Monocular Vision Ranging and Camera Focal Length Calibration

Table 6

Calibration results.

Method	Intrinsic matrix	Radial distortion	Tangential distortion
Zhang [15]
Li [20]
Method	Focal length (regression model)
Proposed	10.37 − 9.465  x + 1.478  y + 2.871  x ^ 2–6.653  x  y − 6.76  y ^ 2 + 3.935  x ^ 2  y + 4.285  x  y ^ 2–2.029  y ^ 3 + 1.354  x   2  y ^ 2 + 3.348  x  y ^ 3 + 1.006  y ^ 4