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Patent for License:

Projector Camera System Auto-Calibration    

A technique for the automatic calibration of a vision system such as a projector and a camera.


The self-recalibration of a structured light vision system comprises defining a camera plane and a projector plane, computing a homography matrix between the camera plane and the projector plane, and determining a translation vector and a rotation matrix from Homography-based constraints.

The technique has high computation efficiency for solving the pose problem which is of critical importance in the semi-calibrated vision systems and especially in the robotic applications where planar surfaces are encountered frequently in a number of robotic tasks such as mobile robot navigation.

Primary Application of the Technology

Object modeling, mobile robot navigation, localization and environment building , etc.

Patent Summary

U.S. Patent Classes & Classifications Covered in this listing:

Class 382: Image Analysis

This is the generic class for apparatus and corresponding methods for the automated analysis of an image or recognition of a pattern. Included herein are systems that transform an image for the purpose of (a) enhancing its visual quality prior to recognition, (b) locating and registering the image relative to a sensor or stored prototype, or reducing the amount of image data by discarding irrelevant data, and (c) measuring significant characteristics of the image.

Subclass 289: Determining amount an image is rotated or skewed
Subclass 293: Changing the image coordinates
Subclass 295: To position or translate an image
Subclass 296: To rotate an image

Class 345: Computer Graphics Processing And Selective Visual Display Systems

Processes and apparatus for selective electrical control of two or more light-generating or light-controlling display elements* in accordance with a received or stored image data signal. The image data includes character, graphical information or display attribute data. The image data may include, for example, information data from a peripheral input device, from the reception of a television signal, from the recognition of image data, or from the generation or creation of image data by a computer.

Subclass 649: Rotation
Subclass 656: Image based (addressing)
Subclass 657: By arbitrary angle
Subclass 659: Image rotates in response to display device orientation
Subclass 672: Translation
Subclass 682: Image based (addressing)

Class 359: Optical: Systems And Elements

Optical elements included in this class are: Lenses; Polarizers; Diffraction gratings; Prisms; Reflectors; Filters; Projection screens; Optical Modulators; Optical Demodulators. Among the optical systems included in this class are: Compound lens systems; Light reflecting signalling systems (e.g., retroreflectors); stereoscopic systems; Binocular devices; Systems of lenticular elements; Systems involving light interference; Glare reducing systems; Light dividing and combining systems; Light control systems (e.g., light valves); building illumination with natural light; Systems for protecting or shielding elements; Optical systems whose operation depends upon polarizing, diffracting, dispersing, reflecting, or refracting light; kaleidoscopes. Further included are certain apertures, closures, and viewing devices of a specialized nature which involve no intentional reflection, refraction, or filtering of light rays. This class also includes optical elements combined with another type of structure(s) to constitute an optical element combined with a nonoptical structure or a perfection or improvement in the optical element.

Subclass 470: Compensates for camera position (e.g., plotting or mapping type)