JP4335829B2 - Printing method and printed image verification method - Google Patents

Description

  The present invention relates to a technique for printing an image such as a guarantee mark on a print medium and a technique for verifying the image printed on the print medium.

  As a technique for preventing forgery of printed matter, there is a technique described in Patent Document 1.

  In Patent Document 1, an m × m pixel first halftone region and an n × n pixel second halftone region for printing a halftone dot for expressing a continuous tone image are provided, and the regions are independent from each other. The plurality of first halftone regions are arranged around the one second halftone region without any gap, and the plurality of second halftone regions are arranged on the outer periphery of the one first halftone region. The first halftone region is embedded with ink (cyan: C, magenta: M, yellow: Y) that does not contain at least one or more infrared absorbing pigments. A technique is disclosed in which an image is arranged with halftone dots and an embedded image composed of ink (black: Bk) containing an infrared absorbing dye is arranged with halftone dots in a second halftone region. According to the technique described in the cited document 1, black printing composed of C ink, M ink, and Y ink and black printing composed of Bk ink seem to be the same with the naked eye (visible light). When observed with an infrared camera, since the Bk ink contains an infrared-absorbing dye, the black print composed of the Bk ink cannot be seen. For this reason, it is possible to record an embedded image that cannot be recognized by the naked eye, and therefore, it is possible to create a printed matter that is difficult to reproduce with a general scanner device or a copying machine.

JP 2003-136828 A

  In recent years, an infrared camera is commercially available for the purpose of crime prevention such as imaging an intruder at night. Said patent document 1 does not consider such a situation. Currently, many commercially available infrared cameras have a low resolution because most of them are for crime prevention purposes. In other words, it has only enough resolution to detect night intruders. For this reason, even if the printed matter created by the technique described in Patent Document 1 is imaged with a commercially available infrared camera, it is considered that only the outline of the embedded image that cannot be recognized with the naked eye can be recognized. However, an unauthorized third party may estimate the details of the image from the image outline.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a technique for printing an embedded image that is difficult to recognize even with an infrared camera or the like. Another object of the present invention is to provide a technique for verifying an embedded image printed by the technique.

  In order to solve the above-described problem, in the first aspect of the present invention, at the time of printing, an embedded image is divided into a plurality of distributed images using a visual secret sharing scheme. A dispersion image (referred to as a print dispersion image) other than at least one of the plurality of dispersion images (referred to as a verification dispersion image) includes a visible light external absorption dye (infrared absorbing dye or ultraviolet absorbing dye). The background image for camouflaging is printed on the print medium with the ink containing the visible light absorbing dye so as not to overlap with the dispersed image components constituting the dispersed image for printing. At the time of verification, a distributed image for printing printed on a print medium is read using a visible light external line imaging device. Then, the read distributed image for printing and the verified distributed image are synthesized by the visual decryption type secret sharing method and output.

  For example, according to a first aspect of the present invention, there is provided a printing method of a print image capable of verifying an embedded image, the step of dividing the embedded image into a plurality of distributed images by a visual decoding secret sharing method, Storing at least one of the dispersion images as a dispersion image for printing, and storing the plurality of dispersion images other than the dispersion image for printing as a dispersion image for verification, and storing the dispersion image for verification as visible light; Printing on a print medium with ink that does not contain an external absorption dye, and printing the background image for camouflage with an ink that contains a visible light external absorption dye so as not to overlap with the dispersed image components constituting the dispersed image for printing Printing. Also, a method for verifying a printed image printed by this printing method, the method comprising: reading a dispersed image for printing included in a printed image printed on a printing medium using a visible light external line imaging device; Synthesizing and outputting the print distributed image and the preliminarily stored verification distributed image by the visual decryption secret sharing method.

  In the second aspect of the present invention, at the time of printing, the embedded image is divided into a plurality of distributed images by the visual decoding secret sharing method. A dispersion image (referred to as a second dispersion image) other than at least one of the plurality of dispersion images (referred to as a first dispersion image) is used as a dispersion image constituting a second dispersion image according to a predetermined rule. The position of the component is converted (referred to as a converted dispersion image). Then, the converted dispersion image is printed on the print medium with an ink that does not contain the visible light external absorption pigment, and the first dispersion image is applied with the visible light external absorption pigment so as not to overlap with the dispersion image components constituting the conversion dispersion image. Print on the print medium with the ink it contains. At the time of verification, a printed image printed on a print medium is read by a visible light imaging device, and a converted dispersion image printed on the print medium is read using a visible light external line imaging device. Then, the first dispersed image is extracted from the difference between the two images, and the transformed dispersed image is inversely transformed into the second dispersed image according to the predetermined rule, and then the first and second dispersed images are visually decoded secret Synthesize and output by dispersion method.

  For example, according to a second aspect of the present invention, there is provided a print image printing method capable of verifying an embedded image, the step of dividing the embedded image into a plurality of distributed images by a visual decoding secret sharing method, and the plurality of distributed images At least one of the images is a first dispersion image, a dispersion image other than the first dispersion image is a second dispersion image, and the position of the dispersion image component constituting the second dispersion image is moved according to a predetermined rule, A step of converting a two-dispersed image into a converted dispersed image, and printing the converted dispersed image on a printing medium with an ink that does not contain a visible light external absorption pigment so as not to overlap with the dispersed image components constituting the converted dispersed image. And a step of printing the first dispersion image on the printing medium with an ink containing a visible light external absorption pigment. Also, a method for verifying a printed image printed by this method, wherein the printed image printed on the print medium is read using a visible light imaging device and printed on the print medium using a visible light external imaging device. A step of reading the transformed dispersion image included in the printed image, a step of extracting the first dispersion image from the difference between the read print image and the transformed dispersion image, and a second of the read transformed dispersion image according to a predetermined rule. A step of inversely transforming into a dispersed image, and a step of synthesizing and outputting the extracted first dispersed image and the inversely transformed second dispersed image by a visual decoding secret sharing method.

  According to the first aspect of the present invention, an image that cannot be recognized under visible light but can be recognized under an external line of visible light is part of a plurality of dispersed images visually dispersed by a visual decoding type secret sharing method (dispersion for printing). Image). Therefore, it is possible to print an embedded image that is difficult to recognize even using an infrared camera or the like. In addition, the embedded image is obtained by combining the distributed image for printing read from the printing medium using the visible light outside-line imaging device with the remaining portions (verified image for verification) of the plurality of distributed images by the visual decoding secret sharing method. Validate. Therefore, only the person who holds the verification dispersed image can verify the embedded image.

  Further, according to the second aspect of the present invention, an image that cannot be recognized under the visible light but can be recognized under the visible light outside line is a part of the plurality of distributed images (first images) visually dispersed by the visual decoding secret sharing method. 2 (dispersed image) is converted according to a predetermined rule (converted distributed image). Therefore, it is possible to print an embedded image that is difficult to recognize even using an infrared camera or the like. In addition, the first distributed image is extracted from the difference between the print image read from the print medium using the visible light imaging device and the transformed distributed image read from the print medium using the visible light external line imaging device, and a predetermined rule is set. Then, the transformed dispersed image is inversely transformed into the second dispersed image, and then the embedded image is verified by synthesizing the first and second dispersed images by the visual decoding type secret sharing method. Therefore, only those who hold the predetermined rule can verify the embedded image.

  Embodiments of the present invention will be described below.

<< first embodiment >>
First, a first embodiment of the present invention will be described. FIG. 1 is a schematic diagram of a guarantee mark issuance / verification system to which the first embodiment of the present invention is applied. As shown in the figure, the warranty mark issuance / verification system of the present embodiment includes a warranty mark issuing system 1, a warranty mark verification system 2, and a warranty mark management server 3 connected to each other via a network 4 such as the Internet. Configured.

  The guarantee mark issuing system 1 generates two distributed images from image data of a guarantee mark that guarantees the quality of a product or the like by a visual decryption type secret sharing method. Then, one of the dispersed images is printed as a dispersed image for printing on a printing medium such as a sticker attached to a product or the like so that it cannot be recognized with the naked eye (under visible light). The other distributed image is transmitted to the guarantee mark management server 3 as a verification distributed image.

  The guarantee mark verification system 2 captures a distributed image for printing that cannot be recognized by the naked eye printed on a print medium. Then, by using the visual decryption type secret sharing method, the captured distributed image for printing and the verification distributed image obtained from the guarantee mark management server 3 are combined to restore the guarantee mark.

  The guarantee mark management server 3 holds image data of guarantee marks. Then, according to the request from the guarantee mark issuing system 1, the image data of the guarantee mark is transmitted to the guarantee mark issuing system 1. Further, the image data of the verification distributed image sent from the guarantee mark issuing system 1 is held. Then, the image data of the verification distributed image is transmitted to the guarantee mark verification system 2 in accordance with a request from the guarantee mark verification system 2.

  Next, the warranty mark issuing system 1 and the warranty mark verification system 2 will be described in more detail. Since the guarantee mark management server 3 can use an existing server such as an FTP (File Transfer Protocol) server, a detailed description thereof will be omitted.

  First, the guarantee mark issuing system 1 will be described.

  FIG. 2 is a schematic diagram of the guarantee mark issuing system 1. As illustrated, the guarantee mark issuing system 1 includes an issuing device 11 and a printing machine 12.

  According to the print data, the printing machine 12 includes cyan (C), magenta (M), yellow (Y) ink that does not contain an infrared absorbing dye (for example, carbon), and black (Bk) ink that contains an infrared absorbing dye. Is used to print an image on a print medium such as a sticker attached to a product or the like. This printing machine 12 is the same as an existing printing machine except that the Bk ink contains an infrared absorbing pigment.

  The issuing device 11 generates a print dispersed image and a verification dispersed image from the guarantee mark image data. Also, print data for causing the printing machine 12 to print a print image including a print dispersed image that cannot be recognized with the naked eye is generated. As illustrated, the issuing device 11 includes a GUI (Graphical User Interface) unit 111 for displaying information and receiving an instruction from a user, a network IF unit 112 for connecting to the network 4, a calculation unit 113, A storage unit 114 and a print control unit 115 that transmits the print data generated by the calculation unit 113 to the printing machine 12 are provided.

  The storage unit 114 includes a guarantee mark storage unit 1141, a verification distributed image storage unit 1142, a printing distributed image storage unit 1143, and a background image storage unit 1144.

  The guarantee mark storage unit 1141 stores guarantee mark image data for guaranteeing the quality of products and the like in advance. Note that the guarantee mark image data used in this embodiment is monochrome image data. For example, the image data is obtained from the guarantee mark management server 3 by the arithmetic unit 113 via the network IF unit 112 and stored in the guarantee mark storage unit 1141.

  The verification distributed image storage unit 1142 stores image data of one of the two distributed images created from the image data of the guarantee mark by the visual decryption secret sharing method as image data of the verification distributed image, and prints it. In the distributed image storage unit 1143, the other image data of the two distributed images is stored as image data of the distributed image for printing.

  The background image storage unit 1144 stores in advance image data of a background image used as a background of the print dispersed image when the print image is generated.

  The calculation unit 113 includes a distributed image generation unit 1131, a verification distributed image registration request unit 1132, and a print image generation unit 1133.

  The distributed image generation unit 1131 generates image data of two distributed images from the guarantee mark image data stored in the guarantee mark storage unit 1141 by the visual decryption secret sharing method.

  Here, the principle of the visual decryption secret sharing method will be briefly described. FIG. 3 is a diagram for explaining the principle of the visual decryption secret sharing method.

  As shown in the figure, it is assumed that the guarantee mark 801 has an m × n image size in which a black circle 803 is drawn on a white background 802. First, two plain images having the same m × n image size as the guarantee mark 801 are prepared.

  Next, the guarantee mark 801 is divided into a plurality of minute regions. Then, for each minute region, two distributed image components 804 having two segments 805 and 806 and having a size smaller than the minute region are created, and one of the dispersed image components 804 is set as one of the plain regions. It arrange | positions in the position corresponding to the said micro area | region of an image, and arrange | positions the other dispersion image component 804 in the position corresponding to the said micro area | region of the other plain image. At this time, the distributed image component 804 sets one of the two segments 805 and 806 as black and the other as white. In addition, for the minute region belonging to the white background 802, two distributed image components 804 in which the black segment and the white segment match are generated, and for the minute region belonging to the black circle 803, Two distributed image components 804 having different black and white segments are generated. By performing this process on all the minute regions, a dispersed image A807 and a dispersed image B808 are created.

  Accordingly, the dispersed image A 807 and the dispersed image B 808 are configured by arranging a plurality of dispersed image components 804 in which one of the two segments 805 and 806 is black and the other is white, as shown in an enlarged view of reference numeral 809. Also, the guarantee mark 801 cannot be recognized only by looking at one of the dispersed image A807 and the dispersed image B808.

  Now, when the dispersion image A 807 and the dispersion image B 808 created as described above are superimposed, as shown in an enlarged view 811, the dispersion image component 804 corresponding to the minute region belonging to the black circle 803 has two segments. 805 and 806 are both black, and in the distributed image constituent element 804 corresponding to the minute area belonging to the white background 802, one of the two segments 805 and 806 is black and the other is white. Therefore, the restored image 810 that can recognize the original guarantee mark 801 can be obtained by superimposing the dispersed image A807 and the dispersed image B808.

  The distributed image generation unit 1131 generates image data of two distributed images from the guarantee mark image data stored in the guarantee mark storage unit 1141 using the above-described visual decoding secret sharing method. That is, two plain image data having the same image size as that of the guarantee mark image data are created. Next, the image data of the guarantee mark is divided into a plurality of minute areas. Then, the following processing is performed for each minute region. That is, if the minute area is white, two dispersed image components in which the black segment and the white segment match are generated, and one of them is arranged at a position corresponding to the minute area of one plain image data. The other is arranged at a position corresponding to the minute area of the other plain image data. On the other hand, if the minute area is black, two dispersed image components having different black and white segments are generated, and one of them is arranged at a position corresponding to the minute area of one plain image data. The other is arranged at a position corresponding to the minute area of the other plain image data. As described above, image data of two distributed images is generated, one of them is stored in the verification distributed image storage unit 1142 as a verification distributed image, and the other is stored as a print distributed image. To remember.

  The distributed image registration request unit 1132 creates a verification distributed image registration request including the image data of the verification distributed image stored in the verification distributed image storage unit 1142, and the guarantee mark management server 3 via the network IF unit 112. Send to.

  The print image generation unit 1133 applies a print image obtained by superimposing the print dispersion image stored in the print dispersion image storage unit 1143 and the background image stored in the background image storage unit 1144 to the print dispersion image. Ck, M ink, and Y ink (black made with C ink, M ink, and Y ink) that do not contain infrared absorbing pigment, and Bk ink (Bk ink) that contains infrared absorbing pigment for the background image Print data to be printed by the printing machine 12 is generated using the generated black) and transmitted to the print control unit 115.

  As shown in FIG. 4, the image data 820 of the background image stored in the background image storage unit 1144 is a background image component having two segments 823 and 824 each drawn randomly in black or white. 822 is provided (see an enlarged view 821). Each background image component 822 in the image data 820 of the background image includes the image data 830 of the print dispersed image when the image data 820 of the background image and the image data 830 of the print dispersed image are superimposed. Are arranged at positions that do not overlap the distributed image component 832 (see the enlarged view 831). Accordingly, by superimposing the image data 830 of the print dispersed image and the image data 820 of the background image, it is possible to create a print image 841 that is camouflaged so that the image data 830 of the print dispersed image cannot be recognized by the naked eye ( (See enlarged view 841).

  FIG. 5 is a diagram for explaining the operation flow of the guarantee mark issuing system 1. This flow is started, for example, when the GUI unit 111 receives a mark issuance instruction from the user.

  First, the distributed image generation unit 1131 reads the guarantee mark image data from the guarantee mark storage unit 1141 (S101). Next, image data of two distributed images is generated from the guarantee mark image data read from the guarantee mark storage unit 1141 using the visual decryption secret sharing method described above, and the image data of one of the distributed images is distributed for verification. The image data of the image is stored in the verification distributed image storage unit 1142, and the image data of the other distributed image is stored in the print distributed image storage unit 1143 as image data of the print distributed image (S102).

  Next, the verification distributed image registration request unit 1132 reads the image data of the verification distributed image from the verification distributed image storage unit 1142 (S103). Next, a verification distributed image registration request including the image data of the verification distributed image read from the verification distributed image storage unit 1142 is created and transmitted to the guarantee mark management server 3 via the network IF unit 112 (S104). . As a result, the image data of the verification distributed image is registered in the guarantee mark management server 3.

  Next, the print image generation unit 1133 reads the image data of the print dispersion image from the print dispersion image storage unit 1143 and also reads the image data of the background image from the background image storage unit 1144 (S105). Next, a print image obtained by superimposing the print dispersion image and the background image is used on the background image using C ink, M ink, and Y ink that do not contain an infrared absorbing dye for the print dispersion image. In this case, print data to be printed by the printing machine 12 is generated using Bk ink containing an infrared absorbing pigment, and is transmitted to the printing machine 12 via the print control unit 115 (S106).

  Next, the printing machine 12 prints a print image on a print medium such as a sticker attached to a product or the like according to the print data sent from the issuing device 11 (S107). At this time, black is printed using C ink, M ink, and Y ink that do not contain an infrared absorbing dye for a dispersed image for printing, and Bk ink that contains an infrared absorbing dye is used for a background image. Print black. As a result, a camouflaged print image can be printed on a print medium so that the dispersed image for printing cannot be recognized with the naked eye.

  Next, the guarantee mark verification system 2 will be described.

  FIG. 6 is a schematic diagram of the guarantee mark verification system 2. As shown in the figure, the guarantee mark verification system 2 includes a verification device 21 and an infrared imaging device (infrared scanner) 22.

  The infrared imaging device 22 irradiates the print medium with infrared rays and detects infrared reflected light from the print media. Thereby, the print medium is imaged. The infrared imaging device 22 is the same as the existing imaging device (scanner) except that infrared rays are used instead of visible light.

  The verification device 21 combines the image data captured by the infrared imaging device 22 with the image data of the detection dispersed image obtained from the warranty mark management server 3 to restore the warranty mark image data. As illustrated, the verification device 21 includes a GUI unit 211 for displaying information and receiving instructions from a user, a network IF unit 212 for connecting to the network 4, a calculation unit 213, a storage unit 214, An imaging control unit 215 that controls the infrared imaging device 22 to obtain captured image data from the infrared imaging device 22.

  The storage unit 214 includes a verification distributed image storage unit 2141, a captured image storage unit 2142, and a composite image storage unit 2143.

  The detection dispersed image storage unit 2141 stores image data of the detection dispersed image in advance. The image data is obtained from the guarantee mark management server 3 by the arithmetic unit 213 via the network IF unit 212 and stored in the detection distributed image storage unit 2141, for example.

  The captured image storage unit 2142 stores a captured image captured by the infrared imaging device 22. Further, the composite image storage unit 2143 stores a composite image of the verification dispersed image stored in the detection dispersed image storage unit 2141 and the captured image stored in the captured image storage unit 2142.

  The calculation unit 113 includes an image detection unit 2131, an image composition unit 2132, and a composite image display unit 2133.

  The image detection unit 2131 controls the infrared imaging device 22 via the imaging control unit 215 and images the print medium set in the infrared imaging device 22 with infrared rays. Then, the captured image is stored in the captured image storage unit 2142. As described above, in the print image 840, the background image 820 is printed using the Bk ink containing the infrared absorbing dye, and the dispersed image for printing 830 uses the C ink, the M ink, and the Y ink not containing the infrared absorbing dye. Printed. Therefore, when the print image 840 printed on the print medium is picked up by the infrared imaging device 22, the background image 820 is not picked up, and only the print dispersed image 830 is picked up.

  The image composition unit 2132 superimposes the image data of the verification distributed image stored in the verification distributed image storage unit 2141 and the image data of the captured image stored in the captured image storage unit 2142 to obtain the image data of the composite image. Generate. Then, the generated composite image image data is stored in the composite image storage unit 2143. When the image data of the captured image stored in the captured image storage unit 2142 is image data of the print dispersed image, as described with reference to FIG. 3, the image data of the print dispersed image and the image of the verification distributed image are used. By overlaying the data, the original guarantee mark image data can be restored.

  The composite image display unit 2133 displays the image data of the composite image stored in the composite image storage unit 2143 on the GUI unit 211.

  FIG. 7 is a diagram for explaining an operation flow of the guarantee mark verification system 2. This flow is started, for example, when the GUI unit 111 receives a mark verification instruction from the user.

  First, the image detection unit 2131 controls the infrared imaging device 22 via the imaging control unit 215, and images the print medium set in the infrared imaging device 22 with infrared rays (S201). Then, the image data of the captured image is obtained from the infrared imaging device 22 via the imaging control unit 215 and stored in the captured image storage unit 2142 (S202).

  Next, the image composition unit 2132 reads the image data of the verification distributed image in the verification unit distributed image storage unit 2141 and reads the image data of the captured image from the captured image storage unit 2142 (S203). Then, the image data of the distributed image for verification and the image data of the captured image are superimposed to generate image data of the composite image, and the image data is stored in the composite image storage unit 2143 (S204). Then, the composite image display unit 2133 reads the image data of the composite image stored in the composite image storage unit 2143 and displays it on the GUI unit 211 (S205). The print image printed on the print medium set in the infrared imaging device 22 is guaranteed by the guarantee mark depending on whether or not the user can recognize the guarantee mark from the image data of the composite image displayed on the GUI unit 211. It can be judged whether or not.

  The first embodiment of the present invention has been described above.

  According to the present embodiment, an image that cannot be recognized under visible light but can be recognized under visible light external lines is a part of a plurality of dispersed images (dispersed images for printing) visually dispersed by the visual decoding secret sharing method. . Therefore, it is possible to print an embedded image that is difficult to recognize even using an infrared camera or the like. Also, the guarantee image is verified by combining the distributed image for printing read from the print medium using the infrared imaging device 22 with the distributed image for verification by the visual decryption type secret sharing method. Therefore, only the person who holds the verification dispersed image can verify the embedded image.

<< Second Embodiment >>
Next, a second embodiment of the present invention will be described. In the first embodiment described above, the guarantee mark is verified using the distributed image for printing read from the print image of the print medium using the infrared imaging device and the distributed image for verification not included in the print image. . On the other hand, in the present embodiment, the guarantee mark can be verified using only the print image of the print medium. The guarantee mark issuance / verification system of this embodiment is the same as the guarantee mark issuance / verification system of the first embodiment shown in FIG. 1, except that the guarantee mark issuance system 1a is used instead of the guarantee mark issuance system 1. Instead of the system 2, a guarantee mark verification system 2a is used.

  First, the guarantee mark issuing system 1a will be described. FIG. 8 is a schematic diagram of the guarantee mark issuing system 1a. The warranty mark issuing system 1a of this embodiment is different from the warranty mark issuing system 1 of the first embodiment shown in FIG. 2 in that an issuing device 11a is used instead of the issuing device 11. Further, the issuing device 11a is different from the issuing device 11 of the first embodiment in that the calculation unit 116 and the storage unit 117 are used instead of the calculation unit 113 and the storage unit 114.

  The storage unit 117 includes a guarantee mark storage unit 1171, a first distributed image storage unit 1172, a second distributed image storage unit 1173, a converted distributed image storage unit 1174, and a conversion rule storage unit 1175.

  The guarantee mark storage unit 1141 stores guarantee mark image data for guaranteeing the quality of products and the like in advance. Note that the guarantee mark image data used in the present embodiment is also monochrome image data as in the first embodiment. The image data is obtained from the guarantee mark management server 3 by the arithmetic unit 116 via the network IF unit 112 and stored in the guarantee mark storage unit 1171, for example.

  In the first distributed image storage unit 1172, one of the two distributed images created from the image data of the guarantee mark by the visual decryption secret sharing method is stored as image data of the first distributed image. The two-dispersed image storage unit 1173 stores the other image data of the two dispersed images as the image data of the second dispersed image.

  The transformed dispersed image storage unit 1174 stores a transformed dispersed image that is an image obtained by transforming the second dispersed image according to a predetermined rule, and the transformed rule storage unit 1175 transforms and distributes the second dispersed image. A predetermined rule for converting to an image is stored. The predetermined rule is obtained from the guarantee mark management server 3 by the arithmetic unit 116 via the network IF unit 112 and stored in the conversion rule storage unit 1175, for example.

  The calculation unit 116 includes a distributed image generation unit 1161, a transformed distributed image generation unit 1162, and a print image generation unit 1163.

  Similar to the distributed image generation unit 1131 of the first embodiment, the distributed image generation unit 1161 generates two distributed image images from the guarantee mark image data stored in the guarantee mark storage unit 1171 by the visual decoding secret sharing method. Generate data. Then, one image data of the generated two dispersed images is stored in the first distributed image storage unit 1172 as the image data of the first distributed image, and the other distributed image storage unit 1173 is used as the second distributed image. To remember.

  The transformed dispersion image generation unit 1162 performs a transformation process on the second dispersion image stored in the second dispersion image storage unit 1173 in accordance with the conversion rules stored in the conversion rule storage unit 1175 to generate a transformed dispersion image. . This converted dispersion image is superimposed on the first dispersion image for print image generation in a print image generation unit 1163 described later. As described above, if the two distributed images created from the image data of the guarantee mark by the visual decryption secret sharing method are simply superimposed, the guarantee mark is restored. Therefore, in the present embodiment, the second dispersed image is converted into a transformed dispersed image according to a predetermined rule, and then a print image is generated by superimposing the first dispersed image.

  Therefore, the predetermined rule is that (1) the guarantee mark is not restored even if the first dispersion image and the transformed dispersion image are superimposed, and “(2) the first dispersion image and the print image are not restored. The transformed dispersion image can be separated (the black segment of the dispersion component of the first dispersion image and the black segment of the transformed dispersion image do not overlap) ”. Here, taking the case where the predetermined rule is a one-segment shift process as an example, the process of generating a transformed dispersed image will be briefly described. FIG. 9 is a diagram for explaining the process of generating the transformed dispersion image. In the present embodiment, the one-segment shift process means that each distributed image constituent element constituting the distributed image is equivalent to one segment (in this embodiment, the distributed image constituent element is composed of two segments). , Refers to the process of shifting in a fixed direction.

  As illustrated, it is assumed that the guarantee mark 851 has an m × n image size in which a black circle 853 is drawn on a white background 852. First, the distributed image generation unit 1161 generates two distributed images each including a plurality of distributed pixel components 854 having two segments from the guarantee mark image data 851 as in the first embodiment. One image data is image data 857 of the first distributed image, and the other image data is image data 858 of the second distributed image. When the image data 857 and 858 of these two dispersed images are overlapped, as shown in the enlarged view 860, the dispersed image component 854 located in the black circle 853 of the guarantee mark 851 is black in both of the two segments. In the distributed image component 854 located on the white background 852, one of the two segments is black and the other is white. Therefore, if the image data 857 of the first dispersion image and the image data 858 of the second dispersion image are simply superimposed, the guarantee mark is recognized from the image data 859 of the restored image obtained by the superposition. .

  Therefore, in the present embodiment, according to the predetermined rule that satisfies the above two conditions (1) and (2), the image data 858 of the second distributed image is converted to generate the image data 862 of the converted distributed image. . Here, as shown in an enlarged view 861 of the image data 858 of the second dispersed image and an enlarged view 863 of the image data 862 of the transformed dispersed image, the respective distributed image components 854 arranged in the image data 858 of the second dispersed image. Is shifted to the right by one segment, thereby generating image data 862 of the transformed dispersion image. As a result, in the image data 864 of the print image obtained by superimposing the image data 862 of the transformed dispersion image and the image data 857 of the first dispersion image, as shown in the enlarged view 865, the arrangement of the black segments is guaranteed. Regardless of whether the mark 851 is located within the black circle 853 or the white background 852, the mark 851 is irregular. Therefore, the guarantee mark can be prevented from being recognized from the image data 864 of the print image.

  The print image generation unit 1163 converts the converted dispersion image stored in the conversion dispersion image storage unit 1174 and the first dispersion image stored in the first dispersion image storage unit 1172 into a converted dispersion image. For the first dispersed image, Ck, M ink and Y ink (black made with C ink, M ink and Y ink) not containing an infrared absorbing dye are used, and Bk containing an infrared absorbing dye is used for the first dispersed image. Using the ink (black created with Bk ink), print data to be printed by the printing machine 12 is generated and transmitted to the print control unit 115.

  FIG. 10 is a diagram for explaining an operation flow of the guarantee mark issuing system 1a. This flow is started when, for example, the GUI unit 111 receives a mark issuance instruction from the user, as in the mark issuance system 1 of the first embodiment.

  First, the distributed image generation unit 1161 reads guarantee mark image data from the guarantee mark storage unit 1171 (S301). Next, image data of two distributed images is generated from the image data of the guarantee mark read from the guarantee mark storage unit 1171 using the above-described visual decryption type secret sharing method, and the image data of one of the distributed images is first distributed. Image data of the image is stored in the first distributed image storage unit 1172, and image data of the other distributed image is stored in the second distributed image storage unit 1173 as image data of the second distributed image (S302).

  Next, the transformed dispersed image generation unit 1162 reads out the image data of the second dispersed image from the second dispersed image storage unit 1173 and also reads out the transformation rules from the transformation rule storage unit 1175 (S303). Then, the image data of the second dispersion image is subjected to conversion processing (for example, 1 segment shift processing) according to the read conversion rule to generate image data of the conversion dispersion image, and is stored in the conversion dispersion image storage unit 1174 (S304).

  Next, the print image generation unit 1163 reads out the image data of the transformed dispersion image from the transformed dispersion image storage unit 1174 and also reads out the image data of the first dispersion image from the first dispersion image storage unit 1171 (S305). Next, a print image obtained by superimposing the converted dispersion image and the first dispersion image is used as the first dispersion image using C ink, M ink, and Y ink that do not contain an infrared absorbing dye for the conversion dispersion image. On the other hand, print data to be printed by the printing machine 12 is generated using Bk ink containing an infrared absorbing dye, and is transmitted to the printing machine 12 via the printing control unit 115 (S306).

  Next, the printing machine 12 prints a print image on a print medium such as a sticker attached to a product or the like according to the print data sent from the issuing device 11a (S307). At this time, black is printed using C ink, M ink, and Y ink that do not contain an infrared absorbing dye for the converted dispersed image, and Bk ink that contains an infrared absorbing dye is used for the first dispersed image. Use to print black. As a result, a camouflaged print image can be printed on a print medium so that the transformed dispersion image cannot be recognized with the naked eye.

  Next, the guarantee mark verification system 2a will be described.

  FIG. 11 is a schematic diagram of the guarantee mark verification system 2a. The warranty mark verification system 2a of the present embodiment is different from the warranty mark verification system 1 of the first embodiment shown in FIG. 6 in that the verification device 21a is used in place of the verification device 21 and the infrared imaging device 22 is used. Instead, an infrared / visible light imaging device 22a is provided.

  The infrared / visible light imaging device 22a is obtained by adding a function as a normal imaging device to the infrared imaging device 22 of the first embodiment. That is, the visible light is irradiated on the print medium, the reflected light of the visible light is detected from the print medium, and the print medium is imaged.

  The verification device 21a differs from the verification device 21 of the second embodiment in that a calculation unit 216 and a storage unit 217 are used instead of the calculation unit 213 and the storage unit 214.

  The storage unit 217 includes an inverse conversion rule storage unit 2171, a first distributed image storage unit 2172, a second distributed image storage unit 2173, a converted distributed image storage unit 2174, a print image storage unit 2175, and a composite image storage. Part 2176.

  The inverse transformation rule storage unit 2171 stores an inverse transformation rule for inversely transforming the transformed dispersed image into the second dispersed image (the inverse of the transformation process indicated by the transformation rule used to transform the second dispersed image into the transformed dispersed image). Rules for defining the conversion process) are stored in advance. The reverse conversion rule is obtained from the guarantee mark management server 3 by the calculation unit 216 via the network IF unit 212 and stored in the conversion rule storage unit 2171, for example.

  The first distributed image storage unit 2172 stores a first distributed image detected by a first distributed image detection unit 2161 described later, and the second distributed image storage unit 2173 stores a second distributed image detection unit 2162 described later. The second dispersion image detected by is stored.

  The transformed dispersion image storage unit 2174 stores a captured image captured with infrared light by the infrared / visible light imaging device 22a. The print image storage unit 2175 stores a captured image captured with visible light by the infrared / visible light imaging device 22a. The composite image storage unit 2164 stores a composite image of the first distributed image stored in the first distributed image storage unit 2172 and the second distributed image stored in the second distributed image storage unit 2173. Is done.

  The calculation unit 216 includes a first distributed image detection unit 2161, a second distributed image detection unit 2162, an image composition unit 2163, and a composite image display unit 2164.

  The first distributed image detection unit 2161 controls the infrared / visible light imaging device 22a via the imaging control unit 215, images the print medium set in the infrared / visible light imaging device 22a with infrared, and uses the print medium. The image data of the transformed dispersion image is read and stored in the transformed dispersion image storage unit 2174. As described above, the printed image is printed using the Bk ink containing the infrared absorbing dye in the first dispersed image, and the C ink, the M ink, and the Y ink containing no infrared absorbing dye. Has been. Therefore, when the print image printed on the print medium is captured with infrared rays, the first dispersed image is not captured, and only the transformed dispersed image is captured.

  The first distributed image detection unit 2161 captures an image of the print medium set in the infrared / visible light imaging device 22a with visible light, reads the image data of the print image from the print medium, and stores the image data in the print image storage unit 2175. To do. Then, the first dispersed image detection unit 2161 extracts the image data of the first dispersed image by subtracting the image data of the transformed dispersed image from the image data of the print image, and this is extracted to the first dispersed image storage unit 2172. Remember. As described above, the print image is formed so that the black segment of the dispersion component of the first dispersion image and the black segment of the transformed dispersion image do not overlap. Therefore, the image data of the first dispersed image can be extracted from the image data of the print image.

  The second distributed image detection unit 2162 performs reverse conversion processing indicated by the reverse conversion rule stored in the reverse conversion rule storage unit 2171 on the image data of the converted distributed image stored in the converted distributed image storage unit 2174. As a result, the image data of the transformed dispersion image is inversely transformed into the image data of the second dispersion image. For example, if the conversion rule used to convert the second dispersion image into the conversion dispersion image is to shift each dispersion image component constituting the second dispersion image to one segment to the right, the inverse conversion rule storage is performed. According to the inverse transformation rule stored in the unit 2171, each variance image constituent element constituting the transformation variance image is shifted one segment to the left, and the transformation variance image is inversely transformed into a second variance image. Then, the obtained second dispersion image is stored in the second dispersion image storage unit 2173.

  The image composition unit 2163 superimposes the image data of the first distributed image stored in the first distributed image storage unit 2172 and the image data of the second distributed image stored in the second distributed image storage unit 2173. Thus, image data of the composite image is generated. Then, the generated composite image image data is stored in the composite image storage unit 2176. The case where the image data of the first distributed image and the image data of the second distributed image stored in the first distributed image storage unit 2172 and the second distributed image storage unit 2173 are correct image data has been described with reference to FIG. In this manner, the original guarantee mark image data can be restored by superimposing the image data of the first dispersion image and the image data of the second dispersion image.

  The composite image display unit 2164 displays the image data of the composite image stored in the composite image storage unit 2176 on the GUI unit 211.

  FIG. 12 is a diagram for explaining an operation flow of the guarantee mark verification system 2a. This flow is started, for example, when the GUI unit 111 receives a mark verification instruction from the user.

  First, the first distributed image detection unit 2161 controls the infrared / visible light imaging device 22a via the imaging control unit 215, and images the print medium set in the infrared / visible light imaging device 22a with infrared light (S401). . Then, the image data of the transformed dispersion image is obtained from the infrared / visible light imaging device 22a via the imaging control unit 215 and stored in the transformed dispersion image storage unit 2174 (S402).

  Next, the first distributed image detection unit 2161 controls the infrared / visible light imaging device 22a via the imaging control unit 215, and images the print medium set in the infrared / visible light imaging device 22a with visible light ( S403). Then, the image data of the print image is obtained from the infrared / visible light imaging device 22a via the imaging control unit 215, and stored in the print image storage unit 2175 (S404).

  Next, the first dispersed image detection unit 2161 reads out the transformed dispersed image image data and the print image image data stored in the transformed dispersed image storage unit 2174 and the print image storage unit 2175 (S405). Then, the image data of the first dispersed image is extracted by subtracting the image data of the transformed dispersed image from the image data of the print image, and this is stored in the first dispersed image storage unit 2172 (S406).

  Next, the second distributed image detection unit 2162 reads out the image data and the conversion rule of the converted distributed image from the converted distributed image storage unit 2174 and the conversion rule storage unit 2171 (S407). Then, the image data of the transformed dispersion image is subjected to the inverse transformation process of the transformation process indicated by the transformation rule, whereby the image data of the transformed dispersion image is inversely transformed into the image data of the second dispersion image, and this is converted into the second dispersion image. It memorize | stores in the memory | storage part 2173 (S408).

  Next, the image composition unit 2163 reads the image data of the first dispersed image from the first distributed image storage unit 2172 and also reads the image data of the second dispersed image from the second distributed image storage unit 2173 (S409). Then, the image data of the first dispersion image and the image data of the second dispersion image are superimposed to generate image data of the composite image, and stored in the composite image storage unit 2176 (S410). Then, the composite image display unit 2164 reads the image data of the composite image stored in the composite image storage unit 2176 and displays it on the GUI unit 211 (S411). Depending on whether or not the user can recognize the guarantee mark from the image data of the composite image displayed on the GUI unit 211, the print image printed on the print medium set in the infrared / visible light imaging device 22a is guaranteed by the guarantee mark. It can be determined whether or not it has been done.

  The second embodiment of the present invention has been described above.

  According to this embodiment, an image that cannot be recognized under visible light but can be recognized under visible light outside line is a part of a plurality of dispersed images (first dispersed images) visually dispersed by the visual decoding secret sharing method. An image (converted dispersion image) converted according to a predetermined conversion rule is obtained. Therefore, it is possible to print an embedded image that is difficult to recognize even using an infrared camera or the like. In addition, the first dispersion image is extracted from the difference between the print image read from the print medium with visible light and the converted dispersion image read from the print medium with infrared light using the infrared / visible light imaging device 22a, and a predetermined inverse operation is performed. The transformed dispersion image is inversely transformed into a second dispersion image according to the transformation rule. Then, the first and second distributed images are synthesized by the visual decryption type secret sharing method to verify the embedded image. Therefore, only those who hold the predetermined rule can verify the embedded image.

  Note that the issuing devices 11 and 11a and the verification devices 21 and 21a described in the first and second embodiments include a CPU 901, a memory 902, and an external storage device 903 such as an HDD as shown in FIG. , I / O for connecting a reading device 904 that reads data from a storage medium such as a CD-ROM, DVD-ROM, or IC card to an input device such as a keyboard, mouse, or scanner and an output device such as a monitor or printer ( Input / Output) 907, a communication device 908 for connecting to the network 4, and a bus 909 for connecting these devices, a program in which the CPU 901 is loaded on the memory 902 It can be realized by executing. This program is downloaded from the storage medium via the reading device 904 or from the network 4 via the communication device 908 to the external storage device 903, and then loaded onto the memory 902 and executed by the CPU 901. May be. Alternatively, it may be loaded directly on the memory 902 and not executed by the CPU 901 without going through the external storage device 903. In this case, a memory 902 or an external storage device 903 is used for the storage units 114, 214, 117, and 217. Further, a communication device 908 is used for the network IF units 112 and 212. The GUI units 111 and 211, the print control unit 115, and the imaging control unit 215 use an I / O 907.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist.

  For example, in the above second embodiment, black is printed using Bk ink containing an infrared-absorbing dye on the converted dispersion image, and C ink and M ink do not contain the infrared-absorbing dye on the first dispersion image. Alternatively, black may be printed using Y ink. In this case, an image captured with infrared rays is the first dispersed image. Therefore, a transformed dispersion image can be obtained by subtracting an image captured with infrared rays from a printed image captured with visible rays.

  Further, for example, in the second embodiment described above, the second variance image detection unit 2162 performs the inverse transformation stored in the inverse transformation rule storage unit 2171 on the transformation variance image stored in the transformation variance image storage unit 2174. By performing the inverse transformation process indicated by the rule, the transformed variance image is inversely transformed from the second variance image and stored in the second variance image storage unit 2173. However, the present invention is not limited to this. For example, the infrared / visible light imaging device 22a may directly capture the second dispersion image.

  FIG. 14 is a diagram showing a modification of the infrared / visible light imaging 22a. The infrared / visible light imaging 22a shown in FIG. 14 includes a mounting table 224 on which the printed material 225 is placed, and a first electronic camera 221a that is arranged so that the imaging surface faces the printed material 225 placed on the mounting table 224. A visible light cut filter 223 that transmits only infrared light attached to the front surface of the imaging surface of the first electronic camera 221a, a half mirror 222 disposed between the first electronic camera 221a and the mounting table 225, A second electronic camera 221b and an XY stage 226 are included. The half mirror 222 transmits part of the natural light reflected by the printed material as it is and reflects the rest. The second electronic camera 221 b is arranged so that the imaging surface faces the printed material 225 placed on the placement table 224 via the half mirror 222. That is, the reflected light reflected by the half mirror 222 is arranged so as to enter the imaging surface perpendicularly. A first electronic camera 221 a is attached to the XY stage 226. The XY stage 226 moves the first electronic camera 221a in the horizontal direction in accordance with a control signal from the verification device 21a.

  The first distributed image detection unit 2161 of the verification device 21a outputs a control signal to the XY stage 226 via the imaging control unit 215, and the imaging position of the first electronic camera 221a is captured by the second electronic camera 221b. Match the position. For example, the center of the printed matter 225 placed on the imaging stand 224 is made to coincide with the center of the imaging surface of each of the first electronic camera 221a and the second electronic camera 221b. Next, each of the first electronic camera 221a and the second electronic camera 221b images the printed matter, and the image data of the captured image (transformed dispersion image) of the first electronic camera 221a is stored in the transformed dispersion image storage unit 2174. At the same time, the captured image (print image) of the second electronic camera 221b is stored in the print image storage unit 2175.

  The second distributed image detection unit 2162 of the verification device 21a outputs a control signal to the XY stage 226 via the imaging control unit 215, and sets the imaging position of the first electronic camera 221a to the second electronic camera 221b. Is shifted by the shift amount indicated by the reverse conversion rule in the opposite direction of the shift direction indicated by the reverse conversion rule stored in the reverse conversion rule storage unit 2171. For example, the center of the imaging surface of the first electronic camera 221a is set in the direction opposite to the segment shift direction indicated by the inverse conversion rule stored in the conversion rule storage unit 2171 from the center of the printed material 225 placed on the imaging table 224. Is shifted by the segment shift amount indicated by the inverse conversion rule. Next, the first electronic camera 221a images the printed matter, and the image data of the captured image (second distributed image) of the first electronic camera 221a is stored in the second distributed image storage unit 2173.

  Further, in each of the above-described embodiments, the distributed image created from the image data of the guarantee mark by the visual decryption type secret sharing method has been described as an example including a plurality of image components composed of two segments. However, the present invention is not limited to this. The distributed image constituent element only needs to have a plurality of segments.

  FIG. 15 illustrates a case where the distributed image component is composed of four segments. When two distributed images are generated from the guarantee mark by the visual decryption type secret sharing method and the distributed image constituent elements of each distributed image are composed of two segments, the white and black expression patterns are as follows. That is, in the case of white, the same segment of the dispersed image constituent elements of each of the two dispersed images is black, and in the case of black, the different segment of the dispersed image constituent elements of each of the two dispersed images is black. On the other hand, as shown in FIG. 15, when the distributed image constituent element is composed of four segments, white and black can be expressed with more expression patterns. For example, as shown in a pattern 870, in the case of white, the upper two segments of the four segments of the distributed image component 870 of each of the two distributed images are black, and in the case of black, one of the two distributed images The upper two of the four segments of the component 870 are black and the lower two of the four segments of the other distributed image component 870 are black. Further, as shown in a pattern 871, in the case of white, the left two segments of the four segments of the distributed image component 870 of each of the two distributed images are black, and in the case of black, one of the two distributed images The left two of the four segments of the component 870 are black and the right two of the four segments of the other distributed image component 870 are black. Further, as shown in the pattern 872, in the case of white, the same two diagonals of the four segments of the distributed image component 870 of each of the two dispersed images are black, and in the case of black, each of the two dispersed images is Two different diagonals of the four segments of the distributed image component 870 are black. By increasing the number of segments of the distributed image component in this way, it is possible to increase the white and black expression patterns, thereby making it more difficult to estimate the guarantee pattern from the distributed image. In addition, by setting n (n ≧ 3) segments constituting the divided image constituent elements, it is possible to generate a dispersion image of guarantee marks having n gray scales.

  The guarantee mark issuance / verification system described in the above embodiments can be used to guarantee the quality of commodities such as agricultural products. FIG. 16 is a diagram for explaining an example in which the guarantee mark issuing / verifying system according to the embodiment of the present invention is used for quality assurance of commodities such as agricultural products. Commodities such as agricultural products are produced by a plurality of producers 970, a wholesaler 910 collects goods from each producer, a middle wholesaler 920 evaluates and prices the products, distributes them to retail stores, and retails. The merchant 930 receives this and sells it to the consumer. For example, producer A 970 produces three products of quality 1 (940), producer B 970 produces one product of quality 1 and one product of quality 2 (941), and producer C 970 produces quality 1. When two products and one product of quality 2 are produced (942), the wholesaler 910 collects the products of each producer 970 and puts them on the market (951), and the intermediate wholesaler 920 Assessing the quality of products, assuming that there are 6 products of quality 1 and 2 products of quality 2, for example, when selling 2 products as a set (952), 3 sets of products of quality 1 Divide the two items into one set. At this time, the wholesaler attaches a seal 961 printed with a print image capable of proving a guarantee mark meaning evaluation of quality 1 to a set 960 of quality 1 products, and quality 2 without a seal is attached. So that it can be distinguished from the product set 962. By using a sticker that is difficult to duplicate or imitate, it is possible to eliminate traders who sell products at an unfair price by misrepresenting the product value of the product.

  Further, in each of the above embodiments, the case where the image data of the guarantee mark is visually dispersed into two dispersed images by the visual decryption type secret sharing method has been described as an example, but the image is visually dispersed into three or more dispersed images. Also good. For example, in the first embodiment described above, one of the three or more dispersed images may be a printed dispersed image, and the remaining may be a verified dispersed image. In the second embodiment, one of the three or more dispersed images may be the first dispersed image, and the rest may be the second dispersed image. Then, each of the second dispersed images is converted into a transformed dispersed image so as not to overlap each of the dispersed image components of the other dispersed images.

  In each of the above embodiments, an image that cannot be recognized with the naked eye (under visible light) is printed with black printed with Bk ink containing an infrared absorbing dye, and with C ink, M ink, and Y ink containing no infrared absorbing dye. It is expressed using black. However, the present invention is not limited to this. For example, an image that cannot be recognized with the naked eye (under visible light) is black printed with Bk ink containing an ultraviolet absorbing dye (fluorescent dye), and black printed with C ink, M ink, and Y ink containing no ultraviolet absorbing dye. You may express using. In this case, an ultraviolet imaging device is used instead of the infrared imaging device to capture an image that cannot be recognized with the naked eye.

FIG. 1 is a schematic diagram of a guarantee mark issuance / verification system to which the first embodiment of the present invention is applied. FIG. 2 is a schematic diagram of the guarantee mark issuing system 1. FIG. 3 is a diagram for explaining the principle of the visual decryption secret sharing method. FIG. 4 is a diagram for explaining the image data 820 of the background image stored in the background image storage unit 1144. FIG. 5 is a diagram for explaining the operation flow of the guarantee mark issuing system 1. FIG. 6 is a schematic diagram of the guarantee mark verification system 2. FIG. 7 is a diagram for explaining an operation flow of the guarantee mark verification system 2. FIG. 8 is a schematic diagram of the guarantee mark issuing system 1a. FIG. 9 is a diagram for explaining the process of generating the transformed dispersion image. FIG. 10 is a diagram for explaining an operation flow of the guarantee mark issuing system 1a. FIG. 11 is a schematic diagram of the guarantee mark verification system 2a. FIG. 12 is a diagram for explaining an operation flow of the guarantee mark verification system 2a. FIG. 13 is a diagram illustrating a hardware configuration example of the issuing devices 11 and 11a and the verification devices 21 and 21a. FIG. 14 is a diagram showing a modification of the infrared / visible light imaging 22a. FIG. 15 is a diagram showing a case where the distributed image constituent element is composed of four segments. FIG. 16 is a diagram for explaining an example in which the guarantee mark issuing / verifying system according to the embodiment of the present invention is used for quality assurance of commodities such as agricultural products.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 1a ... Warranty mark issuing system 2, 2a ... Warranty mark verification system, 3 ... Warranty mark management server, 4 ... Network, 11, 11a ... Issuing device, 12 ... Printing machine, 21, 21a ... Verification device, 22 ... Infrared imaging device, 22a ... infrared / visible light imaging device, 111, 211 ... GUI unit, 112, 212 ... network IF unit, 113, 116, 213, 216 ... arithmetic unit, 114, 117, 214, 217 ... storage unit, 115: Print control unit, 215 ... Imaging control unit

Claims (8)

A print image printing method capable of verifying an embedded image,
Dividing the embedded image into a plurality of distributed images by a visual secret sharing scheme (Visual Secret Sharing Scheme);
Storing at least one of the plurality of dispersion images as a dispersion image for printing, and using the plurality of dispersion images other than the dispersion image for printing as a dispersion image for verification, and storing the dispersion image for verification;
The dispersed image for printing is printed on a print medium with an ink that does not contain a visible light absorption dye, and the background image for camouflage is visible light so as not to overlap with the dispersed image components constituting the dispersed image for printing. Printing on the printing medium with ink containing an external line absorbing dye. A method for verifying a printed image printed by the printing method according to claim 1,
Reading a distributed image for printing included in a print image printed on the print medium using a visible light external imaging device; and
And a step of synthesizing and outputting the read distributed image for printing and the preliminarily stored distributed image for verification by a visual decoding secret sharing method. A print image printing method capable of verifying an embedded image,
Dividing an embedded image into a plurality of distributed images using a visual secret sharing scheme;
At least one of the plurality of dispersion images is a first dispersion image, a dispersion image other than the first dispersion image is a second dispersion image, and the position of the dispersion image component constituting the second dispersion image is moved according to a predetermined rule. Converting the second dispersed image into a transformed dispersed image;
The converted dispersion image is printed on a printing medium with an ink that does not contain a visible light external absorption pigment, and the first dispersion image is coated with a visible light external absorption pigment so as not to overlap with the dispersion image components constituting the conversion dispersion image. And printing on the printing medium with ink containing the printing method. A method for verifying a printed image printed by the printing method according to claim 3,
Reading a print image printed on the print medium using a visible light imaging device, and reading a transformed dispersion image included in the print image printed on the print medium using a visible light external line imaging device;
Extracting a first dispersed image from the difference between the read printed image and the transformed dispersed image;
Back-converting the read transformed dispersion image into a second dispersion image according to a predetermined rule;
And a step of synthesizing and outputting the extracted first distributed image and the inversely transformed second distributed image by a visual decoding secret sharing method. Generate print data for a print image that can verify an embedded image for a printer that prints the same color on a print medium using an ink that does not contain an external light absorption dye and an ink that contains an external light absorption dye. An issuing device, an embedded image storage means for storing an embedded image;
A distributed image generating means for dividing the embedded image into a plurality of distributed images by a visual secret sharing scheme (Visual Secret Sharing Scheme);
Printing dispersed image storage means for storing at least one of the plurality of dispersed images as a printing dispersed image;
A verification distributed image storage means for storing the plurality of distributed images other than the print distributed image as verification distributed images;
Background image storage means for storing a background image;
The dispersed image for printing is printed on a print medium with an ink that does not contain a visible light external absorption pigment, and the background image is absorbed by the visible light external line so as not to overlap with the dispersed image components constituting the dispersed image for printing. A printing image generating unit configured to generate print data for printing on the printing medium with ink containing a coloring matter. A verification device for verifying a print image printed by the issuing device according to claim 5,
Verification distributed image storage means for storing the verification distributed image;
A distributed image storage unit for printing, which stores a distributed image for printing included in the print image, which is imaged by an external visible light imaging device;
Image synthesizing means for synthesizing the verification distributed image stored in the verification distributed image storage means and the print distributed image stored in the print distributed image storage means by a visual decryption type secret sharing method;
And a synthesized image output means for outputting the image synthesized by the image synthesizing means. Generate print data for a print image that can verify an embedded image for a printer that prints the same color on a print medium using an ink that does not contain an external light absorption dye and an ink that contains an external light absorption dye. A distributed image generating unit that divides an embedded image into a plurality of distributed images by a visual secret sharing scheme (Visual Secret Sharing Scheme);
First distributed image storage means for storing at least one of the plurality of distributed images as a first distributed image;
Second distributed image storage means for storing the plurality of dispersed images other than the first dispersed image as a second dispersed image;
Transformed distributed image storage means for converting the second dispersed image into a transformed dispersed image by moving the position of the dispersed image constituent elements constituting the second dispersed image according to a predetermined rule;
The converted dispersion image is printed on a printing medium with an ink that does not contain a visible light external absorption pigment, and the first dispersion image is coated with a visible light external absorption pigment so as not to overlap with the dispersion image components constituting the conversion dispersion image. And a print image generating means for generating print data for printing on the print medium with the ink containing the printing apparatus. A verification device for verifying a print image printed by the issuing device according to claim 7,
Print image storage means for storing a print image captured by a visible light imaging device;
Transformed dispersion image storage means for storing a transformed dispersion image included in the print image, which is imaged by a visible light external line imaging device;
First distributed image detecting means for extracting a first dispersed image from a difference between the printed image stored in the printed image storage means and the transformed dispersed image stored in the transformed dispersed image storage means;
Second distributed image detecting means for inversely transforming the transformed dispersed image stored in the transformed dispersed image storage means into a second dispersed image according to a predetermined rule;
Image synthesizing means for synthesizing the first dispersed image detected by the first dispersed image detecting means and the second dispersed image detected by the second dispersed image detecting means by a visual decoding type secret sharing method;
And a synthesized image output means for outputting the image synthesized by the image synthesizing means.

Images