Method for generating image data of copy-protection printed materials and image data generation software

Abstract

This invention provides a method for creating image data for copy-protection printed materials that allows for the creation of invisible images in a short time without requiring specialized knowledge. [Solution] A method for creating image data for a copy-proof printed material, wherein the image data comprises a latent image on at least a part of the substrate, and the latent image is characterized by having a background portion in which a plurality of pattern units, each having at least one pattern, are arranged periodically, and a latent image portion in which a plurality of halftone units, each having at least one halftone dot, are arranged periodically.

Description

Technical Field

[0001] The present invention relates to software for generating data of a printed matter for preventing forgery and alteration, which can be easily discriminated between genuine and fake when photocopied by a photocopier, in printed matters such as banknotes, stock certificates, bonds and other valuable securities, various certificates, important documents, etc., where there is a need to prevent forgery and alteration.

Background Art

[0002] In printed matters such as banknotes, stock certificates, bonds and other valuable securities, various certificates, important documents, etc., anti-forgery and anti-alteration measures are important elements. Anti-forgery and anti-alteration measures for these printed matters mainly include a method of using patterns with diversified geometric patterns in the design, and a method of applying some means and actions to the printed matter so that a latent image that could not be recognized visually appears. Typical examples of the former are ground patterns, color patterns, relief patterns, etc. widely used in the design of security printed matters, etc., and typical examples of the latter are latent image intaglio printing, functional inks that cannot reproduce colors normally with a color photocopier, copy prevention ruled lines, etc.

[0003] As anti-forgery and anti-alteration measures using the aforementioned geometric patterns, there are ground patterns, color patterns, relief patterns, etc., which are formed by a set of curved lines with a certain line width on a base material. These patterns take into account the design characteristics such as the design of the printed matter, and anti-forgery and anti-alteration measures can be implemented. By making the patterns complex, it is difficult to produce the same pattern in counterfeits, and by using colors that are difficult to reproduce with a color photocopier or using complex ruled lines to generate moiré patterns for the scanning input and output of a color photocopier, a monochrome photocopier or a scanner, the role as an anti-forgery measure is enhanced.

[0004] Furthermore, the aforementioned patterns are widely used globally in the design of securities and other printed materials. They have also been used since ancient times as patterns on printed materials with monetary value, such as banknotes, stock certificates, and bonds, and remain important patterns today as designs that generally convey a sense of luxury. Therefore, background patterns, colored patterns, and relief patterns are indispensable designs for printed materials such as banknotes, stock certificates, bonds, various certificates, and important documents.

[0005] Furthermore, a series of techniques generally referred to as copy-prevention lines are representative methods for creating latent images that could not be perceived by the naked eye by applying some means and action to the aforementioned printed material (see, for example, Patent Documents 1 and 2).

[0006] Many of these techniques create a latent image by varying the density of a screen, in which dots and lines such as halftones and lines are arranged in a continuous pattern at a fixed interval, resulting in a screen with uniform density across the entire printed surface. When a printed material with this latent image is copied using a color or monochrome copier, a density difference occurs between the densely structured screen that is not reproduced and the coarsely structured screen that is reproduced, as shown in the pattern of the copy. This causes the latent image portion of the densely structured screen to become visible against the reproduced coarsely structured screen pattern, making it immediately obvious that the material is a copy. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2008-143117 [Patent Document 2] Patent No. 5910964 [Overview of the project] [Problems that the invention aims to solve]

[0008] The appearance of latent images, which were invisible in the original document, in printed copies made using a color or monochrome copier is considered effective in improving the ability to determine the authenticity of the original document. However, creating invisible images as data requires the work of someone with specialized knowledge and skills, and considering the time required for correcting errors in the created data and for adjustments, this process is extremely inefficient. [Means for solving the problem]

[0009] The present invention provides a method for generating image data of a copy-proof printed material, wherein at least a portion of the substrate has a latent image, and the latent image has a background portion in which a plurality of pattern units, each having at least one pattern, are arranged periodically, and a latent image portion in which a plurality of halftone units, each having at least one halftone dot, are arranged periodically, and the method is configured such that the pattern units and halftone units are of the same color to the naked eye, comprising the steps of inputting the pattern units and the latent image, generating dot units of the same unit size as the pattern units based on the set dot size and dot spacing, and The process involves the steps of: superimposing dot units, extracting duplicate black pixels, and generating generation unit A; superimposing the outline of the expanded pattern unit with the dot unit, extracting duplicate black pixels within the outline, and generating generation unit B; and if the relationship between the number of black pixels in the pattern unit (X), the number of black pixels in generation unit A (Y), and the number of black pixels in generation unit B (Z) satisfies i) XY > Z, then generating unit A is regenerated by combining the black pixels of generation unit A and the black pixels of generation unit B; or ii) if XY > Z is not satisfied, then XY black pixels are extracted from generation unit B to make X = Y. The method is characterized by comprising the steps of: generating a generation unit C; generating a halftone unit by overlapping the black cels of generation unit A and the black pixels of generation unit C; and periodically arranging pattern units in the background of the latent image and periodically arranging halftone units in the latent image portion of the latent image.

[0010] The method for generating image data for copy-proof printed materials according to the present invention is the generation method described above, further comprising the step of inputting a visible image, and the step of superimposing the dot unit and the visible image on the portion that does not overlap with the black pixels of the pattern unit and the halftone unit, and extracting and arranging the overlapping black pixels.

[0011] The image data generation software for copy-protection printed materials in this invention is characterized by being executed by a computer. [Effects of the Invention]

[0012] Creating invisible images from data requires specialized knowledge and skills, and correcting errors in the created data and making adjustments takes considerable time. However, by using the software of this invention, it is now possible to create invisible images in a short time without requiring specialized knowledge. [Brief explanation of the drawing]

[0013] [Figure 1] A diagram showing the set of images necessary for generating copy-proof printed materials according to the present invention. [Figure 2] Figure 1 shows the dot units and halftone image that are automatically generated based on the diagram in Figure 1. [Figure 3] This diagram shows the structure of a copy-proof printed document produced by directly printing data created by the program of the present invention using a printer. [Figure 4] Figure 3 shows the structure of a copy of a copy-proof printed material. [Figure 5] This figure shows the structure of a copy-proof printed material obtained by directly printing data, including a visible image portion, using the program created in the present invention. [Figure 6] Figure 5 shows the structure of a copy of a copy-proof printed material. [Figure 7] Flowchart showing the process for generating data for copy-proof printed materials according to the present invention. [Figure 8]Flowchart showing the process of generating a halftone unit in the present invention [Figure 9] Following FIG. 8, flowchart showing the process of generating a halftone unit in the present invention [Figure 10] Diagram showing an intermediate generated image during the process shown in FIG. 8 [Figure 11] Diagram showing an intermediate generated image during the process shown in FIG. 8 [Figure 12] Diagram showing an intermediate generated image during the process shown in FIG. 8 [Figure 13] Diagram showing the transition of an intermediate generated image during the processes shown in FIGS. 8 and 9 [Figure 14] Diagram showing density adjustment of a visible image portion [Figure 15] Diagram showing an intermediate generated image during the process in FIG. 9 [Figure 16] Diagram showing an anti-counterfeiting printed matter before reducing the visible image portion and an anti-counterfeiting printed matter with the visible image portion reduced [Figure 17] Diagram showing the anti-counterfeiting printed matter of Example 1

Modes for Carrying Out the Invention

[0014] The modes for carrying out the present invention will be described with reference to the drawings. However, the present invention is not limited to the modes for carrying out described below, and other various embodiments are included within the scope of the technical idea described in the claims.

[0015] FIG. 1(a) shows an anti-counterfeiting printed matter (1) in the present invention. The anti-counterfeiting printed matter is formed with a latent image (30) on at least a part of a base material (10), and the latent image (30) has a latent image portion (11) indicated by the alphabet "A" and a background portion (12) serving as its background. Also, a visible image (31) may be formed so as to overlap the latent image (30).

[0016] Figure 1(b) shows the latent image (30) and the visible image (31) that form the latent image (30). The configuration of the visible image (31) will be described later. The latent image (30) is a black and white binary bitmap image, and there are no restrictions on its height and width. There are also no particular restrictions on its shape, but in this embodiment it is either rectangular or square.

[0017] Figure 2 shows an example of units for forming the latent image portion (11) and background portion (12) that make up the latent image (30), specifically a pattern unit (40), a dot unit (50), and a halftone unit (60) composed of the pattern unit (40) and the dot unit (50).

[0018] The area ratio of black pixels in the pattern unit (40) shall be between 5% and 30%. The area ratio of black pixels refers to the proportion of black pixels in the pattern unit (40), since the latent image (30) in this embodiment is formed from a black and white binary bitmap image, and the latent image (30) is composed of white pixels and black pixels. If the area ratio of black pixels is too high, the overall density will be too high, and the design quality of the pattern unit (40) will not be maintained, and if it is too low, the design of the pattern unit (40) itself will not be reproduced. The pattern represented by the pattern unit (40) may be a simple line or curve, or it may be an image with design quality such as a symbol, character, or pattern. The shape of the pattern unit (40) is not particularly limited, but in this embodiment it shall be a rectangle or a square.

[0019] The dot unit (50) consists of a group of dots ranging in size from 0.02 mm to 0.1 mm. The spacing between the dots should be such that the Euclidean distance between the centers of each dot is 0.04 mm or more, as dots that are too close together will not disappear during copying. The arrangement of the dots is arbitrary. The vertical and horizontal dimensions of the dot unit (50) are equal to the vertical and horizontal dimensions of the pattern unit (40).

[0020] The halftone unit (60) is a black and white binary bitmap image with dimensions of 1 mm to 10 mm. The shape of the halftone unit (60) is not particularly limited, but in this embodiment, it is rectangular or square. The halftone unit (60) is composed of a pattern unit (40) and a dot unit (50), and the method for generating the halftone unit (60) will be described later.

[0021] The vertical and horizontal dimensions of the pattern unit (40) and the halftone unit (60) are not particularly limited, but in this embodiment they are assumed to be equal. As an example, a 3.39mm x 3.39mm bitmap image composed of 80 x 80 pixels at 600 dpi is used, but the vertical and horizontal dimensions are not limited to this.

[0022] The pattern unit (40) and the halftone unit (60) shall be color-matched under visible light when printed on the substrate (10). The dot size of the halftone unit (60) shall be between 0.02 mm and 0.1 mm in size, as dots that are too small will not be reproduced and dots that are too large will not disappear during copying. The spacing between the dots shall be such that the Euclidean distance between the centers of each dot is 0.04 mm or more, as dots that are too close together will not disappear during copying. The arrangement of the dots is arbitrary. The image represented by the halftone unit (60) shall be a collection of dots that evokes the image represented by the pattern unit (40).

[0023] Figure 3 shows the structure of a copy-proof printed material (1) printed on a substrate (10) using data generated by the program of the present invention, which is represented by continuously arranging pattern units (40) on the background (12) of a latent image (30) and halftone units (60) on the latent image portion (11). Simultaneously, enlarged views of the structure in which halftone units (60) are continuously arranged on the latent image portion (11) (22a) and the structure in which pattern units (40) are continuously arranged on the background portion (12) (22a) are shown. The continuous arrangement of pattern units (40) and halftone units (60) is not limited to the horizontal or vertical direction, but also includes continuous arrangement at a 45-degree angle or other angles. Furthermore, the units can be arranged closely together without gaps, or they can be arranged with gaps to create a scattered appearance. The latent image (30) is represented by the letter "A", but is not limited to this design, and can be any number, letter, symbol, etc.

[0024] Figure 4 shows a copy (2) of the anti-copying printout shown in Figure 3. In the configuration (21b) where pattern units (40) are arranged continuously on the background (12), the shape of the pattern units (40) is maintained during reproduction. Regarding the configuration (22b) where halftone units (60) are arranged continuously on the latent image (11), the copier cannot reproduce fine dots, so when copied, the original configuration cannot be maintained, resulting in dot loss and disappearance. Therefore, during copying, the color matching of the pattern units (40) and halftone units (60) in the copy (2) of the anti-copying printout is disrupted, and the latent image (11) and background (12) become distinguishable and visible under visible light.

[0025] Figure 5 shows the copy-proof printed material (1) shown in Figure 3 above, including a visible image area (13) represented by the placement of dots. The visible image area (13) consists of an overlapping region between the black pixel portion of the visible image (31) and the white pixel portion of the halftone unit (60) of the latent image area (11), or the white pixel portion of the pattern unit (40) of the background area (12). The dot size placed in the visible image area (13) is set to be between 0.02 mm and 0.1 mm, as dots that are too small will not be reproduced, and dots that are too large will not disappear during copying. The spacing between dots is set so that the Euclidean distance between the centers of each dot is 0.04 mm or more, as dots that are too close together will not disappear during copying. The placement of the dots is arbitrary.

[0026] Figure 6 shows a copy (2) of the anti-copying printout shown in Figure 5. In the configuration (21a) where pattern units (40) are arranged continuously on the background (12), the shape of the pattern units (40) is maintained during reproduction. Regarding the configuration (22a) where halftone units (60) are arranged continuously on the latent image (11), the copier cannot reproduce fine dots, so the copy (2) of the anti-copying printout cannot maintain the configuration from the time of printing, resulting in the effect of dot loss causing it to disappear. Therefore, the color matching of the pattern units (40) and halftone units (60) in the copy (2) of the anti-copying printout is disrupted, and the latent image (11) and background (12) become visible under visible light. At this time, it is also possible to adjust the area ratio occupied by black pixels in the visible image area (13) so that the visible image area (13) disappears due to dot loss during copying.

[0027] Figure 7 is a flowchart showing the process for generating data for the copy-prevention printed material (1) in the present invention. By going through steps (S1) to (S6), data for the copy-prevention printed material in the present invention can be generated.

[0028] Figures 8 and 9 illustrate in detail the step (S2) in Figure 7 for generating the halftone unit (60) in the present invention. All steps shown in Figures 8 and 9 are completed in step (S2).

[0029] The following provides a detailed explanation of each step in the flowchart shown in Figure 7.

[0030] (S1) In this step, the pattern unit (40) and the latent image (30) are registered (input) into the same machine that runs the software of the present invention, and the operation of the software of the present invention is started.

[0031] (S2) First, a dot unit (50) is generated. Next, a halftone unit (60) is generated. The halftone unit (60) is generated based on the aforementioned dot unit (50) and pattern unit (40). The halftone unit (60) uses the same dot configuration as shown in the dot unit (50) and is composed of a shape that maintains the design of the pattern unit (40). The pattern unit (40) and the halftone unit (60) are color-matched under visible light.

[0032] (S3) In the flowchart of Figure 7, pattern units (40) are continuously placed on the background area (12) and halftone units (60) are continuously placed on the latent image area (11) of the latent image (30) input in (S1) to generate image A (not shown). Here, the continuous placement of pattern units (40) and halftone units (60) is not limited to the horizontal and vertical directions, but also includes continuous placement in directions with angles such as 45 degrees diagonally. In addition, the units can be placed without gaps or with gaps to create a scattered appearance. Image A is a black and white binary bitmap image and is assumed to have the same vertical and horizontal dimensions as the latent image (30). Image A is assumed to have equal color between the latent image area (11) and the background area (12), and when viewed under visible light, it is assumed to consist of a constant density, and the latent image area (11) is hidden.

[0033] (S4) If a visible image (31) is provided, proceed to (S5); otherwise, proceed to the end.

[0034] (S5) Input a visible image (31). The visible image (31) is a black and white binary bitmap image and should have the same width and height as the latent image (30). In Figure 5, the visible image (31) is represented by a star symbol, but it is not limited to this design and can be any number, letter, symbol, etc.

[0035] (S6) For the image A generated in (S3), an image (23a) is generated by placing dots continuously in the areas where there are no black pixels in the halftone unit (60) or pattern unit (40) and white pixels, and in the areas that overlap with the black pixels of the input visible image (31). By arranging dots in sequence, the visible image

[0036] The dot size at this stage is set to be between 0.02 mm and 0.1 mm, as if it is too small it will not be reproduced, and if it is too large it will not disappear during copying. The spacing between the dots is set so that the Euclidean distance between the centers of each dot is 0.04 mm or more, as if it is too narrow it will not disappear during copying. The arrangement of the dots is arbitrary. The configuration of these dots can be the same as the dot unit (50) generated in (S2), but it is not limited to this, and any new dot configuration that satisfies the conditions can be used. Image B (not shown) is an image obtained by superimposing the black pixel portion of the visible intermediate image onto image A generated in (S3).

[0037] If a visible image (31) is provided, the image A generated in (S3) is used as the final output image; if a visible image (31) is not provided, the image B generated in (S6) is used as the final output image. This final output image is the image data of the copy-proof printed material (1) according to the present invention. The process of generating the copy-proof printed material (1) according to the present invention is terminated when the image data is obtained. The image data can be displayed and distributed as electronic data, or it can be printed onto a substrate (10) using a printer or the like to become the copy-proof printed material (1). The equipment used and the output resolution are not particularly limited.

[0038] The following provides a detailed explanation of each step in the flowchart for generating the halftone unit (60) in the present invention, as shown in Figures 8 and 9.

[0039] (S2-1) The data creator pre-sets the dot size and spacing of the dot unit (50). For the dot unit (50), dots of the set dot size are arranged across the surface at the set spacing. The size of the dot unit (50) is equal to the vertical and horizontal dimensions of the pattern unit (40). The dot size of the dot unit (50) is set between 0.02mm and 0.1mm, as dots that are too small will not be reproduced and dots that are too large will not disappear during copying. The spacing between dots is set so that the Euclidean distance between the centers of each dot is 0.04mm or more, as dots that are too close will not disappear during copying. The arrangement of the dots is arbitrary.

[0040] (S2-2) Figure 10 schematically shows the process of step (S2-2). The number of black pixels X in the pattern unit (40) is measured. The dot unit (50) generated in (S2-1) and the input pattern unit (40) are superimposed, and the unit obtained by extracting the overlapping portion of black pixels is designated as the generated unit A (61). Here, the number of black pixels Y in the generated unit A (61) is measured.

[0041] (S2-3) Next, as shown in Figure 11, the outline unit (41) and dot unit (50) are superimposed on the pattern unit (40) with the pattern expanded by one pixel, and the unit from which the overlapping black pixels are extracted is designated as generation unit B (62). At this time, the expanded pattern is updated while remaining expanded. Here, the number of black pixels Z in generation unit B (62) is measured.

[0042] (S2-4) If the equation {(number of black pixels X) - (number of black pixels Y) > (number of black pixels Z)} is satisfied, proceed to (S2-5); otherwise, proceed to (1).

[0043] (S2-5) Furthermore, as shown in Figure 12, the combined image is updated as generation unit A(61) by overlapping the black pixel portions of generation unit A(61) and generation unit B(62). At the same time, the number of black pixels Y of generation unit A(61) is measured again and updated. Steps (S2-3) to (S2-5) are repeated until the condition of (S2-4) is no longer met. Figure 13 schematically shows the change in appearance of generation unit A(61) by repeatedly performing steps (S2-3) to (S2-5).

[0044] (S2-6) Step (S2-4) to (S2-6). If the equation {(number of black pixels X) = (number of black pixels Y)} is satisfied, all steps in (S2) are completed. Otherwise, step (S2-7) is completed.

[0045] (S2-7) Figure 14 schematically illustrates the following process. From the generation unit B(62) generated last in (S2-3), {(number of black pixels X)-(number of black pixels Y)} black pixels are randomly extracted to form the image of generation unit C(63). The method for extracting black pixels from unit B(60) is not particularly limited; for example, one could extract from the rightmost black pixel of unit B(60), or one could prioritize extracting black pixels that are separated from each other by a certain distance or more in Euclidean distance.

[0046] The reason for performing S2-7 as described above is that, as shown in Figure 13, the number of black pixels in the pattern unit (pattern unit A) must be increased in stages until it is equal to the number of black pixels X. However, if the number of black pixels in unit B is increased all at once, the number will increase too much. Therefore, as a final adjustment, a generation unit C is created by extracting {(number of black pixels X)-(number of black pixels Y)} pixels and is combined with pattern unit A to make the number of black pixels in the pattern unit equal to {number of black pixels X}.

[0047] Figure 15 schematically illustrates the following process. The black pixel portions of generation unit A (61) and generation unit C (63) are superimposed to form the halftone unit (60) in this invention.

[0048] If the process ends at (S2-6), the halftone unit (60) will be the generation unit A (61). If the process ends at (S2-7), the halftone unit (60) will be a combination of generation unit A (61) and generation unit C (63). Step (S2) is terminated when the generation of the halftone unit (60) in this invention is complete.

[0049] (Adjusting black pixels X) The software in this invention also has a function to adjust the number of black pixels X of the pattern unit (40). The usage rate of the black pixels that the pattern unit (40) initially has can be adjusted, and the number of black pixels X can be calculated using the formula {(number of black pixels X) = (number of black pixels X of the pattern unit (40)) × (usage rate of black pixels %) / 100}. In this calculation, fractions are rounded down, rounded up, or rounded to the nearest integer, and the number of black pixels X is an integer. If the usage rate is entered, the number of black pixels X will be determined according to the above formula, and if the usage rate is not entered or is 100%, the number of black pixels of the pattern unit (40) will remain as the number of black pixels X.

[0050] (Density adjustment of the visible image area) Figure 16 schematically illustrates the adjustment of the density of the visible image area (13). The visible image area (13) is located in the area where the white pixels of the halftone unit (60) or pattern unit (40) where no black pixels are placed overlap with the black pixels of the input visible image (31). By reducing the visible image area (13) to conform to the pattern of the pattern unit (40), the density of the entire visible image (31) can be reduced. It is also possible to adjust the size and spacing of the dots that make up the visible image area (13), as well as the density. As shown in Figure 16, compared to the configuration (70) in which the visible image area (13) was not adjusted, the configuration (71) in which the visible image area (13) was reduced has fewer dots in the visible image area (13) and a lighter density in the visible image area (13).

[0051] (Example 1) Figure 17 shows a copy-proof printed material (1) printed on a substrate (10). The pattern unit (40) was input as a 150 x 150 pixel, 12.7 mm x 12.7 mm bitmap image at 300 dpi, the latent image (30) as a 2000 x 2000 pixel, 170 mm x 170 mm black and white binary bitmap image at 300 dpi, and the visible image (31) as a 2000 x 2000 pixel, 170 mm x 170 mm black and white binary bitmap image at 300 dpi.

[0052] By setting the density of the halftone unit (60) to 90% of that of the pattern unit (40), color matching is achieved when outputting the image data. Since the number of black pixels in the pattern unit (40) during measurement is 482, 482 × 0.9 = 433.8, so the number of black pixels X is 433. Here, the decimal part was truncated, but rounding up or rounding to the nearest integer may also be used. In (S2), after generating the dot unit (50), the halftone unit (60) is generated. After repeating the operations from (S1-3) to (S1-5) six times, black pixel adjustment is performed in (S2-7) to generate halftone units (60) with X black pixels.

[0053] For a unit with the same vertical and horizontal dimensions as a virtually created latent image (30) in the program, a halftone unit (60) was placed in the area corresponding to the latent image (11) of the latent image (30), and a pattern unit (40) was placed in the area corresponding to the background (12) of the latent image (30). Since the virtual canvas has pattern units (40) which are black and white and halftone units (60) placed on it, the only colors on the virtual canvas are white and black.

[0054] Next, the visible image portion (13) is placed. The virtual canvas and the visible image (31) have the same vertical and horizontal dimensions. The virtual canvas and the visible image (31) are superimposed, and the visible image portion (13) is represented by continuously placing dot units (50) in the areas where the white pixels of the canvas and the visible parts of the visible image (31) overlap. Here, the dot units (50) that were used when generating the halftone units (60) are used.

[0055] By outputting the image data created through the above process using a laser printer, we were able to obtain copy-proof printing with a uniform density across the entire printed surface. The time required to generate the image data for the copy-proof printout (1) from the pre-prepared latent image (30), visible image (31), and pattern unit (40) was approximately 1 second, significantly reducing the time required compared to the previous manual process. Furthermore, since the necessary images are automatically generated by inputting them into the software, even those without specialized knowledge could easily generate the image data. [Explanation of symbols]

[0056] 1. Copy-proof printed material 2. Copies of copy-protected printed materials 10 Base material 11 Latent Image 12 Background section 13 Visible Image Section 21a Pattern units arranged continuously in the background. 21b A copy of an image in which pattern units are arranged continuously in the background. 22a A latent image with a series of halftone dot units arranged in the latent image area. 22b A copy of an image in which halftone dot units are arranged in a continuous pattern in the latent image area. 23a A configuration in which dot units are arranged in a continuous pattern on the visible image area. 23b A copy of an image in which dot units are arranged in a continuous pattern on the visible image portion. 30 Latent Image 31 Visible Images 40 pattern units 41 Pattern unit of the extension section 50 dot units 60 Completed halftone units 61 Generation Unit A 62 Generation Unit B 63 Generation Unit C 70. Image where the visible portion was not reduced. 71. Reduced view of the visible image portion.

Claims

1. A method for generating image data of a copy-proof printed material, wherein at least a portion of the substrate has a latent image, the latent image is composed of a background portion that is reproduced by a copier and a latent image portion that is not reproduced by a copier, the background portion is composed of a plurality of pattern units having at least one pattern formed thereon arranged periodically, and the latent image portion is composed of a plurality of halftone units having at least one halftone dot formed thereon arranged periodically, and the pattern units and the halftone units are configured to be of equal color to the naked eye, The steps include inputting the pattern unit and the latent image, A step of generating a dot unit of the same size as the pattern unit, which is made up of multiple dots of a predetermined size, The steps include: superimposing the pattern unit and the dot unit, extracting overlapping black pixels, and generating a generation unit A; The steps include: expanding the pattern at a predetermined magnification, overlaying a contour line unit of the same size as the pattern unit, which consists of contour lines from which only the outline has been extracted, with the dot unit, extracting overlapping black pixels within the contour lines, and generating a generation unit B; The relationship between the number of black pixels (X) in the pattern unit, the number of black pixels (Y) in the generation unit A, and the number of black pixels (Z) in the generation unit B is, If X - Y > Z is satisfied, the generation unit A and the generation unit A' are combined to generate the generation unit A', thereby replacing the generation unit A with the generation unit A', and this process is repeated until X - Y > Z is no longer satisfied. If X - Y > Z is not satisfied, the step of extracting X - Y black pixels from the generation unit B to set X = Y and generating generation unit C, The steps include: generating the halftone unit by superimposing the generation unit A' and the generation unit C; The steps include periodically arranging the pattern units in the background portion of the latent image and periodically arranging the halftone units in the latent image portion of the latent image, A method for generating image data of a copy-proof printed document, characterized by having the following features.

2. A method for generating image data of a copy-proof printed material according to claim 1, The process further includes the step of inputting the aforementioned visible image, The steps include: superimposing the dot unit and the visible image onto the portion of the pattern unit and the halftone unit that does not overlap with the black pixels, extracting and arranging the overlapping black pixels; A method for creating image data of a copy-proof printed material according to claim 1, characterized by having the following features.

3. Image data generation software characterized by causing a computer to execute the method for creating image data of a copy-proof printed material described in claim 1 or 2.

Images