Method of estimating image format and orientation based upon vanishing point location

• US 6,591,005 B1
• Filed: 03/27/2000
• Issued: 07/08/2003
• Est. Priority Date: 03/27/2000
• Status: Expired due to Term

• Current Assignee: Monument Peak Ventures, LLC (Dominion Harbor Enterprises, LLC)
• Original Assignee: Eastman Kodak Company
• Inventors: Gallagher, Andrew C.
• Primary Examiner(s): Johnson, Timothy M.
• Assistant Examiner(s): Bayat, Ali
• Application Number:
  US09/534,739
• Time in Patent Office: 1,198 Days
• Field of Search: 382/154, 382/289, 382/199, 382/286, 382/276, 382/293, 382/106, 345/419, 345/427
• US Class Current: 382/154
• CPC Class Codes: G06T 7/70 Determining position or orientation of objects or cameras camera calibration G06T7/80
• CPC Class Codes: G06V 10/242 by image rotation, e.g. by 90 degrees

Abstract

A method of determining the vertical axis of an image, including the steps of: detecting a set of vanishing points related to the image; selecting a vanishing point based on a predetermined criteria; and identifying the vertical axis with the selected vanishing point.

Claims

1. A method of determining the vertical axis of an image, comprising the steps of:

a) detecting a set of vanishing points related to the image;

b) selecting a vanishing point based on a predetermined criteria of the image; and

c) identifying the vertical axis with the selected vanishing point;

wherein the predetermined criteria is a threshold operation to select a vanishing point that is greater than a predetermined distance from the center of the image.

2. The method claimed in claim 1, wherein the image has x′

and y′

axes and the predetermined criteria is;

3. The method claimed in claim 2, wherein 0.01<

T₁<

0.2 and 0.2<

T₂<

0.95.

4. The method claimed in claim 3, wherein T₁=0.05 and T₂=0.55.

5. A computer readable medium having computer executable instructions for performing the method of claim 4.

6. A computer readable medium having computer executable instructions for performing the method of claim 2.

7. A computer readable medium having computer executable instructions for performing the method of claim 3.

8. The method claimed in claim 1, wherein the image has x′

-axis and y′

-axis and wherein the predetermined criteria is a threshold operation to select a vanishing point that is close to one of the axes of the image.

9. A computer readable medium having computer executable instructions for performing the method of claim 8.

10. The method claimed in claim 1, further comprising the step of detecting the orientation of the image based on the selected vanishing point location.

11. The method claimed in claim 10, wherein the image has x′

and y′

axes and the predetermined criteria is;

If |x_G|<

T₁ and y_G>

T₂, then the negative y′

-axis is determined to be at the top of the image;

If |x_G|<

T₁ and y_G<

−

T₂, then the positive y′

-axis is determined to be at the top of the image;

If |y_G|<

T₁ and x_G>

T₂, then the negative x′

-axis is determined to be at the top of the image; and

If |y_G|<

T₁ and x_G<

−

T₂, then the positive x′

-axis is determined to be at the top of the image,

where the vanishing points are represented by vanishing point vectors v_G=(x_G, y_G, z_G) with relation to a Gaussian sphere located on a z-axis with respect to the image at a distance f away from the image plane, f representing an approximation of the focal length of a camera lens employed to photograph the image; and

T₁ and T₂ are predetermined constants.

12. The method claimed in claim 11, wherein 0.01<

T₁<

0.2 and 0.2<

T₂<

0.95.

13. The method claimed in claim 12, wherein T₁=0.05 and T₂=0.55.

14. A computer readable medium having computer executable instructions for performing the method of claim 13.

15. A computer readable medium having computer executable instructions for performing the method of claim 10.

16. A computer readable medium having computer executable instructions for performing the method of claim 11.

17. A computer readable medium having computer executable instructions for performing the method of claim 12.

18. The method claimed in claim 1, wherein the image is rectangular and further comprising the step of identifying the format of the image based on the relation of the vertical axis to the rectangular axes of the image.

19. A computer readable medium having computer executable instructions for performing the method of claim 18.

20. The method claimed in claim 1, wherein the image has x′

and y′

axes and the predetermined criteria is;

 

|x_G|<

T₁ and T₂<

|y_G|<

T₃;

OR

21. The method claimed in claim 20, wherein:

If |x_G|<

T₁ and y_G>

T₂, then the negative y′

-axis is determined to be at the top of the image;

If |x_G|<

T₁ and y_G<

−

T₂, then the positive y′

-axis is determined to be at the top of the image;

If |y_G|<

T₁ and x_G>

T₂, then the negative x′

-axis is determined to be at the top of the image; and

If |y_G|<

T₁ and x_G<

−

T₂, then the positive x′

-axis is determined to be at the top of the image,

where the vanishing points are represented by vanishing point vectors v_G=(x_G, y_G, z_G) with relation to a Gaussian sphere located on a z-axis with respect to the image at a distance f away from the image plane, f representing an approximation of the focal length of a camera lens employed to photograph the image; and

T₁ and T₂ are predetermined constants.

22. A computer readable medium having computer executable instructions for performing the method of claim 21.

23. The method claimed in claim 20, wherein 0.01<

T₁<

0.2 and 0.2<

T₂<

0.95 and 0.8<

T₃<

0.999.

24. A computer readable medium having computer executable instructions for performing the method of claim 23.

25. The method claimed in claim 20, wherein T₁=0.05 and T₂=0.55 and T₃=0.95.

26. A computer readable medium having computer executable instructions for performing the method of claim 25.

27. A computer readable medium having computer executable instructions for performing the method of claim 20.

28. A computer readable medium having computer executable instructions for performing the method of claim 1.

30. The apparatus claimed in claim 28, wherein the image has x′

and y′

axes and the predetermined criteria is;

31. The apparatus claimed in claim 30, wherein 0.01<

T₁<

0.2 and 0.2<

T₂<

0.95.

32. The apparatus claimed in claim 31, wherein T₁=0.05 and T₂=0.55.

29. Apparatus for determining the vertical axis of an image, comprising the steps of:

a) means for detecting a set of vanishing points related to the image;

by means for selecting a vanishing point based on a predetermined criteria of the image; and

c) means for identifying the vertical axis with the selected vanishing point;

wherein the predetermined criteria is a threshold operation to select a vanishing point that is greater than a predetermined distance from the center of the image.

33. The apparatus claimed in claim 29, wherein the image has x′

-axis and y′

-axis and wherein the predetermined criteria is a threshold operation to select a vanishing point that is close to one of the axes of the image.

34. The apparatus claimed in claim 29, further comprising the step of detecting the orientation of the image based on the selected vanishing point location.

35. The apparatus claimed in claim 34, wherein the image has x′

and y′

axes and the predetermined criteria is;

If |x_G|<

T₁ and y_G>

T₂, then the negative y′

-axis is determined to be at the top of the image;

If |x_G|<

T₁ and y_G<

−

T₂, then the positive y′

-axis is determined to be at the top of the image;

If |y_G|<

T₁ and x_G>

T₂, then the negative x′

-axis is determined to be at the top of the image; and

If |y_G|<

T₁ and x_G<

−

T₂, then the positive x′

-axis is determined to be at the top of the image,

where the vanishing points are represented by vanishing point vectors v_G=(x_G, y_G, z_G) with relation to a Gaussian sphere located on a z-axis with respect to the image at a distance f away from the image plane, f representing an approximation of the focal length of a camera lens employed to photograph the image; and

T₁ and T₂ are predetermined constants.

36. The apparatus claimed in claim 35, wherein 0.01<

T₁<

0.2 and 0.2<

T₂<

0.95.

37. The apparatus claimed in claim 36, wherein T₁=0.05 and T₂=0.55.

38. The apparatus claimed in claim 29, wherein the image is rectangular and further comprising the step of identifying the format of the image based on the relation of the vertical axis to the rectangular axes of the image.

39. The apparatus claimed in claim 29, wherein the image has x′

and y′

axes and the predetermined criteria is;

40. The apparatus claimed in claim 39, wherein:

If |x_G|<

T₁ and y_G>

T₂, then the negative y′

-axis is determined to be at the top of the image;

If |x_G|<

T₁ and y_G<

−

T₂, then the positive y′

-axis is determined to be at the top of the image;

If |y_G|<

T₁ and x_G>

T₂, then the negative x′

-axis is determined to be at the top of the image; and

If |y_G|<

T₁ and x_G<

−

T₂, then the positive x′

-axis is determined to be at the top of the image,

where the vanishing points are represented by vanishing point vectors v_G=(x_G, y_G, z_G) with relation to a Gaussian sphere located on a z-axis with respect to the image at a distance f away from the image plane, f representing an approximation of the focal length of a camera lens employed to photograph the image; and

T₁ and T₂ are predetermined constants.

41. The apparatus claimed in claim 39, wherein 0.01<

T₁<

0.2 and 0.2<

T₂<

0.95 and 0.8<

T₃<

0.999.

42. The apparatus claimed in claim 39, wherein T₁=0.05 and T₂=0.55 and T₃=0.95.