Find camera intrinsics matrix from FOV and resolution

camera_intrinsics_from_FOV.py

#!/usr/bin/env python3
import math
# input
VFOV=60
H=480
W=856

aspRatio=W/H
VFOV_rad=VFOV*math.pi/180.
HFOV_rad= 2 * math.atan( math.tan(VFOV_rad/2) * aspRatio )
fx = (W/2)/math.tan(HFOV_rad/2)
fy = (H/2)/math.tan(VFOV_rad/2)
u0 = W/2
v0 = H/2
print("fx:\t\t\t%.2f" % fx)
print("fy (same as fx):\t%.2f" % fy)
print("u0:\t\t\t%.2f" % u0)
print("v0:\t\t\t%.2f" % v0)
print()
print("Intrinsics matrix:")
print()
print("%.2f\t%.2f\t%.2f" % (fx,0,u0))
print("%.2f\t%.2f\t%.2f" % (0,fy,v0))
print("%.2f\t%.2f\t%.2f" % (0,0,1))