IP Library Granted Patent US 6,850,651
Granted Patent B2
US 6,850,651 · App. 09/897,716 · Granted Feb 1, 2005

Moiré correction in images

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Quick Facts
Patent No.
US 6,850,651
App. No.
09/897,716
Granted
Feb 1, 2005
Kind
B2
Abstract

Image defects in a digital image are reduced by a process comprising: providing a digital image data set in the form of a matrix of pixels; selecting a sub-matrix comprising at least a 5×5 matrix of pixels; identifying a pixel within the sub-matrix to be treated as a central pixel; determining a value for at least one optical property in the central pixel; selecting at least four pixels around the central pixel as averaging pixels, at least two of the averaging pixels being in a position in the sub-matrix that is not adjacent the position in the matrix of the central pixel; determining a value for the at least one optical property for the at least four averaging pixels; averaging the values for the at least one optical property for more than one of the at least four averaging pixels to provide an average treatment value for the central pixel; assigning the average treatment value for the central pixel to the central pixel; and storing the average treatment value assigned to the central pixel.

Claims (64)

1. A method of reducing image defects in a digital image comprising:

providing a digital image data set in the form of a matrix of pixels;

selecting a sub-matrix comprising at least a 5×5 matrix of pixels;

identifying a pixel within the sub-matrix to be treated as a central pixel;

determining a value for at least one optical property in the central pixel;

selecting at least four pixels around the central pixel as averaging pixels, at least two of the averaging pixels being in a position in the sub-matrix that is not adjacent the position in the matrix of the central pixel;

determining a value for the at least one optical property for the at least four averaging pixels;

averaging the values for the at least one optical property for more than one of the at least four averaging pixels to provide an average treatment value for the central pixel;

assigning the average treatment value for the central pixel to the central pixel; and

storing the average treatment value assigned to the central pixel.

2. The method of claim 1 wherein the matrix is an at least 7×7 matrix of pixels.

3. The method of claim 2 wherein at least six averaging pixels are selected.

4. The method of claim 3 wherein more than one but less than all averaging pixels are used to determine the average treatment value.

5. The method of claim 3 wherein at least four averaging pixels are pixels that are not in a position adjacent in the matrix to the central pixel.

6. The method of claim 5 wherein average treatment values are defined, assigned and stored for at least 20% of the pixels in the digital image.

7. The method of claim 3 wherein all averaging pixels are pixels that are not in a position adjacent in the matrix to the central pixel.

8. The method of claim 7 wherein average treatment values are defined, assigned and stored for at least 20% of the pixels in the digital image.

9. The method of claim 7 wherein average treatment values are defined, assigned and stored for at least 80% of the pixels in the digital image.

10. The method of claim 7 wherein the central pixel comprises a group of pixels that is less than all pixels in the sub-matrix.

11. The method of claim 2 wherein at least eight averaging pixels are selected.

12. The method of claim 11 wherein more than one but less than all averaging pixels are used to determine the average treatment value.

13. The method of claim 2 wherein at least three averaging pixels are pixels that are not in a position adjacent in the matrix to the central pixel.

14. The method of claim 13 wherein average treatment values are defined, assigned and stored for at least 20% of the pixels in the digital image.

15. The method of claim 13 wherein average treatment values are defined, assigned and stored for at least 80% of the pixels in the digital image.

16. The method of claim 13 wherein the central pixel comprises a group of pixels that is less than all pixels in the sub-matrix.

17. The method of claim 2 wherein all averaging pixels are pixels that are not in a position adjacent in the matrix to the central pixel.

18. The method of claim 2 wherein at least 8 pixels are averaged to determine corrected values.

19. The method of claim 1 wherein the central pixel comprises a group of pixels that is less than all pixels in the sub-matrix.

20. The method of claim 1 wherein for at least some pixels in the image, the saturation of the at least some pixels is further modified following assigning the average treatment value for the central pixel to the central pixel.

21. The method of claim 1 wherein for at least some pixels in the image, the chroma, C, is calculated and the maximum chroma in the image, C max , is estimated, using C max to determine corrected chroma values C corr according to the formula:

C corr =C max ·( C/C max ) 1/x .,

wherein x is from about 1.01 to about 1.60, and these corrected chroma values are stored as at least part of stored image data.

22. The method of claim 21 wherein all C corr for all pixels in the image are determined and stored.

23. The method of claim 1 wherein selecting a sub-matrix comprising at least a 5×5 matrix of pixels comprises selecting a square filter of width 6k+1 pixels, where k is an integer greater than zero, positioned approximately centrally on an image pixel.

24. The method of claim 23 wherein 6k+1 is 7, and wherein from 2 to 7 pixels are selected from the group of 8 pixels constituting corners and centers of the sides of the square, and the 2 to 7 pixels are used to compute a new corrected color value for the image pixel.

25. The method of claim 23 wherein 6k+1 is selected from the group consisting of 7, 13, 19, and 25 and wherein from 2 to 13 pixels are selected from the group of total pixels in the square and the 2 to 13 pixels comprise at least some corners and centers of the sides of the square, and the 2 to 7 pixels are used to compute a new corrected color value for the image pixel.

26. The method of claim 25 wherein corrected values are determined by averaging values from the 2 to 7 pixels.

27. The method of claim 26 wherein from 4 to 13 pixels are averaged to determine the corrected values.

28. A computer with imaging system associated therewith, the computer containing software therein that directs a process for improving image defects comprising:

providing a digital image data set in the form of a matrix of pixels;

selecting a sub-matrix comprising at least a 5×5 matrix of pixels;

identifying a pixel within the sub-matrix to be treated as a central pixel;

determining a value for at least one optical property in the central pixel;

selecting at least four pixels around the central pixel as averaging pixels, at least two of the averaging pixels being in a position in the sub-matrix that is not adjacent the position in the matrix of the central pixel;

determining a value for the at least one optical property for the at least four averaging pixels;

averaging the values for the at least one optical property for more than one of the at least four averaging pixels to provide an average treatment value for the central pixel;

assigning the average treatment value for the central pixel to the central pixel;

storing the average treatment value assigned to the central pixel; and

displaying the image with the stored average treatment value displayed in the image.

29. The computer with imaging system of claim 28 wherein the matrix is an at least 7×7 matrix of pixels and at least eight averaging pixels are selected.

30. The computer with imaging system of claim 29 wherein the matrix is an at least 7×7 matrix of pixels, average treatment values are defined, assigned and stored for approximately 100% of pixels in the digital image and eight averaging pixels are selected for each pixel for which average treatment values are assigned.

31. The computer with imaging system of claim 28 wherein the matrix is an at least 7×7 matrix of pixels and average treatment values are defined, assigned and stored for at least 80% of the pixels in the digital image.

32. The computer with imaging system of claim 31 wherein the central pixel comprises a group of pixels that is less than all pixels in the sub-matrix.

33. The computer with imaging system of claim 31 wherein average treatment values are defined, assigned and stored for at least 80% of the pixels in the digital image and the central pixel comprises a group of pixels that is less than all pixels in the sub-matrix.

34. A method of reducing moiré defects in a digital image comprising:

providing a digital image data set in the form of a matrix of pixels;

selecting a sub-matrix comprising at least a 5×5 matrix of pixels;

identifying a pixel within the sub-matrix to be treated as a central pixel;

determining a value for at least one optical property in the central pixel;

selecting at least four pixels around the central pixel as averaging pixels, at least two of the averaging pixels being in a position in the sub-matrix that is not adjacent the position in the matrix of the central pixel;

determining a value for the at least one optical property for the at least four averaging pixels;

averaging the values for the at least one optical property for more than one of the at least four averaging pixels to provide an average treatment value for the central pixel;

assigning the average treatment value for the central pixel to the central pixel; and

storing the average treatment value assigned to the central pixel.

Assignments (19)
TERMINATION AND RELEASE OF SECOND LIEN SECURITY INTEREST IN PATENT RIGHTS Recorded May 6, 2026
From: CANTOR FITZGERALD SECURITIES, AS COLLATERAL AGENT
To: CLEARSLIDE INC.; COREL CORPORATION (AS SUCCESSOR IN INTEREST TO CASCADE BIDCO CORP.)
Reel/Frame 075522/0510 →
RELEASE OF SECURITY INTEREST Recorded May 5, 2026
From: CITIBANK, N.A., AS AGENT
To: COREL CORPORATION; CASCADE BIDCO CORP.; COREL INC.; CLEARSLIDE INC.
Reel/Frame 075559/0953 →
SECURITY INTEREST Recorded Jul 3, 2019
From: CASCADE BIDCO CORP.; COREL INC.; CLEARSLIDE INC.
To: CITIBANK, N.A.
Reel/Frame 049678/0950 →
SECURITY INTEREST Recorded Jul 3, 2019
From: CASCADE BIDCO CORP.; COREL INC.; CLEARSLIDE INC.
To: CANTOR FITZGERALD SECURITIES
Reel/Frame 049678/0980 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 13, 2019
From: COREL SOFTWARE LLC
To: COREL CORPORATION
Reel/Frame 048067/0586 →
CHANGE OF NAME Recorded Nov 29, 2018
From: 8324450 CANADA INC.
To: COREL SOFTWARE LLC
Reel/Frame 047675/0950 →
ENTITY DOMICILE CHANGE Recorded Dec 17, 2014
From: 8324450 CANADA INC.
To: 8324450 DELAWARE LLC
Reel/Frame 034651/0817 →
CORRECTIVE ASSIGNMENT TO CORRECT THE ASSIGNEE, AND REPLACE THE ASSIGNMENT PREVIOUSLY RECORDED ON REEL 030427 FRAME 0331. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT TO 8324450 CANADA INC. Recorded Aug 1, 2013
From: COREL CORPORATION
To: 8324450 CANADA INC.
Reel/Frame 030986/0268 →
RELEASE OF SECURITY INTEREST Recorded Jun 11, 2013
From: JPMORGAN CHASE BANK, N.A.
To: COREL CORPORATION; COREL INC.; COREL HOLDINGS CORPORATION; WINZIP COMPUTING LP; WINZIP INTERNATIONAL LLC; WINZIP COMPUTING LLC
Reel/Frame 030591/0454 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 17, 2013
From: VECTOR CC HOLDINGS, SRL; VECTOR CC HOLDINGS III, SRL; VECTOR CC HOLDINGS IV, SRL
To: 8324450 CANADA INC.
Reel/Frame 030427/0403 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 16, 2013
From: COREL CORPORATION
To: VECTOR CC HOLDINGS, SRL; VECTOR CC HOLDINGS III, SRL; VECTOR CC HOLDINGS IV, SRL
Reel/Frame 030427/0331 →
ASSIGNMENT AND ASSUMPTION Recorded Dec 29, 2006
From: MORGAN STANLEY & COMPANY INCORPORATED
To: JPMORGAN CHASE BANK, N.A.
Reel/Frame 018688/0422 →
SECURITY AGREEMENT Recorded May 19, 2006
From: COREL CORPORATION; COREL INC.; COREL HOLDINGS CORPORATION; WINZIP COMPUTING LLC; WINZIP INTERNATIONAL LLC; WINZIP COMPUTING LP
To: MORGAN STANLEY & COMPANY INC.
Reel/Frame 017656/0072 →
RELEASE OF SECURITY INTERESTS Recorded May 17, 2006
From: CREDIT SUISSE TORONTO BRANCH (FKA CREDIT SUISSE FIRST BOSTON TORONTO BRANCH)
To: COREL CORPORATION; COREL US HOLDINGS, LLC
Reel/Frame 017636/0417 →
SECOND LIEN SECURITY AGREEMENT Recorded Aug 2, 2005
From: COREL CORPORATION; COREL US HOLDINGS, LLC
To: CREDIT SUISSE FIRST BOSTON TORONTO BRANON
Reel/Frame 016784/0245 →
SECURITY AGREEMENT Recorded Feb 28, 2005
From: COREL CORPORATION
To: CREDIT SUISSE FIRST BOSTON TORONTO BRANCH
Reel/Frame 016309/0733 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 27, 2004
From: COREL HOLDINGS CORPORATION
To: COREL CORPORATION
Reel/Frame 015292/0556 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 25, 2004
From: JASC SOFTWARE, INC.
To: COREL HOLDINGS CORPORATION
Reel/Frame 015283/0735 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 1, 2001
From: ZAKILKA, KRZYSTOF; MARKOV, NIKOLAI
To: JASC SOFTWARE, INC.
Reel/Frame 012258/0958 →