seem to find sx and sy – Ali P Sep 16 '14 at 18:30
  • 1
    Google the specification of the sensor of you camera, look for things named "dot pitch" (pixels / mm) or "active sensor dimensions" (width, height in mm) – Francesco Callari Sep 17 '14 at 17:31