Extracting embedded information from digital image data

• US 7,206,432 B2
• Filed: 09/03/2004
• Issued: 04/17/2007
• Est. Priority Date: 01/30/1998
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Iwamura, Keiichi
• Primary Examiner(s): Wu; Jingge
• Assistant Examiner(s): Tabatabai; Abolfazl
• Application Number:
  US10/933,295
• Publication Number:
  US 20050033965A1
• Time in Patent Office: 956 Days
• Field of Search: 382/100, 382/232, 382/240, 382/190, 370522-529, 348/461, 348/463, 283/72, 283 74- 81, 283/85, 283/93, 283/113, 283/901, 283/902, 713/176, 713/179, 704/200.1, 704/273, 380/51, 380/54, 380/201, 380/210, 380/252, 380/287, 375/130
• US Class Current: 382/100
• CPC Class Codes: G06T 1/0071 using multiple or alternating watermarks
• CPC Class Codes: G06T 2201/0051 Embedding of the watermark in the spatial domain
• CPC Class Codes: G06T 2201/0052 Embedding of the watermark in the frequency domain
• CPC Class Codes: G06T 2201/0061 Embedding of the watermark in each block of the image, e.g. segmented watermarking
• 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 1/32149 Methods relating to embedding, encoding, decoding, detection or retrieval operations
• CPC Class Codes: H04N 1/32352 Controlling detectability or arrangements to facilitate detection or retrieval of the embedded information, e.g. using markers for decoding, detection or retrieval operations H04N1/32149 and subgroups take precedence
• CPC Class Codes: H04N 2201/3233 of authentication information, e.g. digital signature, watermark
• CPC Class Codes: H04N 2201/327 which are undetectable to the naked eye, e.g. embedded codes

Abstract

The invention extracts third information, which includes first and second information, from image data. The first information (e.g., copyright information) is embedded in the image data using a public embedding method, and the second information (e.g., information used to detect if the copyright has been altered) is embedded in the image data using a private embedding method. The first information is then extracted from the third information using the second information.

Claims

1. An extracting apparatus comprising:

a first extracting unit adapted to extract third information including first and second information from image data, wherein the first information is embedded in the image data in accordance with a first embedding method which uses publicly available information, and the second information is embedded in the image data in accordance with a second embedding method which uses secret information that is not made publicly available; and

a second extracting unit adapted to extract the first information from the third information using the second information.

2. An extracting apparatus according to claim 1, wherein the second information is used to detect whether the first information is altered.

3. An extracting apparatus according to claim 1, wherein the second information is used to recover alteration of the first information.

4. An extracting apparatus according to claim 1, wherein the first information includes information relating to a copyright of the image data.

5. An extracting apparatus according to claim 1, wherein the first information is embedded in a first area of the image data, and the second information is embedded in a second area of the image data.

6. An extracting apparatus according to claim 1, wherein the first information and the second information are invisibly embedded in the image data.

7. A method of extracting information from image data, the method comprising the steps of:

extracting third information including first and second information from image data, wherein the first information is embedded in the image data in accordance with a first embedding method which uses publicly available information, and the second information is embedded in the image data in accordance with a second embedding method which uses secret information that is not made publicly available; and

extracting the first information from the third information using the second information.

8. A method according to claim 7, wherein the second information is used to detect whether the first information is altered.

9. A method according to claim 7, wherein the second information is used to recover alteration of the first information.

10. A method according to claim 7, wherein the first information includes information relating to a copyright of the image data.

11. A method according to claim 7, wherein the first information is embedded in a first area of the image data, and the second information is embedded in a second area of the image data.

12. A method according to claim 7, wherein the first information and the second information are invisibly embedded in the image data.

13. A computer-readable storage medium that stores a computer-executable program for performing a method of extracting information from image data, the method comprising the steps of:

extracting third information including first and second information from the image data, wherein the first information is embedded in the image data in accordance with a first embedding method which uses publicly available information, and the second information is embedded in the image data in accordance with a second embedding method which uses secret information that is not made publicly available; and

extracting the first information from the third information using the second information.

14. A storage medium according to claim 13, wherein the second information is used to detect whether the first information is altered.

15. A storage medium according to claim 13, wherein the second information is used to recover alteration of the first information.

16. A storage medium according to claim 13, wherein the first information includes information relating to a copyright of the image data.

17. A storage medium according to claim 13, wherein the first information is embedded in a first area of the image data, and the second information is embedded in a second area of the image data.

18. A storage medium according to claim 13, wherein the first information and the second information are invisibly embedded in the image data.