Image protection

• US 20030123701A1
• Filed: 12/16/2002
• Published: 07/03/2003
• Est. Priority Date: 12/18/2001
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Dorrell, Andrew James, Tonnison, Alan Valev
• Granted Patent: US 7,251,343 B2
• Time in Patent Office: Days
• US Class Current: 382/100
• CPC Class Codes: G06F 21/64 Protecting data integrity, e.g. using checksums, certificates or signatures
• CPC Class Codes: H04N 1/32144 embedded in the image data, i.e. enclosed or integrated in the image, e.g. watermark, super-imposed logo or stamp
• CPC Class Codes: H04N 1/32267 combined with processing of the image
• CPC Class Codes: H04N 1/32283 Hashing
• CPC Class Codes: H04N 2201/3236 Details of authentication information generation

Abstract

A method (100) of marking an image comprising image data and associated metadata, for modification detection, is disclosed. The method (100) encodes the image data to produce encoded image data and hashes the encoded image data to provide a first hash. The first hash is added to the associated metadata to form augmented metadata the associated metadata is hashed to provide a second hash. The second hash is added to the augmented metadata. An association is created between the encoded image data, the first and second hash, and the augmented metadata, thereby marking the image.

Claims

1. A method of marking an image comprising image data and associated metadata, for modification detection, said method comprising the steps of:

encoding said image data to produce encoded image data;

hashing said encoded image data to provide a first hash and adding said first hash to said associated metadata to form augmented metadata;

hashing said associated metadata to provide a second hash and adding said second hash to said augmented metadata; and

creating an association between said encoded image data, said first and second hash, and said augmented metadata, thereby marking said image.

2. The method according to claim 1, wherein said association is formed by including at least said encoded image data and said augmented metadata in a file.

3. The method according to claim 1, said method further comprising the steps of:

generating an image identifier;

adding at least a portion of said image identifier to said associated metadata; and

encoding said image identifier with said image data to produce said encoded image data.

4. The method according to claim 3, wherein said image identifier is steganographically encoded into said image data.

5. The method according to claim 1, wherein copyright information is included in said associated metadata.

6. A detection method for detecting modification of an image comprising image data and associated metadata, wherein said image is marked according to the method of claim 1, said detection method comprising the steps of:

accessing an encoding/decoding key;

accessing a second hash utilising said key;

determining a third hash for said associated metadata;

comparing said third hash with said second hash; and

determining modification of said associated metadata based on said comparison.

7. The detection method according to claim 6, said method comprising the further steps of:

accessing a first hash;

determining a fourth hash for said image data;

comparing said first hash with said fourth hash; and

determining modification of said image based on said comparison.

8. An apparatus for marking an image comprising image data and associated metadata, for modification detection, said apparatus comprising:

encoding means for encoding said image data to produce encoded image data;

first hashing means for hashing said encoded image data to provide a first hash and adding said first hash to said associated metadata to form augmented metadata;

second hashing means for hashing said associated metadata to provide a second hash and adding said second hash to said augmented metadata; and

association means for creating an association between said encoded image data, said first and second hash, and said augmented metadata, thereby marking said image.

9. A program including computer implemented program codes for marking an image comprising image data and associated metadata, for modification detection, said program comprising:

code for encoding said image data to produce encoded image data;

code for hashing said encoded image data to provide a first hash and adding said first hash to said associated metadata to form augmented metadata;

code for hashing said associated metadata to provide a second hash and adding said second hash to said augmented metadata; and

code for creating an association between said encoded image data, said first and second hash, and said augmented metadata, thereby marking said image.

10. A method for authenticating an image, said image comprising image data and metadata, said method comprising the steps of:

determining availability of said associated metadata;

determining if said associated metadata has been modified upon said metadata being available;

determining if said image data has been modified; and

authenticating said image in the event that neither said metadata nor said image data have been modified, wherein said associated metadata and said image data are independently authenticated.

11. A method according to claim 10, further comprising the step of determining if said image contains authentication metadata.

12. A method according to claim 11, further comprising the steps of:

accessing watermark data in said image data;

utilising said watermark data to determine if said image comprises associated authentication metadata; and

recovering said associated authentication metadata.

13. A method according to claim 12, comprising the further step of utilising said recovered metadata to authenticate said image.

14. A method according to claim 12, wherein said associated authentication metadata is recovered from an independent database.

15. An apparatus for authenticating an image, said image comprising image data and metadata, said apparatus comprising:

means for determining availability of said associated metadata;

means for determining if said associated metadata has been modified upon said metadata being available;

means for determining if said image data has been modified; and

means for authenticating said image in the event that neither said metadata nor said image data have been modified, wherein said associated metadata and said image data are independently authenticated.

16. A computer program for authenticating an image, said image comprising image data and metadata, said program comprising:

code for determining availability of said associated metadata;

code for determining if said associated metadata has been modified upon said metadata being available;

code for determining if said image data has been modified; and

code for authenticating said image in the event that neither said metadata nor said image data have been modified, wherein said associated metadata and said image data are independently authenticated.