Information embedding device, information reading device, and recording media with recorded computer-readable program thereof

• US 20070127769A1
• Filed: 08/18/2004
• Published: 06/07/2007
• Est. Priority Date: 08/22/2003
• Status: Active Grant

• Current Assignee: Sovereign Peak Ventures, LLC (Dominion Harbor Enterprises, LLC)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Inoue, Hisashi, Ejima, Masataka, Noridomi, Kenichi, Katsura, Takashi, Horikami, Shugo
• Granted Patent: US 7,680,296 B2
• Time in Patent Office: Days
• US Class Current: 382/100
• CPC Class Codes: G06T 1/0064 Geometric transfor invariant watermarking, e.g. affine transform invariant
• CPC Class Codes: G06T 2201/0051 Embedding of the watermark in the spatial domain

Abstract

Information embedding is performed by extracting vertices composing a polygon from vector data, and changing the number of points that exist on the sides of the polygon based on the embedment information. Information reading is performed by extracting points existing on the sides of the polygon from the embedment information embedded vector data, and reading the embedment information according to the predetermined rule.

Claims

1. An information embedding device, comprising:

an extracting unit operable to extract information of vertices composing a polygon from vector data including information of the polygon; and

an information embedding unit operable, utilizing the information of vertices extracted by said extracting unit, to embed embedment information into the vector data in a robust manner against rotating operation.

2. The information embedding device as claimed in claim 1, wherein said information embedding unit operates, according to the embedment information, a total number of points of the polygon that the embedment information has been embedded.

3. The information embedding device as claimed in claim 1, wherein said information embedding unit operates, according to the embedment information, a distance between specified points of the polygon that the embedment information has been embedded.

4. The information embedding device as claimed in claim 1, wherein said information embedding unit changes, according to the embedment information, a number of points that exist on sides of the polygon.

5. The information embedding device as claimed in claim 1, wherein said information embedding unit inserts a point on a side of the polygon.

6. The information embedding device as claimed in claim 1, wherein said information embedding unit inserts a point at a position apart from a side of the polygon.

7. The information embedding device as claimed in claim 1, wherein said information embedding unit changes a number of points that exist on sides of the polygon in a manner such that a remainder value and a value M of the embedment information have a fixed correspondence, the remainder value being a remainder value where a number of points existing on sides of the polygon is divided by a constant number N, wherein the constant number N is an integer not less than a value of 2 and the value M is a non-negative integer less than the constant number N.

8. The information embedding device as claimed in claim 7, wherein the fixed correspondence is a relationship that the remainder value equals to the value M of the embedment information.

9. The information embedding device as claimed in claim 4, wherein said information embedding unit comprises:

a constant information inputting unit operable to input a constant number N (N is an integer not less than a value of

     2);

a remainder calculating unit operable to calculate a remainder where a number of vertices extracted by said extracting unit is divided by the constant number N;

an inserting number determining unit operable to determine a number of points to be inserted on a side of the polygon in a manner such that the remainder calculated by said remainder calculating unit and the embedment information have a fixed correspondence; and

an insertion executing unit operable to insert points as many as the number determined by said inserting number determining unit into the polygon.

10. The information embedding device as claimed in claim 1, wherein the constant number N is a constant number that does not depend on a number of vertices of the polygon.

15. The information embedding device as claimed in claim 1, wherein said information embedding unit changes a representative point that has been determined concerning the polygon in a manner such that a correspondence among a plurality of geometrical elements of the polygon changes.

16. The information embedding device as claimed in claim 15, wherein the representative point includes a vertex of the polygon.

17. The information embedding device as claimed in claim 15, wherein the plurality of geometrical elements are selected from a group consisting of a diagonal of the polygon, a center of gravity of the polygon, a vertex of the polygon, and a representative point of the polygon.

18. The information embedding device as claimed in claim 17, wherein the diagonal of the polygon is the longest diagonal.

19. The information embedding device as claimed in claim 18, wherein said information embedding unit changes the representative point in a manner such that the longest diagonal keeps longest nature.

20. The information embedding device as claimed in claim 15, wherein the correspondence is expressed using a distance between the plurality of geometrical elements.

21. The information embedding device as claimed in claim 15, wherein said information embedding unit comprises:

a correspondence determining unit operable to determine a correspondence between a value of the embedment information and the plurality of geometrical elements; and

an embedding unit operable to change the representative point according to the correspondence determined by said correspondence determining unit.

22. The information embedding device as claimed in claim 15, wherein the representative point is a center of gravity of the polygon.

23. The information embedding device as claimed in claim 15, wherein the representative point indicates a facility location.

27. The information embedding unit as claimed in claim 1, wherein said information embedding unit comprises:

an inserting unit operable to determine an insertion point to be inserted between two adjacent vertices among vertices extracted by said extracting unit; and

an embedding unit operable to embed the insertion point determined by said inserting unit between the two adjacent vertices, and

wherein said inserting unit changes, according to the embedment information, a relationship between a center of gravity of a first figure composed of vertices extracted by said extracting unit and a center of gravity of a second figure composed of at least three insertion points determined by said inserting unit.

28. The information embedding device as claimed in claim 27, wherein the first figure is a polygon extracted by said extracting unit, and

wherein the second figure is composed of all insertion points determined by said inserting unit.

29. The information embedding device as claimed in claim 27, wherein the relationship between the center of gravity of the first figure and the center of gravity of the second figure is evaluated according to whether the center of gravity of the first figure and the center of gravity of the second figure agree or not.

11. An information reading device, comprising:

an extracting unit operable to extract points on a polygon from embedment information-embedded vector data; and

an information reading unit operable to read the embedment information according to a number of the points extracted by said extracting unit and a predetermined rule.

12. The information reading device as claimed in claim 11, wherein the predetermined rule is a rule that a remainder value and a value of the embedment information have a fixed relationship, the remainder value being a remainder value where a number of points extracted by said extracting unit is divided by a constant number N (N is an integer not less than a value of 2).

13. The information reading device as claimed in claim 12, wherein the fixed relationship is a relationship that the remainder value equals to the value of the embedment information.

14. The information reading device as claimed in claim 11, wherein said information reading unit comprises:

a number calculating unit operable to calculate a number of the points extracted by said extracting unit;

a constant information inputting unit operable to input a constant number N (N is an integer not less than a value of

     2);

a remainder calculating unit operable to calculate a remainder where the number calculated by said number calculating unit is divided by the constant number N; and

an information reading unit operable to read the embedment information according to the remainder calculated by said remainder calculating unit.

24. An information reading device, comprising:

an extracting unit operable to extract a point on a polygon from embedment information-embedded vector data; and

an information reading unit operable to read the embedment information that has been embedded into the embedment information-embedded vector data according to a correspondence between the point extracted by said extracting unit and a plurality of geometrical elements of the polygon.

25. The information reading device as claimed in claim 24, wherein the plurality of geometrical elements are selected from a group consisting of a diagonal of the polygon, a center of gravity of the polygon, a vertex of the polygon, and a representative point of the polygon.

26. The information reading device as claimed in claim 24, wherein said information reading unit comprises:

a correspondence examining unit operable to examine a correspondence between the point extracted by said extracting unit and the plurality of geometric elements concerning the polygon; and

a reading unit operable, according to an examination result of said correspondence examining unit, to read the embedment information that has been embedded into the embedment information-embedded vector data.

30. An information reading device, comprising:

an extracting unit operable to extract a plurality of points of a polygon from embedment information-embedded vector data;

a classifying unit operable to classify the plurality of points extracted by said extracting unit into a first set and a second set, thereby determining a center of gravity of a first figure composed of a plurality of points belonging to the first set and a center of gravity of a second figure composed of a plurality of points belonging to the second set;

a calculation unit operable to calculate a distance between the center of gravity of the first figure and the center of gravity of the second figure; and

a reading unit operable to read the embedded embedment information according to the distance calculated by said calculation unit.

31. An information reading device, comprising:

an extracting unit operable to extract a plurality of points of a polygon from embedment information-embedded vector data; and

an information reading unit operable to read the embedded embedment information according to the plurality of points extracted by said extracting unit,

wherein said information reading unit comprises;

a classifying unit operable to classify the plurality of points extracted by said extracting unit into a first set and a second set, thereby determining a center of gravity of a first figure composed of a plurality of points belonging to the first set and a center of gravity of a second figure composed of a plurality of points belonging to the second set;

a calculation unit operable to calculate a distance between the center of gravity of the first figure and the center of gravity of the second figure; and

a reading unit operable to read the embedded embedment information according to the distance calculated by said calculation unit.

32. The information reading device as claimed in claim 31, wherein said classifying unit gives serial numbers to the plurality of points extracted by said extracting unit, thereby classifying each of the plurality of points extracted by said extracting unit according to whether a serial number given to each of the plurality of points is even or odd.

33. A recording medium having a program recorded therein, the program comprising processes for:

extracting information of vertices composing a polygon from vector data including information of the polygon; and

embedding, utilizing the information of the vertices extracted in said extracting, embedment information into the vector data in a manner such that the embedment information is held even when a coordinate system of the vector data is operated for rotation.

34. An electric apparatus, comprising:

a device identification value holding unit operable to hold a device identification value; and

an information embedding device operable to insert the device identification value into embedment information, thereafter embedding the embedment information into vector data including information of a polygon,

wherein said information embedding device comprises;

an extracting unit operable to extract information of vertices composing the polygon from the vector data; and

an information embedding unit operable to embed, utilizing the information of the polygon extracted by said extracting unit, the embedment information into the vector data in a robust manner against rotating operation.

35. The electric apparatus as claimed in claim 34, wherein said information embedding unit operates, according to the embedment information, a total number of points of the polygon that the embedment information has been embedded.

36. The electric apparatus as claimed in claim 34, wherein said information embedding unit operates, according to the embedment information, a distance between points of the polygon that the embedment information has been embedded.

37. The electric apparatus as claimed in claim 34, wherein the embedment information is composed of a value of a first bit region storing copyright information and a value of a second bit region storing the device identification value.