JP4352168B2 - Halftone image data authentication program, halftone print authentication system, and halftone image data authentication system - Google Patents

Description

  The present invention relates to a halftone image data or halftone dot printed material creation method, creation device, creation system, and creation program suitable for a certificate and the like, and an authentication method, an authentication device, an authentication system, and an authentication program.

  In recent years, with the increase in image quality of color copiers and the use of computerized color platemaking technologies, counterfeit technologies for banknotes and securities tend to be diversified. In particular, the resolution of image input / output devices used in the printing industry has significantly improved, and it has become easier to extract fine lines and minute characters used in various certificates. This is not only forgery by the general commercial printing method consisting of a halftone dot configuration of four colors, but also composed of black and white binary values such as background pattern, color pattern, relief pattern used in certificates, etc. More accurate counterfeit documents using many special color plates can be extracted with high precision by using I / O devices.

  In Patent Document 1 filed by the present applicant, visible and invisible images are generated by arranging two types of halftone images equally on the same plane for the purpose of providing a forgery prevention measure for continuous tone images. An image mask processing method is disclosed. According to this method, regardless of which type of functional ink is used, the latent image is visually recognized under predetermined viewing conditions corresponding to the optical characteristics of the functional ink used for printing the latent image. can do.

  However, such counterfeit prevention measures can only be applied to products that are economical in terms of production cost because expensive functional materials are required.

JP 2001-205917

  As described above, conventionally, it has been impossible to easily produce a printed material that can be sufficiently counterfeited and prevented from being tampered with at low cost, and cannot determine its authenticity.

  In view of the above circumstances, the present invention is suitable for certificates, has a low cost, high forgery and anti-falsification effect, and can easily determine whether the image is halftone image data or halftone printed matter. It is an object of the present invention to provide a creation system, a creation program, an authentication method, an authentication apparatus, an authentication system, and an authentication program.

The method of creating halftone dot image data of the present invention includes:
Inputting image data used to create a halftone print;
Converting the image data into a monochrome gray-scale image;
A plurality of sets of one first halftone region and a second halftone region having first and second regions adjacent to the first halftone region are arranged from the gray gradation image. Generating halftone images; and
Erasing halftone dots in the first halftone region of the halftone image to generate halftone image data only in the second halftone region;
For coloring the first area for gradation expression in the second halftone area using the halftone dot image data using a predetermined color ink having a first infrared reflectance. Image data processing is performed, and image data processing is performed for coloring the second region using ink of the same color as the predetermined color having a second infrared reflectance higher than the first infrared reflectance. Steps,
And outputting the halftone dot image data obtained by performing the image data processing for coloring.

  The halftone image data is printed using a printing machine to generate a halftone print.

  In the step of performing image data processing for coloring, image data processing for using black ink having infrared absorptivity is performed on the first region in the second halftone region, and the second region Image data processing for using black ink including three primary color inks of cyan, magenta, and yellow that does not have infrared absorptivity in the region may be performed.

  In the step of generating the halftone image, it is preferable that an area of the first halftone region is set to be larger than that of the second halftone region.

A program for causing a computer to execute the method of creating halftone dot image data of the present invention,
Inputting image data used to create a halftone print;
Converting the image data into a monochrome gray-scale image;
A plurality of sets of one first halftone region and a second halftone region having first and second regions adjacent to the first halftone region are arranged from the gray gradation image. Generating halftone images; and
Erasing halftone dots in the first halftone region of the halftone image to generate halftone image data only in the second halftone region;
Using the halftone image data, coloring the first region for gradation expression in the second halftone region using a predetermined color ink having a first infrared reflectance, Performing image data processing for coloring the second region using an ink of the same color as the predetermined color having a second infrared reflectance higher than the first infrared reflectance;
And outputting the halftone dot image data obtained by performing the image data processing for coloring.

A program for causing a computer to execute an authentication method for determining authenticity of halftone dot image data of the present invention,
Inputting image data of the printed matter;
Using the image data, extracting a component printed with ink of a predetermined color having infrared absorptivity contained in the printed matter; and
By comparing the data indicating the extracted component with the data relating to the component printed with the ink of the predetermined color having infrared absorptivity contained in a genuine halftone print, the authenticity of the printed matter is determined. Steps to do,
It is characterized by providing.

An authentication system for determining authenticity of a halftone dot printed matter of the present invention,
An infrared image reading device that extracts a component printed with ink of a predetermined color having a predetermined infrared reflectance from a printed material to be subjected to authenticity determination, and acquires image data related to the component;
A first terminal that transmits the image data to a second terminal via a network;
The second terminal being provided with the transmitted image data,
A storage unit that preliminarily stores data relating to a component printed with the predetermined color ink having the predetermined infrared reflectance, which is included in a genuine halftone dot print;
An arithmetic unit that determines the authenticity of the printed matter by comparing the image data with the data stored in the storage unit;
An output unit for outputting the result of the authenticity determination to the first terminal;
It is characterized by providing.

An authentication system for determining authenticity of halftone dot image data of the present invention,
A first terminal that transmits image data of a printed material to be subjected to authenticity determination to a second terminal via a network;
The second terminal being provided with the transmitted image data,
A storage unit that stores in advance data relating to a component printed with a predetermined color ink having a predetermined infrared reflectance, which is included in a genuine halftone dot print;
By using the image data, extracting the component printed with the ink of the predetermined color having the predetermined infrared reflectance contained in the printed matter, and comparing it with the data stored in the storage unit , An arithmetic unit for determining authenticity of the printed matter;
An output unit for outputting the result of the authenticity determination to the first terminal;
It is characterized by providing.

  As explained above, according to the halftone image data or halftone dot printed matter creation method, creation device, creation system, and creation program of the present invention, and the authentication method, authentication device, authentication system, and authentication program, By using a combination of two color inks that appear to be the same color system with the naked eye under visible light but are identified as different in the environment irradiated with infrared rays, it is easy to create a halftone print with high anti-counterfeit and tamper-proof effects. In addition, it can be created at low cost, and authenticity determination can be performed easily and with high accuracy.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(1) Halftone Print According to Embodiment 1 In the printing industry field, halftone dots are required to represent halftone, that is, continuous tone images, in addition to black and white binary values on printing paper. This is based on the property that a human recognizes a set of fine points as one gradation when visually distinguishing shades.

The technology for expressing halftones using halftone dots in continuous tone images has been led by major plate makers, so it is extremely difficult for users to create halftone prints freely. Met. However, in the recent plate making and printing industry, the PostScript (registered trademark) language, which is one of the computer page description languages, has been developed, and commercial application software based on this Postscript language has become popular. It has become possible to create dot prints.
However, only by using commercially available software, it has not been possible to easily create a halftone print having a sufficient anti-counterfeit effect at a low cost as described above.
Therefore, in this embodiment, basic four-color inks of cyan (C), magenta (M), yellow (Y), and black (Bk) widely used in general commercial printing are used without using special ink. The combination of inks that are used and look the same color with the naked eye under normal visible light but have different characteristics with respect to infrared rays (for example, wavelength 850 nm) is used.

  Of the basic four color inks of cyan (C), magenta (M), yellow (Y), and black (Bk) used in general commercial printing, black (Bk) is a black pigment mainly composed of carbon black. And has absorption characteristics over the entire region from the ultraviolet region to the infrared region.

On the other hand, black inks that are traded in the general market include security recording materials that take advantage of the unique property of not absorbing infrared rays, such as chromo fine black ink manufactured by Dainichi Seika Kogyo Co., Ltd. However, even if such special black ink is not used, the superposition of cyan (C), magenta (M), and yellow (Y) among basic four-color inks has the property of not absorbing infrared rays. Further, it is possible to obtain a black ink which is the same color as black (Bk) but does not absorb infrared rays at a low cost.
As a result, as shown in FIG. 1, the black (Bk) of the basic four-color ink and the superposition of cyan (C), magenta (M), and yellow (Y) are both normal. Despite being recognized as the same color system by the naked eye under visible light, black (Bk) absorbs infrared (reflectance: small), cyan (C), magenta (M), and yellow (Y) with respect to infrared rays. The combined material will have a different characteristic of reflection (reflectivity; large).

  By utilizing such characteristics, when observed using an identification device using infrared rays such as an infrared camera, only an image printed with black (Bk) ink containing carbon black is visually recognized, and cyan (C). Further, it is possible to produce an effect that an image printed by superimposing magenta (M) and yellow (Y) inks is not visually recognized.

A specific example of the halftone print according to the first embodiment using the above phenomenon will be described below.
(1a) Halftone Printed Material According to Example 1 The printed material according to Example 1 is shown in FIG. 2A as an area in which an image is expressed by gradation using a halftone dot (hereinafter referred to as a halftone area). In addition, the first halftone region HT1 and the second halftone region HT2 are included. The first halftone area HT1 and the second halftone area HT2 are arranged so that each one is adjacent to each other to form one set, and a plurality of sets are arranged as a whole. The size of the first halftone region HT1 and the second halftone region HT2 is not limited, but the influence of the first halftone region HT1 with the naked eye under more normal visible light is relatively It is desirable that the first halftone region HT1 is larger so as to be larger. Here, the first halftone region HT1 has, for example, m × m (m is a positive number of 1 or more) pixels, and the second halftone region HT2 has n × n (n is a positive number of 1 or more) pixels. Have

A circular dot 1 is arranged in the first halftone region HT1, and a circular dot 3 and surrounding halftone dots 2 are arranged in the second halftone region HT2. The circular dots 1 in the first halftone region HT1 are arranged so as to constitute the halftone dot image P1 shown in FIG. 2B, and the circular dots 3 in the second halftone region HT2 are arranged in FIG. The halftone dot image P2 shown in c) is arranged.
The circular dot 1 is printed using three color inks of cyan (C), magenta (M), and yellow (Y) that do not contain an infrared absorbing dye, and the circular dot 3 is printed with an infrared absorbing dye (for example, Printing is performed with one color of black (Bk) ink including carbon black. Further, the halftone dot 2 in the second halftone region HT2 is printed by three-color overprinting (three-color solid) of cyan (C), magenta (M), and yellow (Y) that does not contain an infrared absorbing dye.
In the first and second halftone regions HT1 and HT2, circular dots are used as halftone dots, respectively, but the shape is not limited to a circle, but is a triangle, a square, a polygon, or a random shape. Alternatively, a halftone dot shape proposed in Japanese Patent Laid-Open No. 11-268228 filed earlier by the present applicant may be used.

By combining such first and second halftone areas HT1 and HT2, the following visual effects can be obtained.
First, in the second halftone region HT2, the circular dots 3 and the surrounding halftone dots 2 are both visually recognized as black by the naked eye under normal visible light. Therefore, the entire second halftone region HT2 is considered to be uniformly black and solid.
When the entire printed matter is observed with the naked eye under normal visible light, the first halftone region HT1 has a great influence on the viewer, and a full-color image appears. Therefore, the gradation image composed of the circular dots 3 in the second halftone region HT2 is not visually recognized.
However, in an environment where infrared rays are irradiated, for example, when shooting using an infrared camera, the circular dots 3 in the second halftone region and the surrounding halftone dots 2 are distinguished and recognized as different ones. . That is, only the circular dots 3 that absorb infrared rays are visually recognized, and the surrounding halftone dots 2 that reflect infrared rays are not visually recognized, and the gradation image formed by the circular dots 3 is visually recognized.
In this way, by determining whether or not there is a gradation image formed by the circular dots 3 in the second halftone region HT2, it is possible to easily determine whether the printed matter is genuine.

  FIG. 3A shows a halftone dot image P1 formed by the circular dots 1 in the first halftone region HT1, and FIG. 3B shows a partially enlarged view d1 thereof. Further, FIG. 3C shows a halftone dot image P2 formed by the circular dots 3 in the second halftone region HT2, and FIG. 3D shows a partially enlarged view d2. Further, FIG. 3E shows an image generated by an image data processing method proposed in Japanese Patent Application Laid-Open No. 2001-205917 filed earlier by the present applicant, in which two types of halftone images are evenly arranged on the same plane. A partially enlarged view m of the mask is shown. This partial enlarged view m shows a halftone image composed of a cyan (C) -only plate among halftone images composed of cyan (C), magenta (M), yellow (Y), and black (Bk). .

A halftone image d1 ′ that is visible to the naked eye under normal visible light, as shown in FIG. 4A, by performing image operations on the partial enlarged view d1 of the halftone image P1 and the partial enlarged view m of the image mask. Is generated, and the halftone dot image P2 shown in FIG. 4B is not visually recognized by the naked eye under the normal visible light by the image calculation of the partial enlarged view d2 of the halftone dot image P2 and the partial enlarged view m of the image mask. d2 'is generated.
Further, by the image calculation of the halftone image d2 ′ and the partial enlarged view m of the image mask, the periphery of the halftone image d2 ′ shown in FIG. 4C is cyan (C), magenta (M), yellow. (Y) A halftone dot image d3 is generated for multiplying the three ink colors.
The ink that can be used in the first embodiment is not limited to cyan (C), magenta (M), and yellow (Y). A combination of three colors of black (Bk) ink containing an absorbing dye can also be used.
In this case, the circular dot 1 of the first halftone region HT1 shown in FIG. 1 is printed with two-color double tone having a complementary color relationship that does not contain an infrared absorbing dye, and the second halftone region The circular dot 3 of HT2 is printed with one color of black (Bk) ink that is in the same color relationship as two complementary colors and includes an infrared absorbing dye, and the surrounding halftone dot 2 is printed with the first halftone. Printing is performed with a two-color solid having the same color ink as that of the region HT1 and having a complementary color relationship that does not include an infrared absorbing dye.

The printed matter obtained in the first embodiment described above obtains a printed matter in which it is difficult to recognize that the mountain landscape image P1 is recognized with the naked eye and the river landscape image P2 is hidden under normal visible light. It can be visually recognized as a configuration as shown in the partial enlarged view P3 shown in FIG. When this printed matter is observed with an infrared photograph, the gradation image of the river landscape image P2 can be recognized as a latent image.
Thus, it is possible to easily determine whether the gradation image as a latent image that has not been visually recognized by the naked eye under normal visible light is confirmed by infrared photography. According to the first embodiment, it is possible to produce a halftone dot printed material that has a high effect of preventing forgery and tampering and that is easy to determine authenticity at low cost by using ordinary basic four color ink.

(1b) Example 2
A case where the halftone dot printed matter according to the first embodiment is applied to an identification card will be described as a second example. The a part of the identification card shown in FIG. 5 uses a normal method to print and arrange a halftone image using cyan (C), magenta (M), and yellow (Y) inks. Is a halftone image constructed and printed using the same method as in the first embodiment.
Here, in the first halftone region HT1 in the portion b, an image that can be visually recognized under normal visible light is not disposed, and the second halftone region HT2 is visually exposed under normal visible light. An image that cannot be seen with is placed. In this second halftone region HT2, the circular dots 3 are printed using one color of black (bk) ink containing an infrared absorbing dye, and the surrounding halftone dots 2 contain an infrared absorbing dye. There is no cyan (C), magenta (M), or yellow (Y) solid color printing. As a result, the second halftone region HT2 is arranged in the same black solid color with the naked eye under normal visible light.

FIG. 6 shows a halftone dot arrangement state of each color plate in the second halftone region HT2 in the portion b of FIG. When these are superimposed, the black flat uniform state is obtained, and the image P5 cannot be recognized with the naked eye under normal visible light.
As described in Example 1 above, the portion d4 printed with black (bk) ink having infrared absorption characteristics, and cyan (C), magenta (M), and yellow (Y) having infrared reflection characteristics. An image that cannot be seen with the naked eye under normal visible light is printed with black (bk) ink by utilizing the difference in characteristics with respect to infrared rays from the portion d5 printed with the three color inks superimposed. As a result, unless a special appraisal device such as an infrared camera is used, the image P5 composed of part b in FIG. 5 cannot be recognized, and a printed matter with a high effect of preventing counterfeiting and tampering can be obtained at low cost. Can do.

(1c) Example 3
As a third embodiment of the present invention, an example in which the technique according to the first embodiment is applied to on-demand printing of an identification card will be described.
There are various interpretations of what is called “on-demand printing”, which may be short-run color printing, or it may be one that consistently processes up to bookbinding and provides a booklet just in time. The most effective use of such on-demand printing characteristics is page variable printing.
Page variable printing means printing different contents (information), that is, "variable data", and provides text and image information specialized for individuals and companies via paper media quickly and accurately. Used for.

In the first embodiment, images that cannot be viewed with the naked eye under normal visible light are equally arranged on the same plane as the face image c of each individual in FIG. Such four-sided version identification cards P6-1 to P6-4 are variably printed using an on-demand printing machine. Each individual name is also variably printed at the same time, but in the third embodiment, this information is printed as information that can be viewed with the naked eye under normal visible light using a normal printing method.
When this printed matter is observed with an infrared camera, as shown in FIG. 8c, images P6-1 to P6-4 that are not visually recognized by the naked eye under normal visible light are visually recognized, and it is difficult to forge and tamper. The effect as a proper ID is obtained.

(1d) Example 4
As a fourth embodiment of the present invention, a case where the technique according to the second embodiment is applied to on-demand printing of an identification card will be described.
The portion d shown in FIG. 9 is a conventional method for printing a halftone image using cyan (C), magenta (M), yellow (Y), and black (Bk) inks that do not have infrared absorptivity. Deploy. 9 uses the halftone dot configuration according to the first embodiment, performs halftone processing using a method according to the Postscript halftone dot generation method, and performs printing arrangement. As described in the second embodiment, the portion e is in the same color black with a uniform flat mesh state and cannot be visually recognized under normal visible light.

Such identification cards P7-1 to P7-4 are variably printed in a four-sided plate configuration using an on-demand printing machine. Each individual name is also variably printed at the same time. However, in the fourth embodiment, unlike the third embodiment, by using the halftone dot configuration in the second embodiment, information is given as information that is not visually recognized under normal visible light. ing.
When such identification cards P7-1 to P7-4 are observed with an infrared monitor, an e portion that is not visually recognized by the naked eye under normal visible light as shown in FIG. 10 is visually recognized. It is possible to easily determine whether there is a true or false.
In addition, the information such as the personal name and company name shown in the above Examples 2 to 4 is information that can be viewed with the naked eye under normal visible light, or information that is visible by irradiating infrared rays. The degree of freedom in design can be expanded by selecting whether or not to do so.

According to Examples 1 to 4 described above, it is difficult to copy with a general plate-making device, and a continuous tone image composed of halftone dots that can be read using a device using infrared rays is printed. Thus, it is possible to easily obtain a halftone print that can prevent forgery and tampering. In addition, one continuous tone image can be printed in a predetermined area, and two continuous tone images do not overlap each other in the predetermined area, and the two continuous tone images are fused. Therefore, it is possible to obtain a high degree of freedom in design.
Further, by using basic four-color inks of cyan (C), magenta (M), yellow (Y), and black (bk) widely used in the general market, printing can be performed at low cost.
In addition, when applied to on-demand printing, individual information such as letters, symbols, patterns, grayscale images, etc., for printed materials that have different information such as identification cards and that require anti-counterfeiting and tampering prevention. It can be easily printed as information that is not visible to the naked eye under normal visible light.

(2) Halftone dot image data or halftone dot print creation system and authentication system according to Embodiment 2 A system for creating halftone dot print or halftone dot image data according to Embodiment 1 above, and true / false discrimination An authentication system for this will be described with reference to FIG. Here, the administrative station 20, the printing station 30, and the administrative station 40 each include a terminal connected via a network.
In this system, an individual 10 applies for issuance of a certificate to the administrative office 20, for example, when an individual 10 applies for issuance of a tax payment certificate to a tax office, and the obtained certificate is transferred to another administrative office 40. It is suitable for submission.
The individual 10 applies for issuance of a certificate at the office of the administrative station 20 or the individual 10 using a personal computer via a network such as the Internet.

At the time of application, the individual 10 provides image information used for authenticity determination, such as a self-photograph. When applying at the window, take a photo on the spot or create image data from the photos you bring. In the case of electronic application via a network, image information is transmitted.
The administrative station 20 transmits the acquired image data as an original image to the printing station 30 and requests the creation of a certificate.
The printing station 30 creates halftone dot image data for creating the halftone printed matter according to the first embodiment using the transmitted image data, and creates a certificate using the halftone dot image data. . Then, the printing station 30 transmits the certificate image data to the administrative station 20 or sends out the certificate printed out on the printing medium. Further, the created halftone dot image data is stored in an authentication server or the like for use in authentication.

In response to the window application, the administrative station 20 issues a certificate printed on the printing medium 30 to the individual 10 or a certificate obtained by outputting image data of the certificate received by the administrative station 20 using a printer. For electronic applications via the network, the certificate image data is transmitted.
Upon receiving the certificate, the individual 10 submits the certificate at the window or transmits the image data of the certificate via the network to another administrative station 40 that requests the certificate.
The administrative station 40 reads the certificate with a scanner to create and transmit image data, or transmits the transmitted image data to the printing station 30 to request certificate authentication.

The printing station 30 extracts components necessary for authenticity determination, such as a face photograph, included in the transmitted image data, and compares and verifies with authentic data stored in the authentication server or the like. If they match, it is determined that the certificate is authentic. If they do not match, it is determined that the certificate is not an application, and the determination result is transmitted to the administrative station 40. The administrative station 40 accepts the certificate if it is sent as a genuine decision, and rejects the certificate if it is sent as a decision that it is not authentic.
According to this system, by applying the halftone printed matter according to the first embodiment to a certificate, a certificate having a high effect of preventing forgery and falsification can be issued easily and at a low cost, and the authenticity determination can be easily performed. It can be performed with high accuracy.

(3) Device for creating halftone dot image data or halftone dot printed matter according to the third embodiment In the halftone dot image data or halftone dot printed matter creating system according to the second embodiment, the printing station 30 performs halftone dot image data or halftone dot printed matter. An apparatus used when creating the file will be described.
As shown in FIG. 12, the creating apparatus includes an input unit 100, a calculation unit 110, a storage unit 120, an output unit 130, and a printing unit 140 as necessary.
The input unit 100 inputs image data corresponding to an original image including an applicant's face photo.
The calculation unit 110 performs necessary image data processing on the image data, and generates halftone print data. Further, image data necessary for creating a certificate is created using the image data of the halftone printed matter.

The storage unit 120 stores input image data, data necessary for the processing unit 110 to perform processing, generated dot print image data, certificate image data, and the like.
The output unit 130 outputs halftone dot print image data or certificate image data.
The printing unit 140 performs a printing process using the image data, and generates a halftone print.

(4) Method for creating halftone dot image data or halftone dot printed matter, program for creating halftone dot image data according to the fourth embodiment In the halftone dot image data or halftone dot printed matter creating system according to the second embodiment, the printing station 30 FIG. 13 is a flowchart showing a procedure for creating halftone image data or halftone dot printed matter using the creation device according to the third embodiment, and a program for operating the computer as a halftone image data creation device. It explains using.
In step S10, the input unit 100 inputs the image data of the original image. This data is stored in the storage unit 120.
As Steps S20 to S80, the calculation unit 110 generates halftone image data.
First, in step S20, the original image data is converted into a monochrome gray-scale image. Conversion from color image data to a monochrome gray-scale image can be performed using commercially available software.

In step S30, predetermined image data processing is performed as necessary. For example, a change to a desired resolution, a change process to a desired image size, and the like are included. However, it is not always necessary to perform such image data processing.
In step S40, a halftone image is generated from the gray gradation image. Commercially available software can be used for the conversion into halftone dot image data. For example, a halftone dot code called halftone type 16 is assigned in Adobe Postscript (registered trademark) to generate a halftone image.
The obtained halftone image is the same as the halftone dot printed matter according to the first embodiment, for example, as shown in FIG. 14, for example, the first halftone region HT1a and the second halftone region HT1a in which the image is expressed by halftone dots. Halftone region HT2a.

  The first halftone region HT1a and the second halftone region HT2a constitute one set each and are arranged adjacent to each other, and are arranged without a plurality of sets as a whole. . The first halftone region HT1a and the second halftone region HT2a are arranged so that the influence of the first halftone region HT1a with the naked eye under relatively normal visible light becomes relatively large. The tone area HT1a is set larger. Here, the first halftone region HT1a has, for example, 80 × 40 pixels, and the second halftone region HT2a has 40 × 20 pixels.

In the first halftone area HT1a, the dots are arranged so as to expand sequentially from the center position C1a up and down and right and left in accordance with the gradation. Similarly, in the second halftone region HT2a, dots are arranged so as to gradually spread vertically and horizontally from the center position C2a according to the gradation.
Here, the dimensions and positional relationship of the first and second halftone areas are not limited to those shown in FIG. 14. For example, as shown in FIG. 15, the square first halftone area HT1 b and the second halftone area. HT2b may be arranged. In this case, the first halftone region HT1b has, for example, 80 × 80 pixels, and the second halftone region HT2b has 40 × 40 pixels.
Similarly, in the first halftone region HT1b, the dots are arranged so as to expand sequentially from the center position C1b up and down and right and left in accordance with the gradation. In the second halftone region HT2b, dots are arranged so as to gradually spread vertically and horizontally from the center position C2b according to the gradation.

As long as the first and second halftone regions can be arranged without a gap, the shape is not limited to the rectangle and the square as shown in FIGS. It may be composed of two regions having
In step S50, the halftone dot in the first halftone area HT1 is deleted from the halftone image. Specifically, a mask that covers the second halftone region HT2 is used, and the halftone dots of the first halftone region HT1 that are not covered with the mask are removed.
The obtained halftone dot image data of only the second halftone area HT2 is stored in the storage unit 120 such as the authentication server in step S60, and in step S70, the dots in the second halftone area HT2 and the surrounding area thereof are stored. Image data processing for coloring is performed. Note that the image data processing for coloring means that a command for coloring with a printing machine is performed by a computer. The same applies to image processing for coloring.

Specifically, as described in the first embodiment, image data processing for coloring the dots in the second halftone region HT2a using black (Bk) ink having infrared absorptivity is performed. An image for solidly coloring the periphery of the dots in the second halftone region HT2a by overlaying three color inks of cyan (C), magenta (M), and yellow (Y) that do not have infrared absorptivity. Perform data processing.
In step S80, the output halftone dot image data is output by the output unit 130. At this time, if necessary, the calculation unit 110 converts the data format requested by the counterpart (administrative station 20), and then the output unit 130 outputs the halftone image data.
If necessary, in step S100, the halftone dot image data is used to perform a printing process to generate a halftone dot printed matter.

(5) Halftone dot image data or halftone dot printed matter authentication apparatus according to the fifth embodiment In the halftone dot image data or halftone dot printed matter authentication system according to the second embodiment, the printing station 30 uses the certificate or certificate image data. An authentication apparatus used for determining whether the user is true or false will be described.
As shown in FIG. 16, the authentication apparatus includes an input unit 200, a calculation unit 210, a storage unit 220, and an output unit 230.
The input unit 200 receives certificate data submitted by the individual 10 and reads image data created by reading a portion having a predetermined reflectance with respect to infrared using an infrared reader, or image data transmitted from the individual 10. Enter directly.

  The calculation unit 210 performs necessary image data processing on the obtained image data, and compares the image data with genuine halftone dot image data to determine authenticity. For example, when image data is directly input, a process for extracting a component having a predetermined reflectance with respect to infrared rays is performed.

The storage unit 120 stores the given image data, data necessary for the calculation unit 210 to perform processing, and genuine halftone image data as a storage unit of the authentication server.
The output unit 130 outputs the authenticity determination result.

(6) Halftone image data or halftone print authentication method and halftone image data authentication program according to the sixth embodiment In the halftone image data or halftone print authentication system according to the second embodiment, the printing station FIG. 17 is a flowchart showing a procedure for authenticating a certificate or certificate image data using the authentication device according to the fifth embodiment, and a program for operating the computer as an authentication device. I will explain.
In step S100, the input unit 200 acquires the image data by reading the certificate using an infrared reader. Alternatively, the certificate image data is directly input by the input unit 200. This data is temporarily stored in the storage unit 220.

In step S110, the first halftone area HT1 described in the fourth embodiment is erased, and the dots in the second halftone area HT2, that is, components colored with black (Bk) ink that absorbs infrared rays Extract only image data. This processing is necessary when image data is directly input. When the image data is read using an infrared reader, a component having a predetermined reflectance with respect to infrared rays (in this case, colored with black ink). Only the component) is extracted.
In step S120, the extracted image data is compared with the true halftone dot image data of only the second halftone region HT2 described in step S60 in the fourth embodiment, and the authenticity of the printed matter is determined. .

If they match, it is determined in step S130 that the printed material is authentic. If they do not match, it is determined in step S140 that the printed material is not authentic, and the output unit 230 outputs the determination result. .
Creation system of halftone image data or halftone dot printed matter according to the second embodiment, authentication system, creation device according to the third embodiment, creation method and creation program according to the fourth embodiment, and according to the fifth embodiment According to the authentication apparatus, the authentication method and the authentication program according to the sixth embodiment, halftone dot printed matter having a high effect of preventing forgery and tampering can be created easily and at low cost, and such printed matter can be easily and highly accurately applied. False discrimination can be performed.

The above-described embodiments and examples are only examples, and do not limit the present invention. For example, in the halftone print according to the above-described embodiment, black (Bk) ink that absorbs infrared rays and three color inks of cyan (C), magenta (M), and yellow (Y) that do not absorb infrared rays are overcoated. Is used in combination.
However, it is not limited to black ink, but the same color system that is visible to the same color with the naked eye under normal visible light, one of which absorbs relatively more infrared and the other absorbs less If it is, it can be used for the halftone print of the present invention.

In each of the above-described embodiments and examples, the circular dots 3 in the second halftone region HT2 are printed using one color of black (bk) ink, and the surrounding halftone dots 2 are cyan (C), Printing is performed using magenta (M) and yellow (Y).
However, four color inks of cyan (C), magenta (M), yellow (Y), and black (bk) are applied to the circular dots 3 in the second halftone region HT2 and the surrounding halftone dots 2. May be used for printing. In this case, both the circular dot 3 and the surrounding halftone dot 2 have an absorptivity with respect to a certain amount of infrared rays, but the circular dot 3 is relatively more infrared than the surrounding halftone dot 2 (for example, It is necessary to set the ink composition so that the reflectance is low.

Further, in both the above embodiment and examples, as described with reference to FIGS. 14 and 15, the dot 3 of the second halftone region HT2 is set at the center position of the region, and the gradation level is increased. Accordingly, it is configured to expand in a circular shape.
However, as shown in FIG. 18, in the first halftone region HT1c, the center position C1c where the dots sequentially expand vertically and horizontally according to the gradation does not have to be located at the center of the region HT1c. Similarly, in the second halftone area HT2c, the center position C2c where the dots spread according to the gradation may not be located at the center of the area HT2c.

Similarly, as shown in FIG. 19, in the square first halftone region HT1d and second halftone region HT2d, the center positions C1d and C2d at which the dots spread are located at the centers of the regions HT1d and HT2d, respectively. Not necessary.
Also in this case, as long as the first and second halftone regions can be arranged without a gap, the shape is not limited to the rectangle and the square as shown in FIGS. Or you may be comprised by two area | regions which have a curve shape.
Then, taking the case shown in FIG. 19 as an example, as shown in FIGS. 20A to 20D, the dots are sequentially expanded vertically and horizontally from the center positions C1d and C2d according to the gradation. become.

Explanatory drawing shown about the characteristic of the basic 4 color ink used with the halftone dot printed matter by Embodiment 1 of this invention. Arrangement of the first halftone area and the second halftone area provided in the halftone dot printed matter of Example 1 according to Embodiment 1 of the present invention, and the halftone dots formed by the first and second halftone areas, respectively. Explanatory drawing which showed the image. FIG. 3 is an explanatory diagram showing an image obtained by performing halftone processing using a method according to the Postscript halftone dot generation method in the first embodiment. In the first embodiment, among the halftone images that reproduce the full color image using cyan (C), magenta (M), yellow (Y), and black (Bk), the halftone image in the cyan (C) plate is used. FIG. Explanatory drawing which showed Example 2 which applied the halftone dot printed matter by Embodiment 1 of this invention to identification. FIG. 5 is an explanatory diagram showing a halftone dot arrangement state of each color plate in a second halftone area in the second embodiment. Explanatory drawing which showed the image visually recognized under normal visible light in Example 3 which applies the halftone dot printed matter by Embodiment 1 of this invention to identification, and performs on-demand printing. FIG. 6 is an explanatory diagram illustrating a state in which an image that is not visually recognized by the naked eye under normal visible light can be recognized using an infrared camera when on-demand printing is performed by applying the printed matter according to the third embodiment to an identification card. In Example 4 where the halftone dot printed matter according to Embodiment 1 of the present invention is applied to an identification card and the identification card is printed on demand in the same manner as in Example 2 above, it is visually recognized with the naked eye under normal visible light. Explanatory drawing which showed the image. FIG. 5 is an explanatory diagram showing that an infrared ray camera can recognize an image that is not visually recognized under normal visible light when the identification card is printed on demand as in the second embodiment, as in the fourth embodiment. Explanatory drawing which showed the structure of the production system of a halftone dot image data or halftone dot printed matter, and an authentication system by Embodiment 2 of this invention. The block diagram which showed the structure of the production apparatus of the halftone image data or halftone dot printed matter by Embodiment 3 of this invention. The flowchart which showed the structure of the program for operating the procedure of the process in the preparation method of the halftone image data or halftone printed matter by Embodiment 4 of this invention, and operating a computer as a production apparatus. Explanatory drawing which showed an example of the structure of the halftone dot printed matter produced by the same Embodiment 4. FIG. Explanatory drawing which showed the other example of the structure of the halftone dot printed matter produced by the same Embodiment 4. FIG. The block diagram which showed the structure of the authentication apparatus of the printed matter by Embodiment 5 of this invention. The flowchart which showed the structure of the program for operating the procedure of the process in the authentication method of printed matter by embodiment of this invention, and operating a computer as an authentication apparatus. Explanatory drawing which showed the other example of a structure of the halftone dot printed matter shown by FIG. Explanatory drawing which showed the other example of the structure of the halftone dot printed matter shown by FIG. FIG. 20 is an explanatory diagram showing a state in which dots expand in accordance with the gradation in the first and second halftone areas in the halftone printed matter shown in FIG. 19.

Explanation of symbols

10 Individual 20, 40 Administrative station 30 Printing station 100, 200 Input unit 110, 210 Calculation unit 120, 220 Storage unit 130, 230 Output unit 140 Printed matter HT1, HT1a, HT1b, HT1c, HT1d First halftone region HT2, HT2a , HT2b, HT1c, HT1d Second halftone region

Claims (3)

In a program for causing a computer to execute an authentication method for determining authenticity of halftone dot image data of halftone dot printed matter,
A first halftone region and a second halftone region, and each of the first halftone region and the second halftone region constitutes one set and is adjacent to each other. Multiple sets are arranged without gaps,
The vertical pixels in the first halftone region are different from the horizontal pixels, the vertical pixels in the second halftone region are different from the horizontal pixels,
The second halftone region has a first region and a second region;
The first halftone area is printed with ink that does not contain infrared radiation;
The first region of the second halftone region is printed with a predetermined color ink having a first infrared reflectivity;
The second area of the second halftone area is a halftone dot printed matter printed with ink of the same color as the predetermined color and having a second infrared reflectance higher than the first infrared reflectance. Extracting a component printed with ink of a predetermined color having the first infrared reflectance;
By comparing the data indicating the extracted component with the data relating to the component printed with the ink of the predetermined color having the first infrared reflectance, which is included in a true halftone print, the halftone dot A halftone image data authentication program comprising: a step of determining authenticity of a printed material. In an authentication system for authenticating halftone prints,
A first halftone area and a second halftone area that are to be subjected to authenticity determination are provided, and each of the first halftone area and the second halftone area includes one set each. Configured, arranged adjacent to each other without a plurality of gaps,
The vertical pixels in the first halftone region are different from the horizontal pixels, the vertical pixels in the second halftone region are different from the horizontal pixels,
The second halftone region has a first region and a second region;
The first halftone area is printed with ink that does not contain infrared radiation;
The first region of the second halftone region is printed with a predetermined color ink having a first infrared reflectivity;
The second area of the second halftone area is a halftone dot printed matter printed with ink of the same color as the predetermined color and having a second infrared reflectance higher than the first infrared reflectance. An infrared image reading device for extracting a component on which ink of a predetermined color having the first infrared reflectance is printed and acquiring image data relating to the component;
A first terminal that transmits the image data to a second terminal via a network;
The second terminal being provided with the transmitted image data,
A storage unit that stores in advance data relating to a component printed with the ink of the predetermined color having the first infrared reflectance, which is included in a genuine halftone dot print;
An arithmetic unit that determines the authenticity of the halftone print by comparing the image data with the data stored in the storage unit;
An authentication system for halftone printed matter, comprising: the second terminal including an output unit that outputs the result of the authenticity determination to the first terminal. In an authentication system for authenticating halftone image data,
A first halftone area and a second halftone area that are to be subjected to authenticity determination are provided, and each of the first halftone area and the second halftone area includes one set each. Configured, arranged adjacent to each other without a plurality of gaps,
The vertical pixels in the first halftone region are different from the horizontal pixels, the vertical pixels in the second halftone region are different from the horizontal pixels,
The second halftone region has a first region and a second region;
The first halftone area is printed with ink that does not contain infrared radiation;
The first region of the second halftone region is printed with a predetermined color ink having a first infrared reflectivity;
The second region of the second halftone region is a halftone dot printed matter printed with ink of the same color system as the predetermined color having a second infrared reflectance higher than the first infrared reflectance. A first terminal that transmits image data to a second terminal via a network;
The second terminal being provided with the transmitted image data,
A storage unit for storing in advance data relating to a component printed with a predetermined color ink having the first infrared reflectance, which is included in a genuine halftone print;
Using the image data, extracting a component printed with the ink of the predetermined color having the first infrared reflectance contained in the printed matter, and comparing the extracted component with the data stored in the storage unit; And an arithmetic unit for determining the authenticity of the halftone printed matter;
An authentication system for halftone image data, comprising: the second terminal having an output unit that outputs the result of the authenticity determination to the first terminal.

Images