Edge Based Cmy Automatic Picture Registration

• US 20080118144A1
• Filed: 06/27/2005
• Published: 05/22/2008
• Est. Priority Date: 01/27/2005
• Status: Active Grant

• Current Assignee: Thomson Licensing (Vantiva SA)
• Original Assignee: Thomson Licensing (Vantiva SA)
• Inventors: Lin, Shu
• Granted Patent: US 8,014,592 B2
• Time in Patent Office: Days
• US Class Current: 382/162
• CPC Class Codes: G06T 7/12 Edge-based segmentation
• CPC Class Codes: G06T 7/33 using feature-based methods
• CPC Class Codes: G06T 7/90 Determination of colour characteristics
• CPC Class Codes: H04N 1/3876 Recombination of partial images to recreate the original image
• CPC Class Codes: H04N 1/58 Edge or detail enhancement; Noise or error suppression, e.g. colour misregistration correction H04N1/62 takes precedence
• CPC Class Codes: H04N 9/11 Scanning of colour motion picture films, e.g. for telecine

Abstract

An automatic process for performing CMY (Cyan, Magenta, Yellow) registration for film digital restoration. After three color components Cyan, Magenta, and Yellow of a picture are scanned into files, each component is divided into blocks, and edge detection is applied to each block, and an edge match is performed. The data of displacements is processed, and then an affine transform parameters are calculated. The affine transform is then applied for each block, and warping is used to combine the color components and obtain the registered picture of a color component.

Claims

1. A method for automatically registering the color components of a color film, the method comprising the steps of:

determining correlations between the color components of the color film;

processing the correlation data;

determining Affine Transform parameters for the color components;

calculating the Affine Transform for each pixel in the respective color component using the determined parameters; and

combining the color components to re-produce the color film.

2. The method according to claim 1, wherein said determining correlations comprises:

selecting a base color component;

calculating initial displacement coefficient vector values of the other color components with respect to said selected base color component;

dividing each picture frame into blocks;

detecting picture frame edges for the color components; and

matching the detected edges of each color component with respect to a chosen base color component.

3. The method according to claim 2, wherein said processing of the determined correlations comprises calculating new displacement vector values using the initially calculated displacement coefficient vector values.

4. The method according to claim 2, wherein said processing of the determined correlations comprises:

determining whether any large errors are present in the determined correlations;

modifying any large errors;

calculating new displacement value coefficients; and

re-calculating the displacement vector values using the newly calculated displacement value coefficients.

5. The method according to claim 4, wherein said determining is performed using a predetermined threshold.

6. The method according to claim 4, wherein said modifying errors is performed using by using neighboring block values or interpolation/extrapolation.

7. The method according to claim 4, wherein said calculating new displacement value coefficients is performed by applying a 3-order curve or 3-order plane to best fit numbers the error numbers in either direction.

8. The method according to claim 2, wherein said calculating the Affine transform comprises:

determining pixel position in the original picture for each pixel in a block using a nearest block analysis; and

defining affine transform parameters using the determined pixel positions and displacement values of the corresponding nearest blocks.

21. The method according to claim 1, wherein said combining comprises warping non base color components with the base color component to form a registered color image.

22. The method according to claim 21, further comprising converting the color components to a desired file or image format before forming the registered color image.

23. The method according to claim 1, further comprising:

downsampling image data to be registered to a lower resolution to speed up processing; and

upscaling matched displacement vectors to a desired resolution before said combining is performed.

9-20. -20. (canceled)

24. A method for edge based CMY automatic picture registration of a color film, the method comprising the steps of:

determining displacement values between a base color component and other color components of a color film;

processing the correlation data to obtain new displacement value coefficients corresponding to the determined displacement values identify and remove errors;

determining Affine Transform parameters for the other color components;

calculating the Affine Transform for each pixel in the respective color component using the determined parameters; and

combining the color components to re-produce the color film.

25. The method according to claim 24, wherein said processing further comprises re-calculating displacement vector values using the newly calculated displacement value coefficients.

26. The method according to claim 24, wherein said determining correlations comprises:

calculating initial displacement coefficient vector values of the other color components with respect to said selected base color component;

dividing each picture frame into blocks;

detecting picture frame edges for the color components; and

matching the detected edges of each color component with respect to a chosen base color component.

27. The method according to claim 26, wherein said determining Affine Transform parameters comprises:

determining pixel position in the original picture for each pixel in a block using a nearest block analysis; and

defining the affine transform parameters using the determined pixel positions and displacement values of the corresponding nearest blocks.

28. The method according to claim 24, wherein said combining comprises warping the other color components with the base color component to form a registered color image.

29. The method according to claim 28, wherein said warping comprises mapping each pixel in the new picture onto the old picture using the calculated Affine Transform.

30. The method according to claim 27, further comprising converting the color components to a desired file or image format before forming the registered color image.

31. The method according to claim 24, further comprising:

downsampling image data of the color film-to be registered to a lower resolution; and

upscaling matched displacement vectors to a desired resolution before said combining is performed.