Hybrid tracking for augmented reality using both camera motion detection and landmark tracking

• US 6,064,749 A
• Filed: 08/02/1996
• Issued: 05/16/2000
• Est. Priority Date: 08/02/1996
• Status: Expired due to Term

• Current Assignee: Chapel Hill-University of North Carolina
• Original Assignee: Chapel Hill-University of North Carolina
• Inventors: Hirota, Gentaro, State, Andrei
• Primary Examiner(s): Chang, Jon
• Assistant Examiner(s): PATEL, JAYANTI K
• Application Number:
  US08/691,684
• Time in Patent Office: 1,383 Days
• Field of Search: 382/100, 382/154, 382/162, 382/291, 382/294, 382/295, 345/285, 345/7-9, 345/419, 345/424, 345/473-474, 345/112-114, 345/435, 345/439, 356/12, 359/13, 359/630, 348/239, 348/586
• US Class Current: 382/103
• CPC Class Codes: G06F 3/011 Arrangements for interaction with the human body, e.g. for user immersion in virtual reality blind teaching G09B21/00
• CPC Class Codes: G06T 19/006 Mixed reality object pose determination, tracking or camera calibration for mixed reality G06T7/00
• CPC Class Codes: G06T 7/73 using feature-based methods
• CPC Class Codes: G06V 10/245 by locating a pattern; Special marks for positioning

Abstract

Systems, methods and computer program products which have the registration accuracy of vision-based tracking systems and the robustness of magnetic tracking systems. Video tracking of landmarks is utilized as the primary method for determining camera position and orientation but is enhanced by magnetic or other forms of physical tracking camera movement and orientation. A physical tracker narrows the landmark search area on images, speeding up the landmark search process. Information from the physical tracker may also be used to select one of several solutions of a non-linear equation resulting from the vision-based tracker. The physical tracker may also act as a primary tracker if the image analyzer cannot locate enough landmarks to provide proper registration, thus, avoiding complete loss of registration. Furthermore, if 1 or 2 landmarks (not enough for a unique solution) are detected, several may be utilized heuristic methods are used to minimize registration loss. Catastrophic failure may be avoided by monitoring the difference between results from the physical tracker and the vision-based tracker and discarding corrections that exceed a certain magnitude. The hybrid tracking system is equally applicable to see-through and video augmented reality systems.

Claims