Method and apparatus for video object tracking

• US 7,263,207 B2
• Filed: 03/07/2003
• Issued: 08/28/2007
• Est. Priority Date: 03/07/2002
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Jong-ha, Lee, Sung-hee
• Primary Examiner(s): Johns; Andrew W.
• Application Number:
  US10/382,619
• Publication Number:
  US 20030185434A1
• Time in Patent Office: 1,635 Days
• Field of Search: 382/103, 382/107, 382/153, 382/154, 382/287, 382/291, 348/77, 715/863
• US Class Current: 382/103
• CPC Class Codes: G01S 5/163 Determination of attitude using inertial means G01C9/00; control of attitude G05D1/49
• CPC Class Codes: G06F 3/012 Head tracking input arrangements

Abstract

Provided are a method for analyzing a video signal from a camera and determining the position, orientation and direction of motion of a predetermined object and a device for the same. The device for video tracking motions of an object includes: a calibration unit for obtaining intrinsic parameters of a video camera; a camera distortion compensation unit for receiving video data, acquiring by the video camera, of a predetermined object on which at least one principal marker is set and removing lens distortion of the received video data using the intrinsic parameters of the camera; a point coordinate extraction unit for receiving video data from which lens distortions are removed by the camera distortion compensation unit, and extracting two-dimensional coordinates of the video data of the principal marker of the object; and a position, orientation and direction of motion estimation unit for estimating and outputting a position, orientation and direction of motion of the object, based on the two-dimensional coordinates input from the coordinate extraction compensation unit, the intrinsic parameters of the camera input from the calibration unit and three-dimensional coordinates displayed on the object. It is possible to set markers on the predetermined object, processing video data of the filmed object and establishing the position, orientation and direction of motion of the object.

Claims

1. A device for video tracking motions of an object, the device comprising:

a calibration unit for obtaining intrinsic parameters of a video camera;

a camera distortion compensation unit for receiving video data, acquired by the video camera, of a predetermined object on which at least one principal marker having a predetermined position is set and removing lens distortion from the received video data using the intrinsic parameters of the camera;

a principal marker coordinate extraction unit for receiving the video data from which lens distortions are removed by the camera distortion compensation unit, and extracting two-dimensional coordinates of the video data of the principal marker set on the object, wherein the principal marker coordinate extraction unit comprises;

a principal marker labeling unit for receiving the video data from which lens distortions are removed by the camera distortion compensation unit, assigning different labels to each color of marker and separating the markers into principal markers and additional markers,

a noise canceling unit for receiving information about principal points corresponding to the principal markers, and additional points, corresponding to the additional markers from the principal marker labeling unit and canceling noise in two-dimensional regions of the principal markers, and

a principal marker decision unit for receiving information about the two-dimensional regions of the principal markers and the additional points from which noise is canceled by the noise canceling unit and obtaining two-dimensional coordinates of the points in an image; and

a position, orientation and direction of motion estimation unit for estimating and outputting a position, orientation and direction of motion of the object, based on the two-dimensional coordinates input from the principal marker coordinate extraction unit, the intrinsic parameters of the camera input from the calibration unit and three-dimensional coordinates of the at least one principal marker set on the object.

2. The device for video tracking motions of an object of claim 1, wherein the principal marker coordinate extraction unit further comprises a motion estimation unit for receiving the two-dimensional coordinates of the points in the image from the principal marker decision unit and estimating a direction of motion of the points.

3. The device for video tracking motions of an object of claim 1, wherein the principal marker decision unit comprises:

a linking information analysis unit for receiving the labeled video data from which noise is canceled by the noise canceling unit and for separating the regions of the points from the images, based on linking information of the pixels corresponding to each principal marker region in the image;

a principal marker extraction unit for receiving information of the principal marker regions from the linking information analysis unit and extracting principal marker regions from the image by removing regions which are not principal marker regions, based on brightness information of the markers set on the object or relationship information about the markers; and

a first moment calculation unit for receiving information about the extracted principal marker regions, obtaining a mean of coordinate values of the points pixels and obtaining coordinates of the points.

4. The device for video tracking motions of an object of claim 1, wherein the position, orientation and direction estimating unit comprises:

an orientation and position estimation unit for estimating the position and orientation of the object, based on the intrinsic parameters of the camera received from the camera calibration unit, coordinates of the points received from the principal marker decision unit, and three-dimensional coordinates of the markers set on the object; and

a direction estimation unit for estimating a direction of motion of the object, based on the coordinates of the principal makers received from the principal marker decision unit.