A Practical Method for Fully Automatic Intrinsic Camera Calibration Using
Directionally Encoded Light
Abstract
Calibrating the intrinsic properties of a camera is one of
the fundamental tasks required for a variety of computer vision and image processing tasks. The precise measurement
of focal length, location of the principal point as well as distortion parameters of the lens is crucial, for example, for 3D
reconstruction [27]. Although a variety of methods exist to
achieve this goal, they are often cumbersome to carry out,
require substantial manual interaction, expert knowledge,
and a significant operating volume. We propose a novel
calibration method based on the usage of directionally encoded light rays for estimating the intrinsic parameters. It
enables a fully automatic calibration with a small device
mounted close to the front lens element and still enables an
accuracy comparable to standard methods even when the
lens is focused up to infinity.
Our method overcomes the mentioned limitations since it
guarantees an accurate calibration without any human intervention while requiring only a limited amount of space.
Besides that, the approach also allows to estimate the distance of the focal plane as well as the size of the aperture.
We demonstrate the advantages of the proposed method by
evaluating several camera/lens configurations using prototypical devices.