Keystone correction derived from the parameters of projectors

US 6,997,563 B1
Filed: 05/19/2004
Issued: 02/14/2006
Est. Priority Date: 05/19/2004
Status: Active Grant

First Claim

Patent Images

1. An apparatus, comprising:

an image projector to project an image;

a set of inherent parameters including a horizontal resolution Wn₀, a vertical resolution Hn₀, a depth d, and a vertical offset db;

a receiver to receive a vertical tilt angle β

v and a horizontal tilt angle β

h; and

a corrector to compute keystone correction corner points for the image using the set of inherent parameters, the vertical tilt angle β

v, and the horizontal tilt angle β

h using formulae $xp [x, y] = \frac{\cos [β h] \times x}{1 + \frac{\sin [β v] \times y + \cos [β v] \times \sin [β h] \times x}{d}} and$ $yp [x, y] = \frac{\cos [β v] \times y - \sin [β h] \times \sin [β v] \times x - (db - \frac{{Hn}_{0}}{2})}{1 + \frac{\sin [β v] \times y + \cos [β v] \times \sin [β h] \times x}{d^{6}}} + (db - \frac{{Hn}_{0}}{2}), where x and y$

represent an uncorrected pixel location and xp and yp represent a corrected pixel location.

View all claims

3 Assignments

Timeline View

Assignment View

0 Petitions

Accused Products

Abstract

A projector determines horizontal and vertical tilt angles. Using the tilt angles and the inherent properties of the projector, keystone correction corner points for the image can be computed. The keystone correction corner points can be used to perform keystone correction on the image.

Citations

56 Claims

1. An apparatus, comprising:
- an image projector to project an image;
  
  a set of inherent parameters including a horizontal resolution Wn₀, a vertical resolution Hn₀, a depth d, and a vertical offset db;
  
  a receiver to receive a vertical tilt angle β
  
  v and a horizontal tilt angle β
  
  h; and
  
  a corrector to compute keystone correction corner points for the image using the set of inherent parameters, the vertical tilt angle β
  
  v, and the horizontal tilt angle β
  
  h using formulae $xp [x, y] = \frac{\cos [β h] \times x}{1 + \frac{\sin [β v] \times y + \cos [β v] \times \sin [β h] \times x}{d}} and$ $yp [x, y] = \frac{\cos [β v] \times y - \sin [β h] \times \sin [β v] \times x - (db - \frac{{Hn}_{0}}{2})}{1 + \frac{\sin [β v] \times y + \cos [β v] \times \sin [β h] \times x}{d^{6}}} + (db - \frac{{Hn}_{0}}{2}), where x and y$
  
  represent an uncorrected pixel location and xp and yp represent a corrected pixel location.
- View Dependent Claims (2, 3, 4, 5, 6, 7)
- - 2. A projector according to claim 1, wherein the receiver is operative to receive the vertical tilt angle β
    - v and the horizontal tilt angle β
      
      h from a user.
  - 3. A projector according to claim 1, wherein the receiver is operative to determine the vertical tilt angle β
    - v and the horizontal tilt angle β
      
      h relative to a surface.
  - 4. A projector according to claim 1, wherein the corrector performs keystone correction on the image using the keystone correction corner points for the image.
  - 5. A projector according to claim 4, wherein the corrector applies vertical scaling followed by horizontal scaling to the image to perform keystone correction.
  - 6. A projector according to claim 4, wherein the corrector applies horizontal scaling followed by vertical scaling to the image to perform keystone correction.
  - 7. A projector according to claim 1, wherein the receiver includes an adjuster to adjust the horizontal tilt angle β
    - h based on the vertical tilt angle β
      
      v.

8. A projector, comprising:
- means for projecting an image;
  
  means for determining a set of inherent parameters including a horizontal resolution Wn₀, a vertical resolution Hn₀, a depth d, and a vertical offset db;
  
  means for receiving a vertical tilt angle β
  
  v and a horizontal tilt angle β
  
  h; and
  
  means for computing keystone correction corner points for the image using the set of inherent parameters, the vertical tilt angle β
  
  v, and the horizontal tilt angle β
  
  h using formulae $xp [x, y] = \frac{\cos [β h] \times x}{1 + \frac{\sin [β v] \times y + \cos [β v] \times \sin [β h] \times x}{d}} and$ $yp [x, y] = \frac{\cos [β v] \times y - \sin [β h] \times \sin [β v] \times x - (db - \frac{{Hn}_{0}}{2})}{1 + \frac{\sin [β v] \times y + \cos [β v] \times \sin [β h] \times x}{d^{6}}} + (db - \frac{{Hn}_{0}}{2}), where x and y$
  
  represent an uncorrected pixel location and xp and yp represent a corrected pixel location.
- View Dependent Claims (9, 10, 11, 12, 13, 14)
- - 9. A projector according to claim 8, wherein the means for receiving a vertical tilt angle β
    - v and a horizontal tilt angle β
      
      h includes means for receiving the vertical tilt angle β
      
      v and the horizontal tilt angle β
      
      h from a user.
  - 10. A projector according to claim 8, wherein the means for receiving a vertical tilt angle β
    - v and a horizontal tilt angle β
      
      h includes means for determining the vertical tilt angle β
      
      v and the horizontal tilt angle β
      
      h relative to a surface.
  - 11. A projector according to claim 8, further comprising means for performing keystone correction to the image using the keystone correction corner points for the image.
  - 12. A projector according to claim 11, wherein the means for performing keystone correction includes means for performing vertical scaling followed by horizontal scaling to the image to perform keystone correction.
  - 13. A projector according to claim 11, wherein the means for performing keystone correction includes means for performing horizontal scaling followed by vertical scaling to the image to perform keystone correction.
  - 14. A projector according to claim 8, wherein the means for receiving a vertical tilt angle β
    - v and a horizontal tilt angle β
      
      h includes means for adjusting the horizontal tilt angle β
      
      h based on the vertical tilt angle β
      
      v.

15. A method for performing keystone correction in a projector, comprising:
- determining a set of inherent parameters for the projector, the set of inherent parameters including a horizontal resolution Wn₀, a vertical resolution Hn₀, a depth d, and a vertical offset db;
  
  determining a vertical tilt angle β
  
  v;
  
  determining a horizontal tilt angle β
  
  h; and
  
  computing keystone correction corner points using the set of inherent parameters, the vertical tilt angle β
  
  v, and the horizontal tilt angle β
  
  h using formulae $xp [x, y] = \frac{\cos [β h] \times x}{1 + \frac{\sin [β v] \times y + \cos [β v] \times \sin [β h] \times x}{d}} and$ $yp [x, y] = \frac{\cos [β v] \times y - \sin [β h] \times \sin [β v] \times x - (db - \frac{{Hn}_{0}}{2})}{1 + \frac{\sin [β v] \times y + \cos [β v] \times \sin [β h] \times x}{d^{6}}} + (db - \frac{{Hn}_{0}}{2}), where x and y$
  
  represent an uncorrected pixel location and xp and yp represent a corrected pixel location.
- View Dependent Claims (16, 17, 18, 19, 20, 21)
- - 16. A method according to claim 15, further comprising performing keystone correction using the keystone correction corner points.
  - 17. A method according to claim 16, wherein performing keystone correction includes performing vertical scaling followed by horizontal scaling.
  - 18. A method according to claim 16, wherein performing keystone correction includes performing horizontal scaling followed by vertical scaling.
  - 19. A method according to claim 15, wherein determining a horizontal tilt angle β
    - h includes adjusting the horizontal tilt angle β
      
      h based on the vertical tilt angle β
      
      v.
  - 20. A method according to claim 15, wherein determining a vertical tilt angle β
    - v includes receiving the vertical tilt angle β
      
      v as an input from a user.
  - 21. A method according to claim 15, wherein determining a horizontal tilt angle β
    - h includes receiving the horizontal tilt angle β
      
      h as an input from a user.

22. An article comprising a machine-accessible media having associated data, wherein the data, when accessed, results in a machine performing:
- determining a set of inherent parameters for the projector, the set of inherent parameters including a horizontal resolution Wn₀, a vertical resolution Hn₀, a depth d, and a vertical offset db;
  
  determining a vertical tilt angle β
  
  v;
  
  determining a horizontal tilt angle β
  
  h; and
  
  computing keystone correction corner points using the set of inherent parameters, the vertical tilt angle β
  
  v, and the horizontal tilt angle β
  
  h using formulae $xp [x, y] = \frac{\cos [β h] \times x}{1 + \frac{\sin [β v] \times y + \cos [β v] \times \sin [β h] \times x}{d}} and$ $yp [x, y] = \frac{\cos [β v] \times y - \sin [β h] \times \sin [β v] \times x - (db - \frac{{Hn}_{0}}{2})}{1 + \frac{\sin [β v] \times y + \cos [β v] \times \sin [β h] \times x}{d^{6}}} + (db - \frac{{Hn}_{0}}{2}), where x and y$
  
  represent an uncorrected pixel location and xp and yp represent a corrected pixel location.
- View Dependent Claims (23, 24, 25, 26, 27, 28)
- - 23. An article according to claim 22, the machine-accessible data further including associated data that, when accessed, results in performing keystone correction using the keystone correction corner points.
  - 24. An article according to claim 23, wherein performing keystone correction includes performing vertical scaling followed by horizontal scaling.
  - 25. An article according to claim 23, wherein performing keystone correction includes performing horizontal scaling followed by vertical scaling.
  - 26. An article according to claim 22, wherein determining a horizontal tilt angle β
    - h includes adjusting the horizontal tilt angle β
      
      h based on the vertical tilt angle β
      
      v.
  - 27. An article according to claim 22, wherein determining a vertical tilt angle β
    - v includes receiving the vertical tilt angle β
      
      v as an input from a user.
  - 28. An article according to claim 22, wherein determining a horizontal tilt angle β
    - h includes receiving the horizontal tilt angle β
      
      h as an input from a user.

29. An apparatus, comprising:
- an image projector to project an image;
  
  a set of inherent parameters including a horizontal resolution Wn₀, a vertical resolution Hn₀, a depth d, and a vertical offset db;
  
  a receiver to receive a vertical tilt angle β
  
  v and a horizontal tilt angle β
  
  h; and
  
  a corrector to compute keystone correction corner points for the image using the set of inherent parameters, the vertical tilt angle β
  
  v, and the horizontal tilt angle β
  
  h using formulae $xp [x, y] = \frac{\cos [β h] \times x - \sin [β h] \times \sin [β v] \times y}{1 + \frac{\sin [β h] \times x - \cos [β h] \times \sin [β v] \times y}{d}} and$ $yp [x, y] = \frac{\cos [β v] \times y - (db - \frac{{Hn}_{0}}{2})}{1 + \frac{\sin [β h] \times x + \cos [β h] \times \sin [β v] \times y}{d}} + (db - \frac{{Hn}_{0}}{2}),$
  
  where x and y represent an uncorrected pixel location and xp and yp represent a corrected pixel location.
- View Dependent Claims (30, 31, 32, 33, 34, 35)
- - 30. A projector according to claim 29, wherein the receiver is operative to receive the vertical tilt angle β
    - v and the horizontal tilt angle β
      
      h from a user.
  - 31. A projector according to claim 29, wherein the receiver is operative to receive the vertical tilt angle β
    - v and the horizontal tilt angle β
      
      h relative to a surface.
  - 32. A projector according to claim 29, wherein the corrector performs keystone correction on the image using the keystone correction corner points for the image.
  - 33. A projector according to claim 32, wherein the corrector applies vertical scaling followed by horizontal scaling to the image to perform keystone correction.
  - 34. A projector according to claim 32, wherein the corrector applies horizontal scaling followed by vertical scaling to the image to perform keystone correction.
  - 35. A projector according to claim 29, wherein the receiver includes an adjuster to adjust the horizontal tilt angle β
    - h based on the vertical tilt angle β
      
      v.

36. A projector, comprising:
- means for projecting an image;
  
  means for determining a set of inherent parameters including a horizontal resolution Wn₀, a vertical resolution Hn₀, a depth d, and a vertical offset db;
  
  means for receiving a vertical tilt angle β
  
  v and a horizontal tilt angle β
  
  h; and
  
  means for computing keystone correction corner points for the image using the set of inherent parameters, the vertical tilt angle β
  
  v, and the horizontal tilt angle β
  
  h using formulae $xp [x, y] = \frac{\cos [β h] \times x - \sin [β h] \times \sin [β v] \times y}{1 + \frac{\sin [β h] \times x - \cos [β h] \times \sin [β v] \times y}{d}} and$ $yp [x, y] = \frac{\cos [β v] \times y - (db - \frac{{Hn}_{0}}{2})}{1 + \frac{\sin [β h] \times x + \cos [β h] \times \sin [β v] \times y}{d}} + (db - \frac{{Hn}_{0}}{2}),$
  
  where x and y represent an uncorrected pixel location and xp and yp represent a corrected pixel location.
- View Dependent Claims (37, 38, 39, 40, 41, 42)
- - 37. A projector according to claim 36, wherein the means for receiving a vertical tilt angle β
    - v and a horizontal tilt angle β
      
      h includes means for receiving the vertical tilt angle β
      
      v and the horizontal tilt angle β
      
      h from a user.
  - 38. A projector according to claim 36, wherein the means for receiving a vertical tilt angle β
    - v and a horizontal tilt angle β
      
      h includes means for determining the vertical tilt angle β
      
      v and the horizontal tilt angle β
      
      h relative to a surface.
  - 39. A projector according to claim 36, further comprising means for performing keystone correction to the image using the keystone correction corner points for the image.
  - 40. A projector according to claim 39, wherein the means for performing keystone correction includes means for performing vertical scaling followed by horizontal scaling to the image to perform keystone correction.
  - 41. A projector according to claim 39, wherein the means for performing keystone correction includes means for performing horizontal scaling followed by vertical scaling to the image to perform keystone correction.
  - 42. A projector according to claim 36, wherein the means for receiving a vertical tilt angle β
    - v and a horizontal tilt angle β
      
      h includes means for adjusting the horizontal tilt angle β
      
      h based on the vertical tilt angle β
      
      v.

43. A method for performing keystone correction in a projector, comprising:
- determining a set of inherent parameters for the projector, the set of inherent parameters including a horizontal resolution Wn₀, a vertical resolution Hn₀, a depth d, and a vertical offset db;
  
  determining a vertical tilt angle β
  
  v;
  
  determining a horizontal tilt angle β
  
  h; and
  
  computing keystone correction corner points using the set of inherent parameters, the vertical tilt angle β
  
  v, and the horizontal tilt angle β
  
  h using formulae $xp [x, y] = \frac{\cos [β h] \times x - \sin [β h] \times \sin [β v] \times y}{1 + \frac{\sin [β h] \times x - \cos [β h] \times \sin [β v] \times y}{d}} and$ $yp [x, y] = \frac{\cos [β v] \times y - (db - \frac{{Hn}_{0}}{2})}{1 + \frac{\sin [β h] \times x + \cos [β h] \times \sin [β v] \times y}{d}} + (db - \frac{{Hn}_{0}}{2}),$
  
  where x and y represent an uncorrected pixel location and xp and yp represent a corrected pixel location.
- View Dependent Claims (44, 45, 46, 47, 48, 49)
- - 44. A method according to claim 43, further comprising performing keystone correction using the keystone correction corner points.
  - 45. A method according to claim 44, wherein performing keystone correction includes performing vertical scaling followed by horizontal scaling.
  - 46. A method according to claim 44, wherein performing keystone correction includes performing horizontal scaling followed by vertical scaling.
  - 47. A method according to claim 43, wherein determining a horizontal tilt angle β
    - h includes adjusting the horizontal tilt angle β
      
      h based on the vertical tilt angle β
      
      v.
  - 48. A method according to claim 43, wherein determining a vertical tilt angle β
    - v includes receiving the vertical tilt angle β
      
      v as an input from a user.
  - 49. A method according to claim 43, wherein determining a horizontal tilt angle β
    - h includes receiving the horizontal tilt angle β
      
      h as an input from a user.

50. An article comprising a machine-accessible media having associated data, wherein the data, when accessed, results in a machine performing:
- determining a set of inherent parameters for a projector, the set of inherent parameters including a horizontal resolution Wn₀, a vertical resolution Hn₀, a depth d, and a vertical offset db;
  
  determining a vertical tilt angle β
  
  v;
  
  determining a horizontal tilt angle β
  
  h; and
  
  computing keystone correction corner points using the set of inherent parameters, the vertical tilt angle β
  
  v, and the horizontal tilt angle β
  
  h using formulae $xp [x, y] = \frac{\cos [β h] \times x - \sin [β h] \times \sin [β v] \times y}{1 + \frac{\sin [β h] \times x - \cos [β h] \times \sin [β v] \times y}{d}} and$ $yp [x, y] = \frac{\cos [β v] \times y - (db - \frac{{Hn}_{0}}{2})}{1 + \frac{\sin [β h] \times x + \cos [β h] \times \sin [β v] \times y}{d}} + (db - \frac{{Hn}_{0}}{2}),$
  
  where x and y represent an uncorrected pixel location and xp and yp represent a corrected pixel location.
- View Dependent Claims (51, 52, 53, 54, 55, 56)
- - 51. An article according to claim 50, the machine-accessible data further including associated data that, when accessed, results in performing keystone correction using the keystone correction corner points.
  - 52. An article according to claim 51, wherein performing keystone correction includes performing vertical scaling followed by horizontal scaling.
  - 53. An article according to claim 51, wherein performing keystone correction includes performing horizontal scaling followed by vertical scaling.
  - 54. An article according to claim 50, wherein determining a horizontal tilt angle β
    - h includes adjusting the horizontal tilt angle β
      
      h based on the vertical tilt angle β
      
      v.
  - 55. An article according to claim 50, wherein determining a vertical tilt angle β
    - v includes receiving the vertical tilt angle β
      
      v as an input from a user.
  - 56. An article according to claim 50, wherein determining a horizontal tilt angle β
    - h includes receiving the horizontal tilt angle β
      
      h as an input from a user.

Specification

Resources

Litigation Campaign Assessment

Current Assignee
Pixelworks Semiconductor Technology Company Limited
Original Assignee
Pixelworks Incorporated
Inventors
Teng, Tianbing Brian, Wang, Zhongde
Primary Examiner(s)
MAHONEY, CHRISTOPHER E

Application Number

US10/849,998
Time in Patent Office

636 Days
Field of Search

353/69, 353/70, 348/745, 348/806
US Class Current

353/70
CPC Class Codes

G03B 21/14 Details

H04N 9/3185 Geometric adjustment, e.g. ...

Keystone correction derived from the parameters of projectors

First Claim

3 Assignments

0 Petitions

Accused Products

Abstract

Citations

56 Claims

Specification

Solutions

Use Cases

Quick Links

Keystone correction derived from the parameters of projectors

First Claim

3 Assignments

Subscription Required

Subscription Required

0 Petitions

Subscription Required

Accused Products

Subscription Required

Abstract

Citations

56 Claims

Specification

Subscription Required

Solutions

Use Cases

Quick Links