Method and appartus for superposing a digital watermark and method and apparatus for detecting a digital watermark

• US 6,246,775 B1
• Filed: 09/14/1998
• Issued: 06/12/2001
• Est. Priority Date: 09/17/1997
• Status: Expired due to Term

• Current Assignee: Pioneer Electronic Corporation (Pioneer Corporation)
• Original Assignee: Pioneer Electronic Corporation (Pioneer Corporation)
• Inventors: Oriyama, Yoshiaki, Nakamura, Takeshi, Sugaya, Kazumi
• Primary Examiner(s): Johns, Andrew W.
• Assistant Examiner(s): NAKHJAVAN, SHERVIN K
• Application Number:
  US09/152,293
• Time in Patent Office: 1,002 Days
• Field of Search: 382/100, 382/232, 382/175, 380/54
• US Class Current: 382/100
• CPC Class Codes: G06T 1/0064 Geometric transfor invariant watermarking, e.g. affine transform invariant
• CPC Class Codes: G06T 1/0071 using multiple or alternating watermarks
• 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: G06T 2201/0065 Extraction of an embedded watermark; Reliable detection
• CPC Class Codes: H04N 1/32149 Methods relating to embedding, encoding, decoding, detection or retrieval operations
• CPC Class Codes: H04N 1/32165 using cosine transforms
• CPC Class Codes: H04N 1/32203 Spatial or amplitude domain methods H04N1/32309 takes precedence
• CPC Class Codes: H04N 1/32208 involving changing the magnitude of selected pixels, e.g. overlay of information or super-imposition H04N1/32219, H04N1/32224 take precedence
• 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 19/467 characterised by the embedded information being invisible, e.g. watermarking
• CPC Class Codes: H04N 19/60 using transform 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 2201/327 which are undetectable to the naked eye, e.g. embedded codes

Abstract

An apparatus for superposing a digital watermark for superposing digital watermark information on an information data signal bearing original information, superposes digital watermark information on an information data signal bearing original information, for each unit block consisting of a group of pieces of information data. This apparatus is provided with an auxiliary embedding circuit 10 for embedding second digital watermark information in the information data; a blocking circuit 12 for dividing into the unit blocks the changed information data signal obtained by the auxiliary embedding circuit; and a main embedding circuit 20 for embedding first digital watermark information in the changed information data signal for each of the divided blocks. The second digital watermark information bears information for identifying the position of the divided unit block in a predetermined section of the information data signal. On the basis of the second watermark information, a detecting apparatus effects proper blocking with respect to the information data signal with the watermark embedded therein, so as to detect the first watermark information.

Claims

1. A method for superposing a digital watermark containing digital watermark information on an information data signal bearing original information, for each of a plurality of unit blocks containing a group of pieces of information data, comprising:

embedding position information in the information data signal to produce a changed information data signal;

dividing the changed information data signal into the unit blocks; and

embedding the digital watermark information in the changed information data signal for each of the unit blocks,

wherein the position information bears information for recognizing a position of the unit blocks in a predetermined section of the information data signal.

2. The method for superposing a digital watermark according to claim 1, wherein the information data signal is a video signal.

3. An apparatus for superposing a digital watermark containing digital watermark information on an information data signal bearing original information, for each of a plurality of unit blocks containing a group of pieces of information data, comprising:

an auxiliary embedding circuit that embeds position information in the information data signal to produce a changed information data signal;

a blocking circuit that divides the changed information data signal into the unit blocks; and

a main embedding circuit that embeds digital watermark information in the changed information data signal for each of the unit blocks,

wherein the position information bears information for identifying a position of the unit blocks in a predetermined section of the information data signal.

4. The apparatus for superposing a digital watermark according to claim 3, wherein the information data signal is a video signal.

5. The apparatus for superposing a digital watermark according to claim 4, wherein the position information is information of a random pattern generated on the basis of an M-sequence.

6. The apparatus for superposing a digital watermark according to claim 3, wherein the position information is information of a random pattern generated on the basis of an M-sequence.

7. A method for detecting a digital watermark for detecting digital watermark information from a changed information data signal generated by superposing the digital watermark information on an information data signal, for each of a plurality of unit blocks containing a group of pieces of information data, comprising:

detecting position information from the changed information data signal, wherein the position information corresponds to positions of the unit blocks;

recognizing a recognized position of a unit block in a predetermined section of the changed information data signal based on the position information;

dividing the changed information data signal into the unit blocks based on the recognized position; and

detecting the digital watermark information for each of the unit blocks into which the changed information data signal is divided.

8. The method for detecting a digital watermark according to claim 7, wherein the information data signal is a video signal.

9. An apparatus for detecting a digital watermark containing digital watermark information from a changed information data signal generated by superposing the digital watermark information on an information data signal, for each of plurality of unit blocks containing a group of pieces of information data, comprising:

a position information detector that detects position information from the changed information data signal,

wherein the position information corresponds to positions of the unit blocks; and

a recognizing circuit that recognizes a recognized position of a unit block in a predetermined section of the changed information data signal based on the position information;

a blocking circuit that divides the changed information data signal into the unit blocks based on the recognized position; and

a watermark information detector that detects the digital watermark information for each of the unit blocks divided by the blocking circuit.

10. The apparatus for detecting a digital watermark according to claim 9, wherein the information data signal is a video signal.

11. The apparatus for detecting a digital watermark according to claim 10, wherein the video signal bears an image of a letter box type.

12. The apparatus for detecting a digital watermark according to claim 11, wherein said position information detector detects the position information from the changed information data signal on the basis of information of a random pattern generated in accordance with an M-sequence.

13. The apparatus for detecting a digital watermark according to claim 10, wherein the video signal bears an image of a pan scan type.

14. The apparatus for detecting a digital watermark according to claim 13, wherein said position information detector detects the position information from the changed information data signal on the basis of information of a random pattern generated in accordance with an M-sequence.

15. The apparatus for detecting a digital watermark according to claim 10, wherein said position information detector detects the position information from the changed information data signal on the basis of information of a random pattern generated in accordance with an M-sequence.

16. The apparatus for detecting a digital watermark according to claim 9, wherein said position information detector detects the position information from the changed information data signal on the basis of information of a random pattern generated in accordance with an M-sequence.

17. A method for superposing a digital watermark containing digital watermark information on each of a plurality unit blocks created by dividing an information data signal, comprising:

embedding position information in the information data signal, wherein the position information corresponds to a position of the unit blocks in the information data signal;

dividing the information data signal containing the embedded position information into the unit blocks; and

embedding the digital watermark information in each of the unit blocks.

18. The method for superposing a digital watermark according to claim 17, wherein the position information is information of a random pattern generated on the basis of an M-sequence.

19. An apparatus for superposing a digital watermark containing digital watermark information on each of a plurality unit blocks created by dividing an information data signal, comprising:

an auxiliary embedding device that embeds position information in the information data signal, wherein the position information corresponds to a position of the unit blocks in the information data signal;

a blocking device that divides the information data signal into the unit blocks; and

a watermark embedding device that embeds the digital watermark information in each of the unit blocks.

20. The apparatus for superposing a digital watermark according to claim 19, wherein the position information is information of a random pattern generated on the basis of an M-sequence.

21. A method for detecting a digital watermark containing digital watermark information from an information data signal, wherein the digital watermark information is embedded in each of a plurality of unit blocks created by dividing the information data signal and wherein the method comprises:

detecting position information corresponding to a position of the unit blocks in the information data signal;

recognizing the position of the unit blocks;

dividing the information data signal into the unit blocks based on the recognized position; and

detecting the digital watermark information in each of the unit blocks.

22. The method for detecting a digital watermark according to claim 21, wherein the position information is information of a random pattern generated on the basis of an M-sequence.

23. An apparatus for detecting a digital watermark containing digital watermark information from an information data signal, wherein the digital watermark information is embedded in each of a plurality of unit blocks created by dividing the information data signal and wherein the apparatus comprises:

a position information detecting device that detects position information contained in the information data signal, wherein the position information corresponds to a position of the unit blocks;

a recognizing device that recognizes the position of the unit blocks;

a blocking device that divides the information data signal into the unit blocks based on the recognized position; and

a watermark information detecting device that detects the digital watermark information in each of the unit blocks.

24. The apparatus for detecting a digital watermark according to claim 23, wherein the position information detecting device detects the position information from the information data signal based on a random pattern generated in accordance with an M-sequence.