JP4487086B2 - Printed material having a set pattern for continuous tone expression and its authenticity determination method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention requires art printing such as catalogs, pictorial books, and passports, securities, cards, valuable printed matter, etc., and forgery prevention and tampering prevention. It is related with the pattern (pattern) which consists of, and its printed matter.
[0002]
[Prior art]
The representation of the continuous gradation of the pattern on the printed material is that the printed color on the printed material is composed of a group of fine figures such as dots (disconnections) and lines, and the shape and size of the fine figure is represented by the continuous gradation of the pattern. It is controlled according to the concentration. For continuous tone expression, screen continuous tone expression composed of fine component elements consisting of regular polygonal array such as halftone dots, and the outlines and patterns of motifs in the design, There is a line drawing gradation expression method composed of thin lines.
[0003]
The line drawing gradation expression method composed of the above-mentioned pictorial points (disconnections) and thin lines is a method of drawing an arbitrary motif such as a person, a landscape, an object, a pattern or the like using a drawing-like drawing technique. In order to express the texture, the shape and arrangement of the image line are complicated on the printed matter, for example, the points (disconnection) and the thin lines in the design intersect or converge. Therefore, the line drawing gradation expression method composed of the above-mentioned pictorial points (disconnection) and lines is a painting technique that can reflect the design intention. As a main expression method, when the image line is “line”, the image density can be expressed by the image line width and the density of the image line. When the image line is a “point”, the pattern density can be expressed by the size of the point, and the pattern density can also be expressed by the density of the points. In the present specification, the painting technique is referred to as a line drawing method.
[0004]
First, the line point drawing method will be specifically described with reference to the drawings. For example, when a three-dimensional motif as shown in FIG. 1 is represented by a line drawing method, it can be expressed as a group of line points in FIG. In this way, a printed matter having a drawing line in which the drawing line is composed of dots (disconnections) and thin lines by the line drawing method is mainly used for portraits of celebrities when forgery prevention is important, such as banknotes. This is used as a gradation expression method. Furthermore, the line drawing method is generally achieved by the mental activities of those who have studied art, and a person who has a superior sensibility of painting can make high art expression possible.
[0005]
In addition, the line drawing method makes it difficult to copy from a printed material because the image line becomes complicated. In addition, since it is a size line that can be recognized by human vision, it is possible to classify whether or not a general person is a fake by visual inspection in the market distribution process. As a result, it has been widely used worldwide in the design of securities prints and the like, and at the same time has been used as a technique for prints having a monetary value. Even today, it has become an important pattern as a design that generally gives an impression of luxury, and in the printed matter such as banknotes, stock certificates, securities such as bonds, various certificates and important documents, the pattern by the line drawing method is in the design. It has become an indispensable pattern.
However, today, with the advanced functions of color copiers and the sophistication of DTP (desktop publishing) technology, rough patterns can be reproduced even with the line drawing method. It is not enough as a forgery prevention measure.
[0006]
As one of solutions to such a problem, a machine reading inspection method capable of processing a large amount and at a high speed is widely adopted. However, today's machine-reading inspection method for printed materials uses these technologies to detect functional inks such as magnetic ink, infrared reflection-absorbing ink, and fluorescent ink, and materials such as fibers, materials, and chemicals that form printing media. Is caused by specific electromagnetic waves that cannot be detected by humans, and often depends on material suitability for producing printed matter, and can only be applied to products that are economical in terms of production cost.
[0007]
Therefore, the present inventors have described “a printed matter and discrimination method capable of authenticating authenticity, and a method of embedding information in the printed matter” (Japanese Patent Application No. 2001-1519), “printed matter and discriminating method capable of authenticating authenticity, and Already filed a printed product characterized by mechanically identifying printed lines consisting of a group of free curves such as a background pattern and a colored pattern by “Method of embedding information in printed material” (Japanese Patent Application No. 2002-50606). is doing. However, these inventions are applied by subdividing the lines so that they cannot be recognized by human vision, and the effects are only achieved by arranging the subdivided lines based on numerical mechanical rules. It is an invention to be demonstrated.
[0008]
That is, the patent described in the upper part is not a technique applied to what can be recognized by human vision like the line drawing method. Moreover, the mechanical rules of the patent described in the upper part do not exist in the pattern by the line drawing method.
FIG. 2 shows an example of a pattern by the dotted line drawing method. As shown in the enlarged view in the circle in FIG. 2, in the pattern by the line drawing method, the period d1 in which the arrangement of the points is different from the line attribute in the continuous tone that pictorially represents the three-dimensional motif. And regularity of period d2 is seen. When the regularity of the pattern by the dotted line drawing method is described in more detail, a line and point set pattern L as shown in FIG. 3 is obtained. That is, there are a period d 1 and a period d 2 in a pictorial continuous tone, and the distance between the period d 1 and the period d 2 is not a constant, but continuously changes from the distance between adjacent periods, and the distance between the lines and the point The ratio of the inter-distances is arbitrarily changed in the pictorial expression although it is maintained at a ratio approximate to the distance between lines and the distance between points on adjacent periods. Therefore, the pattern of the line drawing method that seems to be regular at first glance is also numerically uniform in the distance between the lines and the distance between the points, except for some expressions (sky, water surface, building walls, etc.). It cannot be a suitable element for machine reading in the patents listed above.
[0009]
Further, the inventors of the present invention have alternately arranged according to the feature of the line drawing method according to the “collective pattern for continuous tone expression” (Japanese Patent Application No. 11-23738), and the highlight portion is a dot (disconnection), and the intermediate portion. The first image group represented by a line from the shadow portion to the first image line group, and alternately arranged while intersecting the first image line group at an arbitrary angle, and further starting from the intermediate portion to the shadow portion. A second floor group represented by the above and a third floor group represented by points or lines arranged so as not to overlap the first and second line groups. We have applied for a collective pattern for key expression. Further, it is generated based on the screen shape data from the density information extracted from the digital image data by the “method for creating a collective pattern for continuous tone expression” (Japanese Patent Application No. 11-23737) realized by using a computer. In a set of geometric figures composed of combinations of points and lines, the image format and resolution of the original digital image data can be completely changed by adding or rewriting the screen shape data in the digital image data. Rather, an application has been filed for a method for creating a collective pattern for gradation expression, characterized by creating a collective pattern of geometric figures composed of combinations of points and lines.
[0010]
However, in the patent described in the upper part, since the distance between the line and the point is all fixed within the range of the basic period of the pattern, it does not have a pattern configuration with redundancy suitable for the machine reading inspection method. It is an invention related to a collective pattern for gradation expression of printed matter.
Therefore, it is a method for preventing counterfeiting and alteration that does not depend on the material suitability, and it is suitable for banknotes, stock certificates, securities such as bonds, various certificates and important documents, etc. Is desired.
[0011]
[Problems to be solved by the invention]
The present invention has been made in view of the above points, and can be applied to graphic elements that can be recognized visually by humans without deteriorating the artistic properties of securities, etc. composed of line drawings for securities, and perceptually recognized. The purpose is to determine the authenticity of the printed matter without impairing its artistic effect by giving an impossible modulation.
[0012]
[Means for Solving the Problems]
In the present invention, a plurality of graphic elements 1 composed of lines having a line configuration and graphic elements 2 composed of dots alternately arranged with the graphic elements 1 or image lines having a dotted line configuration are printed on the same printing surface. It is a printed matter, and the dot interval of the graphic element 2 has a predetermined interval value, and the line width of the graphic element 1 and the size of the graphic element 2 are continuously changed on the same printing surface. The printed matter has a collective pattern for continuous tone expression.
[0013]
The present invention is a printed matter having a continuous tone expressing collective pattern, characterized in that the dots or dotted lines of the graphic element 2 are continuously arranged with regularity.
[0014]
The present invention is a printed matter having a set pattern for continuous tone expression, characterized in that it has a graphic element 3 composed of lines or dots or lines composed of a dotted line intersecting the graphic elements 1 and 2. is there.
[0015]
The present invention is a printed matter having a continuous tone expression collective pattern, wherein the graphic element 3 is composed of dots having the same interval value as the graphic element 2 or image lines having a dotted line structure.
[0016]
The present invention is a printed matter having a collective pattern for continuous tone expression, which has one or more predetermined marks, and graphic elements 1 and 2 are arranged around the marks.
[0017]
The present invention is a printed matter having a continuous tone expression collective pattern, wherein a line-structured image and a dot or a dotted-line image are printed in the same color on the same printing surface.
[0018]
The present invention relates to a graphic element 1 composed of one or more predetermined marks, line-shaped drawing lines, a graphic element 2 consisting of dots arranged alternately with the graphic elements 1, or line-shaped drawing lines, and a line structure. A processing step of inputting an image as a digital image data on a printed matter on which a graphic element 3 consisting of a line or a dot or a graphic element 3 composed of a dotted line is printed, and the graphic element 2 or the graphic element 2 and the graphic element in the digital image data 3. A continuous tone having a processing step of extracting a point interval value consisting of a point or an image line having a dotted line structure, and comparing with a prestored information consisting of a real product interval value This is a method for determining authenticity of a printed matter having an expression set pattern.
[0019]
The present invention includes a processing step of extracting XY position coordinates of a predetermined mark from digital image data, a processing step of specifying a cutout region from the XY position coordinates, and a processing step of displaying an interval value. The authenticity determination method of the printed matter which has the collective pattern for continuous-tone expression characterized by these.
[0020]
In the digital image data, when there is one predetermined mark in the digital image data, a cutout region is specified at the center of the XY position coordinates of the specific mark, and when there are two or more specific marks, the individual marks This is a method for determining the authenticity of a printed matter having a set pattern for continuous tone expression, characterized in that a cutout region is specified by XY position coordinates obtained by obtaining a center position from XY position coordinates.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the drawings based on examples.
[0022]
Example 1
First, a collective pattern for gradation expression for machine reading inspection incorporating the line drawing method and a method for creating the same will be described.
[0023]
In the present invention, when a motif like a portrait is expressed by a line drawing method, for example, it can be composed of lines and points that can be recognized by human vision as shown in FIG. There are a mark m1 and a mark m2 corresponding to the “eye” portion of the collective pattern L and the portrait. An example of the line drawing configuration in FIG. 4 is shown in FIG. A typical expression of the line-point drawing method is a line-structured image line that can be recognized by human vision, and is composed of graphic elements 1 and dots arranged alternately with graphic elements 1 or lines of dotted-line structure. There are a graphic element 2 and a graphic element 1 and a graphic element 3 that intersects the graphic element 2, and at least the graphic element 1 and the graphic element 2 constitute most of the pattern. Note that there are a period d3 and a period d4 in the pictorial continuous gradation, and the distance between the period d3 and the period d4 is irrelevant in the present invention.
[0024]
The role of the graphic element 1 is used to express the shade of the entire basic pattern. The line width is continuous when expressing a high density, and the line width is thin when expressing a low density. The darkness of the symbol is determined by changing the width. The role of the graphic element 2 is to assist human sensory aspects such as the softness and depth of the pattern by the points having arbitrary point intervals or the image line having the dotted line configuration. Further, the graphic element 2 is formed at a predetermined interval d _d having regularity. Further, the graphic element 3 may be displayed in a pattern as necessary, and may be a line or a dot or a dotted line. When the graphic element 3 is a dot or a dotted line, the dot interval d _d may be applied in the same manner as the graphic element 2 in order to improve the accuracy of authenticity determination by subsequent machine reading.
[0025]
Distance d _d graphic element 2 (distance d _d graphic element 3 as needed), there is regularity. With this distance d _d , it can be easily recognized by human vision that the graphic element 2 and the graphic element 3 are an array of points, but at the perception level, the distance d _d itself cannot be recognized. Therefore, humans do not perceive slight modulation of the distance d _d .
[0026]
The interval d _d between the points having regularity can be classified by topological means even if it is not perceived by humans. That is, the correlation of the interval between points is analyzed on a digital device with respect to the printed matter, and this is used as a classification standard for the printed matter.
[0027]
FIG. 6 shows a flow for setting the interval d _d . First, input f1 of digital graphic data of the line drawing method is performed. Next, the selection f2 of the graphic element 2 equivalent part in the digital graphic data of the line drawing method is performed. Next, the interval d _d of the portion corresponding to the graphic element 2 is set f3. Arbitrary and a plurality of interval values can be set as the interval d _d . Also, the relationship between the points and margins, always the sum of the point and the margin is equal to match the spacing d _d, performs application processing f4 distance d _d of the graphic element 2. The application process f4 is performed so that the line area ratio of the graphic element 2 (including the graphic element 3 in some cases) is kept constant regardless of the interval d _d set. Next, the digital graphic data of the line drawing method for machine reading is output at the output f5 of the digital graphic data of the line drawing method diagram. Note that the digital figure data output of the line drawing method can be output by a laser exposure output device, an ink jet printer, an on-demand output printing machine, etc., and does not depend on the device or medium.
[0028]
(Example 2)
Next, a true / false discrimination method by machine reading in a collective pattern for gradation expression for machine reading inspection incorporating a line drawing method will be described.
[0029]
First, the most important thing in the true / false discrimination method by machine reading is to determine the cutout range of the image to be true / false discriminated from the digital image data. In the present invention, as shown in FIG. 7, in order to determine authenticity by digital image data input f6 processing, an output product of a line drawing method figure is input as digital image data by an optical scanner or the like, and template matching or the like is known. XY position coordinates of the mark in the digital image data are extracted f7 using the image processing method of, and the process branches to f8 according to the number of extracted marks “0”, “1”, “2”, When the number of extracted marks is one, the digital image data cut-out area is specified f9 around the mark. When the number of extracted marks is two, the center position coordinates of the two marks are specified, The digital image data cut-out area is specified f9 around the center position coordinate. Digital image data is to be authenticity discrimination cut, subjected to extraction f10 distance d _d, "Yes" in the interval d _d contained in the digital image, the processing branches f11 by "no", the last interval d _d Is displayed and compared with the interval value of the genuine product to complete the process. Each process will be described in detail later.
[0030]
Since the present invention is mainly intended for portraits (portrait), it is desirable that the cutout range of the digital image data is arranged with the face portion at the center. However, human face shapes vary, and the cutout range of digital image data must be determined for each person to be drawn. Accordingly, when attention is paid to the face portion Fa of the portrait as shown in FIG. 8A, the “eye” portion indicated by the arrow can be said to be a substantially common figure in any portrait.
[0031]
Therefore, it is decided to specify the cutout range of the digital image data by finding the “eye” portion in the digital image data obtained by the image input f6 in FIG. As a method of extracting the “eye” portion, for example, extraction can be performed by a known process called template matching shown. In order to extract only the “eye” portion from the digital image data in the mark extraction f7 in FIG. 7, a template t as shown in FIG. 8B is necessary, and the template t approximates the shape of the “eye”. Mark m is given. The template t is stored in advance in the image storage means, and the mark m can be extracted by comparing the stored template t with the mark m.
[0032]
There are two types of extraction of the mark m, when there are one mark m and when there are two marks m. For example, when the cutout range of digital image data is 1024 pixels × 1024 pixels, one mark m is extracted as shown in FIG. In this case, at the branch f8 in FIG. 7, the mark m is set so as to be arranged at the center of the four sides from the XY position coordinate to the center of the four sides by the process of specifying one cutout region f9, as shown in FIG. Thus, in the two cases, the center position is obtained from the XY position coordinates of the mark m1 and the mark m2 by the process of specifying the center position coordinate at the branch f8 in FIG. 7, and the process of specifying the cutout area f9 in FIG. The center position is set to be arranged at the center of the four sides. Note that the angle θ generated by the positional relationship between the mark m1 and the mark m2 is also important in post-processing, which will be described in detail later. In the present embodiment, the description is given assuming that the number of marks m is up to two by treating them as “eyes”. However, the number of marks m is not necessarily “eyes”, and three or more marks m including “mole” are used. Good.
[0033]
It is essential to place the graphic element 1 and the graphic element 2 around the mark m. The collective pattern of the present invention using the graphic element 2 (including the graphic element 3 as necessary) in the pattern formed by the line-point drawing method has a parameter of regularity of intervals at points on the dotted line. The processing of the extraction f10 of the interval d _{d in} FIG. 7 can also be performed by extracting only the correlation in a specific position or a specific direction. For example, a well-known image processing technique called Fourier transform is an example of an effective method. Even if the extracted portion is Fourier transformed, true / false determination can be made by comparison with a genuine product. Hereinafter, a method for extracting the interval d _d will be described in detail by taking, as an example, a case where Fourier transform, which is a known image processing technique, is used.
[0034]
First, the present invention will be described in more detail by comparing those not intentionally provided with the point spacing d _d . The digital image data P in FIG. 10 is bitmap data obtained by inputting a printed matter on which a pattern without a dot interval d _d is intentionally provided by a digital device such as a scanner. The pattern of the digital image data P is provided with the graphic element 1, the graphic element 2, and the graphic element 3. However, the graphic element 2 to be subjected to information is assumed to be a graphic element for clearly explaining the intention of the present invention. Similar to 1, the image of the line configuration was applied.
[0035]
FIG. 11 is a Fourier transform pattern obtained by Fourier transforming the digital image data P of FIG. As shown in FIG. 11, the graphic element 1, the graphic element 2, and the graphic element 3 of the digital image data P can be expressed as frequency features. For example, the distance d _b between the graphic element 1 and the graphic element 2 shown in FIG. 10 is a frequency corresponding to the positional correlation of the distance d _b although there is a partial difference in the distance d _{b in} the entire digital image data P. q _b is remarkably appears in a high strength.
[0036]
Next, a state in which the point intervals are intentionally provided will be described. The digital image data PA in FIG. 12 is bitmap data obtained by inputting a printed matter on which a pattern in a state in which dot intervals are intentionally provided is input by a digital device such as a scanner. The pattern of the digital image data PA is provided with a graphic element 1, a graphic element 2, and a graphic element 3, and the graphic element 2 and the graphic element 3 to be subjected to information are constituted by a dividing line having an interval d _{d1 of} 228 μm.
[0037]
The Fourier transform pattern obtained by Fourier transforming this is as shown in FIG. Compared to FIG. 11 in FIG. 13, not only the frequency q _b corresponding to the correlation of the interval d _b but also the frequency q _d1 corresponding to the correlation of the interval d _d1 of the graphic element 2 and the graphic element 3 is 228 μm. Observed.
[0038]
Also, the digital image data PA in FIG. 14 is bitmap data obtained by inputting a printed matter on which a pattern in a state in which dot intervals are intentionally provided is input by a digital device such as a scanner. Similarly to the digital image data PA, the pattern of the digital image data PB is provided with the graphic element 1, the graphic element 2, and the graphic element 3, and the graphic element 2 and the graphic element 3 to be subjected to information are spaced by d ₌ 326 μm. It was composed of two broken lines.
[0039]
The Fourier transform pattern obtained by Fourier transforming this is as shown in FIG. 15, when compared with FIG. 11, not only the frequency q _b corresponding to the correlation of the interval d _b but also the frequency q _d2 corresponding to the correlation of the interval d _d2 of the graphic element 2 and the graphic element 3 is 326 μm. Observed.
[0040]
Then, if the anisotropy of the Fourier transform pattern with respect to each bitmap data of the digital image data P, the digital image data PA, and the digital image data PB at the time of reading the printed material is eliminated and the intensity is shown in one dimension, or the mark m1 and the mark m1 When the intensities on the lines g, g1, and g2 having angles on the line connecting the centers of m2 with a straight line are shown, as compared with the one-dimensional intensity g in the Fourier transform pattern diagram 11 of the digital image data P as shown in FIG. In the one-dimensional intensity g1 of the Fourier transform pattern diagram 13 of the digital image data PA or the one-dimensional intensity g2 of the Fourier transform pattern diagram 13 of the digital image data PB, the intensity greater than a certain level is identified by the interval and the position correlation strength I. By doing so, it becomes possible to specify the printed matter. That is, if the correlation strengths Iq at the intervals of the frequency q _d1 and the frequency q _d2 of the Fourier transform pattern of the bitmap data are different, the printed matter can be mechanically classified.
[0041]
Further, as shown in FIG. 16, if the location is not affected by the frequency due to the correlation between the higher-order intervals of the frequency q _d1 and the frequency q _d2 of the Fourier transform result, the authenticity determination accuracy can be further improved. .
[0042]
The embodiments of the present invention have been described based on the examples. However, the present invention is not limited to such examples, and various modifications can be made within the scope of the technical matters described in the claims. It goes without saying that there are various examples. For example, there is a method of extracting the interval d _b by converting the image data PA of FIG. 12 or the image data PB of FIG. 14 into a binary image and calculating the interval d _b of the points in the graphic elements 2 to 3 by the distance of the XY coordinates. . Thus extraction method of spacing d _b is not limited in any way.
[0043]
【The invention's effect】
According to the present invention having the above-described configuration, a reference for classifying a printed matter is provided by giving a modulation that is a figure element that can be recognized by human vision but that cannot be perceptually recognized by controlling the interval between points. Can do. Further, the image line used in the present invention does not reduce the artistic effect of the print image line.
[0044]
[Brief description of the drawings]
FIG. 1 is a diagram showing a three-dimensional motif by a line drawing method.
FIG. 2 is a diagram showing a pattern by a conventional line point drawing method;
FIG. 3 is a diagram showing a collective pattern L obtained by a conventional line point drawing method.
FIG. 4 is a diagram expressing a motif like a portrait by a line drawing method.
FIG. 5 is a diagram showing an example of a line drawing configuration of the present invention.
FIG. 6 is a diagram showing a flow for setting an interval d _d in the present invention.
FIG. 7 is a diagram showing a true / false determination flow by machine reading.
FIG. 8 is a diagram illustrating marks for determining a cutout range of digital image data.
FIG. 9 is a diagram illustrating a cutout range of digital image data.
FIG. 10 is a diagram showing digital image data P in a collective pattern in which no point intervals are intentionally provided.
11 is a diagram showing a Fourier transform pattern obtained by Fourier transforming the digital image data P of FIG.
FIG. 12 is a diagram showing a collective pattern of digital image data PA in which point intervals are intentionally provided.
13 is a diagram showing a Fourier transform pattern obtained by Fourier transforming the digital image data PA of FIG.
FIG. 14 is a diagram showing a collective pattern digital image data PB with intentionally provided dot intervals.
15 is a diagram showing a Fourier transform pattern obtained by Fourier transforming the digital image data PA of FIG.
FIG. 16 is a diagram in which the Fourier transform pattern of the digital image data P, the Fourier transform pattern of the digital image data PA, and the Fourier transform pattern of the digital image data PB are compared in distance and position correlation strength I.
[Explanation of symbols]
1 Graphic element 1
2 Graphic element 2
3 Graphic element 3
d2 period d3 period d4 period d _b interval d _d interval d _d1 interval d _d2 interval Fa face part g line having an angle on a line connecting the centers of the mark m1 and the mark m2 with a straight line g1 one-dimensional intensity g2 one-dimensional intensity I position Correlation strength Iq Correlation strength L Collective pattern m Mark m1 Mark m2 Mark P Digital image data PA Digital image data PB Digital image data q _b frequency q _d1 frequency q _d2 frequency t Template θ Angle

Claims (7)

A first graphic element comprising a streaking line configuration, the first or point arranged alternately with graphical elements consist streak dotted configuration, it is continuously arranged by a predetermined interval with regularity and second graphic element is a printed material are a plurality of printing on the same printing surface, said predetermined distance point interval of at least a portion of the second graphic elements successively arranged by said predetermined distance Different from the above, and formed as authenticity determination information that can be extracted by image processing by arranging and modulating the interval value in a range indistinguishable from the predetermined interval when visually confirmed ,
For continuous tone expression, wherein the line width of the first graphic element and the size of the second graphic element are continuously changed on the same printing surface. Printed material with a collective pattern.   2. The continuous floor according to claim 1, further comprising a third graphic element comprising a line or a line or a dotted line that intersects the first graphic element and the second graphic element. Printed material with a collective pattern for tone expression.   3. A printed matter having a set pattern for continuous tone expression according to claim 2, wherein said third graphic element is composed of dots having the same interval value as said second graphic element or image lines having a dotted line structure. Has a predetermined mark of one or more, for continuous tone representation of claims 1 to 3, wherein placing the first graphic element and the second graphical element around the mark Printed material with a collective pattern. A method for determining the authenticity of a printed matter having a collective pattern for continuous tone expression according to any one of claims 1 to 4,
A processing step of inputting an image of the printed matter as digital image data;
An image processing step of extracting the authenticity determination information in the digital image data;
A set pattern for continuous tone expression, characterized in that authenticity determination is performed by comparing authenticity determination information in a genuine product stored in advance with the authenticity determination information extracted in the image processing step. A method for determining the authenticity of a printed material. Comprising a processing step of extracting the XY position coordinates of said predetermined mark from said digital image data, and a processing step of identifying a clipping region for extracting the authenticity discrimination information from the XY coordinates, and said true 6. The method of determining authenticity of a printed matter having a current set pattern for a continuous tone table according to claim 5, further comprising a processing step of displaying false determination information . In the digital image data, when there is one predetermined mark, a cutout region for extracting the authenticity determination information is specified at the center of the XY position coordinates of the specific mark, and two specific marks are present. , the set for the continuous tone representation of claim 5, wherein the identifying the cutout region of the authenticity discrimination information to the XY position coordinates determine the center position from the XY coordinates of each mark not less than A method for determining authenticity of printed matter having a pattern.

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