Hierarchical authentication system for images and video

• US 6,804,356 B1
• Filed: 03/20/2000
• Issued: 10/12/2004
• Est. Priority Date: 03/20/2000
• Status: Expired due to Fees

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Krishnamachari, Santhana
• Primary Examiner(s): Sheikh, Ayaz
• Assistant Examiner(s): Arani, Taghi T.
• Application Number:
  US09/531,700
• Time in Patent Office: 1,667 Days
• Field of Search: 380/201, 380/54, 380/210, 348/571, 348/661, 348/699, 382/232
• US Class Current: 380/201
• CPC Class Codes: H04N 1/32101 Display, printing, storage or transmission of additional information, e.g. ID code, date and time or title
• CPC Class Codes: H04N 1/32106 separate from the image data, e.g. in a different computer file
• CPC Class Codes: H04N 1/32128 attached to the image data, e.g. file header, transmitted message header, information on the same page or in the same computer file as the image for information embedded in the image H04N1/32144
• CPC Class Codes: H04N 2201/3236 Details of authentication information generation
• CPC Class Codes: H04N 2201/327 which are undetectable to the naked eye, e.g. embedded codes

Abstract

A method and system for creating authentication signatures for digital images and video frames is provided. The method and system involves partitioning the image into multiple blocks, comparing characteristics from each block and generating data bits based on the comparison. Each block is then broken up into additional blocks and those blocks are compared to create additional signature bits which are combined with the signature sets from the first set of blocks. Each of these new smaller blocks can be further broken up and the procedure can be repeated to provide an authentication signature of desired length.

Claims

1. A method of creating an authentication signature corresponding to an image, comprising:

partitioning at least a portion of an image into a selected number of first-level blocks of image information;

determining a first-level block value corresponding to a characteristic of the portion of the image contained in each first-level block;

processing the first-level block values for the first-level blocks and generating a first-level signature segment based on the first-level block values as a result of such processing;

subdividing each first-level block into a selected number of second-level sub-blocks;

determining a second-level sub-block value corresponding to a characteristic of the portion of the image contained in each second-level sub-block;

processing the second-level block values for the second-level sub-blocks and generating a second-level signature segment based on the second-level block values as a result of such processing; and

combining at least a portion of the second-level signature segment with at least a portion of the first-level signature segment.

2. The method of claim 1, wherein the characteristic of the image is based on chrominance or luminance values for the blocks or sub-blocks.

3. The method of claim 1, wherein the first-level signature segment is generated by ordering the blocks based on the first-level block value for each block and generating a binary code corresponding to the order of the blocks.

4. The method of claim 3, wherein the second-level signature segment is generated by ordering the sub-blocks based on the second-level value for each sub-block and generating binary codes corresponding to the ordered sub-blocks and the binary codes corresponding to the second-level signature segment are combined with the binary code corresponding to the first-level signature segment.

5. The method of claim 1, wherein there are four first-level blocks which are each divided into four second-level sub-blocks.

6. The method of claim 3, wherein there are four-level blocks which are each divided into four second-level sub-blocks.

7. The method of claim 6, wherein the order of the four first-level blocks are assigned a 5-digit binary code.

8. The method of claim 7, wherein the second-level signature is generated by ordering the sub-blocks based on the second-level sub-block values and assigning 5-digit binary codes to groups of four sub-blocks.

9. The method of claim 8, wherein the blocks are ordered in ascending or descending order of the first-level block values and second-level block values.

10. The method of claim 9, wherein selected binary codes for the signature segment are assigned when the first-level block values or second-level block values of two or more blocks or sub-blocks are equal.

11. The method of claim 1, wherein at least a portion of the second-level sub-blocks are subdivided into a selected number of third-level sub-blocks, third level signature segments are generated from the third-level, sub-blocks and the third-level signature segments are combined with the first and second-level signature segments.

12. A method of creating an authentication signature corresponding to an image, comprising:

partitioning at least a portion of an image into a selected number of first-level blocks of image information;

determining a first-level block value corresponding to a characteristic of the portion of the image contained in each first-level block;

ordering the blocks based on the first-level block values for the first-level blocks and generating a first-level signature segment corresponding to the resulting order;

subdividing each first-level block into a selected number of second-level sub-blocks;

determining a second-level sub-block value corresponding to a characteristic of the portion of the image contained in each second-level sub-block;

ordering the sub-blocks based on the second-level block values and generating a second-level signature segment corresponding to the order of the sub-blocks; and

combining the second-level signature segment with the first-level signature segment.

13. The method of claim 12, wherein there are four blocks and the first level signature segment is a 5 bit binary code.

14. The method of claim 13, wherein each block is divided into four sub-blocks and each of the four sub-blocks is assigned a 5 bit binary code and the four five bit codes are combined to form the second-level signature segment.

15. A system for providing an authentication signature corresponding to a digital image, comprising:

a data processor to receive data representing an image;

partition at least a portion of the image into a selected number of first level blocks of image information;

determine first-level block values corresponding to a characteristic of the portion of the image contained in each first-level blocks;

process the first-level block values for the first-level blocks;

generate a first-level signature segment as a result of such processing;

subdivide each first-level block into a selected number of second-level sub-blocks;

determine a second-level sub-block value corresponding to a characteristic of the portion of the image contained in each second-level sub-block; and

process the second-level block values for the second-level sub-blocks and generate a second-level signature segment as a result of such processing; and

combining at least a portion of the second-level signature segment with at least a portion of the first-level signature segment.

16. The system of claim 15, wherein the data processor determines the first level block value based on chrominance or luminance values for the blocks or sub-blocks.

17. The system of claim 15, wherein the data processor subdivides at least some of the second-level sub-blocks into a selected number of third-level sub-blocks and generate signature segments based on the third-level sub-blocks.

18. A system for creating an authentication signature corresponding to an image, comprising:

a data processor to receive data representing an image;

partition at least a portion of an image into a selected number of first-level blocks of image information;

determine a first-level block value corresponding to a characteristic of the portion of the image contained in each first-level block;

order the blocks based on the first-level block values for the first-level blocks;

generate a first-level signature segment corresponding to the resulting order;

subdivide each first-level block into a selected number of second-level sub-blocks;

determine a second-level sub-block value corresponding to a characteristic of the portion of the image contained in each second-level sub-block;

order to the sub-blocks based on the second-level block values;

generate a second-level signature segment corresponding to the order of the sub-blocks; and

combine the second-level signature segment with the first-level signature segment.

19. The system of claim 18, wherein the data processor divides the image into four blocks and create a 5 bit binary code as the first level signature segment.

20. The system of claim 19, wherein the data processor divides each block into four sub-blocks and each of the four sub-blocks is assigned a 5 bit binary code and the four five bit codes are combined to form the second-level signature segment.

21. A method for storing data on a data storage medium, the data representing an image and a signature corresponding to the image, comprising:

partitioning at least a portion of an image into a selected number of first-level blocks of image information;

determining a first-level block value corresponding to a characteristic of the portion of the image contained in each first-level block;

processing the first-level block values for the first-level blocks and generating a first-level signature segment based on the first-level block values as a result of such processing;

subdividing each first-level block into a selected number of second-level sub-blocks;

determining a second-level sub-block value corresponding to a characteristic of the portion of the image contained in each second-level sub-block;

processing the second-level block values for the second-level sub-blocks and generating a second-level signature segment based on the second-level block values as a result of such processing; and

combining the second-level signature segment with the first-level signature segment.

22. The method of claim 21, wherein the medium is selected from the group consisting of floppy disks, DVDs, video cassettes, and CDs.

23. An image authentication system, comprising:

providing a first image;

generating an authentication signature by a first method comprising partitioning at least a portion of an image into a selected number of first-level blocks of image information;

determining a first-level block value corresponding to a characteristic of the portion of the image contained in each first-level block;

processing the first-level block values for the first-level blocks and generating a first-level signature segment based on the first-level block values as a result of such processing;

subdividing each first-level block into a selected number of second-level sub-blocks;

determining a second-level sub-block value corresponding to a characteristic of the portion of the image contained in each second-level sub-block;

processing the second-level block values for the second-level sub-blocks and generating a second-level signature segment based on the second-level block values as a result of such processing; and

combining the second-level signature segment with the first-level signature segment;

providing a second image which may be identical to the first image;

generating a second signature for the second image by the first method; and

comparing the first signature to the second signature.