Digital-watermark embedding device, digital-watermark embedding method, and digital-watermark detecting device

• US 9,111,358 B2
• Filed: 09/06/2012
• Issued: 08/18/2015
• Est. Priority Date: 12/13/2011
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Kuraki, Kensuke, Anan, Taizo
• Primary Examiner(s): GORADIA, SHEFALI DINESH
• Application Number:
  US13/605,325
• Publication Number:
  US 20130148842A1
• Time in Patent Office: 1,076 Days
• Field of Search: 382/100
• US Class Current: 1/1
• CPC Class Codes: G06T 1/0085 Time domain based watermarking, e.g. watermarks spread over several images
• CPC Class Codes: G06T 2201/0051 Embedding of the watermark in the spatial domain

Abstract

A digital-watermark embedding device includes a content obtaining unit that obtains content; a watermark-information obtaining unit that obtains digital-watermark information; a generating unit that generates a synchronization flag on a basis of the digital-watermark information; and an embedding unit that embeds the digital-watermark information and the synchronization flag into the content.

Claims

1. A digital-watermark embedding device comprising:

a processor; and

a memory which stores a plurality of instructions, which when executed by the processor, cause the processor to execute;

obtaining content which includes a plurality of frames, and digital-watermark information that differs from a first bit string to each frame of the plurality of frames;

generating a synchronization flag, which indicates a position of the first bit string in the frame, and which differs from a second bit string to the each frame of the plurality of frames, on a basis of the first bit string of the digital-watermark information; and

embedding the digital-watermark information and the synchronization flag into the content.

2. The device according to claim 1,

wherein the generating generates a variable-length synchronization flag on a basis of the digital-watermark information.

3. The device according to claim 2,

wherein, with respect to the digital-watermark information, the generating generates the variable-length synchronization flag by using a variable-length table or an encoding algorithm for converting a length into a variable length.

4. The device according to claim 1,

wherein the generating generates the synchronization flag by using at least one of scrambling and exclusive OR.

5. A digital-watermark embedding method executed by a computer, the method comprising:

obtaining content which includes a plurality of frames;

obtaining digital-watermark information that differs from a first bit string to each frame of the plurality of frames;

generating, by a processor, a synchronization flag which indicates a position of the first bit string in the frame, and which differs from a second bit string to the each frame of the plurality of frames, on a basis of the first bit string of the digital-watermark information; and

embedding the digital-watermark information and the synchronization flag into the content.

6. The method according to claim 5,

wherein the generating generates a variable-length synchronization flag on a basis of the digital-watermark information.

7. The method according to claim 6,

wherein, with respect to the digital-watermark information, the generating generates the variable-length synchronization flag by using a variable-length table or an encoding algorithm for converting a length into a variable length.

8. The method according to claim 5,

wherein the generating generates the synchronization flag by using at least one of scrambling and exclusive OR.

9. A digital-watermark detecting device comprising:

an obtaining unit that obtains content;

an extracting unit that extracts a bit string embedded in the content; and

a detecting unit that generates a synchronization flag corresponding to a predetermined bit string in the extracted bit string, determines a correlation value between the synchronization flag and a bit string having the same length as a length of the synchronization flag immediately prior to or subsequent to the predetermined bit string while shifting the predetermined bit string bit-by-bit, and detects a synchronization flag at a position at which the correlation value is the largest in a predetermined range.

10. A digital-watermark embedding device comprising:

a processor; and

a memory which stores a plurality of instructions, which when executed by the processor, cause the processor to execute a process comprising;

obtaining content which includes a plurality of frames;

obtaining digital-watermark information that differs from a first bit string to each frame of the plurality of frames;

generating a synchronization flag which indicates a position of the first bit string in the frame, and which differs from a second bit string to the each frame of the plurality of frames, on a basis of the first bit string of the digital-watermark information; and

embedding the digital-watermark information and the synchronization flag into the content.

11. The device according to claim 10,

wherein the generating generates a variable-length synchronization flag on a basis of the digital-watermark information.

12. The device according to claim 11,

wherein, with respect to the digital-watermark information, the generating generates the variable-length synchronization flag by using a variable-length table or an encoding algorithm for converting a length into a variable length.

13. The device according to claim 10,

wherein the generating generates the synchronization flag by using at least one of scrambling and exclusive OR.