Fast Calibration for Augmented Reality

Information

• Publication Type: Technical Report
• Workgroup(s)/Project(s): not specified
• Date: May 1999
• Number: TR-186-2-99-16
• Keywords: head-mounted displays, tracking, distortion, registration, calibration, Augmented reality

Abstract

Augmented Reality overlays computer generated images over the real world. To correctly depict spatial relations between real and virtual objects, these images have to be generated using transformations which correctly project a point in virtual space onto its corresponding point in the real world. This requires precise knowledge of the viewing projection of the head-mounted display (HMD) and its position. Methods to calibrate the projection parameters of the virtual cameras to that of the HMD have been presented in previous work. Most of these methods are complicated or use special equipment for the calibration process. We present a simple and fast calibration scheme, which does not require additional instrumentation or complicated procedures. This allows us to calibrate HMDs for specific users. The calibration process is presented to the user as interactively guided initialization step, which enables even inexperienced users to adapt the calibration to their eye distance and head geometry. The calibration is stable - meaning that slight errors made by the user do not result in gross miscalibrations - and applicable for see-through and video-based HMDs. Additionally we show a method for correcting the distortions introduced by the camera lens in real-time using standard OpenGL hardware and for registering tracked objects to their augmentations.

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BibTeX

@techreport{Fuhr-1999-Cal,
  title =      "Fast Calibration for Augmented Reality",
  author =     "Anton Fuhrmann and Dieter Schmalstieg and Werner Purgathofer",
  year =       "1999",
  abstract =   "Augmented Reality overlays computer generated images over
               the real world. To correctly depict spatial relations
               between real and virtual objects, these images have to be
               generated using transformations which correctly project a
               point in virtual space onto its corresponding point in the
               real world. This requires precise knowledge of the viewing
               projection of the head-mounted display (HMD) and its
               position. Methods to calibrate the projection parameters of
               the virtual cameras to that of the HMD have been presented
               in previous work. Most of these methods are complicated or
               use special equipment for the calibration process. We
               present a simple and fast calibration scheme, which does not
               require additional instrumentation or complicated
               procedures. This allows us to calibrate HMDs for specific
               users. The calibration process is presented to the user as
               interactively guided initialization step, which enables even
               inexperienced users to adapt the calibration to their eye
               distance and head geometry. The calibration is stable -
               meaning that slight errors made by the user do not result in
               gross miscalibrations - and applicable for see-through and
               video-based HMDs. Additionally we show a method for
               correcting the distortions introduced by the camera lens in
               real-time using standard OpenGL hardware and for registering
               tracked objects to their augmentations.",
  month =      may,
  number =     "TR-186-2-99-16",
  address =    "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria",
  institution = "Institute of Computer Graphics and Algorithms, Vienna
               University of Technology ",
  note =       "human contact: technical-report@cg.tuwien.ac.at",
  keywords =   "head-mounted displays, tracking, distortion, registration,
               calibration, Augmented reality",
  URL =        "https://www.cg.tuwien.ac.at/research/publications/1999/Fuhr-1999-Cal/",
}