JP2001209780A - Method and device for embedding electronic watermark in vector data, storage medium with electronic watermark embedding program in vector data stored therein, method and device for reading electronic watermark and storage medium with electronic watermark reading program stored therein - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide electronic watermark embedding and reading in vector data and methods and devices which can always include vertex coordinates in a watermark processing area and embed and read a watermark in such vector data as to have a bias in a coordinate value, and a storage medium where an electronic watermark embedding and reading program in the vector data is stored. SOLUTION: Inputted vector data are divided into such watermark processing areas where the number of vertexes are the same or almost the same, and common electronic watermark information is embedded in each vertex coordinate included in the divided areas. Vector data where an inputted electronic watermark is embedded are also divided into such watermark processing areas where the number of vertexes are the same or almost the same, and one piece of common information is read from each vertex coordinate included in the divided processing areas per area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and apparatus for embedding a digital watermark in vector data, a storage medium storing a program for embedding a digital watermark in vector data, a method and apparatus for reading a digital watermark, and a program for reading a digital watermark. In particular, the present invention relates to a storage medium that stores therein, by embedding and providing sub-information (digital watermark) for preventing fraudulent acts different from the main information in vector data, and providing a digital watermark from the information in which the digital watermark is embedded. The present invention relates to a method and apparatus for embedding an electronic watermark in vector data to be read, a storage medium storing a program for embedding an electronic watermark in vector data, and a storage medium storing an electronic watermark reading method and apparatus and a program for reading an electronic watermark.

[0002] Since digital contents can be easily processed, edited, and copied, illegal acts unintended by the author are liable to spread, and it is difficult to protect copyrights. For image and audio contents, there is a “digital watermark” technique for adding another sub information to the main information content. This technique has a feature that even if the sub-information is added, it is not perceived by a person, and it is difficult to separate the main information and the sub-information. A method of using this technology to add copyright information to content as sub-information has attracted attention as a powerful process for solving the copyright protection problem.

The present invention relates to vector map data constituting a line image, polygon data representing the shape of a three-dimensional object,
A method and apparatus for embedding and reading digital watermark in vector data, and a method and apparatus for embedding sub-information in digital contents such as a data set having coordinate values indicating the positional relationship of data and reading sub-information from those digital contents The present invention relates to a storage medium storing a program for embedding and reading a digital watermark into a storage medium.

[0004]

2. Description of the Related Art Conventionally, vector data is divided into watermark processing areas each having a predetermined size, and the same information is embedded and read for each processing area unit. Digital watermark processing with digital watermark resistance is possible. This processing is performed by an embedding method using a reference coordinate value calculated from a vertex coordinate value, without using original data without a watermark.
The digital watermark has been successfully read.

[0005]

However, in the above-mentioned conventional method, since the watermark processing area is divided into a certain size, if there is a processing area that does not include the vertex coordinates, the embedding and reading are performed. Processing is not possible.
In addition, since 1-bit embedding is performed in one embedding processing area, the movement of the vertex coordinates in the range where the same reference coordinate value is calculated allows the embedded information to be read accurately. However, if the reading is performed when the vertex coordinates are moved out of this range due to a digital watermark attack or the like, there is a problem that only very low-reliability information can be read.

The present invention has been made in view of the above points, and it is possible to always include vertex coordinates in a watermark processing area, and to transparently embed the vector data in which coordinate values are biased. Another object of the present invention is to provide a method and apparatus for embedding and reading digital watermarks in vector data that can be read, and a storage medium storing a program for embedding and reading digital watermarks in vector data.

It is a further object of the present invention to provide a method for reading vector data which can be read with high reliability when watermark reading is performed from degraded vector data that involves vertex coordinate movement such as a digital watermark attack. It is an object of the present invention to provide a storage medium storing a digital watermark embedding method and apparatus and a digital watermark embedding program in vector data, and a digital watermark reading method and apparatus and a storage medium storing a digital watermark reading program.

[0008]

FIG. 1 is a diagram for explaining the principle of the present invention.

According to the present invention (claim 1), in a method for embedding copyright information as an electronic watermark in vector data so as not to be perceived by a human, the vector data is input (step 1). The input vector data is divided into watermark processing areas having the same or substantially the same number of vertices (step 2).
The common digital watermark information is embedded in each vertex coordinate included in the divided area (step 3).

According to the present invention (claim 2), the embedding processing area is divided into 2 ⁿ areas (where n is the number of dimensions of the vertex coordinate values) of equal size, and the embedding processing area is determined by n bits of embedding information. The digital watermark information is embedded by moving the coordinates to one of the divided areas.

According to the present invention (claim 3), a digital watermark key is input, and information to be embedded is embedded as bit information into which information is spread using the digital watermark key.

According to the present invention (claim 4), a digital watermark key is input, and information to be embedded is embedded as bit information obtained by spreading information using the digital watermark key as digital watermark information.

FIG. 2 is a diagram showing the principle of the present invention.

According to a fifth aspect of the present invention, there is provided an electronic watermark embedding apparatus for embedding copyright information as an electronic watermark in vector data so as not to be perceived by a person, wherein the vector data is used to input vector data. An input unit 10, an area dividing unit 100 for dividing the input vector data into watermark processing areas having the same or substantially the same number of vertices, and vertex coordinates included in the area divided by the area dividing unit 100 A watermark embedding unit 200 for embedding common digital watermark information into the digital watermark information, and an output unit 109 for outputting vector data in which the digital watermark information is embedded by the watermark embedding unit 200.

The present invention (claim 6) provides an area dividing means 1
00, means for dividing the embedding processing area into 2 ⁿ (where n is the number of dimensions of the vertex coordinate value) areas having the same size is provided. Means for embedding digital watermark information by moving vertex coordinates to any of the divided areas.

The present invention (claim 7) further comprises a watermark key input means for inputting a digital watermark key, and a spreading means for spreading information for embedding using the digital watermark key. Means 200 includes means for embedding bit information information-spread by the spreading means as digital watermark information.

The present invention (claim 8) further comprises a watermark key input means for inputting a digital watermark key, and a spreading means for spreading information for embedding using the digital watermark key. Means 200 includes means for embedding bit information information-spread by the spreading means as digital watermark information.

The present invention (claim 9) embeds copyright information as digital watermark in vector data so as not to be perceived by a human, and embeds digital watermark in vector data mounted on a digital watermark embedding device for vector data. A vector data input process for inputting vector data, and an area dividing process for dividing the input vector data into watermark processing areas having the same or substantially the same number of vertices. A watermark embedding process of embedding common digital watermark information at each vertex coordinate included in the area divided by the area dividing process, and an output process of outputting vector data in which the digital watermark information is embedded by the watermark embedding process. Have.

According to the present invention (claim 10), in the area dividing process, there is provided a process of dividing the embedding processing region into 2 ⁿ (where n is the number of dimensions of the vertex coordinate value) regions of equal size. In the watermark embedding process, there is a process of embedding digital watermark information by moving vertex coordinates to any of the divided areas according to n-bit embedding information.

The present invention (claim 11) further comprises a watermark key input process for inputting a digital watermark key, and a spreading process for spreading information for embedding using the digital watermark key. The process includes a process of embedding bit information information-spread by the spreading process as digital watermark information.

The present invention (claim 12) further comprises a watermark key input process for inputting a digital watermark key, and a spreading process for spreading information for embedding using the digital watermark key. The process includes a process of embedding bit information information-spread by the spreading process as digital watermark information.

According to a thirteenth aspect of the present invention, there is provided a digital watermark reading method for reading a digital watermark from vector data in which a digital watermark is embedded so that copyright information is not perceived by a person. Input (Step 4), the input vector data in which the digital watermark is embedded is divided into watermark processing areas having the same or substantially the same number of vertices (Step 5), which are included in the divided processing areas. One common information is read per area from each vertex coordinate (step 6).

According to the present invention (claim 14), the read processing area is divided into 2 ⁿ (where n is the number of dimensions of the vertex coordinate value) areas having the same size, and the area where the vertex coordinates exist is determined. Thereby, n-bit information is read.

In the present invention (claim 15), common information is despread using a digital watermark key to obtain digital watermark information.

According to the present invention (claim 16), electronic watermark information is obtained by despreading n-bit information using an electronic watermark key.

The present invention (Claim 17) is a digital watermark reading apparatus for reading a digital watermark from vector data with a digital watermark embedded therein, so that the copyright information is not perceived by a person. Watermarked vector data input means 40 for inputting data
And an area dividing unit 300 that divides the vector data input by the vector data input unit 40 into watermark processing areas having the same or substantially the same number of vertices, and a processing area divided by the area dividing unit 300. The watermark reading unit 400 reads one piece of common information per area from each vertex coordinate to be read, and the watermark information output unit 506 outputs common information.

According to the present invention (claim 18), in the area dividing means 300, 2 ⁿ having the same size of the read processing area.
(Where n is the number of dimensions of the vertex coordinate value). The watermark reading means 400 has means for reading out n-bit information by determining the area where the vertex coordinates exist.

The present invention (Claim 19) further comprises a watermark key input means for inputting a digital watermark key, and the watermark reading means 400 includes means for despreading common information using the digital watermark key.

The present invention (claim 20) further comprises a watermark key input means for inputting a digital watermark key, and the watermark reading means includes means for despreading the n-bit information using the digital watermark key.

According to the present invention (claim 21), a digital watermark reading program installed in a digital watermark reading apparatus for reading a digital watermark from vector data in which a digital watermark is embedded so that copyright information is not perceived by a person is stored. A storage medium, wherein a watermarked vector data input process for inputting vector data in which a digital watermark is embedded, and a watermark process in which vector data input in the vector data input process have the same or substantially the same number of vertices. An area division process for dividing into areas, a watermark reading process for reading one piece of common information per area from each vertex coordinate included in the processing area divided by the area division process, and a watermark information output process for outputting common information Having.

According to the present invention (claim 22), in the area dividing process, two read processing areas having the same area are used.
ⁿ (where n is the number of dimensions of the vertex coordinate value)
It has a process of reading n-bit information by determining the area where the vertex coordinates exist.

The present invention (claim 23) further comprises a watermark key input process for inputting a digital watermark key, and the watermark reading process includes a process of despreading common information using the digital watermark key.

The present invention (claim 24) further comprises a watermark key input process for inputting a digital watermark key, and the watermark reading process includes a process of despreading n-bit information using the digital watermark key.

As described above, in the present invention, first, it is possible to always include the vertex coordinates in the processing area by using the dividing method in which the watermark processing area is associated with the number of vertices included therein. Digital watermark embedding can be performed even on vector data having a biased coordinate value, and furthermore, digital watermark embedding / reading that is highly resistant to digital watermark attacks such as data overwriting and thinning can be performed.

Second, by embedding n bits of n-dimensional data in the embedding and reading processing area, it becomes possible to embed a digital watermark that is highly resistant to a digital watermark attack involving vertex coordinate movement, further,
It is possible to embed / read a digital watermark that is highly resistant to digital watermark attacks such as data overwriting and thinning.

[0036]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a description will be given of an apparatus configuration for embedding a digital watermark into vector data.

FIG. 3 shows the configuration of the digital watermark embedding device of the present invention.

The digital watermark embedding device shown in FIG. 1 includes a vector data input unit 10 for inputting vector data, and a watermark information input unit 2 for inputting digital watermark embedding information.
0, a watermark key input unit 30 for inputting a digital watermark key, an area dividing unit 1 for dividing the input vector data into area units each having a substantially uniform number of vertices, which is a watermark embedding unit.
00, a watermark embedding unit 200 for embedding a watermark in the vertex coordinates included in the area, and an information decompression unit 10 for bit-expanding input watermark information at a constant spreading factor.
6. An area synthesizing unit 108 that synthesizes each of the embedded areas to generate watermarked vector data, and a bit string output from the area synthesizing unit 108 is spread with a watermark key input from the watermark key input unit 30. , And a watermarked vector data output unit 109 for outputting watermarked vector data.

Here, the configuration of the area dividing section 100 will be described.

FIG. 4 shows the structure of the area dividing section of the present invention.

The area dividing unit 100 shown in FIG. 3 calculates the number of vertices in the data to be divided, determines whether or not to perform a dividing process, and determines whether the data has the same number of vertices in the x-axis direction. Division unit 102 that divides into two equal parts
(In the x-axis direction), a dividing unit 104 (in the y-axis direction) that divides the data into two equal parts so that the number of vertices is equal in the y-axis direction, and a divided vector data output unit 105 that outputs the vector data after the division processing Is done. However, only 1 for the x-axis
From the processing on the dimensional vector data, the x-axis and y-axis
Similarly to the case where the processing can be spread to the processing of the dimensional vector data, the area division processing can be extended even when the input vector data is three-dimensional or more n-dimensional vector data.

Next, the configuration of the watermark embedding unit 200 will be described.

FIG. 5 shows the configuration of the watermark embedding unit of the present invention.

A watermark embedding unit 200 shown in FIG. 2 includes a vertex coordinate data set input unit 201 for inputting a data set of vertex coordinates in an embedding unit area acquired from the area dividing unit 100, and a watermark embedding information subjected to information diffusion processing. A diffusion embedding information input unit 202 for inputting a bit string, an embedding target vertex coordinate search unit 203 for sequentially selecting one vertex coordinate to be embedded, a reference coordinate calculation unit 204 for calculating a reference coordinate value from the vertex coordinate value, and a reference coordinate. Embedded area dividing unit 20 for dividing an embedded area based on a value
5. A vertex coordinate operation unit 206 that operates the vertex coordinate value of the embedding target to the coordinate value of the area divided and classified by the embedding area dividing unit 205 according to the bit string of the watermark embedding information;
It comprises a watermarked vertex coordinate data set output unit 207 that outputs a data set of watermarked vertex coordinates.

Next, the configuration of a digital watermark reading apparatus for reading a digital watermark from vector data with a digital watermark according to the present invention will be described.

The digital watermark reading device reads a watermark from digital watermarked vector data.

FIG. 6 shows the configuration of a digital watermark reading apparatus according to the present invention.

The digital watermark reading apparatus shown in FIG. 3 includes a vector data input unit 40 for inputting vector data with a watermark, a watermark key input unit 50 for inputting a digital watermark key,
An area dividing unit 300 that divides the input vector data into area units each having a substantially uniform number of vertices, which is a watermark reading unit, a watermark reading unit 400 that reads a watermark from vertex coordinate values included in an area, and an input watermark An information despreading unit 504 for despreading the watermark information bit string read using the key, and an information shortening unit 5 for shortening the bit-expanded watermark information to a reciprocal of a constant spreading factor
05, a watermark information output unit 506 for outputting the read watermark information.

It should be noted that the area dividing section 300 is the same as that shown in FIG.
Is the same as that shown in FIG.

Further, the watermark reading section 400 will be described.

FIG. 7 shows the configuration of the watermark reading section of the present invention.

The watermark reading unit 400 shown in FIG. 5 includes a vertex coordinate data set input unit 401 for inputting a data set of vertex coordinates in a reading unit area acquired from the area dividing unit 300, and sequentially reads one vertex to be read. A read target vertex coordinate search unit 402 to select, a reference coordinate calculation unit 403 to calculate the reference coordinate value from the vertex coordinate value, a read area division unit 404 to divide the read area based on the reference coordinate value, and read the position of the vertex coordinates A vertex coordinate position determination unit 405 that reads out the embedded bit string by determining which of the areas classified by the area division unit 404 is included, compares the bit strings read from all the vertex coordinates of the read target, A read information averaging unit 406 that performs a majority decision process, and a read that outputs a bit string of read information Ri an information output unit 407.

[0053]

Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] In this embodiment, an electronic watermark embedding apparatus for vector data will be described.
Hereinafter, description will be made based on the configuration of FIG.

FIG. 8 is a flowchart of the digital watermark embedding process according to the first embodiment of the present invention.

Step 601) The digital watermark embedding apparatus first receives vector data from the vector data input unit 10, digital watermark information from the watermark information input unit 20,
An electronic watermark key is input from the watermark key input unit 30.

The input vector data is vector data such as vector map data constituting a line image, polygon data representing the shape of a three-dimensional object, and a set of data including coordinate values indicating a positional relationship between data. Anything is fine.

The input vector data is divided into areas in units of digital watermarking processing by a dividing process described later of the area dividing unit 100.

Step 602) The input digital watermark information expansion unit 106 expands the data to a predetermined bit length, and performs an exclusive OR operation with the digital watermark key input by the information expansion unit 107 to obtain an embedded bit sequence. Become.

Step 603) The obtained embedded bit sequence is output to the watermark embedding unit 200 by two bits for two-dimensional vector data and three bits for three-dimensional vector data.

Step 604) The watermark embedding unit 20
In the case of 0, the bit string obtained in step 604 is embedded in a data set of coordinate values included in the divided area by a watermark embedding process described later. This watermark embedding process is repeated for the divided unit areas.

Step 605) Each of the unit areas subjected to the watermark embedding processing is combined with the watermarked vector data by the area combining unit 108 and output by the watermarked vector data output unit 109.

Next, the area dividing process in step 601 will be described.

FIG. 9 is a flowchart showing the operation of the area dividing unit according to the first embodiment of the present invention, and FIG. 10 shows an image of the vector data area dividing process according to the first embodiment of the present invention.

In the following, a description will be given of a division process into areas having a uniform number of vertices.

Step 701) In the input vector data, the number of vertices included in the data is counted in the division condition determination unit 101, it is determined whether the number of vertices is equal to or more than a certain value, and the division unit (x-axis direction) Output to

Step 702) Dividing section (x-axis direction) 1
In step 02, the input data is sorted by the x-coordinate, and the data is divided into two at boundaries where the number of vertices is the same.

Step 703) The number of vertices included in each data divided into two in the previous step is counted, and if the number of vertices is equal to or more than a certain value, the result is output to the dividing unit (y-axis direction) 104.

Step 704) Dividing section (x-axis direction) 1
In step 02, each piece of input data is sorted by the y-coordinate, and the data is divided into two at the boundaries having the same number of vertices.

Step 705) From the divided two to four
Step 701 to Step 70
Step 4 is repeated until the number of vertices in all the divided unit areas satisfies the condition of the division condition determination unit 101. If the condition is satisfied, the divided vector data is output by the divided vector data output unit 105.

Here, the division processing of the two-dimensional vector data has been described, but in the case of the three-dimensional vector, the area division processing can be realized by adding the processing in the z-axis direction.

Further, here, an example in which the division processing is performed in the x-axis direction and the y-axis direction has been described, but the order does not matter as long as synchronization is achieved with the digital watermark reading time.

Next, the operation of the watermark embedding unit 200 will be described.

FIG. 11 is a flowchart showing the operation of the watermark embedding unit according to the first embodiment of the present invention.
9 shows an information embedding processing image for the vertex coordinate values of the two-dimensional vector data according to the first embodiment of the present invention.

Step 801) The watermark embedding unit 20
At 0, when a vertex coordinate value within an area unit is input from the vertex coordinate data set input unit 201 from the area division unit 100, the embedding target vertex coordinate search unit 203 sequentially selects one vertex coordinate to be embedded. In the reference coordinate calculation unit 204, for example, a reference coordinate of the coordinate value is calculated by a logical OR operation with a fixed coordinate mask such as 1111000B, and the bit inversion Br of the coordinate mask is calculated.
Using (M), E × E with reference point of coordinate value as origin
Is calculated.

Step 802) Embedding area dividing section 2
05, the above-mentioned space area V is equally divided in the x-axis direction and the y-axis direction, and the numbers from 00B to 11B are set to 00B and 1B.
Numbering is performed so that the number of 1B is farthest.

Step 803) Vertex coordinate operation unit 206
Changes the vertex coordinate value to one of the numbered four coordinate areas according to the input 2-bit embedding information.

Step 804) Steps 801 to 8 are executed for all vertex coordinate values in the unit area.
After repeating the process of step 03, the watermarked vertex coordinate data set output unit 207 outputs watermarked data.

FIG. 13 is a flowchart of the process of embedding the three-dimensional vector data into the vertex coordinates according to the first embodiment of the present invention. FIG. 14 is a flowchart of the process of embedding the three-dimensional vector data according to the first embodiment of the present invention. 7 shows an image of an information embedding process for a vertex coordinate value.

Here, the watermark embedding process of two-dimensional vector data has been described. However, in the case of three-dimensional vector data, the watermark embedding process can be realized only by adding the process in the z-axis direction. , The description of which is omitted.

[Second Embodiment] In this embodiment, a digital watermark reading apparatus for reading a digital watermark from watermarked vector data according to the present invention will be described.

The following description is based on the configuration shown in FIG.

FIG. 15 is a flowchart of a digital watermark reading process according to the second embodiment of the present invention.

Step 1001) In the digital watermark reading apparatus, first, the watermarked vector data is input from the watermarked vector data input unit 40, and the digital watermark key is input from the watermark key input unit 50.

The input vector data is vector data such as vector map data constituting a line image, polygon data representing the shape of a three-dimensional object, and a set of data including coordinate values indicating a positional relationship between data. Anything is fine.

The input vector data corresponds to the first
The area is divided into digital watermarking treatment unit areas by the dividing process of the area dividing unit 300 used in the embodiment.

Step 1002) Watermark reading section 4
Reference numeral 00 reads watermark bit information in a state where information is spread from a data set of coordinate values included in the divided area by a watermark reading process described later. This watermark reading process is repeatedly performed for the divided unit areas.

Step 1003) The obtained watermark bit information is subjected to an exclusive OR operation with the inputted digital watermark key by the information despreading unit 504 to calculate the watermark information in the information expanded state. , Information shortening unit 5
05 and the information length is 1 / SR using a constant spreading factor SR
And output by the watermark information output unit 506.

Hereinafter, the watermark reading process from the vertex coordinates of the two-dimensional vector data in step 1002 will be described with reference to the configuration of FIG.

FIG. 16 is a flowchart of a process for reading two-dimensional vector data from vertex coordinates according to the second embodiment of the present invention.

Step 1101) Area dividing section 300
The vertex coordinate values within the area unit input to the vertex coordinate data set input unit 401 are sequentially selected as one vertex coordinates to be read by the read target vertex coordinate search unit 402, and the reference coordinate calculation unit 403 selects For example, a reference coordinate is calculated by a logical OR operation with a fixed coordinate mask such as 1111000B, and the magnitude of E × E with the reference coordinate of the coordinate value as the origin is calculated by using the bit inversion Br (M) of the coordinate mask. Is calculated.

Step 1102) The reading area dividing unit 404 equally divides the space area V in the x-axis direction and the y-axis direction so that the numbers from 00B to 11B are the farthest from the numbers 00B and 11B. Perform numbering.

Step 1103) The vertex coordinate position judging section 405 judges in which range of the numbered space area the vertex coordinates exist, and outputs the number of the existing space area.

Step 1104) After repeating the processing of steps 1101 to 1103 for all the vertex coordinate values in the unit area, the read information output unit 4
In the step 07, a majority decision is made for all the output space numbers, and the largest number value is output.

FIG. 17 is a flowchart of a process for reading three-dimensional vector data from vertex coordinates according to the second embodiment of the present invention.

In the flowchart of FIG. 16 described above, the watermark reading processing of two-dimensional vector data has been described. However, as shown in the flowchart of FIG. 17, processing in the z-axis direction is also added to three-dimensional vector data. ,
Since the watermark reading process is feasible, here,
Description of the three-dimensional vector data is omitted.

Also, as for multidimensional vector data, 2
The digital watermark reading can be realized by extending the processing in the same manner as the method of extending the dimension from three dimensions.

Further, the digital watermark embedding process and the digital watermark reading process in the first and second embodiments are constructed as a program, and are used as the digital watermark embedding device and the digital watermark reading device. The present invention can be easily realized by storing in a portable storage medium such as a disk device, a floppy disk, a CD-ROM, or the like connected to the storage device and installing the present invention when implementing the present invention.

The present invention is not limited to the above embodiment, but can be variously modified and applied within the scope of the claims.

[0100]

As described above, according to the present invention, it is possible to always include the vertex coordinates in the processing area by using the dividing method in which the watermark processing area is associated with the number of vertices included therein. It is also possible to embed and read a watermark into vector data in which the coordinate values are biased.

Furthermore, by performing n-bit embedding of n-dimensional data in the embedding and reading processing area, when watermark reading is performed from degraded vector data that involves vertex coordinate movement such as a digital watermark attack, Highly reliable watermark information can be read.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining the principle of the present invention.

FIG. 2 is a principle configuration diagram of the present invention.

FIG. 3 is a configuration diagram of a digital watermark embedding device of the present invention.

FIG. 4 is a configuration diagram of an area dividing unit according to the present invention.

FIG. 5 is a configuration diagram of a watermark embedding unit according to the present invention.

FIG. 6 is a configuration diagram of a digital watermark reading device of the present invention.

FIG. 7 is a configuration diagram of a watermark reading unit according to the present invention.

FIG. 8 is a flowchart of a digital watermark embedding process according to the first embodiment of this invention.

FIG. 9 is a flowchart showing an operation of the area dividing unit according to the first embodiment of the present invention.

FIG. 10 is an image diagram of an area division process of vector data according to the first embodiment of the present invention.

FIG. 11 is a flowchart illustrating an operation of the watermark embedding unit according to the first embodiment of this invention.

FIG. 12 is an image diagram of information embedding processing for vertex coordinate values of two-dimensional vector data according to the first embodiment of this invention.

FIG. 13 is a flowchart of a process of embedding three-dimensional vector data into vertex coordinates according to the first embodiment of this invention.

FIG. 14 is an image diagram of information embedding processing for vertex coordinate values of three-dimensional vector data according to the first embodiment of this invention.

FIG. 15 is a flowchart of a digital watermark reading process according to the second embodiment of the present invention.

FIG. 16 is a flowchart of a process of reading two-dimensional vector data from vertex coordinates according to the second embodiment of the present invention.

FIG. 17 is a flowchart of a process of reading three-dimensional vector data from vertex coordinates according to the second embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 10 vector data input unit, vector data input unit 20 watermark information input unit 30 watermark key input unit 40 watermarked vector data input unit, watermarked vector data input unit 50 watermark key input unit 100 area division unit, area division unit 101 division condition Judgment unit 102 Dividing unit (x-axis direction) 103 Dividing condition judging unit 104 Dividing unit (y-axis direction) 105 Divided vector data output unit 106 Information decompression unit 107 Information expanding unit 108 Area combining unit 109 Watermarked vector data output unit, output Means 200 watermark embedding unit, watermark embedding unit 201 vertex coordinate data set input unit 202 diffusion embedding information input unit 203 embedding target vertex coordinate search unit 204 reference coordinate calculation unit 205 embedding area division unit 206 vertex coordinate operation unit 207 watermark vertex coordinates Data set output unit 300 Area division unit, area division unit 400 Watermark reading unit, watermark reading unit 401 Vertex coordinate data set input unit 402 Target vertex coordinate search unit 403 Reference coordinate calculation unit 404 Reading area division unit 405 Vertex coordinate position judgment Unit 406 read information averaging unit 407 read information output unit 504 information despreading unit 505 information shortening unit 506 watermark information output unit, watermark information output means 1301 whole range of vector data 1302 vertex of vector data 1303 x-axis in first processing Direction division boundary line 1304 Processing first y-axis direction division boundary line 1305 Processing second-time x-axis direction division boundary line 1401 Watermark processing space area 1402 Vertex coordinates 1403 Reference coordinates 1404 00B Destination area for changing vertex coordinates when embedding 140B 00B 140 Vertex coordinate change destination area when embedding 01B 1406 Vertex coordinate change destination area when embedding 10B 1407 Vertex coordinate change destination area when embedding 11B 1501 Watermark processing space area 1502 Vertex coordinate 1503 Reference coordinate 15044000B Vertex coordinate change destination area for embedding vertex coordinates 1505 001B in case 1506 010B embedding vertex coordinate change destination area 1507 011B for embedding vertex coordinate change destination area 1508 100B for embedding Vertex coordinate change destination area 1509 Vertex coordinate change destination area when embedding 101B 1510 Vertex coordinate change destination area when 110B is embedded 1511 Vertex coordinate change destination area when embedding 111B

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yoichi Takashima 2-3-1 Otemachi, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation F-term (reference) 5B057 AA11 CA13 CA17 CC03 CE08 CF10 DA08 DB03 DC07 DC36 5C076 AA01 AA14 BA09 5J104 AA14 9A001 EE01 LL01 LL03 (54) [Title of the Invention] Digital watermark embedding method and apparatus in vector data, storage medium storing digital watermark embedding program in vector data, and digital watermark reading method , Device, and storage medium storing digital watermark reading program

Claims (24)

[Claims] 1. A method for embedding copyright information as an electronic watermark in vector data so as not to be perceived by a person, wherein the number of vertices of input vector data is the same or substantially the same. A method for embedding digital watermarks in vector data, wherein the digital watermark embedding is performed by dividing the area into such watermark processing areas and embedding common electronic watermark information in each vertex coordinate included in the divided area. 2. An embedding processing area is divided into 2 ⁿ areas (where n is the number of dimensions of vertex coordinate values) of equal size, and the vertex coordinates of the divided area are determined by n bits of embedding information. 2. The method for embedding digital watermark in vector data according to claim 1, wherein the electronic watermark information is embedded by moving to any one of them. 3. The digital watermark embedding into vector data according to claim 1, wherein a digital watermark key is input, and bit information, which is information-spread, using the digital watermark key and information to be embedded is embedded as digital watermark information. Method. 4. A digital watermark embedding into vector data according to claim 2, wherein a digital watermark key is inputted, and bit information, which is information-spread, is embedded as digital watermark information by using the digital watermark key. Method. 5. An electronic watermark embedding apparatus for embedding copyright information as an electronic watermark in vector data so as not to be perceived by a person, comprising: vector data input means for inputting vector data; Area dividing means for dividing the vector data into watermark processing areas having the same or substantially the same number of vertices; and a watermark for embedding common digital watermark information in each vertex coordinate included in the area divided by the area dividing means. An electronic watermark embedding apparatus for vector data, comprising: an embedding unit; and an output unit that outputs vector data in which the electronic watermark information is embedded by the watermark embedding unit. 6. The watermark embedding means, wherein the area dividing means has means for dividing the embedding processing area into 2 ⁿ (where n is the number of dimensions of vertex coordinate values) areas of equal size. 6. The apparatus for embedding digital watermark in vector data according to claim 5, further comprising means for embedding digital watermark information by moving vertex coordinates to one of the divided areas according to n-bit information to be embedded. 7. A watermark key inputting means for inputting a digital watermark key, and a spreading means for spreading information for embedding using the digital watermark key, wherein the watermark embedding means comprises: 6. The apparatus for embedding digital watermark in vector data according to claim 5, further comprising means for embedding bit information information-spread by the means as digital watermark information. 8. A watermark key inputting means for inputting a digital watermarking key, and a spreading means for spreading information for embedding using the digital watermarking key, wherein the watermarking embedding means comprises: 7. The apparatus for embedding digital watermarks in vector data according to claim 6, further comprising means for embedding bit information information-spread by means as digital watermark information. 9. A storage medium storing a digital watermark embedding program for vector data mounted on an electronic watermark embedding device for vector data, wherein the copyright information is embedded in the vector data so as not to be perceived by a human. A vector data input process for inputting vector data, an area dividing process for dividing the input vector data into watermark processing areas having the same or substantially the same number of vertices, and an area dividing process. A watermark embedding process for embedding common digital watermark information at each vertex coordinate included in the set area, and an output process for outputting vector data in which the digital watermark information is embedded by the watermark embedding process. Stores a digital watermark embedding program in vector data Storage medium. 10. The area embedding process includes a process of dividing an embedding processing area into 2 ⁿ (where n is the number of dimensions of vertex coordinate values) equal-sized areas. 10. A storage storing a program for embedding a digital watermark in vector data according to claim 9, comprising a process of embedding digital watermark information by moving vertex coordinates to any of the divided areas according to n-bit information to be embedded. Medium. 11. A watermark key input process for inputting a digital watermark key, and a spreading process for spreading information of an embedding target using the digital watermark key, wherein the watermark embedding process includes: 10. The storage medium storing a program for embedding digital watermark in vector data according to claim 9, including a process of embedding bit information information-spread by the process as digital watermark information. 12. A watermark key input process for inputting a digital watermark key, and a spreading process for spreading information for embedding using the digital watermark key, wherein the watermark embedding process includes 11. The method according to claim 10, further comprising the step of embedding bit information information-spread by the process as digital watermark information.
A storage medium storing a program for embedding a digital watermark in the described vector data. 13. A digital watermark reading method for reading a digital watermark from vector data in which a digital watermark is embedded so that the copyright information is not perceived by a person. Alternatively, the area is divided into approximately equal numbers of watermark processing areas, and 1 is calculated from each vertex coordinate included in the divided processing area.
A digital watermark reading method, wherein one common information is read per area. 14. The read processing area of equal size 2 ⁿ
14. The digital watermark reading method according to claim 13, wherein n-bit information is read by dividing the area into (n is the number of dimensions of the vertex coordinate value) areas and determining the area where the vertex coordinates exist. 15. The digital watermark reading method according to claim 13, wherein the common information is despread using a digital watermark key to obtain digital watermark information. 16. The digital watermark reading method according to claim 14, wherein the n-bit information is despread using a digital watermark key to obtain digital watermark information. 17. A digital watermark reading device for reading a digital watermark from vector data in which a digital watermark is embedded so that copyright information is not perceived by a person, wherein a watermarked vector for inputting vector data in which a digital watermark is embedded is provided. A data input unit, an area dividing unit that divides the vector data input by the vector data input unit into watermark processing areas having the same or substantially the same number of vertices, and an area dividing unit that divides the vector data by the area dividing unit. An electronic watermark reading device, comprising: a watermark reading unit that reads one piece of common information per area from each vertex coordinate included in a processing area; and a watermark information output unit that outputs the common information. 18. The area dividing means has means for dividing into 2 ⁿ (where n is the number of dimensions of a vertex coordinate value) equal-sized read processing areas, and wherein the watermark reading means comprises: 18. The digital watermark reading device according to claim 17, further comprising means for reading out n-bit information by determining an area where the vertex coordinates exist. 19. The digital watermark reading device according to claim 17, further comprising a watermark key input device for inputting a digital watermark key, wherein the watermark reading device includes a device for despreading the common information using the digital watermark key. Method. 20. The digital watermark according to claim 18, further comprising a watermark key input unit for inputting a digital watermark key, wherein said watermark reading unit includes a unit for despreading said n-bit information using a digital watermark key. Reader. 21. A storage medium storing a digital watermark reading program mounted on a digital watermark reading apparatus for reading a digital watermark from vector data in which a digital watermark is embedded so that copyright information is not perceived by a person. A vector data input process for inputting vector data in which a watermark is embedded, and an area for dividing the vector data input in the vector data input process into a watermark processing area having the same or substantially the same number of vertices. A dividing process; a watermark reading process of reading one piece of common information per area from each vertex coordinate included in the processing area divided by the area dividing process; and a watermark information outputting process of outputting the common information. Digital watermark reading Storage medium storing a program taken. 22. The area dividing process includes a process of dividing the area into 2 ⁿ (where n is the number of dimensions of the vertex coordinate value) equal-sized read processing regions. 22. The storage medium storing a digital watermark reading program according to claim 21, further comprising a process of reading n-bit information by determining an area where vertex coordinates exist. 23. The digital watermark according to claim 21, further comprising a watermark key input process for inputting a digital watermark key, wherein the watermark reading process includes a process of despreading the common information using the digital watermark key. A storage medium that stores a reading program. 24. The electronic device according to claim 22, further comprising a watermark key input process for inputting a digital watermark key, wherein the watermark reading process includes a process of despreading the n-bit information using the digital watermark key. A storage medium storing a watermark reading program.