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US 8,009,930 B2Granted
Auto-calibration method for a projector-camera system
AssigneeCity University of Hong Kong
InventorsYoufu Li, Beiwei Zhang
Life of this patent
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Abstract
A method for self-recalibration of a structured light vision system including a camera and a projector. A camera plane and a projector plane are defined, a Homography matrix between the camera plane and the projector plane is computed, and a translation vector and a rotation matrix are determined from Homography-based constraints. A computer vision system implementing the method is also described.
Claims8
A method for self-recalibration of a structured light vision system comprising a camera and a projector, the method comprising:
- defining a camera plane and a projector plane;
- computing a Homography matrix between the camera plane and the projector plane;
- determining a translation vector and a rotation matrix from Homography-based constraints;
- wherein prior to determining the translation vector, if intrinsic parameters of the camera are known, a scale factor and its sign are determined;
- and
- wherein the scale factor λ is determined from an equation:
- λ2[t]x HHT[t]x=[t]x [t]x wherein [t]x comprises a skew matrix of the translation vector t, and wherein H comprises calibrated Homography.
4 more elements
A computer vision system, comprising:
- a projector for projecting a light pattern onto an object in a scene, a camera for obtaining an image of said object, and a computer for controlling the vision system, wherein said computer implements a self-recalibration method comprising:
- defining a camera plane and a projector plane;
- computing a Homography matrix between the camera plane and the projector plane;
- determining a translation vector and a rotation matrix from Homography-based constraints;
- wherein prior to determining the translation vector, if intrinsic parameters of the camera are known, a scale factor and its sign are determined;
- and
- wherein the scale factor λ is determined from an equation:
- λ2[t]x HHT[t]x=[t]x [t]x wherein [t]x comprises a skew matrix of the translation vector t, and wherein H comprises calibrated Homography.
5 more elements
Dependencies are inferred from the claim text.