JP2024053283A - Anti-counterfeiting printed matter, method for creating data for anti-counterfeiting printed matter, and software for creating the same - Google Patents

Abstract

[Problem] To provide an anti-counterfeiting printed matter that can be printed out on both production and household printers, that has a necessary and sufficient density in the visible image, and that can be used to put images with gradations such as facial photographs into practical use, as well as a method for creating data for the anti-counterfeiting printed matter and software for creating the same. [Solution] The anti-counterfeiting printed matter comprises a visible image formed with ink that does not contain an infrared absorbing dye, an invisible image formed with ink that contains an infrared absorbing dye, and a camouflage image for camouflaging the invisible image, formed with ink that does not contain an infrared absorbing dye, and is characterized in that the visible image and the camouflage image do not contain any areas where the three colors cyan (C), magenta (M), and yellow (Y) are mixed. [Selected Figure] Figure 6

Description

This invention relates to a forgery prevention print that can be easily authenticated using a discriminator for passports, various certificates, important documents, and other printed matter that require prevention of forgery and tampering, and is applicable to card, passport, and certificate types, as well as a method and software for creating data for such forgery prevention prints.

It is important to provide high security to printed materials such as passports, various certificates, and important documents by providing them with anti-counterfeit and anti-tampering properties. A common method for providing these printed materials with anti-counterfeit and anti-tampering properties is to apply some means and action to the printed material to make an invisible image that cannot be recognized by the naked eye appear. Typical examples include applying functional inks that do not allow colors to be reproduced properly by color copiers, and applying copy-protection lines to the printed material that are composed of lines that cannot be reproduced by copying.

However, in recent years, the performance of color copiers has improved, and the resolution of copies and image reproducibility have improved, making the copy prevention effect of copy prevention lines obsolete. In addition, the use of functional inks such as fluorescent inks, which are invisible to the naked eye under normal light, on printed materials has also become less effective in preventing counterfeiting, as fluorescent ink materials are now commercially available and easily available to anyone.

In order to solve these problems, the applicant has filed an application for a line print that, as a measure to prevent counterfeiting caused by copying using a high-resolution copying machine without using special ink, allows a gradation image to be seen when observed with the naked eye under normal light, but allows a different gradation image to be seen when observed using a distinguishing tool such as an infrared camera or IR (Infrared) viewer (see, for example, Patent Document 1).

This is a line print that is characterized in that, as a counterfeit prevention measure for high-resolution hard copies, multiple sets of one visible image area and one invisible image area adjacent to the visible image area are arranged, each invisible image area is surrounded by multiple visible image areas, the visible image area is larger in area than the invisible image area, the invisible image area has a 2a area formed using black ink containing infrared absorbing pigment and a 2b area that is blackish and is formed using ink not containing infrared absorbing pigment, and a gradation image is formed by the 2a areas in the multiple invisible image areas according to the ratio of the 2a area and the 2b area in each invisible image area, and will be explained using Figure 1. Figure 1 (a) corresponds to an enlarged view of the counterfeit prevention image (3a), Figure 1 (b) shows a visible image that is visible when the counterfeit prevention image (3a) is observed with the naked eye under normal light, and Figure 1 (c) shows an invisible image formed with ink containing infrared absorbing pigment that constitutes the counterfeit prevention image (3a).

As shown in FIG. 1(a), the anti-counterfeiting image (3a) is arranged in a plurality of sets of units each having one visible image area (101a) and one invisible image area (101b) adjacent to the visible image area, and each invisible image area (101b) is surrounded by a plurality of visible image areas (101a).

The visible image area (101a) has a larger area than the invisible image area (101b). The invisible image area (101b) is composed of an image line that reproduces gradation using black (K) ink containing an infrared absorbing pigment, and a square-shaped image line that reproduces gradation using ink made of a composite color of cyan (C), magenta (M), and yellow (Y) that does not contain any infrared absorbing pigment to conceal the image line.

When observed with a discriminating tool such as an infrared camera, an image having gradations made up of lines formed with black ink (for example, the letters "NPB" shown in FIG. 1(c)) is visible. In the visible image region (101a), a gradation image is formed using cyan (C), magenta (M), and yellow (Y) inks that do not contain infrared absorbing pigments, and a color gradation image like a visible image is visible to the naked eye under normal light.

However, in the invention described in Patent Document 1, in order to ensure the resolution of the invisible image with continuous gradations shown in FIG. 1(c), the invisible image area had to have the minimum number of pixels necessary. However, with an output device with low resolution, it was not possible to set the number of pixels necessary to provide continuous gradations, and the color reproducibility of the anti-counterfeit image (3a) was extremely low.

For example, in a color printer with an output resolution of 600 dpi, to form an invisible image with 16 gradations, the invisible image area (101b) needs at least four pixels vertically and horizontally, and the visible image area (101a) needs at least eight pixels vertically and horizontally. The line count calculated from this results in an image resolution equivalent to 70 lines/inch, which is perceived by the observer as a low-resolution, unclear image.

In addition, as shown in FIG. 1(a), the image lines in the print described in Patent Document 1 have different shapes for the image lines forming the visible image area (101a) and the image lines forming the invisible image area (101b). Therefore, this print cannot be produced using a general screen (such as an amplitude modulation (AM) screen with circular dots or square dots, or a frequency modulation (FM) screen) used in normal printing, and a special screen must be used, which serves to deter counterfeiting. However, on the other hand, there are production constraints in that it cannot be produced using a general screen.

The applicant has also filed an application for an invention that forms a visible image area and an invisible image area without using a special screen (see, for example, Patent Document 2).

More specifically, in an area where an invisible image is formed using black (K) ink containing an infrared absorbing dye, the density of the invisible image is subtracted from the visible image formed using cyan (C), magenta (M) and yellow (Y) inks that do not contain an infrared absorbing dye, thereby making the invisible image invisible.

With this invention, when an expensive production printer is used, the cyan (C), magenta (M) and yellow (Y) image signals constituting a visible image, and the black (K) image signal constituting an invisible image are input to the printer, and the visible image is printed directly using cyan (C), magenta (M) and yellow (Y) inks, and the invisible image is printed using black (K) ink, making it possible to print out anti-counterfeiting printed material.

However, in the case of widely used general-purpose printers for home use, in order to accommodate the large differences in ink hues between manufacturers, when image signals for cyan (C), magenta (M) and yellow (Y) as well as the image signal for black (K) that constitutes the invisible image are input to the printer, the built-in printer driver first converts these into image signals for red (R), green (G) and blue (B), which have a wider color reproduction range, and then converts them again into image signals for cyan (C), magenta (M) and yellow (Y) for printing.

Here, in the process of converting the input cyan (C), magenta (M) and yellow (Y) image signals into red (R), green (G) and blue (B) image signals, the black (K) image signal containing the infrared absorbing pigment that constitutes the latent image disappears, and in the process of converting the red (R), green (G) and blue (B) image signals into cyan (C), magenta (M) and yellow (Y) image signals, black (K) ink is often used in areas where the three colors overlap, at the discretion of the printer driver. For this reason, it was not possible to print by accurately distinguishing between visible and invisible images as intended. As a result, there was a problem that it was impossible to print out counterfeit-proof printed materials using general home printers.

The applicant has therefore filed an application (Patent Application No. 2021-48023) for an invention for anti-counterfeiting printed matter that can be printed not only by production printers but also by general home printers.

In this invention, a visible image is formed using pixels having only one of the four colors cyan (C), magenta (M), yellow (Y) and black (K) using image signals of red (R), green (G) and blue (B), and an invisible image is formed using black (K) pixels, thereby preventing the three colors cyan (C), magenta (M) and yellow (Y) from overlapping in the same area in the visible image area and being converted to black (K) by the printer driver.

However, with this invention, each pixel has only one color, so the maximum density is only about 25% of the original image, and the contrast of the visible image is extremely low. This makes it difficult to put images with gradations, such as facial photographs, into practical use as visible images.

Japanese Patent No. 3544536 JP 2022-123294 A

In view of the above circumstances, the present invention aims to provide an anti-counterfeiting printout that can print out visible and invisible images accurately as intended, not only by production printers but also by general home printers, that can obtain sufficient density in visible images, and that can put images with gradations such as facial photographs into practical use, as well as a method and software for creating data for anti-counterfeiting printouts.

The anti-counterfeiting printed matter of the present invention is an anti-counterfeiting printed matter having an image forming area, and is provided with a visible image formed in the image forming area with ink that does not contain an infrared absorbing dye, an invisible image formed in the image forming area with ink that contains an infrared absorbing dye, and a camouflage image for camouflaging the invisible image formed in the image forming area with ink that does not contain an infrared absorbing dye, and is characterized in that the visible image and the camouflage image do not have areas where the three colors cyan (C), magenta (M), and yellow (Y) are mixed.

The visible image is formed of a plurality of pixels having either a single color of cyan (C), a single color of magenta (M), a single color of yellow (Y), a two-color mixture of cyan (C) and magenta (M), a two-color mixture of magenta (M) and yellow (Y), a two-color mixture of cyan (C) and yellow (Y), or a colorless color (W) that does not contain an infrared absorbing dye, the invisible image is formed of a plurality of pixels having a single color of black (K) that contains an infrared absorbing dye and has a predetermined density, and the camouflage image is formed of a plurality of pixels having either a single color of cyan (C), a single color of magenta (M), a single color of yellow (Y), a two-color mixture of cyan (C) and magenta (M), a two-color mixture of magenta (M) and yellow (Y), or a two-color mixture of cyan (C) and yellow (Y) that does not contain an infrared absorbing dye and has a predetermined density.

The camouflage image may be formed in at least a portion of the area of the image formation region where no invisible image is formed.

The camouflage image may be formed in at least a portion of the periphery of the area in which the invisible image is formed in the image forming area.

The camouflage image may be formed so as to cover the entire area of the image formation region where no invisible image is formed.

In the image formation area, at least a portion of the visible image and at least a portion of the invisible image may be formed so as to share the same area, and at least a portion of the visible image and at least a portion of the camouflage image may be formed so as to share the same area.

The density of the image forming area may be equal to or greater than a predetermined density in all areas.

The method for creating data for the above-mentioned anti-counterfeiting printed matter of the present invention includes the steps of inputting first image data that is the base image for the visible image and second image data that is the base image for the invisible image, acquiring image data for a visible image of cyan (C), magenta (M) and yellow (Y) that does not contain infrared absorbing dye using the first image data, acquiring image data for an invisible image that contains infrared absorbing dye using the second image data, acquiring image data for a camouflage image of cyan (C), magenta (M) and yellow (Y) that does not contain infrared absorbing dye based on the image data for the invisible image, and synthesizing the image data for the visible image, the image data for the invisible image and the image data for the camouflage image, and replacing the image data for the visible image and the image data for the camouflage image with any of a two-color mixture of cyan (C) and magenta (M), a two-color mixture of magenta (M) and yellow (Y), or a two-color mixture of cyan (C) and yellow (Y) in the area where the three colors of cyan (C), magenta (M) and yellow (Y) are mixed.

In an area where the three colors cyan (C), magenta (M) and yellow (Y) are mixed, when replacing with a two-color mixture of cyan (C) and magenta (M), a two-color mixture of magenta (M) and yellow (Y), or a two-color mixture of cyan (C) and yellow (Y), the replacement may be performed so that the number of pixels having a two-color mixture of cyan (C) and magenta (M), pixels having a two-color mixture of magenta (M) and yellow (Y), and pixels having a two-color mixture of cyan (C) and yellow (Y) are uniform and distributed without bias.

The output level of the second image data may be adjusted so that the invisible image has a predetermined density.

The software for creating data for anti-counterfeit printed matter of the present invention is characterized by having a computer execute the above-mentioned method for creating data for anti-counterfeit printed matter.

The present invention makes it possible to accurately distinguish between visible and invisible images as intended when using not only production printers but also general home printers, and also to obtain sufficient density in visible images, making it possible to put images with gradations such as facial photographs into practical use.

1A and 1B are partially enlarged views showing the structure of a counterfeit prevention print according to the prior art, and explanatory diagrams showing a visible image visible to the naked eye under normal visible light and an invisible image visible under infrared irradiation. An explanatory diagram showing that in areas of a counterfeit prevention printed matter according to one embodiment of the present invention, visible images are formed using cyan (C), magenta (M), yellow (Y), pseudo blue (B) which is a combination of cyan (C) and magenta (M), pseudo green (G) which is a combination of cyan (C) and yellow (Y), and pseudo red (R) which is a combination of magenta (M) and yellow (Y) in a density of 20% or more, invisible images are formed using black (K) in areas of a density less than 20%, and camouflage images are formed using cyan (C), magenta (M) and yellow (Y) in areas of a density less than 20%. 13 is an explanatory diagram showing that the anti-counterfeiting print according to the embodiment is created by superimposing a camouflage image and an invisible image formed in an area where no visible image or invisible image is formed. FIG. FIG. 13 is an explanatory diagram showing pseudo blue (B) obtained by multiplying the two colors cyan (C) and magenta (M), pseudo green (G) obtained by multiplying the two colors cyan (C) and yellow (Y), and pseudo red (R) obtained by multiplying the two colors magenta (M) and yellow (Y), which are used in areas where the three colors cyan (C), magenta (M), and yellow (Y) are mixed in the visible image of the anti-counterfeiting printed matter according to the embodiment. 1 is an explanatory diagram showing that in a visible image in an anti-counterfeit printed matter according to the embodiment, a visible image having cyan (C), magenta (M), and yellow (Y) is formed by pixels colored in any of the following colors: single color cyan (C), single color magenta (M), single color yellow (Y), pseudo red (R) obtained by multiplying the two colors magenta (M) and yellow (Y), pseudo green (G) obtained by multiplying the two colors cyan (C) and yellow (Y), and pseudo blue (B) obtained by multiplying the two colors cyan (C) and magenta (M). The forgery prevention printed matter according to the embodiment is a visible pattern in which the areas of a single color of cyan (C), a single color of magenta (M), a single color of yellow (Y), or a mixture of the three colors of cyan (C), magenta (M) and yellow (Y) are replaced with a pattern of pseudo red (R) obtained by multiplying the two colors of magenta (M) and yellow (Y), pseudo green (G) obtained by multiplying the two colors of cyan (C) and yellow (Y), and pseudo blue (B) obtained by multiplying the two colors of cyan (C) and magenta (M). An explanatory diagram showing that an image is formed by overlaying an invisible image formed in black (K), a camouflage image in which an area where the three colors cyan (C), magenta (M) and yellow (Y) are mixed is replaced with a pattern of pseudo red (R) formed by multiplying magenta (M) and yellow (Y), pseudo green (G) formed by multiplying cyan (C) and yellow (Y), and pseudo blue (B) formed by multiplying cyan (C) and magenta (M). 1 is a block diagram showing a configuration of an apparatus for creating data for anti-counterfeit prints according to an embodiment of the present invention; 4 is a flowchart showing the steps of a method for creating data for anti-counterfeit printed matter according to an embodiment of the present invention. FIG. 11 is an explanatory diagram showing an example in which, in the method for creating data for anti-counterfeit printed matter according to the embodiment, when a pixel in a visible image contains a mixture of the three colors cyan (C), magenta (M), and yellow (Y), the pixel is replaced with one painted with either pseudo blue (B) formed by multiplying the two colors cyan (C) and magenta (M), pseudo green (G) formed by multiplying the two colors cyan (C) and yellow (Y), or pseudo red (R) formed by multiplying the two colors magenta (M) and yellow (Y).

The following describes an embodiment of the present invention, a method for creating data for anti-counterfeit printed matter, and software for creating the data, with reference to the drawings.

An anti-counterfeit printed matter according to one embodiment of the present invention has an image formation area (not shown), which includes a visible image that is visible to the naked eye under normal visible light, an invisible image that is difficult to see with the naked eye under normal visible light but is visible when irradiated with infrared light by an infrared camera, IR viewer, or the like, and a camouflage image that camouflage the invisible image so that the camouflage image is difficult to see with the naked eye under normal visible light.

Visible images, invisible images, and camouflage images are formed with distinctions in density regions as shown in Figure 2.

In areas with a predetermined density or higher, for example a density of 20% or higher, visible images are formed using toner or pigment inks that do not contain infrared absorbing dyes, and include monochrome cyan (C), magenta (M) and yellow (Y), as well as pseudo blue (B) which is a combination of cyan (C) and magenta (M), pseudo green (G) which is a combination of cyan (C) and yellow (Y), and pseudo red (R) which is a combination of magenta (M) and yellow (Y).

In areas with a density of less than 20%, invisible images are formed using black (K) toner, pigment ink, etc., which contain infrared absorbing pigments, while camouflage images are formed using monochrome cyan (C), monochrome magenta (M), monochrome yellow (Y), pseudo blue (B) which is a combination of the two colors cyan (C) and magenta (M), pseudo green (G) which is a combination of the two colors cyan (C) and yellow (Y), and pseudo red (R) which is a combination of the two colors magenta (M) and yellow (Y), which do not contain infrared absorbing pigments, in areas with a density of less than 20%.

The interrelationships between the visible image 11, invisible image 12, and camouflage image 13 in an anti-counterfeit print according to one embodiment of the present invention will be explained using FIG. 3.

Anti-counterfeiting printed matter has a visible image 11, an invisible image 12, and a camouflage image 13 formed in at least a portion of the printed area on a substrate not shown.

The visible image 11 is a color image capable of having continuous gradations suitable for, for example, facial images, and is not limited to facial images, but may be any image, such as letters, numbers, symbols, figures, marks, designs, patterns, facial images, landscape images, etc., and is formed in at least a portion of the printing area.

The invisible image 12 is an image intended to be visible when irradiated with infrared light, and has any image, such as letters, numbers, symbols, figures, marks, designs, patterns, facial images, landscape images, etc., and is formed in at least a portion of the printing area. At least a portion of the invisible image 12 and at least a portion of the visible image 11 may be formed so as to share the same area, or they may not share the same area.

The camouflage image 13 may be formed in at least a part of the area in the printing area where the invisible image 12 is not formed. For example, it may be formed in at least a part of the periphery of the area where the invisible image 12 is formed, or it may be formed so as to cover the periphery of the invisible image 12, or it may be formed so as to cover the entire part of the printing area where the invisible image 12 is not formed. At least a part of the camouflage image 13 and at least a part of the visible image 11 may be formed so as to share the same area, or they may not share the same area.

The visible image 11, invisible image 12, and camouflage image 13 are superimposed in the printing area to form a composite image 21.

As a result, the anti-counterfeiting print has a predetermined overall density, for example, 20% or more. In addition, the invisible image 12 formed with black (K) of less than 20% density, the camouflage image 13 formed with monochromatic cyan (C), magenta (M), and yellow (Y) of less than 20% density, pseudo blue (B) obtained by multiplying the two colors cyan (C) and magenta (M), pseudo green (G) obtained by multiplying the two colors cyan (C) and yellow (Y), and pseudo red (R) obtained by multiplying the two colors magenta (M) and yellow (Y) are superimposed on the visible image 11 and synthesized, so that the synthesized image 21 has a high density color tone that appears slightly gray to the naked eye under normal visible light.

The "predetermined density" referred to here is set appropriately and is determined based on the density required for the concealment of invisible images when the anti-counterfeit print is viewed with the naked eye under normal visible light, and the density required when it is desired to express the gradation of a face photograph or the like as a visible image.

The camouflage image 13 is perceived to be the same color as the invisible image 12, and the camouflage image 13 and the invisible image 12 have a negative-positive inverted relationship such that the maximum density of the camouflage image 13 is the same as the maximum density of the invisible image 12, and the minimum density of the camouflage image 13 is observed by the naked eye as the minimum density of the invisible image 12.

Figure 4 shows the monochromatic colors cyan (C), magenta (M), and yellow (Y) used in the visible image 11. In the base image of the visible image 11, pseudo blue (B) is a combination of cyan (C) and magenta (M), pseudo green (G) is a combination of cyan (C) and yellow (Y), and pseudo red (R) is a combination of magenta (M) and yellow (Y), which are used in place of the three colors cyan (C), magenta (M), and yellow (Y) in the areas where these three colors are mixed.

Figure 5 shows a number of pixel patterns regularly arranged in a matrix, including pixel pattern 31, which includes pixels coated with a single color of cyan (C) and uncoated colorless (W) pixels, pixel pattern 32, which includes pixels coated with a single color of magenta (M) and uncoated colorless (W) pixels, and pixel pattern 33, which includes pixels coated with a single color of yellow (Y) and uncoated colorless (W) pixels.

In the composite image 41 obtained by superimposing pixel patterns 31, 32, and 33, there are pixels that are colorless (W), pixels that are painted with one of the colors cyan (C), magenta (M), and yellow (Y), pixels that are painted with either pseudo blue (B) which is a combination of the two colors cyan (C) and magenta (M), pseudo green (G) which is a combination of the two colors cyan (C) and yellow (Y), or pseudo red (R) which is a combination of the two colors magenta (M) and yellow (Y), as well as pixels that are a mixture of the three colors cyan (C), magenta (M), and yellow (Y), as described below, which are replaced with any two colors, that is, pseudo blue (B) which is a combination of the two colors cyan (C) and magenta (M), pseudo green (G) which is a combination of the two colors cyan (C) and yellow (Y), or pseudo red (R) which is a combination of the two colors magenta (M) and yellow (Y).

Figure 6 shows specific examples of a visible image 11, an invisible image 12, and a camouflage image 13 in an anti-counterfeit printed matter.

The facial image is represented in a single color of cyan (C), magenta (M) and yellow (Y), and these three color images are superimposed to form the visible image 11.

An invisible image 12 is formed in a single color of black (K) (with a density of, for example, less than 20%). Camouflage images 13 are expressed in a single color of cyan (C), a single color of magenta (M) and a single color of yellow (Y), and these three color images are superimposed to form the camouflage image 13.

As described above, in the visible image 11 and the camouflage image 13, the areas where the three colors cyan (C), magenta (M) and yellow (Y) are mixed are replaced with either pseudo blue (B) which is a combination of the two colors cyan (C) and magenta (M), pseudo green (G) which is a combination of the two colors cyan (C) and yellow (Y), or pseudo red (R) which is a combination of the two colors magenta (M) and yellow (Y).

As a result, the pixels that make up the visible image 11 and the camouflage image 13 are painted with either colorless (W), solid cyan (C), solid magenta (M), solid yellow (Y), pseudo blue (B) which is a combination of the two colors cyan (C) and magenta (M), pseudo green (G) which is a combination of the two colors cyan (C) and yellow (Y), or pseudo red (R) which is a combination of the two colors magenta (M) and yellow (Y), and there are no pixels that are painted with a mixture of the three colors cyan (C), magenta (M), and yellow (Y).

This article describes a device, method, and software for creating data for anti-counterfeit printed matter according to one embodiment of the present invention.

The data creation device, creation method, and creation software create a visible image 11 using a color image with continuous gradations such as a face image as the base image, create an invisible image 12 using the visible image 11 such as a face image and any image such as letters, numbers, symbols, figures, marks, designs, patterns, face images, landscape images, etc. that are somehow related as personal information, create a camouflage image 13 that camouflage the invisible image 12, and create data for an anti-counterfeit print by combining the three images.

(Data creation device)
As shown in FIG. 7, the device for creating data for anti-counterfeit prints according to this embodiment comprises an input means M1, an editing means M2, a display means M3, an output means M4, a communication interface M5, a database M6, and a storage means M7.

The communication interface M5 connects a computer terminal connected to a network (not shown) with the device for creating data for anti-counterfeit printed materials.

Database M6 pre-stores image data corresponding to the base images of the visible image 11 and the invisible image 12.

The input means M1 includes a visible image input means M1a and an invisible image input means M1b.

The visible image input means M1a obtains the base image of the visible image 11 by inputting the desired image data via the communication interface M5, or by inputting image data that has been previously stored in the database M6.

The invisible image input means M1b, like the visible image input means M1a, inputs desired image data via the communication interface M5, or inputs image data previously stored in the database M6, thereby acquiring the base image of the invisible image 12. Note that the image data of the camouflage image 13 can be acquired by forming the base image of the invisible image 12 in an area where the invisible image 12 is not formed.

The editing means M2 includes an output level adjustment means M2a, a CMYK image and grayscale image conversion means M2b, a synthesis means M2c, and a pattern replacement means M2d.

The output level adjustment means M2a adjusts the output level of the base image of the visible image 11 acquired by the input means M1, image data corresponding to the base image of the invisible image 12, and image data of the camouflage image 13. The method of adjusting the output level will be explained in the data creation method described later.

The CMYK image and grayscale image conversion means M2b converts the image data of the visible image 11, whose output level has been adjusted, and the image data of the invisible image 12, between a CMYK image having continuous gradations of the colors cyan (C), magenta (M), and yellow (Y) and a grayscale image having continuous gradations of black and white, as necessary.

Most image data that is the base image of the visible image 11 is in RGB format, such as a facial photograph. Therefore, it is necessary to convert the RGB image data into image data in CMYK format. Even if the image data of the base image of the visible image 11 is in CMYK format, it is necessary to make it CMYK format image data that does not contain a black (K) pattern, as described below, so processing by this CMYK image/grayscale image conversion means M2b is necessary. If the base image of the invisible image 12 is a color image, it is necessary to convert it into a grayscale image with continuous black and white tones by this CMYK image/grayscale image conversion means M2b, and if the base image is a grayscale image, no conversion processing is performed.

The synthesis means M2c synthesizes the image data of the visible image 11 and the invisible image 12, which have been converted between a CMYK image and a grayscale image, with the image data of the camouflage image 13 to be formed in the area where the invisible image 12 is not formed.

The pattern replacement means M2d performs a process of replacing areas where the three colors cyan (C), magenta (M) and yellow (Y) overlap in the CMYK images of the visible image 11 and the camouflage image 13 with a pattern of pseudo blue (B) obtained by multiplying the two colors cyan (C) and magenta (M), pseudo green (G) obtained by multiplying the two colors cyan (C) and yellow (Y), and pseudo red (R) obtained by multiplying the two colors magenta (M) and yellow (Y), as described below.

The display means M3 displays the image input by the input means M1 and the image edited by the editing means M2 on a monitor.

The output means M4 is a production printer such as a color laser printer, or a general home printer such as a color inkjet printer, and receives image data from the editing means M2 and prints it out.

The storage means M7 stores image data input via the input means M1, the communication interface M5, and the database M6, and stores data necessary for processing by the editing means M2, processed data, etc.

(How to create data)
8 shows the procedure for creating data for anti-counterfeit prints according to one embodiment of the present invention. Note that the explanation will be given starting from step 1, but as shown in FIG. 8, after data creation has started, steps 1 and 4 may be executed simultaneously.

In step S1, image data that will be the base image for the visible image 11 is acquired by the visible image input means M1a.

In step S2, the output level of the image data that is the base image for the acquired visible image 11 is adjusted by the output level adjustment means M2a.

In step S3, the CMYK image/grayscale image conversion means M2b converts the image data of the visible image 11, whose output level has been adjusted, into CMYK image data V(x,y) (=Cv(x,y)+Mv(x,y)+Yv(x,y)+Kv(x,y)). Here, Kv(x,y) is a white image.

As mentioned above, most image data that is the base image of the visible image 11 is in RGB format, so the RGB image data is converted to image data in CMYK format. Even if the image data of the base image of the visible image 11 is in CMYK format, it is necessary to convert it to CMYK format image data that does not include a black (K) pattern, as described below.

When converting RGB format image data into CMYK format image data, a color conversion table called a profile is used. The conversion result differs depending on the color conversion table used. In this case, it is necessary to convert the visible image 11 to a white image composed only of cyan (C), magenta (M) and yellow (Y) and containing no black (K) patterns, so a dedicated color conversion table must be used.

In addition, in step S4, the invisible image input means M1b acquires image data that will be the base image of the invisible image 12. As described above, the image data of the camouflage image 13 can be acquired by forming the base image of the invisible image 12 in an area where the invisible image 12 is not formed using the base image of the invisible image 12. In other words, the camouflage image 13 is acquired in this step and is included in step 1, which acquires the base image of the visible image 11. Thereafter, the output level of step 2 is adjusted so that the camouflage image 13 is included in the visible image 11.

In step S5, the output level of the image data that is the base image of the acquired invisible image 12 is adjusted by the output level adjustment means M2a. The output level of the camouflage image 13 is set to be the same as the output level of the invisible image 12.

Note that adjusting the output level means adjusting the density so that the invisible image cannot be seen under specular light. The gray levels of each of the RGB channels of a 24-bit RGB image are 0 to 255. If the maximum density of the invisible image 12 is 20%, the corresponding gray level is 204. Therefore, by adjusting the output level of the base image, the gray level is compressed to 0 to 204. It is compressed and adjusted so that pixels exist only at gray levels 0 to 204. Compression means eliminating pixels that exist at gray levels 205 to 255 and sorting them into gray levels 0 to 204. In other words, the minimum density value of the base image data is 20%.

Adjusting the output level is achieved using common image processing methods, such as changing the image's histogram or changing the image's tone curve.

In step S6, if the image data of the invisible image 12 whose output level has been adjusted is a color image, the CMYK image/grayscale image conversion means M2b converts it into grayscale image data H(x, y) (= Kh(x, y)).

In step S7, the image data of the visible image 11 (V(x,y) = Cv(x,y) + Mv(x,y) + Yv(x,y) + Kv(x,y)) and the image data of the invisible image 12 (H(x,y) = Kh(x,y)) are synthesized to obtain synthesized image data (I(x,y) = Cv(x,y) + Mv(x,y) + Yv(x,y) + Kh(x,y)). Furthermore, an image of the camouflage image 13 to be formed in the area where the invisible image 12 is not formed is synthesized.

In step S8, the pattern replacement means M2d performs a process in which, when there are pixels in the CMYK images of the visible image 11 and the camouflage image 13 where the three colors cyan (C), magenta (M) and yellow (Y) overlap, the pixels are replaced with pixels painted with either pseudo blue (B) made by multiplying the two colors cyan (C) and magenta (M), pseudo green (G) made by multiplying the two colors cyan (C) and yellow (Y), or pseudo red (R) made by multiplying the two colors magenta (M) and yellow (Y).

In the flow shown in FIG. 8, the replacement process in step S8 is performed after the merging process in step S7. However, the replacement process in step S8 may be performed before step S7.

As shown in FIG. 9, the color picture of the visible image 11 has 8×8 pixels and is composed of pixel patterns 51 coated with any of the following colors: colorless (W), monochromatic cyan (C), monochromatic magenta (M), monochromatic yellow (Y), pseudo blue (B) obtained by multiplying the two colors cyan (C) and magenta (M), pseudo green (G) obtained by multiplying the two colors cyan (C) and yellow (Y), pseudo red (R) obtained by multiplying the two colors magenta (M) and yellow (Y), and black (C+M+Y) obtained by overlapping the three colors cyan (C), magenta (M), and yellow (Y) and not containing infrared absorbing pigment.

This pixel pattern 51 can be separated into pixel pattern 53, which is an overlapping combination of the three colors cyan (C), magenta (M) and yellow (Y) and is painted with black (C+M+Y) that does not contain infrared absorbing pigments, and pixel pattern 52, which is the rest.

On the other hand, pixel pattern 62 is prepared, which has the same number of pixels and size as pixel pattern 51, and is painted with either pseudo blue (B) obtained by multiplying two colors, cyan (C) and magenta (M), pseudo green (G) obtained by multiplying two colors, cyan (C) and yellow (Y), or pseudo red (R) obtained by multiplying two colors, magenta (M) and yellow (Y). This pixel pattern 62 has 3x3 pixels, and corresponds to a repetition of pixel pattern 61, which is made up of pixels painted with either pseudo blue (B) obtained by multiplying two colors, cyan (C) and magenta (M), pseudo green (G) obtained by multiplying two colors, cyan (C) and yellow (Y), or pseudo red (R) obtained by multiplying two colors, magenta (M) and yellow (Y).

Pixel pattern 61 is a 3x3 pixel pattern in which the number of pixels painted with pseudo blue (B), a combination of cyan (C) and magenta (M), pixels painted with pseudo green (G), a combination of cyan (C) and yellow (Y), and pixels painted with pseudo red (R), a combination of magenta (M) and yellow (Y), is uniform at three, and the pixels are arranged in a dispersed manner so that the same colors are not concentrated in an uneven manner.

The arrangement is dispersed so that the same color is not concentrated. In this embodiment, although there are arrangements in which two pixels of the same color are adjacent, the arrangement is such that there are no three adjacent pixels of the same color. Therefore, even in pixel pattern 61 in which pixel pattern 61 is arranged repeatedly, there are arrangements in which two pixels of the same color are adjacent, but the arrangement is such that there are no three adjacent pixels of the same color.

In this embodiment, the picture is described as 8x8 pixels, pixel pattern 61 as 3x3 pixels, and pixel pattern 62 as 8x8 pixels, but they are not limited to this and can be set appropriately. Therefore, pixel pattern 61 is also described as being arranged so that no three pixels of the same color are adjacent to each other, but they are not limited to this and can be set according to the size of the picture, the number of pixels corresponding to the gradation, etc.

Pixel pattern 54 is generated by extracting and replacing the color of pixels in pixel pattern 62 arranged in the same position as the pixels coated with black (C+M+Y) that does not contain infrared absorbing pigment in pixel pattern 53. The generated pixel pattern 54 is coated with either pseudo blue (B) which is a combination of two colors, cyan (C) and magenta (M), pseudo green (G) which is a combination of two colors, cyan (C) and yellow (Y), or pseudo red (R) which is a combination of two colors, magenta (M) and yellow (Y), instead of black (C+M+Y) which does not contain infrared absorbing pigment, and the total number of each color is almost uniform, and the pixels are distributed so that the same color is not biased.

This pixel pattern 54 is combined with pixel pattern 52, which is composed of pixels other than the pixels where the three colors cyan (C), magenta (M) and yellow (Y) overlap, to obtain pixel pattern 55.

In this way, pixels in the visible image 11 and the camouflage image 13 where the three colors cyan (C), magenta (M) and yellow (Y) overlap can be replaced with pixels painted with either pseudo blue (B) which is a combination of the two colors cyan (C) and magenta (M), pseudo green (G) which is a combination of the two colors cyan (C) and yellow (Y), or pseudo red (R) which is a combination of the two colors magenta (M) and yellow (Y).

This makes it possible to avoid a situation in which the pixels contained in the visible image 11 and the camouflage image 13 are converted to black (K) containing infrared absorbing pigment and printed, making it impossible to accurately reproduce the visible image 11 and the camouflage image 13 as intended, even when a general household printer is used.

The anti-counterfeit printed matter according to this embodiment can be printed out using any printer, whether it is a production printer or a general home printer.

A production printer is given data for cyan (C), magenta (M) and yellow (Y), and instructs the printer to apply cyan (C), magenta (M) and yellow (Y) directly onto the substrate before printing. This is possible because production printers have high color reproducibility with almost no variation in the hues of the inks.

On the other hand, in general home printers, the hues of the inks vary greatly from manufacturer to manufacturer, and color reproducibility is extremely poor. For this reason, if data for cyan (C), magenta (M) and yellow (Y) is given and cyan (C), magenta (M) and yellow (Y) are applied directly to a substrate, the resulting printed matter will have hues that vary greatly from manufacturer to manufacturer.

So the printer is equipped with conversion driver software that first converts the cyan (C), magenta (M), yellow (Y) and black (K) data into red (R), green (G) and blue (B) data, which have a wider color reproduction range, and then converts it back into cyan (C), magenta (M), yellow (Y) and black (K) data based on a dedicated color profile that takes into account the hue of each manufacturer's ink, before printing it out.

When such a general-purpose printer for home use is given data of cyan (C), magenta (M), and yellow (Y) that do not contain infrared absorbing dyes and form the visible image 11, and data of black (K) that contains infrared absorbing dyes and forms the invisible image 12, as described above, this data is first converted into data of red (R), green (G), and blue (B), and then converted into data of cyan (C), magenta (M), and yellow (Y). When this data is then converted into data of cyan (C), magenta (M), and yellow (Y), the driver software converts the black that does not contain infrared absorbing dyes, which is a mixture of the three colors cyan (C), magenta (M), and yellow (Y), into black (K) that does contain infrared absorbing dyes, resulting in a situation in which the visible image 11 and the invisible image 12 cannot be reproduced as intended.

Therefore, in the anti-counterfeiting printed matter according to this embodiment, as described above, the visible image 11 and the camouflage image 13 are formed with pixels that have only one of the following colors, without using pixels that are a mixture of the three colors cyan (C), magenta (M) and yellow (Y): single color cyan (C), single color magenta (M), single color yellow (Y), pseudo blue (B) obtained by multiplying the two colors cyan (C) and magenta (M), pseudo green (G) obtained by multiplying the two colors cyan (C) and yellow (Y), pseudo red (R) obtained by multiplying the two colors magenta (M) and yellow (Y), or colorless (W, indicating the color of the base material).

If there is an area in the visible image 11 where the three colors cyan (C), magenta (M) and yellow (Y) are mixed, it is replaced by a pattern that combines pixels having either pseudo blue (B) which is a combination of the two colors cyan (C) and magenta (M), pseudo green (G) which is a combination of the two colors cyan (C) and yellow (Y), or pseudo red (R) which is a combination of the two colors magenta (M) and yellow (Y).

This prevents the printer driver from replacing areas of the visible image 11, which does not contain infrared absorbing dye and is a mixture of the three colors cyan (C), magenta (M) and yellow (Y), with black (K), which does contain infrared absorbing dye, and makes it possible to reproduce the visible image 11 and invisible image 12 as intended.

Here, whether the pixels forming the visible image 11 are monochromatic cyan (C), monochromatic magenta (M), monochromatic yellow (Y), pseudo blue (B) obtained by multiplying the two colors cyan (C) and magenta (M), pseudo green (G) obtained by multiplying the two colors cyan (C) and yellow (Y), pseudo red (R) obtained by multiplying the two colors magenta (M) and yellow (Y), or colorless (W) is determined according to the visible image 11.

Furthermore, if the visible image 11 is formed using only one of the colors cyan (C), magenta (M), or yellow (Y), the maximum density of the visible image 11 will be approximately 25% of the original image, resulting in extremely low density and low contrast.

In contrast, according to the present embodiment, the visible image 11 is formed using a pseudo blue (B) obtained by multiplying the two colors cyan (C) and magenta (M), a pseudo green (G) obtained by multiplying the two colors cyan (C) and yellow (Y), and a pseudo red (R) obtained by multiplying the two colors magenta (M) and yellow (Y) in addition to the single colors cyan (C), magenta (M), and yellow (Y). This increases the density and improves the contrast. This is particularly useful for visible images 11 with gradations such as face images that are often used on certificates, etc., as it improves visibility.

(Data creation software)
The following describes software for creating data for anti-counterfeit printed matter.

Data for anti-counterfeit printed matter can be created using software that causes a computer to execute the data creation method according to this embodiment.

Although an embodiment of the present invention has been described, this embodiment is presented as an example and is not intended to limit the technical scope of the invention. This novel embodiment can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included within the technical scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.

For example, in the above embodiment, the visible image, which is a non-infrared image that does not contain an infrared absorbing dye, includes all seven colors: cyan (C), magenta (M), yellow (Y), pseudo blue (B) which is a combination of cyan (C) and magenta (M), pseudo green (G) which is a combination of cyan (C) and yellow (Y), pseudo red (R) which is a combination of magenta (M) and yellow (Y), and colorless (W). However, the visible image does not necessarily need to include all seven colors as long as there are no areas where the three colors cyan (C), magenta (M), and yellow (Y) are mixed.

The method and software for creating anti-counterfeit printed matter and data for anti-counterfeit printed matter according to the present embodiment described above allows printouts to be made not only by production printers but also by general home printers, as described above, and also provides sufficient density in visible images, making it possible to put images with gradations such as facial photographs into practical use.

11 Visible image 12 Invisible image 13 Camouflage image 21 Composite images 31-33, 51-55, 61-63 Pixel pattern 41 Composite image M1 Input means M1a Visible image input means M1b Invisible image input means M2 Editing means M2a Output level adjustment means M2b CMYK image/grayscale image conversion means M2c Composite means M2d Pattern replacement means M3 Display means M4 Output means M5 Communication interface M6 Database M7 Storage means

Claims (6)

A counterfeit prevention printed matter having an image forming area,
a visible image formed in the image forming area using ink that does not contain an infrared absorbing dye;
an invisible image formed in the image forming area using an ink containing an infrared absorbing dye;
a camouflage image formed in the image forming area using an ink containing no infrared absorbing pigment, the camouflage image having a negative-positive relationship with the invisible image and for camouflaging the invisible image;
Equipped with
The counterfeit prevention print is characterized in that the visible image and the camouflage image do not include any areas where the three colors cyan (C), magenta (M) and yellow (Y) are mixed. the visible image is formed of a plurality of pixels having any of a single color of cyan (C), a single color of magenta (M), a single color of yellow (Y), a two-color mixture of cyan (C) and magenta (M), a two-color mixture of magenta (M) and yellow (Y), a two-color mixture of cyan (C) and yellow (Y), or colorless (W), which does not contain an infrared absorbing dye;
the invisible image is formed of a plurality of pixels having a single color of black (K) containing an infrared absorbing pigment, and has a predetermined density;
2. The anti-counterfeiting printed matter according to claim 1, characterized in that the camouflage image is formed of a plurality of pixels having any of the following colors that do not contain an infrared absorbing dye: a single color of cyan (C), a single color of magenta (M), a single color of yellow (Y), a two-color mixture of cyan (C) and magenta (M), a two-color mixture of magenta (M) and yellow (Y), or a two-color mixture of cyan (C) and yellow (Y), and has the predetermined density. A method for creating data for an anti-counterfeit printed matter according to claim 1 or 2, comprising the steps of:
inputting first image data that is to be a base image of the visible image and second image data that is to be a base image of the invisible image;
acquiring image data of the invisible image, the image data including an infrared absorbing dye, using the second image data;
A step of acquiring a camouflage image having a negative-positive inversion relationship with image data of the visible image of cyan (C), magenta (M) and yellow (Y) not containing an infrared absorbing dye and image data of the invisible image using the first image data;
combining image data of the visible image, image data of the invisible image, and image data of the camouflage image;
Equipped with
A method for creating data for anti-counterfeiting printed matter, characterized in that in areas where the three colors cyan (C), magenta (M) and yellow (Y) are mixed, the image data of the visible image and the image data of the camouflage image are replaced with either a two-color mixture of cyan (C) and magenta (M), a two-color mixture of magenta (M) and yellow (Y), or a two-color mixture of cyan (C) and yellow (Y). The method for creating data for anti-counterfeiting prints according to claim 3, characterized in that when replacing in an area where the three colors cyan (C), magenta (M) and yellow (Y) are mixed with either a two-color mixture of cyan (C) and magenta (M), a two-color mixture of magenta (M) and yellow (Y), or a two-color mixture of cyan (C) and yellow (Y), the replacement is performed so that the number of pixels having a two-color mixture of cyan (C) and magenta (M), pixels having a two-color mixture of magenta (M) and yellow (Y), and pixels having a two-color mixture of cyan (C) and yellow (Y) are uniform and distributed without bias. The method for creating data for anti-counterfeiting printed matter according to claim 3, characterized in that the output level of the second image data is adjusted so that the invisible image has a predetermined density. A software for creating data for anti-counterfeit printed matter, comprising:
4. Software for creating data for anti-counterfeit printed matter, said software causing a computer to execute the method for creating data for anti-counterfeit printed matter according to claim 3.

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