The focal length in the camera-calibration result is in pixels,but i need the value in mm.How to calculate?
I used OpenCV to calibrate the camera and got the internal parameter matrix.I also get the camera sensor size in the logitech community.
the camera matrix is
[1432.379199223981, 0, 949.4032591833937;
0, 1432.97806149025, 518.5291260500587;
0, 0, 1]
and the size of sensor is 6.00mm, width of 4.80mm and height of 3.60mm (16:9 format).
I want to get the focal length in mm ,how to calculate?