Method and apparatus for processing image data and computer program

• US 7,952,766 B2
• Filed: 03/25/2004
• Issued: 05/31/2011
• Est. Priority Date: 11/28/2003
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Moroo, Jun, Noda, Tsugio
• Primary Examiner(s): Thompson; James A
• Application Number:
  US10/808,563
• Publication Number:
  US 20050117774A1
• Time in Patent Office: 2,623 Days
• Field of Search: 358/3.28, 358/504, 358/518, 358/1.9, 358/515, 382/100
• US Class Current: 358/3.28
• CPC Class Codes: H04N 1/32309 in colour image data

Abstract

A dividing unit divides image data into a plurality of blocks. An extracting unit extracts a feature index of a first color component and a feature index of a second color component in each of the blocks. A registration unit registers information about a correspondence between the feature index of a second color component and a change in the feature index for the first color component. A code embedding unit embeds a predetermined code into the image data, by changing the feature index of the first color component based on the feature index of the second color component, using the information registered.

Claims

1. An image data processing apparatus comprising:

a dividing unit that divides image data into a plurality of blocks;

a block extracting unit that extracts a pair of blocks from the divided blocks;

an index extracting unit that extracts two feature indices of a first color component and two feature indices of a second color component which differs from the first color component from the pair of blocks, one of the two feature indices being extracted from one of the pair of blocks and the other of the two feature indices being extracted from the other of the pair of blocks; and

a code embedding unit that embeds a code into the pair of blocks, by changing at least one of the extracted two feature indices of the first color component of the pair of blocks based on a magnitude relationship between the extracted two feature indices of the second color component of the pair of blocks and a value determined by at least one of the extracted two feature indices of the second color component.

2. The image data processing apparatus according to claim 1, wherein the first color component is a yellow component.

3. The image data processing apparatus according to claim 2, wherein the second color component is a magenta component.

4. The image data processing apparatus according to claim 1, further comprising a code extracting unit that extracts the code embedded into the image data.

5. A method of processing image data comprising:

dividing image data into a plurality of blocks;

extracting a pair of blocks from the plurality of blocks;

extracting two feature indices of a first color component and two feature indices of a second color component which differs from the first color component from the pair of blocks, one of the two feature indices being extracted from one of the pair of blocks and the other of the two feature indices being extracted from the other of the pair of blocks; and

embedding, by a computer processor, a code into the pair of blocks of the image data, by changing at least one of the extracted two feature indices of the first color component of the pair of the blocks based on a magnitude relationship between the extracted two feature indices of the second color component of the pair of blocks and a value determined by at least one of the extracted two feature indices of the second color component.

6. The method according to claim 5, wherein the first color component is a yellow component.

7. The method according to claim 6, wherein the second color component is a magenta component.

8. The method according to claim 5, further comprising extracting the code embedded into the image data.

9. A computer-readable recording medium that stores a computer program that, when executed by a computer, makes the computer perform a process comprising:

dividing image data into a plurality of blocks;

extracting a pair of blocks from the divided block;

extracting two feature indices of a first color component and two feature indices of a second color component which differs from the first color component from the pair of blocks, one of the two feature indices being extracted from one of the pair of blocks and the other of the two feature indices being extracted from the other of the pair of blocks; and

embedding a code into the pair of blocks of the image data, by changing at least one of the extracted two feature indices of the first color component of the pair of blocks based on a magnitude relationship between the extracted two feature indices of the second color component of the pair of blocks and a value determined by at least one of the extracted two feature indices of the second color component.

10. The computer-readable recording medium according to claim 9, wherein the first color component is a yellow component.

11. The computer-readable recording medium according to claim 10, wherein the second color component is a magenta component.

12. The computer-readable recording medium according to claim 9, further making the computer perform extracting the code embedded into the image data.

13. An embedding unit that is included in an image data processing apparatus

wherein

the embedding unit embeds a code into a pair of blocks, the pair of blocks being extracted from divided into blocks of image data, by changing at least one of extracted two feature indices of a first color component, the two feature indices of the first color component being extracted from the pair of blocks, based on a magnitude relationship between extracted two feature indices of a second color component different from the first color component and extracted from the other block of the pair of blocks and a value determined by at least one of the extracted two feature indices of the second color component.

14. A method of configuring an embedding unit that is included in an image data processing apparatus for embedding a code into an image data, comprising:

configuring a computer processor in the image processing apparatus to execute;

dividing image data into a plurality of blocks;

extracting a pair of blocks from the plurality of blocks; and

extracting two feature indices of a first color component and two feature indices of a second color component which differs from the first color component from the pair of blocks, one of the two feature indices being extracted from one of the pair of blocks and the other of the two feature indices being extracted from the other of the pair of blocks, wherein

the embedding includes embedding the code into the pair of blocks of the image data, by changing at least one of the extracted two feature indices of the first color component of the pair of the blocks based on a magnitude relationship between the extracted two feature indices of the second color component of the pair of blocks and a value determined by at least one of the extracted two feature indices of the second color component.

15. A computer-readable recording medium that stores a computer program, that when executed by a computer, makes the computer perform embedding a code into image data comprising:

dividing the image data into a plurality of blocks;

extracting a pair of blocks from the divided block; and

extracting two feature indices of a first color component and two feature indices of a second color component which differs from the first color component from the pair of blocks, one of the two feature indices being extracted from one of the pair of blocks and the other of the two feature indices being extracted from the other of the pair of blocks, wherein

the embedding includes embedding the code into the pair of blocks of the image data, by changing at least one of the extracted two feature indices of the first color component of the pair of blocks based on a magnitude relationship between the extracted two feature indices of the second color component of the pair blocks and a value determined by at least one of the extracted two feature indices of the second color component.