I'm trying to display 3D chessboard image(involved rotation, translation) like matlab's camera calibration tool box, using openCV, openGL.
To make this, I'm studying camera calibration, homogeneous, etc.. My question is the function calibrateCamera(), I wonder how openCV calculates(estimates) focal length using only chessboard corner's object points(vec3), image points(vec2).
please tell me any equation or principle..
sorry to my bad english Thank you