METHOD FOR DETERMINING THE POSITION OF AN OBJECT FROM A DIGITAL IMAGE

• US 20090129628A1
• Filed: 11/28/2005
• Published: 05/21/2009
• Est. Priority Date: 11/30/2004
• Status: Active Grant

• Current Assignee: IEE International Electronics & Engineering SA (Aerospace Hi-Tech Holding Group Company Limited)
• Original Assignee: IEE International Electronics & Engineering SA (Aerospace Hi-Tech Holding Group Company Limited)
• Inventors: Ginhoux, Romuald, Castillo Franco, Marta, Mirbach, Bruno
• Granted Patent: US 8,396,251 B2
• Time in Patent Office: Days
• US Class Current: 382/103
• CPC Class Codes: G06T 7/73 using feature-based methods

Abstract

Method for determining the position of an object point in a scene from a digital image thereof acquired through an optical system is presented. The image comprises a set of image points corresponding to object points and the position of the object points are determined by means of predetermined vectors associated with the image points. The predetermined vector represents the inverted direction of a light ray in the object space that will produce this image point through the optical system comprising all distortion effects of the optical system.

Claims

1. Method for determining the position of an object point in a scene from a digital image of said scene acquired through an optical system, said image comprising an image point corresponding to said object point, wherein the position of said object point is determined by means of a predetermined vector associated with said image point, said predetermined vector representing the direction of a light ray in the object space that will produce this image point through said optical system.

2. Method according to claim 1, wherein said source image comprises a number of image points corresponding to respective object points, and wherein a respective predetermined vector is associated with each of said image points.

3. Method according to claim 1, wherein each predetermined vector indicates the direction of a light ray passing through the optical centre of the lens assembly of said optical system.

4. Method according to claim 1, wherein each predetermined vector is determined by calibration.

5. Method according to claim 1, wherein distance information is associated with an image point, and the position of the corresponding object point is determined based on the predetermined vector and said distance information associated with said image point.

6. Method according to claim 5, wherein measured distance information is associated with each image point, said distance information being indicative of the measured remoteness of the corresponding object point.

7. Method according to claim 6, wherein each predetermined vector is a unitary vector in a reference coordinate system;

and the coordinates of an object point corresponding to an image point are determined by multiplying the measured distance information by the predetermined vector associated with this image point.

8. Method according to claim 7, wherein said measured distance information is indicative of the distance from the centre of said optical system to the corresponding object point.

9. Method according to claim 1, wherein said digital image is acquired by means of an image sensor array.

10. Method according to claim 1, wherein a grey value is associated with each image point.

11. Method according to claim 1, wherein the coordinates of said predetermined vectors expressed in reference coordinate system are transformed in another coordinate system.

12. Use of the method according to claim 1 in a method for detecting and classifying vehicle occupants of an automotive occupant protection system.

13. Method according to claim 5, wherein each predetermined vector indicates the direction of a light ray passing through the optical centre of the lens assembly of said optical system.