ELECTRONIC WATERMARK SYSTEM

• US 20010040977A1
• Filed: 02/12/1998
• Published: 11/15/2001
• Est. Priority Date: 02/12/1997
• Status: Active Grant

• Current Assignee: NEC Personal Computers, Ltd. (Lenovo Group Ltd.)
• Original Assignee: NEC Corporation
• Inventors: NAKANO, HIROTAKA
• Granted Patent: US 6,421,450 B2
• Time in Patent Office: Days
• US Class Current: 382/100
• CPC Class Codes: G06T 1/0021 Image watermarking
• CPC Class Codes: G06T 2201/0052 Embedding of the watermark in the frequency domain
• CPC Class Codes: G06T 2201/0065 Extraction of an embedded watermark; Reliable detection
• CPC Class Codes: G11B 20/00086 Circuits for prevention of unauthorised reproduction or copying, e.g. piracy indicating unauthorised use of record carriers in general G11B23/28; scrambling for television signal recording H04N5/913; network architectures or network protocols for network security H04L63/00; cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00
• CPC Class Codes: G11B 20/00094 involving measures which result in a restriction to authorised record carriers
• CPC Class Codes: G11B 20/0021 involving encryption or decryption of contents recorded on or reproduced from a record carrier
• CPC Class Codes: G11B 20/00557 wherein further management data is encrypted, e.g. sector headers, TOC or the lead-in or lead-out areas
• CPC Class Codes: G11B 20/00855 involving a step of exchanging information with a remote server
• CPC Class Codes: G11B 20/00884 involving a watermark, i.e. a barely perceptible transformation of the original data which can nevertheless be recognised by an algorithm
• CPC Class Codes: H04N 1/32154 Transform domain methods H04N1/32309 takes precedence
• CPC Class Codes: H04N 1/32165 using cosine transforms
• CPC Class Codes: H04N 1/32277 Compression
• CPC Class Codes: H04N 19/467 characterised by the embedded information being invisible, e.g. watermarking
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 21/23892 involving embedding information at multiplex stream level, e.g. embedding a watermark at packet level
• CPC Class Codes: H04N 21/8358 involving watermark protecting executable software by watermarking G06F21/16; image watermarking in general G06T1/0021; watermarks inserted in still images for transmission purposes H04N1/32144; inserting watermarks during video coding H04N19/467
• CPC Class Codes: H04N 2201/3233 of authentication information, e.g. digital signature, watermark
• CPC Class Codes: H04N 2201/3235 Checking or certification of the authentication information, e.g. by comparison with data stored independently
• CPC Class Codes: H04N 2201/327 which are undetectable to the naked eye, e.g. embedded codes
• CPC Class Codes: H04N 2201/3274 Storage or retrieval of prestored additional information
• CPC Class Codes: H04N 5/781 : on disks or drums
• CPC Class Codes: H04N 9/8042 : involving data reduction
• CPC Class Codes: H04N 9/8063 : using time division multiplex of the PCM audio and PCM video signals

Abstract

An electronic watermark system invisibly embeds watermark information into original image data and the watermarked image data is transferred to a first medium. At the same time, the embedded watermark information is transferred to a second medium. When a medium questioned is found, its watermark information can be easily identified by searching the second medium. Alternatively, the watermarked image data and the embedded watermark information are transferred to different storage areas of the same medium, respectively.

Claims

1. A system comprising:

an information generator for generating watermark information;

a combiner for invisibly embedding the watermark information into original image data to produce watermarked image data; and

a transfer controller for transferring the watermarked image data to a first medium and the watermark information to a second medium.

2. The system according to

claim 1

, wherein the transfer controller further transfers medium identification information identifying the first medium to the second medium.

3. The system according to

claim 2

, wherein the second medium stores the watermark information and the medium identification information to allow retrieval.

4. The system according to

claim 1

, wherein

the first medium is a first storage medium for storing the watermarked image data;

and

the second medium is a second storage medium for storing the watermark information and medium identification information identifying the first storage medium to allow retrieval.

5. The system according to

claim 4

, wherein the medium identification information is a manufacture serial number of the first storage medium.

6. The system according to

claim 1

, wherein

the first medium is a communication medium through which the watermarked image data is transmitted to a destination in a communication network;

and

the second medium is a storage medium for storing the watermark information and medium identification information identifying the destination to allow retrieval.

7. The system according to

claim 6

, wherein the medium identification information is an address of the destination in the communication network.

8. A system comprising:

an information generator for generating information;

a combiner for invisibly embedding the watermark information into original image data to produce watermarked image data; and

a transfer controller for transferring both the watermarked image data and the watermark information to a single medium.

9. The system according to

claim 8

, wherein the single medium is a storage medium having a first storage area for storing the watermarked image data and a second storage area for storing the watermark information, wherein the second storage area is dedicated to the watermark information so that only the watermark information is allowed to be read.

10. The system according to

claim 8

, wherein the transfer controller encrypts the watermark information and transfers encrypted watermark information to the single medium.

11. The system according to

claim 10

, wherein the single medium is a storage medium having a first storage area for storing the watermarked image data and a second storage area for storing the encrypted watermark information, wherein the second storage area is dedicated to the encrypted watermark information so that only the encrypted watermark information is allowed to be read.

12. An authorization check system for checking whether a medium questioned is authorized, comprising:

a storage for storing watermark information and medium identification information identifying a medium, the medium storing watermarked image data which is produced by invisibly embedding the watermark information into original image data;

a retrieval controller for retrieving watermark information corresponding to medium identification information of the medium questioned from the storage;

watermark extractor for extracting watermark information questioned from image data stored in the medium questioned; and

a checker for checking whether the medium questioned is authorized by comparing the extracted watermark information with the retrieved watermark information.

13. The authorization check system according to

claim 12

, wherein the medium identification information is a manufacture serial number of the medium.

14. The authorization check system according to

claim 12

, wherein the medium is a communication medium through which the watermarked image data is transmitted to a destination in a communication network, wherein the medium identification information is an address of the destination in the communication network.

15. An authorization check system for checking whether a medium questioned is authorized, the medium questioned having a first storage area for storing watermarked image data and a second storage area for storing watermark information, the system comprising:

a watermark extractor for extracting watermark information from image data stored in the medium questioned; and

a checker for checking whether the medium questioned is authorized by comparing the extracted watermark information with the watermark information stored in the second storage area of the medium questioned.

16. The authorization check system according to

claim 15

, wherein the watermark information stored in the second storage area is encrypted.

17. A method for checking whether a medium questioned is authorized, comprising the steps of:

generating watermark information;

invisibly embedding the watermark information into original image data to produce watermarked image data;

transferring the watermarked image data to an authorized medium;

transferring the watermark information and medium identification information identifying the authorized medium to a retrieval medium;

retrieving watermark information corresponding to medium identification information of the medium questioned from the retrieval medium;

extracting watermark information questioned from image data stored in the medium questioned; and

checking whether the medium questioned is authorized by comparing the extracted watermark information with the retrieved watermark information.

18. The method according to

claim 17

, wherein the medium identification information is a manufacture serial number.

19. A method for checking whether image data questioned is authorized, comprising the steps of:

generating watermark information;

invisibly embedding the watermark information into original image data to produce watermarked image data;

transmitting the watermarked image data to an authorized destination through a network;

transferring the watermark information and medium identification information identifying the authorized destination to a retrieval medium;

retrieving watermark information corresponding to identification information of a data provider providing the image data questioned from the retrieval medium;

extracting watermark information from the image data questioned received from the data provider; and

checking whether the image data questioned is authorized by comparing the extracted watermark information with the retrieved watermark information.

20. A method for checking whether a medium questioned is authorized, comprising the steps of:

generating watermark information;

invisibly embedding the watermark information into original image data to produce watermarked image data;

transferring both the watermarked image data and the watermark information to an authorized medium;

extracting watermark information from image data stored in the medium questioned; and

checking whether the medium questioned is authorized by comparing the extracted watermark information with watermark information stored in the medium questioned.

21. The method according to

claim 20

, wherein the authorized medium is a storage medium having a first storage area for storing the watermarked image data and a second storage area for storing the watermark information, wherein the second storage area is dedicated to the watermark information so that only the watermark information is allowed to be read.

22. The method according to

claim 21

, wherein the watermark information is encrypted and encrypted watermark information is stored to the authorized medium.