JP2001319257A - Printed matter authenticating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent identification information embedded in a printed matter from being illegally read and the printed matter from being forged or altered by making mutually different a method for embedding the identification information into the printed matter and a method for extracting the identification information from the printed matter. SOLUTION: This printed matter authenticating device is composed of an identification information embedding device for embedding the identification information into the printed matter and an identification information recognizing device for extracting the identification information from the printed matter and collating the information. The identification information embedding device is provided with an image input part, a preprocessing part, an array replacing part and an image output part, and the identification information recognizing device is provided with an identification information extracting device for extracting the identification information and an identification information collating device for collating the extracted identification information with previously stored reference identification information data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed matter authentication apparatus for embedding predetermined identification information in a printed matter and extracting and collating the predetermined identification information embedded in the printed matter to authenticate the printed matter. Banknotes, stamps, stamps, stamps,
This technology can be used for identification of printed matter including passports, identification cards, pass cards, membership cards, and credit cards, and for authenticity determination.

[0002]

2. Description of the Related Art As a technique for embedding identification information in an image,
Each modulation method of amplitude, frequency and phase has been proposed,
In general, the same method is used for embedding identification information and extracting identification information. Among these, as an example of embedding identification information using amplitude modulation, there is a method of directly modulating by modulo operation (Japanese Patent Application No. 08-213540).
If this is applied to a printed matter, the printing method is limited to a sublimation type thermal transfer method capable of halftone expression or a printing method such as gravure. In addition, it is difficult to stably extract embedded identification information because it is easily affected by unevenness in density of ink, fading due to lapse of time, uneven lighting, and the like.

As an example of embedding identification information by frequency modulation, an example using orthogonal transform (Nakamura, Matsui: "Synthetic coding method of gray image and text data using discrete orthogonal transform", IEICE, Vol. J72-D-II, No.3, pp.363-368,
1989). In this method, since identification information is generally embedded in a complicated portion of light and shade, an embedding area is limited by a picture. If the embedding area when applied to printed matter is small, it may be difficult to extract identification information when the area is dirty or blurred.

An example of embedding identification information using phase modulation is based on a density pattern method (Japanese Patent Application No. 08-058617).
And the dither method (Japanese Patent Application No. 62-047310). Since these methods modulate the positions of the pixels of the binary image in which the density is converted into the density, they can be applied to a wide range of printing methods. Further, if the density gradation is appropriately converted, it becomes possible to embed the identification information in a wide range of the image, so that the printed matter is resistant to stains and fading. However, when extracting identification information, highly accurate positioning is required. In addition, when extracting identification information, it is necessary to binarize a multi-valued image input from an image scanner or a video camera. It may not be possible to restore.

[0005]

SUMMARY OF THE INVENTION The present invention relates to an apparatus for embedding predetermined identification information in a printed matter and extracting and collating the predetermined identification information embedded in the printed matter, thereby performing authentication of the printed matter and authenticity determination. The object of the present invention is to solve the conventional problems as described above, and when embedding identification information in a printed matter, the arrangement of white pixels in a predetermined pixel array between two types of array replacement images. When embedding identification information by the phase modulation method using different properties and extracting identification information from the printed material, the identification information is obtained by using the property that the Fourier spectrum deflection is different between the two types of array replacement images. The method of extracting the identification information from the printed matter and the method of extracting the identification information from the printed matter are different from each other so that the identification information embedded in the printed matter is different. Forgery of unauthorized reading and the printed matter,
An object is to prevent alteration.

Another object of the present invention is to realize authentication of a printed material by comparing identification information extracted from the printed material with reference identification information data set in advance. At this time, in the present invention, the printed matter in which the identification information is embedded provides one bit of information with one piece of image data. However, a plurality of bits of identification information are embedded in the printed matter using a plurality of pieces of image data. Accordingly, it is an object of the present invention to realize a printed matter authentication apparatus that can reliably identify a printed matter and determine authenticity by comparing a large amount of information with reference identification information data.

[0007]

A printed matter authentication apparatus according to the present invention includes a printed matter authentication apparatus comprising an identification information embedding apparatus for embedding identification information in a printed matter, and an identification information recognition apparatus for extracting and collating the identification information from the printed matter. A device,
The identification information embedding device includes an image input unit, a preprocessing unit,
The image input unit includes an array replacement unit and an image output unit, and the image input unit converts input image data respectively corresponding to n (where n ≧ 1; n is an integer) digital image data. And inputs n digital image data. The pre-processing unit binarizes the n digital image data to generate n binary images, and then generates the n binary image data. Each of the images is enlarged vertically and horizontally at a predetermined magnification to create n enlarged images, and the array replacing unit creates two types of array replaced images for each enlarged image of the n enlarged images. Thus, 1-bit identification information is embedded in each type of array replacement image of the two types of array replacement image, and the image output unit outputs the two types of array for each of the n enlarged images. Replacement image By outputting image data of any type of array replacement image and printing n number of array replacement images, a printed matter in which n bits of identification information is embedded in total is produced, and the identification information recognition device includes the an identification information extracting device for extracting n-bit identification information; and an identification information collating device for collating the extracted n-bit identification information with n-bit reference identification information data stored in advance. The extraction device includes an image reading unit, a fast Fourier transform unit, a Fourier spectrum extraction unit, and a Fourier spectrum output unit, and the image reading unit reads image data of the n array replacement images read from the printed matter, respectively. Converting the digital image data into digital image data to generate n digital image data, the fast Fourier transform unit, The extraction unit and the Fourier spectrum output unit respectively process the n digital image data generated by the image reading unit, and perform the two types of array replacement for each of the n enlarged images. The n-bit identification information is extracted from the printed material by utilizing the fact that the Fourier spectra of the respective types of array replacement images have different polarizations, and the identification information matching device includes the identification information extraction device. The n-bit identification information extracted in
The bit reference identification information data is collated, and when there is a predetermined relationship between the n-bit identification information and the n-bit reference identification information data, the printed matter is identified as a genuine printed matter.

Further, in the printed matter authentication apparatus of the present invention, the image input unit includes an image input device including an image scanner or a video camera, and the n pieces of original image data are respectively converted using the image input device. By taking in, n pieces of input image data are created, and each of the n pieces of input image data is converted into digital image data to obtain the n pieces of digital image data.

Further, in the printed matter authentication apparatus according to the present invention, the pre-processing unit binarizes the n digital image data input from the image input unit to generate the n binary images. , The n number of binary images are vertically and horizontally doubled to generate the n number of enlarged images.

Further, in the printed matter authentication apparatus according to the present invention, the arrangement replacement unit may be configured to convert the n enlarged images, which are black and white binary images each composed of a white pixel having a value of 1 and a black pixel having a value of 0, into each other. Divide each enlarged image into an array of 2 × 2 pixels,
By changing the number and arrangement of the white pixels in accordance with a predetermined array replacement rule in all the 2 × 2 pixel unit arrays for each of the n enlarged images, Two kinds of array replacement images of the second array replacement image are created, and the white image is generated between the first array replacement image and the second array replacement image for each of the n enlarged images. It is characterized in that 1-bit identification information is embedded in the first array replacement image and the second array replacement image using the property of different pixel arrangement.

Further, in the printed matter authentication apparatus of the present invention, the image output section includes an image output device including a printer or a printing machine, and each of the n enlarged images is enlarged by using the image output device. By outputting image data of any one of the two types of array replacement images for each image to the surface of a predetermined base, n array replacement images are printed on the surface of the base. It is characterized by:

Further, in the printed matter authentication apparatus according to the present invention, the image reading unit includes an image reading device including an image scanner or a video camera, and each of the n enlarged images is read using the image reading device. By reading any type of array replacement image of the two types of array replacement image output from the image output unit to the surface of the base material for each enlarged image and converting it into digital image data, n It is characterized in that a number of digital image data are generated.

Further, in the printed matter authentication apparatus according to the present invention, the fast Fourier transform unit performs fast Fourier transform on the n digital image data generated by the image reading unit to obtain n numerical data. Features.

Further, in the printed matter authentication apparatus according to the present invention, the Fourier spectrum extracting section extracts n Fourier spectrum data from the n number of numerical data obtained by the fast Fourier transform section, and outputs n Fourier spectrum data. The feature is to obtain the data.

Further, in the printed matter authentication apparatus of the present invention, the Fourier spectrum output section outputs the n pieces of Fourier spectrum data obtained by the Fourier spectrum extraction section to the identification information matching apparatus as binary data. It is characterized by doing.

Further, in the printed matter authentication apparatus according to the present invention, the predetermined arrangement replacement rule may be such that the 2 × 2 pixel array Ci (i = 1, 2,...) Is provided for each of the n enlarged images. ,Five)
Using the pixel value Pxy (x = 1, 2; y = 1, 2) as Ci = {P11, P2
1, P12, P22}, C1 = {0,0,0,0}, C2 = {1,
1,1,1}, C3 = {1,0,0,0}, C4 = {1,0,1,1} and C5
= {1,1,0,1}, and when creating the first array replacement image, after replacing the C1 with the C3, replacing the C2 with the C4, the second array When creating a replacement image, after replacing the C1 with the C3, the C2 is replaced with the C5
It is characterized by being replaced with

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a printed matter authentication apparatus according to the present invention will be described with reference to the drawings based on embodiments, and the embodiments of the printed matter authentication apparatus according to the present invention will be described below. The present invention is not limited to the embodiments, and various embodiments can be adopted as long as they fall within the technical scope described in the claims of the present invention. In particular, in the following embodiment, two types of array replacement images are created from an enlarged image obtained by enlarging the binary image corresponding to the original image data both vertically and horizontally twice, and two types of array replacement images are created. A case in which 1-bit identification information is embedded in each type of array replacement image will be described. A predetermined array is obtained from an enlarged image obtained by enlarging a binary image corresponding to the original image data at a predetermined magnification in each of the vertical and horizontal directions. It is also possible to configure the printed matter authentication apparatus of the present invention by creating two types of array replacement images according to the replacement rules and embedding 1-bit identification information in each type of array replacement image of the two types of array replacement images. is there.

(Whole Printed matter Authentication Apparatus) FIG. 1 is a diagram for explaining the overall configuration of an embodiment of a printed matter authentication apparatus according to the present invention. As shown in FIG. 1, the printed matter authentication apparatus according to the present invention outputs image data in which identification information is embedded (in this embodiment, “array replacement images” A to D described later) and the identification information is embedded. The identification information embedding device for producing the printed material and the identification information are extracted from the printed material and collated (identification of the printed material and authenticity determination by comparing the contents of the identification information with preset reference identification information data. )
And an identification information recognition device. The identification information recognizing device includes an identification information extracting device that extracts and outputs identification information, and an identification information matching device that matches the extracted identification information with preset reference identification information data.

Here, the identification information embedding device constituting the printed material authentication device according to the present invention is required when producing a printed material in which the identification information is embedded. Then, the identification information recognition device constituting the printed matter authentication device according to the present invention is required when authenticating the printed matter in which the identification information is embedded.

In the printed matter authentication apparatus according to the present invention, the identification information embedded in the printed matter is n pieces (where n ≧ 1; n
Is an integer. Hereinafter, "n" is similarly defined. ), And 1-bit identification information can be embedded in a print using one piece of image data. Therefore, it is possible to extract n-bit identification information from a printed matter on which n pieces of image data are printed.

In the embodiment shown in FIG. 1, in the identification information embedding device, four pieces of image data of array replacement images A to D, which will be described later, are respectively output as identification information on a predetermined base material to produce a printed matter. Then, the identification information extracting device extracts the identification information from each of the four pieces of image data read from the printed matter, binarizes the extracted identification information, and outputs 4-bit identification information. Next, the output 4-bit identification information is compared with reference identification information data stored in advance in an identification information matching device, and the contents are identified and authenticated, and the extracted identification information is recognized. .

The features of the printed matter authentication apparatus according to the present invention are as follows. (1) In the printed matter authentication apparatus according to the present invention, a method of embedding identification information in a printed matter is different from a method of extracting identification information embedded in a printed matter. Therefore, when the identification information is embedded in the printed matter, the identification information embedded in the printed matter cannot be grasped simply by reading the n pieces of image data printed on the printed matter. That is, according to the printed matter authentication device of the present invention, it is possible to produce a printed matter in which concealed identification information is embedded. A method of embedding identification information by the identification information embedding device and a method of extracting identification information by the identification information extracting device will be described later in detail.

(2) In the printed matter authentication apparatus according to the present invention,
One piece of image data printed on a printed matter provides 1-bit identification information. Therefore, when printing n pieces of image data and embedding n-bit identification information in a printed matter, 2
It is possible to embed n kinds of identification information in a printed matter. That is, when n-bit identification information is embedded in a printed matter, one piece of image data printed on the printed matter provides 1-bit information constituting the n-bit identification information embedded in the printed matter.

For example, when the printed matter authentication apparatus according to the present invention is used as an authentication apparatus for a membership card, a member's personal identification number can be given by n-bit identification information.
Also, in a membership card with a photo, one-bit identification information of the n-bit identification information is provided in association with a personal characteristic of the member (whether or not wearing glasses) that can be grasped by a photograph. May be.

(Identification Information Embedding Apparatus) Hereinafter, a specific configuration of the printed matter authentication apparatus according to the present invention will be described. First,
An identification information embedding device for embedding identification information in a printed matter will be described.

FIG. 2 is a block diagram showing an embodiment of the identification information embedding device and the identification information extracting device of the printed matter authentication device according to the present invention. The identification information embedding device 1 shown in FIG. 2 includes an image input unit 3, a preprocessing unit 4, an array replacement unit 5, and an image output unit 6, and the identification information extraction device 2 includes an image reading unit 7, a fast Fourier transform unit 8, a Fourier spectrum extraction unit 9 and a Fourier spectrum output unit 10.

The image input unit 3 includes an image scanner, a video camera, and the like, and inputs the original image 11 and converts it into digital image data. The preprocessing unit 4 binarizes the digital image data of the original image 11 to create a binary image,
Thereafter, the binary image is enlarged twice vertically and horizontally to create an enlarged image. The array replacement unit 5 creates two types of array replacement images by changing the number and arrangement of white pixels having a value of 1 in accordance with the array replacement rule in all arrays obtained by dividing the enlarged image into 2 × 2 pixel units. . This will be described later in detail.

The image output unit 6 is provided with an image output device such as a printer or a printing machine. The image output unit 6 outputs n array replacement images on a predetermined base material including paper, plastic, metal, and cloth, respectively. Produce printed matter, including securities, banknotes, stamps, stamps, stamps, passports, identification cards, passports, membership cards, and credit cards.

(Identification Information Recognition Apparatus) The identification information recognition apparatus is composed of an identification information extraction apparatus for extracting identification information and an identification information collation apparatus for collating the extracted identification information with reference identification information data previously stored in a storage device. Be composed. The identification information extracting device includes an image reading unit, a fast Fourier transform unit,
It has a Fourier spectrum extraction unit and a Fourier spectrum output unit.

In the identification information extracting device 2 shown in FIG.
The image reading unit 7 includes an image scanner, a video camera, and the like, reads an array replacement image from the printed material 12 in which identification information is embedded, and converts the image into digital image data. The fast Fourier transform unit 8 performs fast Fourier transform on the array-replaced image converted into digital image data.
The Fourier spectrum extracting unit 9 extracts a Fourier spectrum from numerical data (real part, imaginary part, phase, Fourier spectrum) obtained by performing a fast Fourier transform on the array replacement image.

The Fourier spectrum output unit 10 outputs the Fourier spectrum data extracted by the Fourier spectrum extraction unit 9 and the reference Fourier spectrum previously set in the storage unit of the Fourier spectrum output unit 10 in correspondence with each array replacement image. By comparing the data with comparison means,
Binary data of "1" or "0" or "non-genuine"
Will output one of the results.

In the identification information extracting device 2, the Fourier spectrum data extracted by the Fourier spectrum extracting unit 9 is displayed on a display device such as a CRT or a liquid crystal display, or extracted by the Fourier spectrum extracting unit 9. It is also possible to output the Fourier spectrum data using an output device such as a printer or a printing machine to provide information that can be viewed, and then visually authenticate the printed material.

The identification information matching device includes a matching means and a storage device. The identification information matching device stores the n-bit binary data output from the Fourier spectrum output unit 10 with reference identification information data stored in the storage device in advance. Check by matching means.
By this collation, it is determined whether or not predetermined identification information is given to the printed matter, and the printed matter is authenticated.

(Operation of Identification Information Embedding Apparatus) The operation of the embodiment of the identification information embedding apparatus and the identification information extracting apparatus in the printed matter authentication apparatus according to the present invention will be described with reference to the flowchart shown in FIG. FIG. 4A is a flowchart of a process in the identification information embedding device 1 of FIG. 2, and FIG. 4B is a flowchart of a process in the identification information extraction device 2 of FIG.

First, the identification information embedding routine will be described with reference to FIG. In step 100, the original image is read and converted into digital image data. Step 101
Then, the digital image data of the fetched original image is binarized to create a binary image. In step 102, the binary image is vertically and horizontally doubled, and the enlarged image Fgt (x, y)
Create

In step 103, in each array obtained by dividing Fgt (x, y) in units of 2 × 2 pixels, the number and arrangement of white pixels having a value of 1 are changed in accordance with a predetermined array replacement rule to obtain two types of white pixels. Create an array replacement image.

FIG. 3 is a diagram showing an array of 2 × 2 pixels defined by a predetermined array replacement rule according to the present invention.
The enlarged image is Fgt (x, y) (t = 1, 2, ...), the first array replacement image is Fst (x, y) (t = 1, 2, ...), and the second array Let the replacement image be F'st (x, y) (t = 1, 2,...). Fgt (x, y)
Is divided into 2 × 2 pixel units, and is always either C1 or C2.

The array replacing means replaces C1 with C3 in each array obtained by dividing Fgt (x, y) in units of 2 × 2 pixels.
Create Fst (x, y) by replacing C2 with C4, and set Fgt (x, y) to 2
After replacing C1 with C3 in each array divided into × 2 pixel units, replace C2 with C5 to create F'st (x, y). Fs
Since C4 in t (x, y) and C5 in F'st (x, y) are different from each other in the arrangement of white pixels having a value of 1, Fst (x, y) and F'st (x,
It is possible to embed 1-bit identification information in y).

In step 104, Fst (x, y) or F'st (x,
By outputting any of the image data of y) using a device such as a printer or a printing machine, a printed matter in which the identification information is embedded is produced, and the identification information embedding routine is terminated.

FIG. 5 is a diagram showing an example of a printed material in which identification information according to the present invention is embedded. As shown in FIG.
The difference between Fs1 (x, y) in FIG. 5 and F's1 (x, y) in FIG. 5B cannot be easily distinguished.

By the way, in the printed matter authentication apparatus according to the present invention, one piece of image data printed on the printed matter provides 1-bit identification information. It is also possible to print one image data on a predetermined base material, embed 1-bit identification information in a printed matter, extract 1-bit identification information from the printed matter and collate it, After printing data on a predetermined base material and embedding a plurality of bits of identification information in a printed matter, it is also possible to extract and collate the plurality of bits of identification information from the printed matter. In any case, the printed matter authentication device according to the present invention can embed 2n (n bits) identification information in a printed matter produced by outputting n image data on a predetermined base material.

As described above, the present invention employs the following configuration in order to embed the identification information in the printed matter and to extract the identification information from the printed matter for collation. That is, the identification information embedding device includes an image input unit, a preprocessing unit, an array replacement unit, and an image output unit, and the image input unit converts input image data respectively corresponding to n pieces of original image data. After converting the digital image data into digital image data and inputting n digital image data, the preprocessing unit binarizes the n digital image data to generate n binary images, and then generates the n binary images. Are enlarged vertically and horizontally at a predetermined magnification to create n enlarged images, and the array replacement unit performs two types of array replacement images for each of the n enlarged images. By creating, the 1-bit identification information is embedded in each type of the array replacement image of the two types of array replacement images, and the image output unit outputs By printing the n pieces of sequence substitutions image by outputting the image data of any kind of sequence substitutions image of the serial two types of sequence substitutions image, n in total
Create a printed material in which the bit identification information is embedded. Here, all the original image data of the n pieces of original image data can be configured to be the same original image data, but all the original image data of the n pieces of original image data are all the same original image data. It is not necessary to configure so that
FIG. 1 shows a case where four array replacement images A to D are printed with n = 4 and 4-bit identification information is embedded.

(Operation of Identification Information Recognition Apparatus) Next, FIG.
The identification information extraction routine will be described with reference to FIG. In step 200, the array replacement image is read from the printed matter in which the identification information is embedded, and is converted into digital image data. In step 201, the array replacement image converted into digital image data is subjected to fast Fourier transform.

In step 202, a Fourier spectrum is extracted from numerical data obtained by performing a fast Fourier transform on the array replacement image. In step 203, the extracted Fourier spectrum data is compared with the reference Fourier spectrum data set in advance in the storage unit of the Fourier spectrum output unit corresponding to each array replacement image by the comparison unit, thereby obtaining "1". Alternatively, either the binarized data of “0” or the result of “non-genuine” is output, and the identification information extraction routine ends. In the identification information extraction routine, the Fourier spectrum data extracted by the Fourier spectrum extraction unit is displayed on a display device such as a CRT or a liquid crystal display, or the Fourier spectrum data extracted by the Fourier spectrum extraction unit is output to a printer. It is also possible to provide information that can be output and viewed using an output device such as a printer or a printing machine, and then visually authenticate the printed material.

FIG. 6 is a diagram showing an example in which a Fourier spectrum relating to the image data of each printed matter in FIG. 5 according to the present invention is output using a printer. | Fs1 (u, v) in FIG. 6 (a)
| Is the Fourier spectrum of Fs1 (x, y) in FIG. 5A, in which circular or semicircular patterns are vertically arranged. on the other hand,
| F′s1 (u, v) | in FIG. 6 (b) is the Fourier spectrum of F′s1 (x, y) in FIG. 5 (b), and a circular or semi-circular pattern Lined up.

Thus, | fs1 (u, v) | and | f's1 (u, v) |
Since the deflection (direction bias) of the Fourier spectrum is different between and, the difference between | fs1 (u, v) | and | f's1 (u, v) | In addition, it can be easily recognized visually. Therefore, it is possible to extract 1-bit identification information embedded in Fs1 (x, y) and F's1 (x, y).

FIG. 7 shows an enlarged image Fg having a circular pattern.
FIG. 2 is a diagram showing 2 (x, y), a first array replacement image Fs2 (x, y), and a second array replacement image F's2 (x, y). The difference between Fs2 (x, y) and F's2 (x, y) cannot be visually discriminated.

FIG. 8 shows the Fourier spectrum | fs2 (u, v) | of Fs2 (x, y) in FIG. 7B and the Fourier spectrum | f of F's2 (x, y) in FIG. 7C. It is the figure which showed 's2 (u, v) |. | fs2
Since (u, v) | and | f's2 (u, v) | have different Fourier spectrum deflections, the difference can be easily compared by comparing means described later, and also visually. It can be easily identified. Therefore, the array replacement images Fs2 (x, y) and F's2 (x,
It is possible to extract identification information from y).

FIG. 9 is a diagram showing Fs2 (x, y) of FIG. 7 (b) and two images Fa2 (x, y) and Fb2 (x, y) constituting the same. Fa2 (x, y) is an image obtained by tightening C3 and has the same size as Fs2 (x, y). Fb2 (x, y) is obtained from Fs2 (x, y) by Fa
This is a difference image obtained by subtracting 2 (x, y), and the relationship between the images is given by Expression 1.

[0050]

## EQU1 ## Fs2 (x, y) = Fa2 (x, y) + Fb2 (x, y)

FIG. 10 is a diagram showing F's2 (x, y) of FIG. 7 (c) and two images F'a2 (x, y) and F'b2 (x, y) constituting the same. It is. The relationship between the images is given by Equation 2.

[0052]

## EQU2 ## F's2 (x, y) = F'a2 (x, y) + F'b2 (x, y)

However, Equation 3 holds between F'a2 (x, y) and Fa2 (x, y).

[0054]

## EQU3 ## F'a2 (x, y) = Fa2 (x, y)

FIG. 11 is a diagram showing a Fourier spectrum of each image of FIG. For optical display, the center of each Fourier spectrum is the DC component. Let the domain of each Fourier spectrum be DR1. DR1 is -1 / 2≤u <1/2, and -1 /
This is a region that satisfies 2 ≦ v <1/2. Since the row of v = 1/2 and the column of u = 1/2 are not included in DR1, | fa2 (u, v) |
Fourier spectra appear at four points (-1/2, -1/2), (0, -1/2), (-1 / 2,0), (0,0). These four points are defined as a domain DR2. The domain excluding DR1 and DR2 is DR3. | F in DR3
Since a2 (u, v) | = 0, fa2 (u, v) = 0 holds in DR3. From the addition rule of the Fourier transform, Equation 4 holds in DR3.

[0056]

Fs2 (u, v) = fb2 (u, v)

As a result, Equation 5 holds for DR3.

[0058]

| Fs2 (u, v) | = | fb2 (u, v) |

FIG. 12 is a diagram showing a Fourier spectrum of each image of FIG. Where | f'a2 (u, v) | and | fa2 (u,
v) | is given by Equation 6.

[0060]

| F′a2 (u, v) | = | fa2 (u, v) |

In DR3, equation 7 holds.

[0062]

| F′s2 (u, v) | = | f′b2 (u, v) |

The effect of | fa2 (u, v) | is that DR2 of | fs2 (u, v) |
And the effect of | f'a2 (u, v) | appears in DR2 of | f's2 (u, v) |, but the ratio of DR2 to DR1 is extremely small. Therefore, in DR3, which accounts for the majority of DR1,
Holds, | fb2 (u, v) | is the main factor that causes a deviation in the Fourier spectrum distribution of | fs2 (u, v) |, and the Fourier spectrum distribution of | f's2 (u, v) | It can be seen that the main element that causes the deflection to | f'b2 (u, v) |.

Since Fs2 (x, y) is composed of C3 and C4, | fb
In the spatial image Fb2 (x, y) of 2 (u, v) |, white pixels having a value of 1 in a row where all the pixel values are not 0 appear continuously in two or more pixels (a multiple of 2). On the other hand, for each column of Fb2 (x, y), in the column where all the pixel values are not 0, both sides of the white pixel having the value 1 are always 0
Black pixel. Therefore, | fb2 (u, v) | has a small proportion of the Fourier spectrum existing in the high-frequency region (1/4 ≦ u <1/2) in the u-axis direction, and ≤
(v <1/2) indicates that the proportion of the Fourier spectrum present in the region is large.

Since F's2 (x, y) is composed of C3 and C5, in the spatial image F'b2 (x, y) of | f'b2 (u, v) | A white pixel having a value of 1 in a non-zero column appears continuously for two or more pixels (a multiple of 2). On the other hand, for each row of F'b2 (x, y), in a row where all pixel values are not 0, both sides of a white pixel having a value of 1 are always black pixels having a value of 0.

Therefore, | f'b2 (u, v) | has a small proportion of the Fourier spectrum existing in the high frequency region (1/4 ≦ v <1/2) in the v-axis direction, Area (1/4 ≦ u <1 /
This shows that the proportion of the Fourier spectrum present in 2) is large. Since | fb2 (u, v) | and | f'b2 (u, v) | have different Fourier spectrum deflections, it is possible to extract identification information from an array replacement image in which identification information is embedded. .

According to the present invention, the n-bit identification information embedded in the printed matter is extracted and collated as described above, but this can be specifically realized by the configuration of the identification information recognition device shown in FIG. .

That is, the identification information recognizing device includes an identification information extracting device for extracting n-bit identification information and an identification information recognizing device for collating the extracted n-bit identification information with n-bit reference identification information data stored in advance. The identification information extracting device comprises an image reading unit,
A fast Fourier transform unit, a Fourier spectrum extractor, and a Fourier spectrum output unit are provided. The image reading unit converts the image data of the n array replacement images read from the printed matter into digital image data and converts the image data into n digital images. Generate image data, fast Fourier transform unit,
The Fourier spectrum extraction unit and the Fourier spectrum output unit respectively process the n pieces of digital image data generated by the image reading unit.
N bits from the printed material using the fact that the Fourier spectra of the two types of array replacement images created for each of the original image data have different polarizations from each other The identification information collating device extracts the n-bit identification information and the n-bit reference identification information data extracted by the identification information extracting device, and identifies the n-bit identification information and the n-bit reference identification information. When there is a predetermined relationship between the data, the printed matter is identified as a genuine printed matter.

The Fourier spectrum output unit in the identification information extracting device compares the extracted Fourier spectrum data with the reference Fourier spectrum data set in advance in the storage unit of the Fourier spectrum output unit in correspondence with each array replacement image. By means of the comparison, either binary data of “1” or “0” or a result of “non-authentic” is output.

To explain this point in detail, the Fourier spectrum output unit includes a storage unit and a comparison unit, and the storage unit stores data of the reference Fourier spectrum in advance. Then, the data of the Fourier spectrum extracted by the Fourier spectrum extraction unit is compared with the data of the reference Fourier spectrum by comparison means. Specifically, data of | fst (u, v) | and | f'st (u, v) | are stored in advance in the storage unit, and the data of the extracted Fourier spectrum is | fst (u, v) |
Outputs “1” when st (u, v) | and outputs “0” when extracted Fourier spectrum data corresponds to | f'st (u, v) | If the data of the Fourier spectrum does not correspond to any of them, a signal indicating unauthorized use is output.

In the identification information recognizing device, the Fourier spectrum data extracted by the Fourier spectrum extracting unit is displayed on a display device such as a CRT or a liquid crystal display, or the Fourier spectrum extracted by the Fourier spectrum extracting unit is displayed. It is also possible to output information using an output device such as a printer or a printing machine, provide information that can be viewed, and then visually authenticate the printed material.

The identification information collating device includes a collating means and a storage device. The n-bit binarized data output from the Fourier spectrum output unit of the identification information extracting device is stored in a storage device. A predetermined relationship is established between the n-bit binarized data output from the Fourier spectrum output unit of the identification information extracting device and the reference identification information data stored in advance in the storage device by collating with the identification information data by the matching means. At some point, a print is authenticated as a genuine print.

For example, when the printed matter authentication device of the present invention is used as a passport authentication device, "0101" is stored in advance in the storage device of the identification information verification device as reference identification information data, and the identification information embedded in the passport is used. The binarized data output from the Fourier spectrum output unit of the identification information extraction device as information is the reference identification information data “01”.
There is also a usage method that allows passage when the number matches "01".

Although the embodiments of the printed matter authentication apparatus according to the present invention have been described based on the specific embodiments, the embodiments of the printed matter authentication apparatus according to the present invention are limited to the above-described embodiments. Instead, various modes can be adopted as long as they fall within the technical scope described in the claims of the present invention. In particular, in the above-described embodiment, two types of array replacement images are created from enlarged images obtained by enlarging the binary image corresponding to the original image data vertically and horizontally twice, and the two types of array replacement images are created. Although the case where 1-bit identification information is embedded in each type of array replacement image has been described, a predetermined array is obtained from an enlarged image obtained by enlarging a binary image corresponding to the original image data at a predetermined magnification in each of the vertical and horizontal directions. Two types of array replacement images are created according to the replacement rules, and one type is added to each type of array replacement image of the two types of array replacement images.
By embedding the identification information of the bits, the printed matter authentication apparatus of the present invention can be configured. Further, in producing a printed matter in which n pieces of array replacement images are embedded in an identification information embedding apparatus and n bits of identification information are embedded, at least one array using ink having predetermined characteristics under predetermined conditions. After printing the replacement image, the identification information extracting device may extract the predetermined characteristic indicated by the ink under the predetermined condition and read the image data of the at least one array replacement image.

[0075]

The printed matter authentication apparatus according to the present invention is a binary image in which white pixels having a value of 1 and black pixels having a value of 0 are arranged in accordance with a predetermined arrangement replacement rule, wherein predetermined identification information is embedded. Since the identification information is extracted from the printed matter produced by outputting the binary image thus formed on a predetermined base material, compared with the case where the identification information is extracted from the grayscale image of the printed matter, the density unevenness of the ink and the fading due to the passage of time. In addition, it is hardly affected by illumination unevenness and the like, and it is possible to stably extract identification information from a printed material and accurately perform authentication of the printed material. Further, in the printed matter authentication apparatus according to the present invention, since the identification information is embedded using the phase modulation in the entire binary image including the white pixels having the value 1 and the black pixels having the value 0, the frequency modulation is used. Unlike the case where the identification information is embedded in the printed matter, the area where the identification information is embedded is not limited by the picture.

In the printed matter authentication device according to the present invention,
Since the identification information is extracted by using the deflection appearing in the Fourier spectrum of the image data read from the printed matter in which the identification information is embedded, high-precision alignment is required when extracting the identification information from the printed matter. Absent. Furthermore,
In the printed matter authentication apparatus according to the present invention, when extracting identification information from a printed matter, it is not necessary to binarize image data read from an image scanner or a video camera. Less susceptible to unevenness. For this reason, in the printed matter authentication device according to the present invention, it is possible to stably and accurately perform the authentication of the printed matter as compared with the related art.

The printed matter authentication apparatus according to the present invention creates two types of array replacement images for each of the n pieces of original image data, thereby obtaining each type of array of the two types of array replacement images. Since it is possible to embed 1-bit identification information in the replacement image and extract and collate n-bit identification information from the printed material, it is possible to accurately authenticate the printed material using more identification information. .
In addition, the printed matter in which the identification information created by using the printed matter authentication apparatus according to the present invention is embedded is a binary image in which white pixels having a value of 1 and black pixels having a value of 0 are arranged in accordance with a predetermined arrangement replacement rule. This is a printed matter in which a binary image in which predetermined identification information is embedded is simply printed on various media such as paper, plastic, metal, and cloth using various output devices such as a printer and a printing machine. The printed matter authentication device of the invention is:
It can be used in various fields that require identification and authenticity of printed matter including securities, bills, stamps, stamps, stamps, passports, identification cards, passports, membership cards, and credit cards.

[Brief description of the drawings]

FIG. 1 is a view for explaining the overall configuration of an embodiment of a printed matter authentication apparatus according to the present invention.

FIG. 2 is a block diagram showing an example of an identification information embedding device and an identification information extraction device.

FIG. 3 is a diagram showing an array of 2 × 2 pixels defined by an array replacement rule.

FIG. 4 is a flowchart illustrating a method for embedding and extracting identification information.

FIG. 5 is a diagram illustrating an example of a printed matter in which identification information is embedded.

FIG. 6 is a diagram showing an example in which a Fourier spectrum relating to image data of each printed matter in FIG. 5 is output using a printer.

FIG. 7 is an enlarged image Fg2 (x, y) having a circular pattern;
The figure which shows the 1st sequence substitution image Fs2 (x, y) and the 2nd sequence substitution image F's2 (x, y).

8 is a Fourier spectrum | fs of Fs2 (x, y) in FIG. 7 (b).
FIG. 8 is a diagram showing a Fourier spectrum | f′s2 (u, v) | of F′s2 (x, y) in FIG. 7C.

FIG. 9 is a diagram showing Fs2 (x, y) of FIG. 7B and two images Fa2 (x, y) and Fb2 (x, y) constituting the Fs2 (x, y).

FIG. 10 is a diagram showing F′s2 (x, y) of FIG. 7 (c) and two images F′a2 (x, y) and F′b2 (x, y) constituting the same.

FIG. 11 is a diagram showing a Fourier spectrum of each image in FIG. 9.

FIG. 12 is a view showing a Fourier spectrum of each image in FIG. 10;

FIG. 13 is a diagram illustrating an identification information recognition device of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 identification information embedding device 2 identification information extraction device 3 image input unit 4 preprocessing unit 5 array replacement unit 6 image output unit 7 image reading unit 8 fast Fourier transform unit 9 Fourier spectrum extraction unit 10 Fourier spectrum output unit 11 original image 12 identification Printed material with embedded information

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) G07D 7/12 G07D 7/12 H04N 1/387 H04N 1/387 1/40 1/40 Z F-term (reference) 2C005 HA02 HB01 HB02 HB10 JB40 LB38 3E041 AA01 AA02 AA03 BA11 CB03 5B057 AA11 BA02 BA29 CA02 CA06 CA12 CA16 CB02 CB12 CB16 CB18 CC02 CD05 CE08 CE09 CE20 CG07 CH08 DA08 DA16 DA17 DB02 DB05 DB08 DC33 5C076 A PP68 PQ04 PQ08 PQ20 RR02

Claims (10)

[Claims] 1. A printed matter authentication apparatus comprising: an identification information embedding apparatus for embedding identification information in a printed matter; and an identification information recognizing apparatus for extracting and collating the identification information from the printed matter, wherein the identification information embedding apparatus comprises: Image input unit, preprocessing unit,
An array replacement unit and an image output unit, wherein the image input unit converts input image data respectively corresponding to n (where n ≧ 1; n is an integer) original image data into digital image data And inputs n digital image data. The pre-processing unit binarizes the n digital image data to generate n binary images.
Each of the two binary images is enlarged vertically and horizontally at a predetermined magnification and n
The array replacement section creates two types of array replacement images for each of the n enlarged images, thereby creating two types of array replacement images. Embedding 1-bit identification information in the array-replaced image of the above, and the image output unit outputs an image of one of the two types of array-replaced image for each of the n enlarged images. By outputting data and printing n array replacement images, a printed matter in which identification information of a total of n bits is embedded is produced, and the identification information recognition device extracts identification information of the n bits. An identification information collating device for collating the extracted n-bit identification information with an n-bit reference identification information data stored in advance; An image reading unit, a fast Fourier transform unit, a Fourier spectrum extracting unit, and a Fourier spectrum output unit, wherein the image reading unit converts the image data of the n array replacement images read from the printed matter into digital image data. The fast Fourier transform unit, the Fourier spectrum extraction unit and the Fourier spectrum output unit convert the n digital image data generated by the image reading unit into n digital image data, respectively. Processing, from the printed matter by utilizing that the Fourier spectrum of each type of array replacement image of each of the two types of array replacement images has a different polarization from each other for each of the n enlarged images. Extracting the n-bit identification information; The n-bit identification information extracted by the information extraction device is compared with the n-bit reference identification information data, and when there is a predetermined relationship between the n-bit identification information and the n-bit reference identification information data, A printed matter authentication apparatus, wherein the printed matter is identified as a genuine printed matter. 2. The image input unit includes an image input device including an image scanner or a video camera. The input device acquires n pieces of the original image data by using the image input device, and inputs n pieces of the input image data. Create data,
2. The printed matter authentication apparatus according to claim 1, wherein said n pieces of input image data are respectively converted into digital image data to be said n pieces of digital image data. 3. The pre-processing unit generates the n binary images by binarizing each of the n digital image data input from the image input unit, and generates the n binary images. 2. The n enlarged images are created by enlarging each of the two images vertically and horizontally.
Or the printed matter authentication device according to 2. 4. The array replacing unit converts the n enlarged images, which are black and white binary images composed of white pixels having a value of 1 and black pixels having a value of 0, into 2 × The array is divided into two pixel units, and the number and arrangement of the white pixels are changed according to a predetermined arrangement replacement rule in all the 2 × 2 pixel unit arrays for each of the n enlarged images. By creating two types of array replacement images of a first array replacement image and a second array replacement image, the first array replacement image and the second array replacement image for each of the n enlarged images 4. A 1-bit identification information is embedded in the first array replacement image and the second array replacement image by utilizing the characteristic that the arrangement of the white pixels differs between the array replacement images. The printed matter authentication device according to the above. 5. The image output unit includes an image output device including a printer or a printing machine, and the two types of arrays are used for each of the n enlarged images by using the image output device. 2. A method according to claim 1, wherein the image data of any type of array replacement image of the replacement image is output to the surface of a predetermined base material, thereby printing n array replacement images on the surface of the base material. To 4
The printed matter authentication device according to any one of the above. 6. The image reading unit includes an image reading device including an image scanner or a video camera, and using the image reading device, outputs the image output unit for each of the n enlarged images. By reading any one of the two types of array-substituted images output from the substrate on the surface of the substrate and converting it into digital image data, n digital image data is generated from the printed matter 2. The method according to claim 1, wherein
6. The printed matter authentication apparatus according to any one of claims 1 to 5. 7. The fast Fourier transform unit according to claim 1, wherein the n digital image data generated by the image reading unit is fast Fourier transformed to obtain n numerical data. The printed matter authentication device according to any one of the above. 8. The Fourier spectrum extractor extracts Fourier spectrum data from each of the n numerical data obtained by the fast Fourier transform unit to obtain n Fourier spectrum data. The printed matter authentication apparatus according to claim 1. 9. The Fourier spectrum output section outputs the n pieces of Fourier spectrum data obtained by the Fourier spectrum extraction section to the identification information matching device as binary data. 9. The printed matter authentication device according to any one of 1 to 8. 10. The predetermined array replacement rule is as follows: 2 × 2 for each of the n enlarged images.
The pixel array Ci (i = 1, 2,..., 5) is converted to a pixel value Pxy (x = 1,
2; y = 1, 2), when Ci = {P11, P21, P12, P22}, C1 = {0, 0, 0, 0}, C2 = {1, 1, 1, 1}, C3 = {1,
0,0,0}, C4 = {1,0,1,1} and C5 = {1,1,0,1}, When creating the first sequence replacement image, Said
After replacing C3, replacing the C2 with the C4, when creating the second sequence replacement image, the C1 the
The printed matter authentication device according to claim 4, wherein after replacing C3, C2 is replaced with C5.