Automated Camera Calibration for Augmented Reality
Background
Camera calibration is an important field in computer vision. It
is the process whereby we calculate the perspective projection
of any 3D point in the world to it's 2D position in the camera
image. An excellent resource including software is provided by
Jean-Yves Bouguet:
Jean-Yves Bouguet's
home page
Camera calibration is a vital component of systems that provide
3D reconstruction and also those that aim to mix virtual and
real structures with correct alignment - a process known as
augmented reality.
Project Details
This project will examine a number of ways that this process
might be improved upon. Firstly, the implementations available
on Bouguet's page involve manual marking of the corners of the
calibration pattern. If a large number of images are taken (for
example a video sequence) this can be rather laborious.
The identification of the calibration pattern could be automated
in a number of ways. For a video sequence the corners can be
marked in the first image only and be tracked in subsequent
images. It may also be possible to automate the corner
identification in any individual image by a number of
techniques (Hough transform, spatial Fourier transform, grid
extrapolation).
The accuracy of the calibration itself may be improved upon by
using further information in each of the images. At present just
the detected corner points are used. Use of full linear features
or comparison with a rendering of the calibration pattern should
increase the amount of image information used and hopefully
improve accuracy.
Finally, an alternative parametrisation of the camera is
proposed that reduces the interdependence of the internal and
external parameters. This should certainly result in improved
error estimation and may also increase the accuracy of the
overall calibration.
Existing libraries can be used for some parts of the project,
but algorithm development by the student will be required.
Software will be written in either Matlab or C++ with OpenGL for
3D rendering. If successful the output of this project could be
incorporated into the freely available software which would
significantly raise the student's international profile.
Eddie Edwards
Last modified: Wed Oct 17 19:10:37 BST 2007