Improving Static and Dyanmic Registration in an Optical See-Through HMD

Ronald Azuma and Gary Bishop


In Augmented Reality, see-through HMDs superimpose virtual 3D objects on the real world. This technology has the potential to enhance a user's perception and interaction with the real world. However, many Augmented Reality applications will not be accepted until we can accurately register virtual objects with their real counterparts. In previous systems, such registration was achieved only from a limited range of viewpoints, when the user kept his head still. This paper offers improved registration in two areas. First, our system demonstrates accurate static registration across a wide variety of viewing angles and positions. An optoelectronic tracker provides the required range and accuracy. Three calibration steps determine the viewing parameters. Second, dynamic errors that occur when the user moves his head are reduced by predicting future head locations. Inertial sensors mounted on the HMD aid head-motion prediction. Autocalibration methods measure the orientation of these sensors. Accurate determination of prediction distances requires low-overhead operating systems and eliminating unpredictable sources of latency. On average, prediction with inertial sensors produces errors 2-3 times lower than prediction without inertial sensors, and 5-10 times lower than using no prediction at all. Future steps that may further improve registration are outlined.

CR Categories and Subject Descriptors: I.3.1 [Computer Graphics]: Hardware Architecture -- three-dimensional displays; I.3.7 [Computer Graphics]: Three- Dimensional Graphics and Realism -- virtual reality

Additional Key Words and Phrases: Augmented Reality, registration, calibration

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