CN1754380A - Information embedding device, information read device, and computer-readable recording medium containing program for them - Google Patents

Abstract

Information embedding is performed by extracting vertexes constituting a polygon from vector data and modifying the number of points existing on the sides of the polygon according to the embedded information. Embedded information is read by extracting points existing on the sides of the polygon and using a predetermined rule.

Description

Information embedding device, information reading device, and computer-readable recording medium recording programs for these devices

technical field

The present invention relates to an information embedding device for embedding embedded information into vector data and related technologies.

Background technique

With the popularity of car navigation systems and the Internet, the need for electronic maps has increased. Digital content such as an electronic map can be easily copied. Therefore, illegal copying tends to increase, and copyright protection becomes an important issue.

Document 1 (Japanese Patent Laid-Open No. 2001-78019) discloses the following information embedding method.

The embedding method of the information disclosed in Document 1 will be described with reference to FIG. 34 . In each graph of FIG. 34 , the horizontal axis and the vertical axis are the x-coordinate axis and the y-coordinate axis, respectively.

First, the reference point S is calculated from the embedding object point A. More specifically, the reference point S is obtained by masking the lower bits of the coordinates of the embedding target point A from the embedding information.

The shaded area in FIG. 34( a ) indicates the range in which the reference point S is obtained for the embedding target point A. FIG.

Furthermore, the hatched area in FIG. 34( a ) is divided into the area α in FIG. 34( b ) and the area β in FIG. 34( c ). The area α is used when information "1" is embedded, and the area β is used when information "0" is embedded.

That is, in the case of embedding information "1", the embedding object point A is moved to point B in Fig. 34(b), for example, and in the case of embedding information "0", the object point A is moved to ) point B.

In order to read the embedded information ("1" or "0"), the reference point S is obtained in the same manner as above, and the region α ( FIG. 34( b )) and the region β ( FIG. 34( c )) are obtained. Then, the embedding information is determined according to which of the area α and the area β the point B belongs to.

Furthermore, Document 2 (Japanese Patent Laid-Open No. 2002-300374 ) discloses the following technology.

First, as shown in FIG. 35( a ), two reference points A and B are extracted. Either of these reference points A and B is an end point of the graph.

Next, based on the x-coordinates of the reference points A and B, the reference point AB is divided into n equal parts (here, n=5), and 1-bit information is embedded in each section.

Here, in the case of embedded information "0", the number of certain points in the interval is set to an even number, and in the case of embedded information "1", the number of certain points in the interval is set to an odd number.

Furthermore, in order to read the embedded information, as described above, each interval is determined, and the value of the embedded information may be determined to be "1" or "0" depending on whether the number of points in these intervals is odd or even.

In Documents 1 and 2, it is not possible to predict the change of the xy coordinate system between the time of embedding information and the time of reading information, and of course, it cannot cope with it. Therefore, if the operation pattern is rotated between the time of embedding the information and the time of reading the information, the embedded information cannot be read out correctly based on only the manipulated vector data.

This becomes noticeable when, for example, rotation operations are performed multiple times, such as map data, and the methods of Documents 1 and 2 cannot actually be applied to vector data having such properties.

Contents of the invention

Therefore, an object of the present invention is to provide an information embedding device that can cope with rotation operations of vector data.

The information embedding device of the first invention includes: an extracting unit that extracts information on vertices constituting the polygon from vector data including information on the polygon; and an information embedding unit that uses the information on the vertices extracted by the extracting unit to stabilize against rotation In the state of , the embedding information is embedded in the vector data.

According to this structure, even if the vector data is subjected to a rotation operation, the embedded information is held, and no trouble occurs when the embedded information is read later.

In the information embedding device of the second invention, the information embedding unit operates on the total number of points of the polygon in which the information is embedded, based on the embedding information.

In this configuration, even if the polygon is rotated, the total number of points of the polygon does not change, and even if a malicious third party moves the points of the polygon to invalidate the embedded information, there will be no trouble in reading the embedded information later.

In the information embedding device of the third invention, the information embedding unit operates the distance between specific points of the polygon in which the information is embedded, based on the embedding information.

In this structure, even if the polygon is rotated, the distance between specific points of the polygon does not change, and no hindrance occurs when the embedded information is read later.

In the information embedding device of the fourth invention, the information embedding unit changes the number of points existing on the side of the polygon based on the embedding information.

According to this structure, the total number of points of the polygon varies.

In the information embedding device of the fifth invention, the information embedding unit inserts points on sides of the polygon.

According to this structure, the shape of the polygon does not change even after the point is inserted.

In the information embedding device according to the sixth invention, the information embedding unit inserts points at positions away from sides of the polygon.

According to this configuration, the shape of the polygon can be distorted by interpolation of points.

In the information embedding device of the seventh invention, the information embedding unit changes the number of points existing on the side of the polygon so that the number of points existing on the side of the polygon is divided by a constant N (N is an integer greater than or equal to 2). There is a certain correspondence between the remainder value and the value M of the embedded information (M is a non-negative integer, M<N).

In the information embedding device of the eighth invention, the fixed correspondence relationship is a relationship in which the remainder value is equal to the value M of the embedded information.

In the information embedding device of the ninth invention, the information embedding unit includes: a constant information input unit, which inputs a constant N (N is an integer greater than or equal to 2); a remainder calculation unit, which divides the number of vertices extracted by the extraction unit by the constant N. The remainder is calculated; the insertion number determination unit determines the number of points embedded on the side of the polygon, so that the remainder calculated by the remainder calculation unit has a certain correspondence with the embedded information; and the insertion execution unit determines the number of points embedded by the insertion number determination unit A determined number of points are embedded in the polygon.

According to these structures, the embedded information can be easily specified based on the correspondence relationship between the remainder value and the value of the embedded information.

In the information embedding device of the tenth invention, the constant N is a constant independent of the number of vertices of the polygon.

According to this structure, the embedding information is embedded with a certain rule regardless of the number of sides of the polygon.

An information reading device according to an eleventh invention includes: an extraction unit for extracting points on a polygon from vector data in which information has been embedded; Get embedded information.

In the information reading device of the twelfth invention, the prescribed rule is a rule that the remainder value of dividing the number of points extracted by the extraction unit by a constant N (N is an integer greater than or equal to 2) has a certain corresponding relationship with the value of the embedded information. .

In the information reading device of the thirteenth invention, the fixed correspondence relationship is a relationship in which the remainder value and the value M of the embedded information are equal.

According to these structures, it is possible to surely read the embedded information without being lost by the rotation operation.

The information reading device of the 14th invention, the information reading device includes: a number calculation part, which calculates the number of points extracted by the extraction part; a constant information input part, which inputs a constant N (N is an integer greater than or equal to 2); a calculation unit that calculates a remainder of dividing the number calculated by the number calculation unit by a constant N; and an information reading unit that reads the embedded information based on the remainder calculated by the remainder calculation unit.

According to this structure, embedded information can be specified from the remainder.

In the information embedding device according to the fifteenth invention, the information embedding unit changes the representative point set in advance for the polygon based on the embedding information so that the correspondence relationship of the plurality of geometric elements related to the polygon changes.

In the information embedding device of the sixteenth invention, the representative points include vertices of polygons.

In the information embedding device according to the seventeenth invention, the plurality of geometric elements are geometric elements selected from the group consisting of diagonal lines of polygons, centroids of polygons, vertices of polygons, and representative points of polygons.

According to these structures, it is possible to reflect the geometric properties of polygons and embed embedded information into polygons.

In the information embedding device of the eighteenth invention, the diagonal line is the longest diagonal line.

In the information embedding device of the nineteenth invention, the information embedding unit changes the representative point so that the longest diagonal line remains the longest.

According to these structures, it is possible to easily designate a diagonal line to be a target.

In the information embedding device of the twentieth invention, the correspondence relationship is represented by the distance between a plurality of geometric elements.

According to this structure, correspondence can be expressed by distance.

In the information embedding device of the twenty-first invention, the information embedding unit includes: a correspondence relationship determination unit that determines a correspondence relationship between a value of embedded information and a plurality of geometric elements; and an embedding unit that changes a representative point on the correspondence relationship determined by the correspondence relationship determination unit .

In the information embedding device of the twenty-second invention, the representative point is the center of gravity of the polygon.

According to these structures, it is possible to reflect the geometric properties of polygons and to embed embedding information in polygons.

In the information embedding device of the twenty-third invention, the representative point indicates the location of the facility.

According to this configuration, embedding information can be embedded in the polygon without changing the shape of the polygon.

Description of drawings

FIG. 1 is a functional block diagram of an information embedding device in Embodiment 1 of the present invention.

FIG. 2 is a flowchart of the information embedding device in Embodiment 1 of the present invention.

3(a) to 3(d) are illustrations of polygons according to Embodiment 1 of the present invention.

Fig. 4(a) is an illustration of a polygon according to Embodiment 1 of the present invention.

Fig. 4(b) is a relationship diagram of embedding information according to Embodiment 1 of the present invention.

5(a) to 5(e) are explanatory diagrams of examples of information embedding in Embodiment 1 of the present invention.

FIG. 6( a ) is an illustration of polygons in Embodiment 1 of the present invention.

FIG. 6( b ) is a relationship diagram of embedding information in Embodiment 1 of the present invention.

7(a) to 7(e) are explanatory diagrams of examples of information embedding in Embodiment 1 of the present invention.

FIG. 8 is a functional block diagram of an information reading device according to Embodiment 2 of the present invention.

9 is a flowchart of an information reading device in Embodiment 2 of the present invention.

10(a) to 10(b) are relationship diagrams of embedding information in Embodiment 2 of the present invention.

Fig. 11 is a block diagram of an information embedding/reading device in Embodiment 2 of the present invention.

Fig. 12 is a functional block diagram of an information embedding device in Embodiment 3 of the present invention.

Fig. 13 is a flowchart of an information embedding device in Embodiment 3 of the present invention.

14(a) to 14(c) are illustrations of polygons in Embodiment 3 of the present invention.

15(a) to 15(b) are explanatory diagrams of the center of gravity in Embodiment 3 of the present invention.

Fig. 16 is a functional block diagram of an information reading device according to Embodiment 4 of the present invention.

17 is a flowchart of an information reading device in Embodiment 4 of the present invention.

18(a) to 18(b) are illustrations of polygons in Embodiment 4 of the present invention.

Fig. 19 is a functional block diagram of an information embedding device in Embodiment 5 of the present invention.

Fig. 20 is a flowchart of an information embedding device in Embodiment 5 of the present invention.

21( a ) to 21( c ) are illustrations of polygons in Embodiment 5 of the present invention.

Fig. 22 is a functional block diagram of an information reading device according to Embodiment 6 of the present invention.

23 is a flowchart of the information reading device in Embodiment 6 of the present invention.

24(a) to 24(b) are illustrations of polygons in Embodiment 6 of the present invention.

Fig. 25 is a functional block diagram of an information embedding device according to Embodiment 7 of the present invention.

Fig. 26 is a flowchart of an information embedding device in Embodiment 7 of the present invention.

27(a) to 27(b) are explanatory diagrams of the center of gravity in Embodiment 7 of the present invention.

Fig. 28 is a functional block diagram of an information reading device in Embodiment 8 of the present invention.

Fig. 29 is a flowchart of an information embedding device in Embodiment 8 of the present invention.

30(a) to 30(b) are explanatory diagrams of the center of gravity in Embodiment 8 of the present invention.

Fig. 31(a) is a system configuration diagram of an electronic device in Embodiment 9 of the present invention.

Fig. 31(b) is a functional block diagram of an electronic device in Embodiment 9 of the present invention.

Fig. 32(a) is a data structure diagram of embedding information in Embodiment 9 of the present invention.

Fig. 32(b) is a step diagram for disclosing illegal copying in Embodiment 9 of the present invention.

33 is a flowchart of the electronic device in Embodiment 9 of the present invention.

34(a) to 34(c) are explanatory diagrams of conventional information embedding/information reading.

35(a) to 35(b) are explanatory diagrams of conventional information embedding/information reading.

Detailed ways

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)

Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a functional block diagram of an information embedding device in Embodiment 1 of the present invention.

As shown in FIG. 1 , the information embedding device has an extraction unit 1 and an information embedding unit 2 . The information embedding unit 2 has a constant information input unit 3 , an insertion number determination unit 4 , a remainder calculation unit 5 , and an insertion execution unit 6 . The information embedding unit 2 uses the vertex information extracted by the extracting unit 1 to embed the embedded information in the vector data while maintaining the embedded information even if the coordinate system of the vector data is edited.

The extraction unit 1 receives vector data including polygon information, and extracts data of a plurality of vertices constituting the polygon from the vector data.

The constant information input unit 3 inputs a constant N (an integer greater than or equal to 2).

The remainder calculation unit 5 calculates the remainder value obtained by dividing the number of extracted vertices by the constant N determined by the constant information input unit 3 . Furthermore, the insertion number determination unit 4 determines the number of insertion points for the polygon so that the remainder value calculated by the remainder calculation unit 5 has a certain correspondence with the value of the embedded information (both are equal in this embodiment).

The insertion execution unit 6 inserts the number of insertion points determined by the insertion number determination unit 4 into the side of the extracted polygon, thereby executing embedding of the embedding information.

Fig. 2 is a flowchart of the information embedding device according to Embodiment 1 of the present invention.

As shown in FIG. 2 , in step 10 , the information reading unit 11 extracts polygons from the input vector data, and in step 11 , extracts vertices of the extracted polygons.

In step 12, the constant information input unit 3 inputs a constant N.

In step 13, the remainder calculation unit 5 calculates a remainder value obtained by dividing the number of extracted vertices by a constant N. In step 14, the insertion number determination unit 4 uses the remainder value as the value of the embedded information.

The insertion execution unit 6 determines the side where the insertion point is to be inserted in step 15, and inserts the number of points to be inserted into the side of the extracted polygon in step 16, thereby embedding the embedded information.

Also, the constant N input in step 12 is used as key information when information is read.

The polygon extracted in this embodiment is a quadrilateral, and information is embedded by inserting points into the sides of the quadrilateral.

FIG. 3( a ) shows an example of the extracted polygon (a quadrilateral, vertices P1 (x1, y1), P2 (x2, y2), P3 (x3, y3), P4 (x4, y4)). In the example of FIG. 3( a ), the number of extracted polygons is "4".

Furthermore, it is assumed that the constant N=N0 and the embedded information M=M0. At this time, the number of insertion points is determined so that the remainder of the sum of the number of insertion points and the number of vertices "4" of the extracted polygon divided by N0 is equal to M0. That is, by inserting M0 points, the embedding information M0 is embedded.

In this embodiment, a fixed correspondence relationship in which the remainder value is equal to the embedding information M0 is used. However, the fixed correspondence relationship is not limited to this example, and can be changed arbitrarily as long as one can uniquely determine the other. For example, if N0=4, M0=2, then 2 points can be inserted.

Furthermore, in this embodiment, points are inserted as follows.

That is, among the four sides of the polygon P1P2P3P4 shown in FIG. 3( a ), each point is inserted into the three sides P1P2 , P2P3 , and P3P4 .

At this time, as shown in FIG. 3(b), midpoints Q1(x5, y5), Q2(x6, y6), and Q3(x7, y7) of the three sides P1P2, P2P3, and P3P4 are used as insertion points. And it doesn't matter if the insertion point is not the midpoint.

The extracted polygon may also be a concave polygon as shown in FIG. 3(c) or a polygon “with a loop inside” as shown in FIG. 3(d).

FIG. 4( a ) shows an example of the extracted polygon (quadrilateral, each vertex P1 (0, 100), P2 (0, 0), P3 (100, 0), P4 (100, 100)).

Fig. 4(b) shows the correspondence between the embedded information value and the remainder value for the quadrilateral shown in Fig. 4(a).

Here, Z is the number of vertices of the extracted polygon, N is the constant, Q is the number of insertion points, and W is the sum of Z and Q. Furthermore, the value of the embedded information is set to M.

When such values Z, N, M, Q, and remainder values have a corresponding relationship, when the value M is changed, the value Q is changed.

FIG. 4(b) shows an example of embedding the values of M=0, 1, 2, and 3 in the case of Z=4 and N=4. If the number Q to be inserted is determined so that the remainder values are 0, 1, 2, 3 respectively, then Q is equal to 0, 1, 2, 3 respectively.

FIG. 5 shows an example of inserting points on the sides of the quadrilateral using the correspondence relationship in FIG. 4( b ) when the extracted polygon is a quadrilateral and the constant N is 4.

In Figure 5(a), (b), (c), (d), (e), point Pi (i=1, 2, 3, 4) is the four extracted vertices, point Qi (i= 1, 2, 3) are insertion points.

Fig. 5(a) shows that the extracted polygon is a quadrilateral (vertex: P1, P2, P3, P4), which is a polygon before embedding.

FIG. 5(b) shows an example of embedding information "0" when the constant N is 4. In FIG. This example corresponds to the case where information "0" is embedded in FIG. 4(b). At this time, the remainder of dividing the value "4" of W by the value "4" of N is "0", and the value of the embedded information M is "0".

Fig. 5(c) shows an example of embedding information "1" when the constant N is "4". This example corresponds to the case where information "1" is embedded in FIG. 4(b). At this time, the remainder of dividing the value "5" of W by the value "4" of N is "1", and the value of the embedded information M is "1". Therefore, as shown in FIG. 5(c), the midpoint of the side P1P2 is used as the insertion point Q1.

FIG. 5( d ) shows an example of embedding information "2" when the constant N is 4. As shown in FIG. This example corresponds to the case where information "2" is embedded in FIG. 4(b). At this time, the value of the remainder of dividing the value "6" of W by the value "4" of N is "2", and the value of the embedded information M is "2". Therefore, as shown in FIG. 5(d), the midpoint Q1 of the side P1P2 and the midpoint Q2 of the side P2P3 are selected as insertion points.

FIG. 5(e) shows an example of embedding information "3" when the constant N is 4. In FIG. This example corresponds to the case where information "3" is embedded in FIG. 4(b). At this time, the value of the remainder of dividing the value "7" of W by the value "4" of N is "3", and the value of the embedded information M is "3". Therefore, as shown in FIG. 5(e), midpoint Q1 of side P1P2, midpoint Q2 of side P2P3, and midpoint Q3 of side P3P4 are selected as insertion points.

Next, a case where the extracted polygon is a pentagon will be described. Furthermore, the present invention can be similarly applied to polygons of more than hexagon.

The pentagon in Fig. 6(a) has five vertices P1 (0, 100), P2 (0, 0), P3 (100, 0), P4 (120, 50), and P5 (100, 100).

FIG. 6( b ) shows changes in the number of inserted points when changing the value of the embedding information for the pentagon shown in FIG. 6( a ).

The respective values M, Z, Q, W and the remainder in FIG. 6(b) are the same as those in FIG. 4(a).

FIG. 6( b ) shows an example of embedding values of M=0, 1, 2, and 3 in the case of Z=5 and N=4. If the number Q of insertion points is determined so that the remainder values are 0, 2, 1, 3 respectively, then Q is equal to 3, 1, 0, 2 respectively.

FIG. 7 shows an example where the extracted polygon is a pentagon and the constant N is 4, using the correspondence relationship in FIG. 6( b ) to insert an insertion point on the side of the pentagon.

In Figure 7 (a), (b), (c), (d), (e), point Pi (i=1, 2, 3, 4, 5) is the five extracted vertices, point Qi ( i=1, 2, 3) is the insertion point.

Fig. 7(a) shows that the extracted polygon is a pentagon (vertices: P1, P2, P3, P4, P5), and the state before embedding.

FIG. 7(b) shows an example of embedding information "0" when the constant N is 4. In FIG. This example corresponds to the case where information "0" is embedded in FIG. 6(b). At this time, the value of the remainder of dividing the value "8" of W by the value "4" of N is "0", and the value of the embedded information M is "0". The number Q of insertion points is "3".

Therefore, as shown in FIG. 7(b), midpoint Q1 of side P1P5, midpoint Q2 of side P4P5, and midpoint Q3 of side P3P4 are selected as insertion points.

FIG. 7(c) shows an example of embedding information "1" when the constant N is 4. In FIG. This example corresponds to the case where information "1" is embedded in FIG. 6(b). At this time, the value of the W value "6" divided by the value of N "4" is "2", the value of the embedding information M is "1", and the number Q of insertion points is "1". Therefore, as shown in FIG. 7(c), the midpoint Q1 of the side P1P5 is selected as the insertion point.

FIG. 7(d) shows an example of embedding information "2" when the constant N is 4. In FIG. This example corresponds to the case where information "2" is embedded in FIG. 6(b). At this time, the value of the remainder of dividing the value of W by "4" of N is "1", the value of embedded information M is "2", and the number of insertion points Q is "0". Therefore, there is no insertion point in this case.

FIG. 7(e) shows an example of embedding information "3" when the constant N is 4. In FIG. This example corresponds to the case where information "3" is embedded in FIG. 6(b).

At this time, the value of W divided by the value "4" of N is "3", the value of embedded information M is "3", and the number Q of insertion points is "2". Therefore, as shown in FIG. 7( e ), the midpoint Q1 of the side P1P5 and the midpoint Q2 of the side P2P3 are selected as insertion points.

This form can be changed as follows.

(Modification point 1) The correspondence relationship between the remainder and the embedded information can be changed.

(Modification 2) When there is no embedded object on the side of the polygon, the insertion point can be inserted at a position away from the side.

According to the present invention, the following effects are obtained.

(Effect 1) It is not necessary to set a reference parameter and a variation parameter as in the conventional example.

(Effect 2) By inserting points on the side of the polygon, it is possible to suppress the shape change of the polygon before and after the insertion.

(Effect 3) Even if a malicious third party tries to move one or more vertices among vertices constituting the polygon, falsify vector data, and erase embedded information, such operations can be invalidated. This is because even if a plurality of vertices of a polygon are moved, the number of vertices cannot be changed, and troubles cannot be caused in storing embedded information and subsequent reading.

(Embodiment 2)

FIG. 8 is a functional block diagram of an information reading device according to Embodiment 2 of the present invention.

As shown in FIG. 8 , this information reading device has an extraction unit 10 and an information reading unit 11 . The information reading unit 11 has a number calculation unit 12 , a constant information input unit 13 , a remainder calculation unit 14 , and a reading unit 15 .

The extraction unit 10 extracts a polygon from the information-embedded vector data, and further extracts vertices of the extracted polygon.

The number calculation unit 12 calculates the number of vertices of the polygon.

The constant information input unit 13 inputs a constant which is an integer of 2 or more.

The remainder calculation unit 14 calculates the remainder obtained by dividing the number calculated by the number calculation unit 12 by the constant N input from the constant information input unit 13 .

The reading unit 15 reads embedded information from the remainder.

9 is a flowchart of an information reading device in Embodiment 2 of the present invention.

In step 20, the extraction unit 10 extracts polygons from the vector data.

In step 21, the number calculation unit 12 calculates the number of vertices of the extracted polygon.

In step 22, the constant information input unit 13 inputs a constant N.

In step 23 , the remainder calculation unit 14 calculates the remainder of dividing the number of vertices by the constant N.

In step 24, the reading unit 15 reads embedded information based on the remainder.

Here, W is the number of points existing on the sides of the extracted quadrilateral, and M is the value of the embedded information. Corresponding to Embodiment 1, in Embodiment 2, tables shown in FIG. 10( a ) and FIG. 10( b ) are prepared for quadrilaterals. Fig. 10(a) shows the correspondence between the remainder value of dividing the number W by the constant N and the value of the embedded information M when the value of N is equal to "4". Furthermore, both the embedding information device side and the reading device side determine the correspondence relationship shown in FIG. 10( a ) as digital watermark key information.

For example, when the number W of vertices of the extracted polygon is "5", the value of N "4" produces a value of remainder R of "1", and the reading section 15 utilizes the relationship in FIG. 10(b) to read The value of embedded information M is "1".

Furthermore, as can be seen from FIG. 10( b ), the number of vertices of the polygon before insertion is "4", and the number Q of insertion points is "1". Also, basically the same processing as above is performed for the pentagon.

According to the present invention, the following effects are obtained.

(Effect 1) Embedded information can be read using the correspondence shown in Fig. 10(a) and Fig. 10(b).

(Effect 2) As shown in FIG. 10(b), since the application includes the correspondence relationship of the number of vertices of the polygon, not only the value of the embedded information but also the number of insertion points can be clarified.

Furthermore, each constituent element of the information embedding device and reading device in Embodiments 1 and 2 or all embodiments described later may be constructed as a program, installed in a computer, or distributed via a network.

As shown in FIG. 11 , this program is typically stored in a storage medium 31 such as a CD-ROM or a floppy disk, and installed into a storage device 28 such as a hard disk via a drive 30 and an I/O 29 .

Then, when the CPU 25 accesses the ROM 26, the RAM 27, the hard disk 28, and the like, and executes the program, the information embedding device and the reading device in each of the above-described embodiments can be realized.

(Embodiment 3)

Fig. 12 is a functional block diagram of an information embedding device in Embodiment 3 of the present invention. This information embedding device has an extraction unit 41 and an information embedding unit 42 . The information embedding unit 42 has a correspondence relationship determining unit 43 and an embedding unit 44 .

As in the first embodiment, the extraction unit 41 receives vector data and extracts vertices of polygons included in the vector data.

The correspondence relationship determination unit 43 determines the correspondence relationship between the value of the embedded information and the plurality of geometric elements with respect to the plurality of geometric elements. A plurality of geometric features are selected from the group consisting of the diagonal of the polygon, the center of gravity of the polygon, the vertices of the polygon, and the representative point of the polygon. In this embodiment, the diagonal of the polygon and the center of gravity of the polygon are selected.

The corresponding relationship of geometric elements can be determined by "the distance between the diagonal of the polygon and the center of gravity of the polygon", "the distance between the diagonal of the polygon and the representative point of the polygon" and "the distance between the center of gravity of the polygon and the representative point of the polygon" any one of the performance.

In the present embodiment, this correspondence relationship is represented by "the distance between the diagonal line of the polygon and the center of gravity of the polygon".

Moreover, when the embedded information is binary, the threshold T is determined for the distance selected from the above-mentioned multiple distances. When the above-mentioned selected distance is less than or equal to T, the embedded information is set to "0", and when the above-mentioned selected distance exceeds T , set the embedded information to "1". The above is the correspondence relationship of this embodiment.

The embedding unit 44 performs embedding processing by changing the representative point of the polygon based on the correspondence relationship determined by the correspondence relationship determination unit 43 . The representative point may be a vertex, or a point that does not represent the geometric properties of the polygon (for example, a point that is simply attached to the polygon). The representative point in this embodiment is the center of gravity of the polygon.

Fig. 13 is a flowchart of an information embedding device in Embodiment 3 of the present invention. The extraction unit 41 extracts a polygon from the input vector data in step 30 , and extracts vertices of the polygon in step 31 .

In step 32, the correspondence determination unit 43 obtains the center of gravity and the longest diagonal of the polygon as geometric elements of the polygon, and obtains the coordinates of the center of gravity and the longest diagonal of the extracted polygon in step 33.

The correspondence relationship determination unit 43 inputs the embedded information in step 34 , and determines the correspondence relationship between the embedded information and the geometric elements in step 35 . In step 36, the correspondence determining unit 43 determines the coordinates of the specified vertex from among the vertices of the polygon so that the distance between the center of gravity of the polygon and the longest diagonal is less than or equal to the threshold value when the embedding information is "0". T (this distance is 0 in this embodiment). Furthermore, in step 36, the correspondence relationship determination unit 43 determines the coordinates of the specified vertex from among the vertices of the polygon so that when the embedding information is "1", the distance between the centroid of the polygon and the longest diagonal exceeds the threshold T .

Moreover, the advantage of selecting the longest diagonal here is that, except for the case where there are multiple diagonals of the same length, the diagonal can be uniquely specified.

14(a) to 14(c) show the information embedding process in Embodiment 3 of the present invention.

Fig. 14(a) illustrates a polygon before information embedding. In this example the polygon has four vertices P1 (0, 100), P2 (0, 0), P3 (100, 0), P4 (100, 100).

When the polygon is a quadrangle, the plurality of geometric elements in this embodiment are the longest diagonal of the quadrangle and the center of gravity of the quadrangle. In the quadrilateral P1P2P3P4 in FIG. 14( a ), the longest diagonal is P1P3 (=P2P4). And the coordinates of the center of gravity G of the quadrilateral P1P2P3P4 are (50, 50).

As the arrangement information of the geometric elements, the distance between the center of gravity G and the longest diagonal line P1P3 is obtained. The distance between the center of gravity G and the longest diagonal line P1P3 is the length of the foot H of the vertical line hanging from the center of gravity G to the longest diagonal line P1P3.

Here, this distance is calculated|required by the following formula.

GH＝((X _G -X _H ) ² +(Y _G -Y _H ) ² ) ^1/2

Here, the coordinates of G and H are (X _G , Y _G ), (X _H , Y _H ).

The range of possible values of the distance is generally any real number greater than or equal to "0". Here, the embedding information is set to "0" or "1", and a threshold T is introduced (T=1 in this embodiment).

Then, make the distance when the information "0" is embedded less than or equal to the threshold T, and make the distance when the information "1" is embedded exceed the threshold T.

More fundamentally, the vertex (vertex P2 in the example of FIG. The distance of the longest diagonal line P1P3 is greater than or equal to "0" and less than or equal to the threshold T"1", and when the embedded information is "1", the distance between the center of gravity G and the longest diagonal line P1P3 is greater than the threshold T"1".

Fig. 14(b) shows an example of embedding information "0". In this example, since the center of gravity G is located on the longest diagonal line P1P3, the distance between the center of gravity G and the longest diagonal line P1P3 is "0".

Fig. 14(c) shows an example in which information "1" is embedded. The coordinates of the center of gravity G of the embedded quadrilateral P1P3P4P5 (vertices P1 (0, 100), P2 (20, 0), P3 (100, 0), P4 (100, 100)) are (55, 50) The longest pair The corner lines are P1P3. Thus, the distance between the center of gravity G and the longest diagonal line P1P3 is "3.5" (>T).

This embodiment can be changed as follows.

(1) Although the vertex is manipulated so that the position of the longest diagonal line is maintained while the center of gravity changes, the vertex can also be operated on the contrary so that the position of the center of gravity is maintained while the position of the diagonal line changes. (However, while maintaining maximality).

(2) Embedded information ("0", "1") may be replaced.

(3) Although the value of the threshold T is set to "1", it may be replaced with any other value greater than or equal to "0".

(4) In the example of FIG. 14, the center of gravity G is obtained using the coordinates of all vertices of the polygon. However, the center of gravity of the circumscribed rectangle and the center of gravity of the inscribed rectangle of the polygon can also be used. For example, when the pentagon P1P2P3P4P5 shown in FIG. Or find the center of gravity G2 of its inscribed rectangle Q1Q2P4P5.

When the center of gravity G1 is used, the center of gravity is obtained without using some vertices P2 constituting the polygon. Alternatively, when the center of gravity G2 is used, the center of gravity is obtained using virtual vertices Q1 and Q2 not originally included in the vertices of the polygon.

Furthermore, when the polygon is the octagon P5P6P7P8P9P10P11P12 shown in FIG. 15(b), the center of gravity G3 of the circumscribed rectangle Q3Q4P11P12 can be obtained. Or you can find the center of gravity G4 of its inscribed rectangle P5P10P11P12.

When the center of gravity G3 is used, the vertices P5, P6, P7, P8, P9, and P10 constituting a part of the polygon are not used, and the center of gravity is obtained using virtual vertices Q3 and Q4 that are not vertices of the original polygon. Alternatively, when using the center of gravity G4, the center of gravity is obtained without using the vertices P6, P7, P8, and P9 constituting a part of the polygon.

In either case, as long as the method of obtaining the center of gravity to be used is uniquely determined, the method of obtaining the center of gravity can be set arbitrarily. This point is also the same in each embodiment described later.

(Embodiment 4)

Fig. 16 is a functional block diagram of an information reading device according to Embodiment 4 of the present invention. This information reading device has an extraction unit 51 and an information reading unit 52 . The information reading unit 52 has a correspondence relationship research unit 53 and a reading unit 54 .

The extraction unit 51 inputs vector data (embedding information of Embodiment 3) including information on a polygon, and extracts information on vertices constituting the polygon from the vector data.

Next, the correspondence relationship research unit 53 studies the same correspondence relationship as the correspondence relationship used by the correspondence relationship determination unit 43 of the third embodiment. The geometric elements in this correspondence are the center of gravity and the longest diagonal of the polygon. Of course, the same threshold T as that in Embodiment 3 is used for the threshold T as well. That is, the correspondence relationship research unit 53 finds the distance between the centroid of the polygon and the longest diagonal, and outputs the distance to the reading unit 54 .

The reading unit 54 compares the distance obtained by the correspondence relationship research unit 53 with the threshold T, and reads the embedded information based on the comparison result. More specifically, if the distance is less than or equal to the threshold T, information "0" is read, and if the distance is greater than the threshold T, information "1" is read.

17 is a flowchart of an information reading device according to Embodiment 4 of the present invention. The extraction unit 51 extracts a polygon from the input vector data in step 40 , and extracts vertices of the polygon in step 41 .

The correspondence research unit 53 selects the center of gravity and the longest diagonal of the polygon as geometric elements in step 42 , and finds the center of gravity and the longest diagonal of the polygon in step 43 . In step 44 , the correspondence relationship research unit 53 studies the correspondence relationship, calculates the distance and outputs it to the reading unit 54 .

In step 45, the reading unit 54 performs the size comparison described above, and as a result, reads embedded information ("0" or "1").

As shown in Figure 18(a), when the extracted polygon is a quadrilateral P1P2P3P4 (vertex P1 (0, 100), P2 (0, 0), P3 (100, 0), P4 (100, 100)), the most The long diagonal is P1P3 (=P2P4). Also, the coordinates of the center of gravity G of the quadrilateral P1P2P3P4 are (50, 50). And, the distance between the center of gravity G(50, 50) and the longest diagonal line P1P3 is "0". Therefore, the value of the embedded information is determined to be "0".

Or, as shown in Figure 18(b), the extracted polygon is a quadrilateral P1P2P3P4 (vertex P1 (0, 100), P2 (20, 0), P3 (100, 0), P4 (100, 100)), The longest diagonal is P1P3. Moreover, the distance between the center of gravity G(55, 50) and the longest diagonal line P1P3 is "3.5" (>T). Therefore, the value of the embedded information is determined to be "1".

Furthermore, in Embodiments 1 and 2, if the range of the value of embedded information is changed, it can be extended to multi-values other than binary ("0" or "1"). For example, set the geometric elements as the diagonal and the center of gravity, and set N (N is an integer greater than or equal to 2) embedding information as "0", "1", ..., "N-1". Furthermore, the arrangement information of the geometric elements is the distance between two geometric elements, that is, the information on the distance between the diagonal and the center of gravity, and the distance is represented by d (d is a real number greater than or equal to 0). At this time, as long as the so-called "information of "0" is embedded" is "d is the arrangement state of the diagonal line and center of gravity such that d is greater than or equal to 0 and less than 1/N", "information of "1" is embedded" is "d The arrangement state of the diagonal line and the center of gravity such that it is greater than or equal to 1/N and less than 2/N ", ..., "N" information is embedded" is "d is a diagonal line such that it is greater than or equal to (N-1)/N It is only necessary to determine each corresponding relationship in the same way as the configuration state of the center of gravity.

According to Embodiment 2, there are the following effects.

(Effect 1) By changing the value range of embedded information, it is possible to expand to multiple values other than binary values ("0" and "1").

(Effect 2) Since the arrangement state of the geometric element is used for reading, the resistance to rotation operation is improved.

This embodiment can be modified as follows.

(1) Replacement of embedded information ("0", "1") is also possible.

(2) Although the value of the threshold T is set to "1", it may be replaced with any other value greater than or equal to "0".

(Embodiment 5)

FIG. 19 is a functional block diagram of the information embedding device in the fifth embodiment. This information embedding device has an extraction unit 61 and an information embedding unit 62 . The information embedding unit 62 has a correspondence relationship determining unit 63 and an embedding unit 64 .

As in the first embodiment, the extraction unit 61 receives vector data, and extracts vertices of polygons included in the vector data.

The correspondence relationship determining unit 63 selects a geometric element from a group consisting of a diagonal line of a polygon, a center of gravity of a polygon, and a representative point of a polygon, and determines a correspondence relationship with the arrangement information of the selected geometric element. In this embodiment, the representative point is assumed to be a facility position not directly related to the geometric properties of the polygon. Here, the so-called facility refers to buildings such as houses, schools, and hospitals, and the so-called facility location refers to the name or abbreviation of the facility whose outline is represented by the polygon, or the location represented by being associated with the polygon.

Furthermore, the geometric element in this form is the center of gravity of the polygon, and the correspondence relationship is expressed by the distance between the center of gravity G of the polygon and the facility position. For this distance, the threshold T is determined in the same manner as in Embodiment 1 (T=1 in this embodiment). When embedding information "0", the distance is set to be less than or equal to the threshold T, and when information "1" is embedded, the distance is set to exceeds the threshold T. Furthermore, the correspondence relationship determination unit 63 operates the facility position instead of the center of gravity G, the vertex, and the like for the operation of the distance.

Fig. 20 is a flowchart of an information embedding device in Embodiment 5 of the present invention. The extraction unit 61 extracts a polygon from the input vector data in step 50 , and extracts vertices of the polygon in step 51 .

In step 52, the correspondence relationship determination unit 63 selects the center of gravity of the polygon as the geometric element, and selects the facility position as the representative point of the polygon. In step 53 , the correspondence relationship determination unit 63 calculates the distance between the center of gravity of the polygon and the facility position.

The correspondence relation determination unit 63 inputs the embedding information in step 54 , and determines the facility position of the extracted polygon according to the value of the input embedding information in step 55 . The correspondence relationship determination unit 63 makes the distance equal to or less than the threshold T when the information “0” is embedded, and makes the threshold exceed the threshold T when the information “1” is embedded. The embedding unit 64 moves the polygonal facility position to the determined facility position in step 55 . From this, information is embedded.

FIG. 21( a ) exemplifies a polygon before embedding information (quadrilateral P1P2P3P4: vertices P1 (0, 100), P2 (0, 0), P3 (100, 0), P4 (100, 100)). This polygon has facility positions (coordinates: (30, 20)) as representative points.

The coordinates of the center of gravity G of the quadrilateral P1P2P3P4 in FIG. 21( a ) are (50, 50).

Fig. 21(b) shows an example in which information "0" is embedded in the quadrilateral in Fig. 21(a). The coordinates of the facility position are (50, 50), and the distance between the center of gravity G and the facility position is "0".

FIG. 21(c) shows an example in which information "1" is embedded in the quadrilateral in FIG. 21(a). The coordinates of the facility location are (30, 20), and the distance between the center of gravity G and the facility location is "36.1" (>T).

According to this embodiment, a reference is not required as in the conventional example.

This embodiment can be changed as follows.

(1) Although one of the two geometric elements is set as the center of gravity, information can be embedded by the same operation as the diagonal.

(2) Embedded information ("0", "1") can also be replaced.

(3) Although the coordinates of the facility position are changed, conversely, the position of the center of gravity may be changed. However, when the center of gravity is changed, the coordinates of the vertices of the quadrilateral are changed, so the shape changes. Therefore, it is desirable to change the location of the facility.

(4) Although the value of the threshold T is set to "1", it may be replaced with any other value greater than or equal to "0".

(Embodiment 6)

Fig. 22 is a functional block diagram of an information embedding device in Embodiment 4 of the present invention. The information reading device of the present embodiment processes vector data embedded with information by the information reading device of the fifth embodiment. This information reading device has an extraction unit 71 and an information reading unit 72 . The information reading unit 72 has a correspondence relationship research unit 73 and a reading unit 74 .

The extraction unit 71 receives vector data including information on polygons (embedded with information in Embodiment 5), and extracts information on vertices constituting the polygon from the vector data.

The correspondence relationship research unit 73 studies the same correspondence relationship as in the fifth embodiment. More specifically, the correspondence relationship research unit 73 calculates the distance between the center of gravity of the polygon and the facility position, and outputs it to the reading unit 74 . Of course, the same threshold T as in Embodiment 5 is used.

The reading unit 74 reads embedded information. More specifically, the reading unit 74 reads information "0" when the distance is less than or equal to the threshold T, and reads information "1" when the distance exceeds the threshold T.

23 is a flowchart of the information reading device in Embodiment 6 of the present invention.

The extracting unit 71 extracts polygons from the input vector data in step 60 , and extracts vertices of the polygons in step 61 .

In step 62, the correspondence relationship research unit 73 selects the centroid of the polygon as the geometric element, and selects the facility position as the representative point of the polygon. The correspondence research unit 73 calculates the distance between the center of gravity of the polygon and the facility position in step 63 , and studies the correspondence in step 64 . The reading unit 74 reads information "0" when the distance is equal to or less than the threshold T in step 65, and reads information "1" when the distance exceeds the threshold T.

The extracted polygon is shown in Figure 24(a), which is a quadrilateral P1P1P3P4 (vertex P1(0, 100), P2(0, 0), P3(100, 0), P4(100, 100)), and its facilities When the coordinates of the position are (50, 50), the coordinates of the center of gravity G of the quadrilateral P1P2P3P4 are (50, 50). Also, the distance between the center of gravity G and the facility position is "0" (<T). Therefore, it is determined that information "0" is embedded.

And, as shown in Fig. 24 (b), the extracted polygon is quadrilateral P1P1P3P4 (vertex P1(0,100), P2(0,0), P3(100,0), P4(100,100)), When the coordinates of the facility position are (30, 20), the coordinates of the center of gravity G of the quadrilateral P1P2P3P4 are (50, 50). Also, the distance between the center of gravity G and the facility position is "36.1" (>T). Therefore, it is determined that information "0" is embedded.

Furthermore, according to the present embodiment, as in the second embodiment, by changing the value range of embedded information, it is also possible to expand to multiple values other than binary values ("0" or "1").

This embodiment can be changed as follows.

(1) Embedded information ("0", "1") can also be replaced.

(2) Although the value that determines the value range of the embedded information is set to "1", it may be replaced with any other value greater than or equal to "0".

(3) The range of possible values of the distance can be changed, that is, the configuration information of the geometric elements can be changed.

(Embodiment 7)

Fig. 25 is a functional block diagram of an information embedding device in Embodiment 7 of the present invention. This information embedding device has an extraction unit 81 and an information embedding unit 82 . The information embedding part 82 has an insertion part 83 and an embedding part 84 .

The extraction unit 81 inputs vector data including definition information of a polygon, and extracts a plurality of vertices constituting the polygon.

The insertion unit 83 determines insertion points to be inserted between two adjacent vertices among the plurality of vertices extracted by the extraction unit 81 (the number of which is N, here, N=1 in this embodiment). For example, when the polygon is a quadrilateral, the number of vertices of the polygon is "4", so the number of insertion points is "4".

The embedding unit 84 embeds all the insertion points determined by the interpolation unit 83 into the extracted polygon.

Next, the relationship between insertion points and embedded information will be described with reference to FIG. 27 . In addition, below, the value of the embedded information is assumed to be 1 bit ("0" or "1").

Let the polygon before embedding be a quadrilateral P1P2P3P4 as shown in FIG. 27( a ). At this time, the center of gravity G1 of the quadrilateral P1P2P3P4 can only be the intersection of two diagonals P1P3 and P2P4.

As shown in Figure 27(b), if the insertion points Q1, Q2, Q3, and Q4 are set as the midpoints of each line segment P1P2, P2P3, P3P4, and P4P1, the quadrilateral Q1Q2Q3Q4 formed by the insertion points Q1, Q2, Q3, and Q4 The center of gravity G2 of the quadrilateral P1P2P3P4 coincides with the center of gravity G1 of the quadrilateral P1P2P3P4.

In the present embodiment, the case where the centers of gravity G1 and G2 are matched corresponds to the case where the value of the embedded information is "0". Furthermore, in order to ensure the allowable range of errors, etc., a small threshold T (for example, T=1) is introduced, and when the distance between the centers of gravity G1 and G2 is less than or equal to the threshold T, the two centers of gravity G1 and G2 are regarded as coincident.

On the other hand, in FIG. 27(c), the center of gravity G2 of the quadrilateral Q1Q2Q3Q4 composed of four insertion points Q1, Q2, Q3, and Q4 is separated from the center of gravity G1, and the distance between the centers of gravity G1G2 exceeds the threshold T. In this embodiment, the case where the two centers of gravity G1G2 do not coincide (more strictly speaking, the case where the distance between G1G2 exceeds the threshold T) corresponds to the case where the value of the embedded information is "1".

In FIG. 26 , the insertion unit 83 determines a plurality of insertion points so as to satisfy the above-mentioned relationship (the relationship between the value of the embedded information and the distance between two centers of gravity).

Fig. 26 is a flowchart of an information embedding device in Embodiment 7 of the present invention. In step 70 , the extraction unit 81 extracts a plurality of vertices constituting a polygon from the vector data, and outputs information of the extracted plurality of vertices to the insertion unit 83 .

In step 71, the insertion unit 83 checks the value of the embedded information, and if the value is "0", it goes to step 72, and if the value is "1", it goes to step 73.

In step 72, for example, as shown in FIG. 27(b), the insertion unit 83 determines all the insertion points so that the center of gravity of the polygon formed by the insertion points coincides with the center of gravity of the extracted polygon.

In step 73, for example, as shown in FIG. 27(c), the insertion unit 83 determines all the insertion points so that the center of gravity of the polygon formed by the insertion points is separated from the center of gravity of the extracted polygon by a distance greater than the threshold T.

In step 74, the embedding unit 84 embeds the insertion point determined by the interpolation unit 83 into the extracted polygon, and outputs the result as vector data embedding completed information.

When inserting points in this embodiment, since the insertion points are arranged on the straight line connecting each point P1 and P2, point P2 and point P3, point P3 and point P4, and point P4 and point P1, it is possible to Data suppresses the shape change of the original data.

This embodiment can be changed as follows.

(1) Although new points are inserted one by one between the extracted vertices, the present invention is not limited to this. If the number N of insertion points is set to be greater than "1", it is also possible to cope with the case where the embedded information is multi-valued.

(2) Although the operation is performed so that the distance between the center of gravity G1 and the center of gravity G2 is less than or equal to the threshold T in the case of embedding information "0" and the center of gravity G1 and center of gravity G2 in the case of embedding information "1" The distance is greater than the threshold T, however, the same effect can be obtained even in the opposite case where "0" and "1" are replaced. Also, although the threshold T=1, it is not limited thereto.

(3) For the embedding process, although in the case of embedding information "0", the insertion point Qi is inserted at the midpoint of the point P1 and the point P2, the point P2 and the point P3, the point P3 and the point P4, and the point P4 and the point P1 , in the case of embedding information "1", the insertion point Qi is inserted with a shift from the midpoint, but the present invention is not limited thereto.

(Embodiment 8)

Fig. 28 is a functional block diagram of an information reading device in Embodiment 8 of the present invention. This information reading device has an extraction unit 91 and an information reading unit 92 . The information reading unit 92 has a classification unit 93 , a distance calculation unit 94 between centers of gravity, and a reading unit 95 .

The extracting unit 91 inputs vector data in which information has been embedded (in which information according to Embodiment 7 is embedded), and extracts a plurality of polygonal points from the vector data.

The information reading unit 92 reads embedded information from the points extracted by the extracting unit 91 .

The classifying unit 93 classifies the plurality of points extracted by the extracting unit 91 into a first set and a second set, and obtains the center of gravity of the first graphic composed of the plurality of points belonging to the first set, and the center of gravity of the first graphic composed of the plurality of points belonging to the second set. The center of gravity of the second shape formed. More specifically, the classification unit 93 assigns serial numbers to the points extracted by the extraction unit, and classifies the points extracted by the extraction unit according to the parity of the serial numbers. The above is because the number N=1 of insertion points is the same as that of the seventh embodiment. When the number N is greater than "1", the points extracted by the extraction unit are classified into the first set, the second set, . . . , the (N+1)th set.

The center-of-gravity distance calculation unit 94 calculates the distance between the center of gravity of the first figure and the center of gravity of the second figure.

The reading unit 95 reads the embedded information based on the distance calculated by the inter-centroid distance calculating unit 94 .

Fig. 29 is a flow chart of the read information acquisition device of the present invention. In step 80 , the extraction unit 91 extracts a polygon from the vector data in which the information is embedded, and in step 81 , extracts a plurality of vertices from the extracted polygon. In addition, in this state, the vertex and the insertion point in the seventh embodiment are not distinguished, and are handled as simple vertexes.

In step 81 , the classification unit 93 assigns consecutive numbers M (M=1, 2, . . . ) to a plurality of vertices. In step 83, the classifying unit 93 classifies the vertices into two vertex groups according to the parity of the serial number M. One of these vertex groups is a set having vertices in Embodiment 7 as elements, and the other is a set having the same insertion point in Embodiment 7 as elements.

In step 84 , the classification unit 93 sets the polygon formed by the vertex group belonging to one set as the first polygon, and sets the polygon formed by the vertex group belonging to the other set as the second polygon. Then, the classification unit 93 outputs the information of the first and second polygons to the inter-centroid distance calculation unit 94 .

In step 85 , the center-of-gravity calculation unit 94 finds the center of gravity of the first polygon and the center of gravity of the second polygon, calculates the distance between these centers of gravity (step 85 ), and outputs these distances to the reading unit 95 .

In step 86, the reading unit 95 compares the calculated distance with the threshold T. If the distance is less than or equal to the threshold T (refer to FIG. 30(a)), it is determined that the information "0" has been embedded. (Refer to FIG. 30(b)), it is judged that information "1" is embedded (step 87).

According to this embodiment, there are the following effects.

(Effect 1) Since the information is read using information that does not depend on the rotation operation, it is possible to read embedded information even from vector data that has been subjected to the rotation operation.

This embodiment can be changed as follows.

(1) The remainder (odd-even) is classified into two sets, but it is not limited to this.

(2) Although the threshold T=1, it is not limited to this.

According to the present invention, by inserting new points on the sides of polygons, information embedding can be performed in which shape changes of original data are suppressed. Furthermore, by manipulating the number of points constituting the polygon independent of the rotation operation, it is possible to correctly read the embedded information even when the vector data and the original data to which the rotation operation has been applied cannot be obtained.

(Embodiment 9)

Next, Embodiment 9 will be described with reference to FIGS. 31 to 33 . Embodiments 1 to 8 relate to an information embedding device or an information reading device. In this embodiment, an information embedding device is installed in electronic equipment to suppress illegal copying of vector data. In this embodiment, the vector data is map data, and the electronic device is a car navigation device using the map data. However, the information embedding device and information reading device of the present invention can be applied to various electronic devices using vector data, such as mobile phones equipped with a GPS function, computer graphics devices using polygons, and the like.

FIG. 31( a ) is a system configuration diagram of an electronic device according to Embodiment 9 of the present invention, and FIG. 31( b ) is a functional block diagram thereof.

The system shown in Fig. 31(a) assumes the case of an infringer who makes an illegal copy. An infringer purchases a legitimate storage medium 100 , installs the legitimate storage medium 100 in the car navigation device 200 , and obtains an illegal storage medium 250 by illegally duplicating the personal computer 230 connected to the car navigation device 200 . Furthermore, printing is performed by the printer 231 connected to the personal computer 230, and an illegal paper medium 251 is intended to be obtained.

In the car navigation device 200, the GPS antenna 205 communicates with a stationary satellite, and inputs information for knowing the current position and direction. The display unit 201 displays the current position, direction, surrounding roads, buildings, and the like. Various changes occur in the direction and position of the car in which the car navigation device 200 is installed, so the map data read from the legal recording medium 100 frequently accepts rotation operations, and as illustrated in FIG. displayed in an easy-to-understand manner. The buttons 202 and the ten keys 203 correspond to the operation input unit 216 shown in FIG. 31( b ), and accept user's operation input.

The car navigation device 200 is equipped with an input/output port 204 and can communicate with an external device (for example, a personal computer 230 etc.) via the input/output port 204 . Even if such a port is not provided, an intruder may damage a part of the car navigation device 200 and forcibly copy the data of the legitimate recording medium 100, so here assumes a case where a port is provided.

As shown in FIG. 31(b), the car navigation device 200 has the following elements.

The control unit 210 controls each element of the car navigation device 200 according to the flowchart of FIG. 33 . The device intrinsic value holding unit 212 holds the intrinsic value fixedly assigned to the car navigation device 200 . The intrinsic value may be any value as long as the car navigation device 200 can be uniquely distinguished. However, for example, a product lot number, a manufacturing factory name, or a value indicating the date of manufacture may be used.

The information embedding device 213 and the information reading device 218 may have any configurations in Embodiments 1 to 7. In this embodiment, embedded information shown in FIG. 32( a ) is used. This embedded information is multi-valued. However, even if an information embedding device or an information reading device that can only embed/read one bit is used, since the map data includes many vectors of buildings, roads, etc., for example, the highest bit is assigned to the first vector, When assigning the highest next highest bit to the second vector and performing the same assignment below (that is, when the bit relationship can be uniquely determined), it is possible to correspond to multi-valued embedding information. Of course, it is desirable that the rule of allocation is configured so that it is difficult for a malicious third party to see through.

The car navigation processing unit 211 performs car navigation processing. Furthermore, since the present invention is not characterized by car navigation processing itself, a detailed description of car navigation processing will be omitted.

The temporary storage unit 214 is constituted by a RAM or the like, and stores data necessary for processing by the control unit 210 .

When a value is input from the control unit 210 , the hash value calculation unit 219 calculates the hash value using a hash function, and returns the calculated hash value to the control unit 210 .

The interface 215 mediates communication between the control unit 210 and external devices. In the example shown in FIG. 31( b ), the operation input unit 216 , the display unit 201 , the input/output port 204 , and the driver 217 are connected to the interface 215 . The drive 217 reads the data recorded on the legal recording medium 100 . In the present embodiment, the car navigation device 200 inputs the map data via a recording medium such as the authorized recording medium 100 , but the present invention is also applicable to the case of inputting the map data via a network. Furthermore, it does not matter that the legitimate recording medium 100 is a read-only recording medium such as DVD-ROM or CD-ROM. This is because it is sufficient to write information as described later on the recording medium of the destination (piracy) where illegal copying has been performed.

Next, the operation of embedding information will be described with reference to Fig. 32(a) and Fig. 32(b).

First, the embedding information of the present embodiment as described above is multivalued data as shown in FIG. 32( a ). The embedded information stores the value of copyright owner information (for example, the author's name or name) in the first bit area, and stores the device-specific value of the electronic device in the second bit area (the device-specific value storage unit 212 holds it). The lengths of the bits in the first bit area and the second bit area may be appropriately selected. If the length of each bit is increased, the reliability becomes higher, but the processing load becomes heavier. The length of each bit is determined in consideration of this trade-off relationship. It is more desirable that the regulation is made by a group that manages copyright.

As shown in the upper part of FIG. 32( b ), the copyright owner (copyright owner 1) who has the right to sell the legal recording medium 100 or the person who has obtained his permission uses the first area of the embedded information as the area representing the copyright owner 1. The value of the copyright holder information is a hash value indicating the value of the copyright holder information of the copyright holder 1 in the second digit field. Then, the copyright holder 1 uses the information embedding device 105 to create embedded map data in which the embedded information is embedded in the map data, records it on the legal recording medium 100, and sells the recorded legal recording medium 100. Of course, as mentioned above, delivery via the network is also possible.

As shown in the middle part of FIG. 32( b ), an infringer using the device 1 uses the car navigation system 200 and the personal computer 230 to create an illegal recording medium 250 with the intention of selling it to a third party. Furthermore, the offender uses the car navigation device 200, the personal computer 230, and the printer 231 to create an illegal paper medium 251 with the intention of selling it to a third party. Then, the infringer sells the illegal recording medium 250 and the illegal paper medium 251 to others to obtain profit. In this case, in the second bit area, instead of a hash value embedded in the value of the copyright owner information, a device-specific value of the car navigation device 200 (device 1 ) is embedded.

As shown in the lower part of FIG. 32( b ), the checker (could also be the copyright owner) obtains a pirated or suspected illegal recording medium 250 or illegal paper medium 251, and uses the information reading device 301 to read the embedded information. Furthermore, the preprocessing unit 300 performs necessary preprocessing in order to output the information-embedded map data to the information reading device 301 .

The inspector obtains the value indicating the copyright owner 1 from the first digit area of the read embedded information, and identifies the copyright owner as the copyright owner information of the illegal recording medium 250 or the illegal paper medium 251 . Also, it is checked whether the value of the second bit field is a hash value of the value of the first bit field. If it is a hash value, it can be determined that the illegal recording medium 250 or illegal paper medium 251 is legally sold, but since the device intrinsic value of the car navigation device 200 (device 1) has been embedded in the illegal recording medium 250 or illegal paper medium 251 , so it is determined to be an illegal copy. Furthermore, it can be confirmed that this illegal duplication was carried out by the car navigation device 200 (equipment 1). Thereby, the offender who uses the car navigation device 200 (device 1) can be held accountable.

Next, the flow of processing of the car navigation device 200 will be described with reference to FIG. 33 . First, in step 90 , the control unit 210 waits until the recording medium 100 is mounted in the drive 217 and readable.

In step 91 , the control unit 210 reads the map data from the recording medium 100 , and uses the information reading device 218 to read the values of the first bit area and the second bit area.

In step 92 , the control unit 210 checks whether the value of the second bit field matches the unique value held by the device specific value holding unit 212 . If they match, the process goes to step 96 , and if they don't match, the process goes to step 93 .

In step 93, the control unit 210 causes the hash value calculation unit 219 to obtain a hash value of the value of the first bit field, and checks whether the hash value matches the value of the second bit field (step 94). If they do not match, in step 95, the control unit 210 warns that illegal copying has been performed, and stops the processing. As a result, the illegally copied recording medium cannot be used practically. If they match, the process moves to step 96 .

In step 96 , the control unit 210 reads out necessary map data, and stores the read map data in the temporary storage unit 214 . Next, in step 97, the control unit 210 embeds the second bit field as embedding information of device specific values into the map data, and stores the embedding completed map data in the temporary storage unit 214 (step 98).

Then, the control unit 210 outputs the embedded map data to the car navigation processing unit 211 for navigation processing. In step 99, the car navigation processing unit 211 obtains information such as the current position and direction of the car from the GPS antenna 205, and performs navigation processing based on the embedded map data. At this time, the map data frequently receives rotation operations.

In step 100 , the control unit 210 inputs the processing result from the car navigation processing unit 211 and displays it on the display unit 201 via the interface 215 . In this way, even when the embedded map data is output to the interface 215 and the map data is transferred to the personal computer 230 via the input/output port 204 connected to the interface 215, the transferred map data is map data embedded with device-specific values. Therefore, even if the personal computer 230 is used to obtain the illegal recording medium 250 and the illegal paper medium 251 , traces of illegal copying by the offender himself remain on the illegal recording medium 250 and the illegal paper medium 251 without knowing it.

Then, in step 101, the control unit 210 repeats the processing from step 96 onwards.

Also, generally speaking, when illegal copying of paper media is performed, it is often unclear whether or not it has been illegally copied among pirated or suspected paper media and originals. In this case, in the printed state, the map data is rotated from the original state in most cases.

However, if it is processed as shown in FIG. 32(b), the information embedding of the present invention is robust to the rotation operation, so it is a good situation that illegality can be rediscovered from the illegal paper medium 251.

Fields of use of the present invention

The present invention can be suitably used, for example, in an information processing device or the like that processes vector data such as map data.

Claims (37)

1, a kind of information embedding device comprises:

Extraction unit is extracted the information that constitutes polygonal summit from the vector data that comprises polygonal information; And

The information Embedded Division utilizes the information by the summit of described extraction unit extraction, under the state firm for rotary manipulation, embedding information is embedded in the described vector data.

2, information embedding device as claimed in claim 1,

Described information Embedded Division is according to embedding information, and the sum of the polygonal point that embedded information is operated.

3, information embedding device as claimed in claim 1,

Described information Embedded Division is operated the distance between the polygonal specified point that has embedded information according to embedding information.

4, the information embedding device shown in claim 1,

Described information Embedded Division is according to embedding information, and change is present in the number of the point on the polygonal limit.

5, the information embedding device shown in claim 1,

Described information Embedded Division insertion point on polygonal limit.

6, the information embedding device shown in claim 1,

Described information Embedded Division is in the insertion point, position of leaving polygonal limit.

7, the information embedding device shown in claim 1,

Described information Embedded Division change is present in the number of the point on the polygonal limit, make that (M is a nonnegative integer, and M＜N) has certain corresponding relation divided by the remainder values of constant N (N for more than or equal to 2 integer) and the value M of the information of embedding for the number be present in the point on the polygonal limit.

8, information embedding device as claimed in claim 7,

Described certain corresponding relation is the relation that described remainder values equates with the value M of described embedding information.

9, information embedding device as claimed in claim 4,

Described information Embedded Division comprises:

The constant information input unit, input constant N (N is the integer more than or equal to 2);

The remainder calculating part calculates the number on the summit of being extracted by the described extraction unit remainder divided by described constant N;

Insert the number determination section, the number of the point that decision is inserted on described polygonal limit, the remainder and the embedding information that make described remainder calculating part calculate have certain corresponding relation; And

Insert execution portion, will insert in the polygon by the point of the number of described insertion number determination section decision.

10, information embedding device as claimed in claim 1,

Described constant N is the constant that does not rely on polygonal number of vertex.

11, a kind of information read device comprises:

Extraction unit embeds the point that extracts the vector data of finishing on the polygon from information; And

The information reading part, number and predetermined rule according to the point that has described extraction unit to extract read embedding information.

12, information read device as claimed in claim 11,

Described predetermined rule is that the number of the point that extracted by described extraction unit has the rule of certain corresponding relation divided by the remainder values of constant N (N for more than or equal to 2 integer) and the value of the information of embedding.

13, information read device as claimed in claim 12,

Described certain corresponding relation is the relation that the value M of described remainder values and described embedding information equates.

14, information read device as claimed in claim 11,

Described information read device comprises:

The number calculating part calculates the number by the point of described extraction unit extraction;

The constant information input unit, input constant N (N is the integer more than or equal to 2);

The remainder calculating part calculates the number calculated by the described number calculating part remainder divided by described constant N; And

The information reading part reads embedding information according to the remainder that is calculated by described remainder calculating part.

15, information embedding device as claimed in claim 1,

Described information Embedded Division makes for the predefined representative point of described polygon to change, so that the corresponding relation of a plurality of geometric elements relevant with described polygon changes according to embedding information.

16, information embedding device as claimed in claim 15,

Described representative point comprises described polygonal summit.

17, information embedding device as claimed in claim 15,

Described a plurality of geometric element is the geometric element of selecting from the group that described polygonal diagonal, described polygonal center of gravity, described polygonal summit and described polygonal representative point constitute.

18, information embedding device as claimed in claim 17,

Described diagonal is the longest diagonal.

19, information embedding device as claimed in claim 18,

Described information Embedded Division changes described representative point, and is the longest so that the longest described diagonal keeps.

20, information embedding device as claimed in claim 15,

Described corresponding relation shows with the distance between described a plurality of geometric elements.

21, information embedding device as claimed in claim 15,

Described information Embedded Division comprises:

The corresponding relation determination section determines the corresponding relation of value and described a plurality of geometric elements of described embedding information; And

Embedded Division changes according to the above representative point of corresponding relation by described corresponding relation determination section decision.

22, information embedding device as claimed in claim 15,

Described representative point is described polygonal center of gravity.

23, information embedding device as claimed in claim 15,

Described representative point indication facility position.

24, a kind of information read device comprises:

Extraction unit is extracted the point on the polygon from the vector data of finishing the information embedding; And

The information reading part reads the information that is embedded in the described vector data according to the corresponding relation of point that is extracted by described extraction unit and a plurality of geometric elements relevant with described polygon.

25, information read device as claimed in claim 24,

Described a plurality of geometric element is the geometric element of selecting from the group that described polygonal diagonal, described polygonal center of gravity, described polygonal summit and described polygonal representative point constitute.

26, information read device as claimed in claim 24,

Described information reading part comprises:

Corresponding relation research department, the corresponding relation of point that research is extracted by described extraction unit and a plurality of geometric elements relevant with described polygon; And

Reading part, the result of study according to described corresponding relation research department reads the information that is embedded in the described vector data.

27, information embedding device as claimed in claim 1,

Described information Embedded Division comprises:

The insertion section, in the summit of being extracted by extraction unit, decision should be inserted the insertion point between adjacent two summits; And

Embedded Division will be inserted between described adjacent two summits by the insertion point of described insertion section decision,

Described insertion section is according to embedding information, the center of gravity of first figure that the summit constituted that change is extracted by described extraction unit and by the relation of the center of gravity of the second graph that at least three insertion points constituted of described extraction unit decision.

28, information embedding device as claimed in claim 27,

Described first figure is the polygon that is extracted by described extraction unit, and described second graph is made of all insertion points of described insertion section decision.

29, information embedding device as claimed in claim 27,

The relation of the center of gravity of described first figure and the center of gravity of described second graph by the center of gravity of described first figure whether with consistent evaluation of center of gravity of described second graph.

30, a kind of information read device comprises:

Extraction unit embeds the polygonal a plurality of points of extraction the vector data of finishing from information;

Division will be categorized as first set and second set by a plurality of points that described extraction unit is extracted, and ask the center of gravity of first figure that a plurality of points of belonging to described first set are constituted, and the center of gravity of second graph that belongs to a plurality of somes formations of described second set;

Calculating part calculates the distance of the center of gravity of the center of gravity of described first figure and described second graph; And

Reading part is according to reading the information of embedding by described calculating part calculated distance.

31, a kind of information read device comprises:

Extraction unit embeds the polygonal a plurality of points of extraction the vector data of finishing from information; And

The information reading part reads the information of embedding according to a plurality of points that extracted by described extraction unit,

Described information reading part comprises:

Division, a plurality of points that described extraction unit is extracted are categorized as first set and second set, ask the center of gravity of first figure that a plurality of points of belonging to described first set are constituted and belong to the center of gravity of the second graph that described second a plurality of points of gathering are constituted;

Calculating part calculates the distance of the center of gravity of the center of gravity of described first figure and described second graph; And

Reading part is according to reading the information of embedding by described calculating part calculated distance.

32, information read device as claimed in claim 31,

Described division is given consecutive number to a plurality of points that extracted by described extraction unit, by described consecutive number a plurality of points that extracted by described extraction unit is classified.

33, a kind of computer-readable recording the recording medium of program, this program comprises:

Leaching process extracts the information that constitutes polygonal summit from the vector data that comprises polygonal information;

The information telescopiny is utilized the information on the summit extract in described leaching process, even also keep the state of information with the coordinate of the described vector data of rotary manipulation, embedding information is embedded described vector data.

34, a kind of electronic equipment comprises:

Equipment eigenvalue maintaining part keeps the equipment eigenvalue; And

Information embedding device, the equipment eigenvalue that described equipment eigenvalue maintaining part is kept is contained in embedding information, embedding information embedded comprise in the vector data of polygonal information,

Described information embedding device comprises:

Extraction unit is extracted the information that constitutes polygonal summit from described vector data; And

The information Embedded Division utilizes the information by the summit of described extraction unit extraction, with for the firm state of rotary manipulation, embedding information is embedded in the described vector data.

35, electronic equipment as claimed in claim 34,

Described information Embedded Division is according to embedding information, and the sum of the polygonal point that embedded information is operated.

36, electronic equipment as claimed in claim 34,

Described information Embedded Division is operated the distance between the polygonal specified point that has embedded information according to embedding information.

37, electronic equipment as claimed in claim 34,

Described embedding information is made of the value in first zone of preserving copyright information and the value in the deputy zone of preserving described equipment eigenvalue.

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