A camera mounted on or for a vehicle has camera rotational parameters φ, θ, ψ and camera translational parameters xc, yc, zc in a camera image coordinate system, and the vehicle has a vehicle coordinate system. A method for online or on-the-fly calibration of the camera involves two independent steps, namely while the vehicle is moving relative to the ground, calibrating the camera rotational parameters using a parallel geometrical calibration process, and calibrating at least some of the camera translational parameters xc, yc independently of the camera rotational parameters.