Authenticity determination device and program

Abstract

To provide an authenticity determination device, for example, for determining the authenticity of different types of cards.SOLUTION: An authenticity determination device 3 determines the authenticity of an ID card from an image of an inspection region of an ID card. The authenticity determination device 3 includes: acquisition means 301 for acquiring an image taken of the ID card and type identification information for identifying the type of the ID card; and authenticity determination means 302 for acquiring an image of the inspection region in a position varied according to the type of the ID card on the basis of the taken image of the ID card and the type identification information of the ID card and determining the authenticity of different types of ID cards by using a common algorithm from the image of the inspection region.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an authenticity determination device and a program therefor. [Background technology]

[0002] When opening an account, it is common for a user to go to a financial institution and submit their ID card, and the financial institution will then verify the user's identity in person using the ID card. There are also attempts to make various procedures more convenient by automatically obtaining various information from the user's ID card.

[0003] In such situations, it is important to determine whether the ID card is authentic and not counterfeit, altered, etc. Patent Document 1 describes a technology for determining the authenticity of an ID card from an image of the ID card, which makes it possible to automatically determine the authenticity of an ID card based on the characteristics of the image of the ID card. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-34535 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technology in Patent Document 1 is designed to determine the authenticity of ID cards with specific characteristics, but is not designed to determine the authenticity of other types of ID cards. In situations such as those described above, multiple types of ID cards are often available, and a system that can determine the authenticity of these multiple types of ID cards has been desired.

[0006] The present invention has been made in view of the above problems, and has as its object to provide an authenticity determination device and the like for determining the authenticity of a plurality of types of cards. [Means for solving the problem]

[0007] A first invention for solving the above-mentioned problems is an authenticity determination device that determines the authenticity of a card from an image of an inspection area of ​​the card, and includes: an acquisition means that acquires a photographed image of the card and type identification information that can identify the type of the card; and an authenticity determination means that acquires an image of the inspection area at a position that differs depending on the type of the card based on the photographed image and the type identification information, and determines the authenticity of a plurality of types of cards from the image of the inspection area using a common algorithm. The photographed images of the card are a pair of photographed images taken by turning on light sources provided on both sides of the card, one on each side, and the image of the inspection area is an image in a difference image created by taking the difference in gradation values ​​of the image of the card obtained from each of the pair of photographed images, and the common algorithm determines a judgment value based on the number of bright points in the image of the inspection area and compares the judgment value with a threshold value. The authenticity determination device is characterized by the above.

[0008] Although the configuration of the card face differs depending on the type of card, the present invention determines the authenticity of cards from images of inspection areas at different positions depending on the type of card, to which a common algorithm can be effectively applied based on the card type identification information. As a result, the present invention can determine the authenticity of multiple types of cards without switching algorithms for each type of card.

[0009] Book In the present invention, when a card is falsified by attaching a piece of paper or the like with false card information printed on it, or by scratching off the card's card information and then writing in false card information, a step is created on the card due to the attachment marks or scratch marks, and this step appears as a light or dark area when the card is photographed with a light source located on one side of the card turned on, and this can be used to determine the authenticity of the card. Also, by obtaining an image of the card from each of a pair of photographed images taken with the light sources on both sides of the card turned on, and then taking the difference between these images, only the area where the step has occurred can be extracted as a difference image, allowing for appropriate authentication.

[0010] A second invention is an authenticity determination device that determines the authenticity of a card from an image of an inspection area of ​​the card, comprising: an acquisition means that acquires a photographed image of the card and type identification information that can identify the type of the card; and an authenticity determination means that acquires an image of the inspection area at a position that differs depending on the type of the card based on the photographed image and the type identification information, and determines the authenticity of multiple types of cards from the image of the inspection area using a common algorithm;The photographed images of the card are a visible light image and an infrared image of the card, and the common algorithm calculates a discrimination value as the number of pixels within the inspection area whose shading in the visible light image and the infrared image meets a predetermined standard, and determines whether the inspection area is positive or negative based on the comparison result between the discrimination value and a threshold value. In the present invention, genuine cards are manufactured by printing each area of ​​the card surface using a predetermined printing method, and the appearance of the shading in these areas differs between visible light images and infrared images depending on the ink used, etc. This can be used to determine authenticity. For example, areas printed with ink containing an infrared-absorbing component, such as carbon, appear as dark areas (high-density areas) in both visible light images and infrared images, while areas printed with ink that does not absorb infrared light appear as dark areas in visible light images and light areas (low-density areas) in infrared images. This makes it possible to effectively detect cases of counterfeiting or alteration using ink with different infrared absorption characteristics from the ink used on genuine cards.

[0011] It is desirable that a plurality of inspection areas are set for each of a plurality of types of cards. This improves the accuracy of authenticity determination.

[0012] No. 3 The invention is an authenticity determination device that determines the authenticity of a card from an image of an inspection area of ​​the card, and includes: an acquisition means that acquires a photographed image of the card and type identification information that can identify the type of the card; and an authenticity determination means that acquires an image of the inspection area at a position that differs depending on the type of the card based on the photographed image and the type identification information, and determines the authenticity of multiple types of cards from the image of the inspection area using a common algorithm. The photographed images of the card are a pair of photographed images taken by turning on light sources provided on both sides of the card, one on each side, and the image of the inspection area is an image in a difference image created by taking the difference in gradation values ​​of the image of the card obtained from each of the pair of photographed images, and the common algorithm determines a judgment value based on the number of bright points in the image of the inspection area and compares the judgment value with a threshold value. The program is for causing the device to function as an authenticity determination device characterized by the above. No. 3 The present invention is a program for the authenticity determination device of the first invention. A fourth invention is a program for causing a computer to function as an authenticity determination device that determines the authenticity of a card from an image of an inspection area of ​​the card, comprising: an acquisition means for acquiring a photographed image of the card and type identification information that can identify the type of the card; and an authenticity determination means for acquiring an image of the inspection area at a position that varies depending on the type of card based on the photographed image and the type identification information, and determining the authenticity of multiple types of cards from the image of the inspection area using a common algorithm, wherein the photographed image of the card is a visible light image and an infrared image of the card, and the common algorithm calculates a discrimination value as the number of pixels in the inspection area whose shading in the visible light image and the infrared image meets a predetermined standard, and determines whether the inspection area is genuine or not based on the result of comparing the discrimination value with a threshold. The fourth invention is a program for the authenticity determination device of the second invention. . [Effects of the Invention]

[0013] The present invention makes it possible to provide an authenticity determination device or the like for determining the authenticity of multiple types of cards. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 shows an authenticity determination system 1. [Figure 2] FIG. 2 is a diagram showing a visible light camera 21 and a light source 22 in the reading device 2. [Figure 3] FIG. 2 is a diagram showing the hardware configuration of the authenticity determination device 3. [Figure 4] FIG. 1 is a diagram showing an example of an ID card 10. [Figure 5] FIG. 2 is a diagram showing the function of the authenticity determination device 3. [Figure 6] 1 is a flowchart showing an outline of an authenticity determination method. [Figure 7] 1A and 1B are diagrams for explaining photographing of an ID card 10. [Figure 8] 10 is a flowchart showing the procedure for determining authenticity. [Figure 9] 1 is a diagram showing a piece of paper 101 and scraping marks 104 on an ID card 10. FIG. [Figure 10] 10 is a flowchart showing a procedure for determining authenticity using a step detection image. [Figure 11] FIG. 2 is a diagram for explaining the creation of a difference image 140. [Figure 12] 3 shows an example of setting information 310 and an inspection area a. [Figure 13] FIG. 10 is a diagram showing a histogram of the number of bright spots. [Figure 14] 10 is a flowchart showing the procedure for determining authenticity by comparing a comparison image with an infrared image. [Figure 15] 2A and 2B are diagrams showing binary images 200 and 300 of a spectral image and an infrared image. [Figure 16] 10 shows an example of setting information 320 and an inspection area b. [Figure 17] FIG. 10 is a diagram for explaining a method for determining whether an inspection area b is correct or not. [Figure 18]FIG. 10 is a diagram for explaining a method for determining whether an inspection area b is correct or not.

[0015] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

[0016] (1. Authenticity Determination System 1) Fig. 1 is a diagram showing an authenticity determination system 1 having an authenticity determination device 3 according to an embodiment of the present invention. As shown in Fig. 1, the authenticity determination system 1 is configured by connecting a reading device 2 and an authenticity determination device 3 so that they can communicate with each other via wired or wireless communication. In the authenticity determination system 1, a photographed image of an ID card 10 is transmitted from the reading device 2 to the authenticity determination device 3, and the authenticity determination device 3 determines the authenticity of the ID card 10 from the photographed image, etc.

[0017] The reading device 2 has a photographing device 20 that photographs the ID card 10 and a card reader 30 that reads the IC chip of the ID card 10. In particular, in this embodiment, the photographing device 20 is provided with a visible light camera and visible light illuminator, and an infrared camera and infrared illuminator.

[0018] When photographing with a visible light camera, the visible light camera receives visible light emitted from a visible light illuminator and reflected from the ID card 10. When photographing with an infrared camera, the infrared camera receives infrared light emitted from an infrared illuminator and reflected from the ID card 10. Hereinafter, an image of the ID card 10 photographed with a visible light camera will be referred to as a visible light image, and an image of the ID card 10 photographed with an infrared camera will be referred to as an infrared image.

[0019] The above-mentioned visible light camera photographs the ID card 10 from directly above it, but in this embodiment, a pair of light sources 22 are provided as visible light illumination diagonally above on both sides of the ID card 10, as shown in Figure 2. Reference numeral 21 in the figure denotes a visible light camera that photographs the ID card 10 from directly above it.

[0020] 3 is a diagram showing the hardware configuration of the authenticity determination device 3. The authenticity determination device 3 can be realized by a computer configured by connecting a control unit 31, a storage unit 32, a communication unit 33, a display unit 34, etc. via a bus or the like. However, the authenticity determination device 3 is not limited to this, and various other configurations can be used as appropriate.

[0021] The control unit 31 is composed of a CPU, ROM, RAM, etc. The CPU loads programs related to the processing of the authenticity determination device 3 stored in storage media such as the memory unit 32 and ROM into a work area on the RAM and executes them. The ROM is a non-volatile memory that permanently stores programs such as the boot program and BIOS, as well as data. The RAM is a volatile memory that temporarily stores programs and data loaded from the memory unit 32, ROM, etc., and also has a work area that the control unit 31 uses to perform various processes.

[0022] The storage unit 32 is a hard disk drive, a solid state drive, a flash memory, or the like, and stores programs executed by the authenticity determination device 3 in the processes described below, data required for program execution, an OS, and the like.

[0023] The communication unit 33 is a communication interface that mediates communication with the reader 2. The display unit 34 is a liquid crystal display or the like, and displays various information related to determining whether the ID card 10 is authentic or not.

[0024] (2. ID Card 10) In this embodiment, the ID card 10 is an identification card that is the subject of authentication determination. Identification cards are cards used for administrative procedures and identity verification by various government agencies, financial institutions, mobile phone carriers, etc., and include, for example, a driver's license, My Number card, residence card, special permanent resident certificate, etc. However, the ID card 10 is not limited to these.

[0025] 4(a) and (b) are schematic diagrams showing examples of the faces of a driver's license and a residence card, respectively, as ID cards 10. ID card 10 is a roughly rectangular card substrate on which face information such as the card holder's name, date of birth, address, expiration date, and photograph is printed, but other face information according to the type of ID card 10 is also printed, such as the type of license in the case of a driver's license or the residence status in the case of a residence card, and the content and position of the face information on ID card 10 differs depending on the type of ID card 10.

[0026] In this embodiment, type identification information indicating the type of the ID card 10 is stored in an IC chip (not shown) that the ID card 10 has, and this type identification information is read by the card reader 30.

[0027] (3. Functions of the Authentication Device 3) 5 is a block diagram showing the functions of the authenticity determination device 3. The authenticity determination device 3 includes an acquisition means 301, an authenticity determination means 302, and the like.

[0028] The acquisition means 301 is a means for the control unit 31 of the authenticity determination device 3 to receive and acquire the photographed image of the ID card 10 and the type identification information of the ID card 10 from the reading device 2 via the communication unit 33. The photographed image of the ID card 10 includes the above-mentioned visible light image and infrared image.

[0029] The authenticity determination means 302 is a device in which the control unit 31 of the authenticity determination device 3 acquires an image of an inspection area at a position that varies depending on the type of ID card 10 based on the photographed image of the ID card 10 and the type identification information of the ID card 10, and determines the authenticity of multiple types of ID cards 10 from the image of the inspection area using a common algorithm. Details of authenticity determination will be described later.

[0030] (4. Overview of authenticity determination method) Fig. 6 is a flowchart showing an outline of the authenticity determination method executed by the authenticity determination system 1. S1 to S3 in Fig. 6 are processes executed by a control unit (not shown) of the reading device 2 by controlling each unit of the reading device 2, and S4 to S6 are processes executed by a control unit 31 of the authenticity determination device 3 by controlling each unit of the authenticity determination device 3.

[0031] In this embodiment, the user first sets the ID card 10 in a predetermined position on the reading device 2, and the reading device 2 reads the IC chip on the ID card 10 in response to the user's operation to obtain type identification information for the ID card 10 (S1), and then photographs the ID card 10 using the visible light camera 21 and the infrared camera (S2).

[0032] Here, in S2, when the ID card 10 is photographed by the visible light camera 21, the reading device 2 turns on both light sources 22 to photograph the ID card 10 as shown in Figure 7(a), and then turns on only one of the light sources 22 to photograph the ID card 10 as shown in Figure 7(b), and then turns on only the other light source 22 to photograph the ID card 10 as shown in Figure 7(c).

[0033] As shown in Figure 7(a), a photographed image (visible light image) taken with both light sources 22 turned on is used for comparison with an infrared image, which will be described later. Also, as shown in Figures 7(b) and 7(c), a pair of photographed images (visible light images) taken with the light sources 22 located on both sides of the ID card 10 turned on, one on each side, are used for detecting a step, which will be described later. Hereinafter, the former photographed image may be referred to as a "comparison image," and the latter pair of photographed images may be referred to as "step detection images."

[0034] The reader 2 transmits the photographed image obtained by photographing the ID card 10 in S2 and the type identification information of the ID card 10 obtained by reading the IC chip in S1 (hereinafter referred to as "photographed image, etc.") to the authenticity determination device 3 (S3). The authenticity determination device 3 receives the photographed image, etc. (S4) and determines the authenticity of the ID card 10 using the photographed image, etc. (S5).

[0035] It should be noted that the captured images of the ID card 10, both visible light images and infrared images, are images in which the color of each pixel is expressed by the gradation values ​​of the R (red), G (green), and B (blue) components. In infrared images, the R, G, and B gradation values ​​of each pixel are approximately the same. However, infrared images of the ID card 10 captured with an infrared camera may be grayscale images in which the brightness of each pixel is expressed by gradation values. In such cases, grayscale conversion in S205 (see FIG. 14), which will be described later, is not necessary.

[0036] The authenticity determination device 3 displays the authenticity determination result of the ID card 10 on the display unit 34 (S6), and ends the process. The person in charge can then take appropriate action after viewing the display unit 34. The authenticity determination device 3 may display instructions according to the determination result along with the authenticity determination result of the ID card 10 on the display unit 34, to prompt the person in charge to take appropriate action.

[0037] (5. Authentication of ID card 10) In S5, as shown in the flowchart of Fig. 8, a judgment is made based on the step detection image, which is a visible light image (S10), and a judgment is made based on a comparison between the comparison image, which is a visible light image, and the infrared image (S20). If both judgments determine that the ID card 10 is genuine (S30; YES), the ID card 10 is finally determined to be genuine (S40). On the other hand, if either judgment determines that the ID card 10 is not genuine (S30; NO), the ID card 10 is determined to be counterfeit (S50). Each judgment will be explained below.

[0038] (5-1. Judgment using step detection images) In the above-mentioned S10, when the ID card 10 is falsified by pasting a piece of paper or the like on which false face information is printed, or by scratching off the face information of the ID card 10 and then writing in false face information, a step is generated on the ID card 10 due to the traces of pasting or scratching, and the step appears in the step detection image, and by utilizing this, the authenticity of the ID card 10 is determined.

[0039] For example, as shown in Figure 9(a), if a piece of paper 101 is attached to an ID card 10, when one of the light sources 22 is turned on to illuminate the ID card 10 with illumination light 221 during photography, the edge 102 of the piece of paper 101 closest to the light source 22 will appear bright due to the diffuse reflection of the illumination light 221 caused by the step. On the other hand, the edge 103 farthest from the light source 22 will appear dark due to the shadow caused by the step. Therefore, tampering such as attaching a piece of paper 101 to the ID card 10 can be detected from such bright or dark areas.

[0040] On the other hand, as shown in Figure 9(b), if there is a scratch mark 104 on the ID card 10, when one of the light sources 22 is turned on and illumination light 221 is irradiated during a photograph of the ID card 10, the vicinity of the edge 105 of the scratch mark 104 closest to the light source 22 will appear dark due to the shadow caused by the step. On the other hand, the edge 106 farther from the light source 22 will appear bright due to the diffuse reflection of the illumination light 221 caused by the step. Therefore, tampering such as scratching off the face information of the ID card 10 can be detected from such bright or dark areas.

[0041] 10 is a flowchart showing the procedure for authenticity determination in S10. In this embodiment, in S10, first, the area of ​​the ID card 10 is cut out from each of the pair of step detection images received in S4, and used as an image of the ID card 10 (S101).

[0042] The authenticity determination device 3 resizes and reduces the pair of ID card 10 images cut out from the pair of step detection images, and then performs grayscale conversion on both images (S102). This speeds up subsequent processing. The specific method of grayscale conversion is not particularly important.

[0043] Next, the authenticity determination device 3 calculates the difference in gradation values ​​between the two images to create a difference image (S103). More specifically, the difference in gradation values ​​between pixels at corresponding positions in the two images is calculated, and the absolute value is used as the gradation value of the pixel at that position to create the difference image.

[0044] Fig. 11(a) is an example of an ID card 10 that has been altered by attaching a piece of paper 101, and Fig. 11(b) is an example of a pair of images 130 of the ID card 10 obtained by the processing up to S102. In S103, the difference in the gradation values ​​of these images 130 is taken to obtain a difference image 140 as shown in Fig. 11(c).

[0045] In the example of Figure 11(a), a piece of paper 101 has been pasted in the name, address, and photograph fields of the driver's license of Figure 3(a), and in the image 130 shown in Figure 11(b), light areas 131 and dark areas 132 appear as traces of the pasting on both sides of the piece of paper 101. The part that appears as the light area 131 in one image 130 appears as the dark area 132 in the other image 130. As a result, as shown in Figure 11(c), in the difference image 140, the gradation values ​​on both sides of the piece of paper 101 are higher.

[0046] Thereafter, the authenticity determination device 3 compares the gradation value of each pixel of the difference image 140 with a predetermined threshold value, and detects pixels with gradation values ​​greater than the threshold value as bright spots (S104).

[0047] The authenticity determination device 3 counts the number of bright spots, and if the number is equal to or less than a reference value (S105; YES), it determines that the ID card 10 is authentic (S106) and ends the process.

[0048] On the other hand, if the number of bright spots exceeds the reference value (S105; NO), the authenticity determination device 3 acquires setting information from the memory unit 32 (S107), and based on this setting information, cuts out a specified inspection area from the difference image 140 to acquire an image of the inspection area (S108), and creates a histogram showing the number of bright spots at each position in a specified direction within the inspection area (S109).

[0049] Fig. 12(a) is a diagram showing the setting information 310 acquired in S107. In this setting information 310, position information 312 of the inspection area a in the image 130 of the ID card 10 is set for each type 311 of the ID card 10. The position of the inspection area a (position information 312) differs for each type 311 of the ID card 10, as shown in Fig. 12(b), and multiple positions are set for each type of ID card 10.

[0050] In S108, this setting information 310 is referenced, and position information 312 of the inspection area a corresponding to the type 311 of the ID card 10 is obtained from the type identification information of the ID card 10 obtained in S4, and this position information 312 is used to cut out the inspection area a from the difference image 140. In addition, in the setting information 310, a threshold value 313 to be applied to each inspection area a in S111 described later is also set corresponding to the position information 312 of each inspection area a.

[0051] Figure 13(a) shows an image of inspection area a of the name and date of birth of ID card 10 in Figure 3(a) cut out from difference image 140 in S108, and an example of a histogram created for inspection area a in S109, with the specified direction being the long side direction of ID card 10.The number of bright spots is higher in the area where bright spots are lined up in the short side direction of ID card 10 (bright line).

[0052] The authenticity determination device 3 extracts a continuous range C, which is a continuous range of positions where bright spots exist, from the histogram of each inspection area a (S110). Figure 13(b) is an enlarged view of the continuous range C on the left side of Figure 13(a). Within the continuous range C, there is a portion between positions c1 and c2 where bright spots exist, where the number of bright spots is zero. However, even if positions c1 and c2 where bright spots exist are separated from each other, as long as the separation is equal to or less than a reference length, these positions c1 and c2 are considered to be continuous and are included in the continuous range C. The reference length can be determined as appropriate.

[0053] The authenticity determination device 3 calculates the total number of bright points within each continuous range C as a determination value for all continuous ranges C extracted from each inspection area a. If the determination value for all continuous ranges C is equal to or less than the threshold value 313 (see FIG. 12(a)) (S111; YES), the ID card 10 is determined to be authentic (S106), and the process ends.

[0054] This is because even if bright spots are present in the differential image 140, if they are not present in a certain cluster, they are likely to be noise unrelated to the authenticity of the ID card 10. For example, the continuous range C on the right side of the histogram in Figure 13(c) is due to noise, and the total number of bright spots within continuous range C is small. Therefore, if it is considered that all of continuous range C is due to such noise, the ID card 10 is deemed to be authentic.

[0055] The threshold value 313 is calculated by multiplying the height (number of pixels in the vertical direction) of each inspection area a by a predetermined coefficient, and is set to a value according to the height of the inspection area a. The value of the coefficient can be determined appropriately, for example, to be 1.2. The judgment value may be based on the number of bright spots in the inspection area a, and the calculation method is not limited to the above. For example, it may simply be the total number of bright spots in the inspection area a. The threshold value 313 also differs depending on the calculation method of the judgment value.

[0056] If the determination value exceeds the threshold value 313 in any of the continuous ranges C (S111; NO), the authenticity determination device 3 determines that the ID card 10 is not authentic (S112) and ends the process.

[0057] In S10, the authenticity determination process for the ID card 10 can be performed as described above. Alteration by attaching a piece of paper 101 or the like is often performed on specific face information such as a name or address, and the position of this face information varies depending on the type of ID card 10. However, in this embodiment, by referencing the setting information 310 and cutting out a different inspection area a depending on the type of ID card 10 and performing the determination, a common algorithm corresponding to S109 to S111 in Fig. 10 can be applied to face information that is expected to be altered for different types of ID cards 10.

[0058] In the above example, the ID card 10 was determined to be inauthentic based on bright spots resulting from the attachment marks on the ID card 10. However, if there are scratch marks 104 on the ID card 10, bright spots will appear in the differential image 140 in the same manner as above, and such an ID card 10 can be detected as inauthentic.

[0059] (5-2. Judgment by comparing the comparison image and the infrared image) In the above-mentioned S20, the genuine ID card 10 is manufactured by printing each area of ​​the card face using a predetermined printing method, and the authenticity is determined by utilizing the fact that the appearance of the shading of these areas differs between the visible light image and the infrared image depending on the ink used, etc.

[0060] For example, a portion printed with ink containing an infrared absorbing component such as carbon appears as a dark area (high density area) in both the visible light image and the infrared image, whereas a portion printed with ink that does not absorb infrared appears as a dark area in the visible light image and a light area (low density area) in the infrared image. Therefore, it is possible to effectively detect cases where a card has been counterfeited or altered using ink with different infrared absorption characteristics from the ink used on the genuine ID card 10.

[0061] 14 is a flowchart showing the steps of authenticity determination in S20. In this embodiment, in S20, the comparison image (visible light image) and infrared image received in S4 are first resized to a predetermined size (S201). This speeds up subsequent processing. The comparison image and the infrared image have the same size, and may be reduced to about half the original size of the comparison image and infrared image, for example, but are not limited to this.

[0062] Next, the authenticity determination device 3 masks the facial photograph portion in the resized comparison image and the infrared image (S202). This process is to prevent the gradation values ​​of the pixels in the facial photograph from affecting the binarization process that will be performed later. The masking process is performed by replacing the gradation values ​​of the pixels in the facial photograph with specific mask values.

[0063] Next, the authenticity determination device 3 creates a spectral image from the comparison image after masking (S203). In this process, an image is created as the spectral image, with the gradation values ​​of the R, G, and B components of each pixel in the comparison image as the gradation values ​​of each pixel. Hereinafter, an image based on the gradation values ​​of the B component will be referred to as the B image, an image based on the gradation values ​​of the G component as the G image, and an image based on the gradation values ​​of the R component as the R image. The B image, G image, and R image are spectral images that show the shades of the R, G, and B components, respectively.

[0064] In S203, a spectral image is created in which the maximum gradation value of the R, G, and B components of each pixel in the comparison image is used as the gradation value for each pixel. This image shows the degree of brightness of each pixel in the comparison image as a shade, and is hereinafter referred to as a V (brightness) image. For example, if the gradation values ​​of the R, G, and B components of a pixel in the comparison image are (R, G, B) = (10, 20, 30), the gradation value of the corresponding pixel in the V image will be 30.

[0065] As a result, in subsequent processing, the shading of the comparison image (visible light image) will be the shading for each color component of the comparison image, or the shading indicating the degree of brightness of each pixel of the comparison image.

[0066] The authenticity determination device 3 binarizes each of the spectral images created in S203 (S204). There are no particular limitations on the binarization method, but in this embodiment, binarization is performed using Otsu's method. Otsu's method is a technique that automatically determines a threshold value for binarization from a gradation value histogram of the entire image, and is well known in the image processing field. However, binarization can also be performed using a predetermined threshold value.

[0067] 15(a) is an example of a binary image 200 of a spectral image (B image, G image, R image, V image). In these binary images 200, high density areas (dark areas) in the spectral image are represented by black pixels and low density areas (light areas) are represented by white pixels, and the printed areas are basically represented by black pixels (dark areas).

[0068] However, in the binary image 200 of the B, G, and R images, the parts printed in these colors (for example, the parts printed in red in the R image) do not appear as black pixels but as white pixels (light areas).On the other hand, the parts printed in colors close to the complementary colors of these colors (for example, the parts printed in red in the B image) appear as black pixels.

[0069] The authenticity determination device 3 also performs grayscale conversion on the infrared image after the masking process, and then performs binarization processing (S205). Grayscale conversion is performed because the gradation values ​​of the R, G, and B components of the pixels in the infrared image may differ from one another, but as mentioned above, this can be omitted if the infrared image is a grayscale image. Grayscale conversion can be performed using a known method.

[0070] Unlike the previous method, the infrared image is binarized using a predetermined threshold value. It is desirable to set an appropriate threshold value depending on the type of ID card 10. However, as before, binarization may also be performed using Otsu's method. Figure 15(b) is an example of a binary image 300 of an infrared image. In an infrared image, areas printed with ink containing components that absorb infrared rays become high-density areas (dark areas), and in the binary image 300, these areas appear as black pixels.

[0071] After creating binary images 200, 300 for the spectral image and the infrared image, respectively, the authenticity determination device 3 acquires setting information from the memory unit 32 (S206), and based on this setting information, cuts out an inspection area from the binary images 200, 300 of the spectral image and the infrared image, and acquires an image of the inspection area (S207).

[0072] 16(a) is a diagram showing setting information 320 acquired in S206. In this setting information 320, position information 322 of the inspection area b in the ID card 10 corresponding to the type 321 of the ID card 10 is set, and the position (position information 322) of the inspection area b differs for each type of ID card 10, as shown in FIG. 16(b), and multiple positions of the inspection area b are set for each type of ID card 10. In S306, this setting information 320 is referenced, and position information 322 of the inspection area b corresponding to the type 321 of the ID card 10 is acquired based on the type identification information of the ID card 10 acquired in S4, and this position information 322 is used to cut out the inspection area b from both of the binary images 200, 300.

[0073] In the setting information 320, a discrimination method 323 (mode A or mode B described later) to be applied to each inspection area b in S208 described later, a threshold value 324 used for discrimination, and information 325 of a spectroscopic image used for discrimination are set corresponding to position information 322 of the inspection area b. The discrimination method 323 will be described later.

[0074] The authenticity determination device 3 determines whether the inspection area b is genuine (whether the inspection area b is of a genuine ID card 10) based on the pixel values ​​of the binary images 200 and 300 (S208).

[0075] In S208, based on the pixel values ​​of the binary images 200 and 300, the number of pixels in the inspection area b whose shading in the spectral image and the infrared image meets a predetermined standard is calculated as a discrimination value, and the inspection area b is judged to be correct or incorrect based on the comparison result between the discrimination value and a threshold value 324. In particular, in this embodiment, the above-mentioned predetermined standard, etc. differs for each inspection area b. More specifically, it differs depending on whether the inspection area b is a part printed with ink containing a component that absorbs infrared rays or a part printed with ink that does not. Below, the differences in the methods (called modes) for discriminating the correct or incorrectness of the inspection area b will be explained.

[0076] <Mode A. When inspection area b is a part printed with ink containing a component that absorbs infrared rays> If the inspection area b is a part of a genuine ID card 10 that is printed with ink containing a component that absorbs infrared rays, that printed part will appear as a dark area in both the spectral image and the infrared image, as shown in Figure 17(a), and will appear as black pixels in these binary images 200 and 300.

[0077] 17(b) shows an ID card 10 with writing 12 made with ink that does not absorb infrared light in the inspection area b. In this case, the area with writing 12 appears as a dark area in the spectral image and a light area in the infrared image, and appears as a black pixel in the binary image 200 of the spectral image, but as a white pixel in the binary image 300 of the infrared image.

[0078] 17(c) shows pixels that are black in the binary image 200 of the spectral image and white in the binary image 300 of the infrared image as white pixels, and other pixels as black pixels. In order to detect falsification caused by writing 12 with inks having different infrared absorption characteristics as described above, the authenticity determination device 3 counts the number of pixels that are black in the binary image 200 of the spectral image and the binary image 300 of the infrared image in an inspection area b cut out from the former binary image 200 and the latter binary image 300 (white pixels in FIG. 17(c)), and uses the counted number as a discrimination value.

[0079] The discrimination value is then compared with a threshold value 324, and if the discrimination value is equal to or less than the threshold value 324, it is determined that the inspection area b is positive, and if the discrimination value is greater than the threshold value 324, it is determined that the inspection area b is not positive. In this case, the predetermined criterion is "a dark area in the spectral image and a light area in the infrared image (a black pixel in the binary image 200 and a white pixel in the binary image 300)."

[0080] <Mode B. When inspection area b is printed with ink that does not absorb infrared rays> If the inspection area b is a portion of a genuine ID card 10 that is printed with ink that does not absorb infrared rays, the printed portion will appear as a dark area in the spectral image and a light area in the infrared image, as shown in Figure 18(a), and will appear as black pixels in the binary image 200 of the spectral image and as white pixels in the binary image 300 of the infrared image.

[0081] 18(b) shows an example in which the portion of the inspection area b of the ID card 10 that would normally be printed with ink that does not absorb infrared rays has been printed with ink that contains a component that absorbs infrared rays. In this case, the printed portion 14 appears as a dark area in both the spectral image and the infrared image, and appears as a black pixel in both the binary image 200 of the spectral image and the binary image 300 of the infrared image.

[0082] 18(c) shows pixels that are black in both the binary spectroscopic image 200 and the binary infrared image 300 as white pixels, and other pixels as black pixels. In order to detect counterfeiting or alteration caused by printing with inks that have different infrared absorption characteristics as described above, the authenticity determination device 3 counts the number of pixels that are black in both the binary spectroscopic image 200 and the binary infrared image 300 (white pixels in FIG. 18(c)) for an inspection area b cut out from both the binary spectroscopic image 200 and the binary infrared image 300, and uses the counted number as a discrimination value.

[0083] The discrimination value is then compared with a threshold value 324, and if the discrimination value is equal to or less than the threshold value 324, the inspection area b is determined to be positive, and if the discrimination value is greater than the threshold value 324, the inspection area b is determined to be negative. In this case, the predetermined criterion is "a dark area in the spectral image and the infrared image (a black pixel in the binary images 200, 300)."

[0084] In this way, in S208, by referencing the setting information 320, a discrimination method 323 defined for each inspection area b according to differences in the ink used, etc., is implemented to determine whether the inspection area b extracted in S206 is positive. Figure 16(b) also shows the discrimination methods 323 (mode A, mode B) applied to some of the inspection areas b. As shown in Figure 16(b), due to differences in the ink used when printing each area of ​​the ID card 10, the position of the inspection area b to which mode A is applied differs among multiple types of ID cards 10, and similarly, the position of the inspection area b to which mode B is applied also differs among multiple types of ID cards 10.

[0085] Furthermore, the spectral images used for discrimination in Mode A and Mode B should basically be V images because the inspection area b is set mainly to the character portion, but as an exception, for portions printed in color, it is desirable to use a color close to the complementary color of the printed color so that the portion appears as a dark portion in the spectral image.In this way, information 325 (see FIG. 16(a)) regarding which spectral image to use for discrimination for each inspection area b is also set in the setting information 320 and is referenced in S208 together with the threshold value 324.

[0086] The authenticity determination device 3 repeats the processes of S207 to S208 until the above determination is made for all inspection areas b (S209; NO), and after determining whether the result is positive or negative for all inspection areas b (S209; YES), it determines the authenticity of the ID card 10 based on the determination results for each inspection area b.

[0087] In this embodiment, if all the inspection areas b are determined to be positive (S210; YES), the ID card 10 is determined to be genuine (S211), and otherwise (S210; NO), the ID card 10 is determined to be not genuine (S212), but this is not limiting. For example, if the number of inspection areas b determined to be positive is equal to or greater than a predetermined number, the ID card 10 can also be determined to be genuine.

[0088] In S20, the authenticity determination process for the ID card 10 can be performed as described above. As described above, the position of each piece of face information, such as name and address, differs depending on the type of ID card 10, and the ink used when printing each piece of face information also differs depending on the type of ID card 10. In this embodiment, by referencing the setting information 320 and cutting out an inspection area b at a different position depending on the type of ID card 10 and performing the determination, a common algorithm corresponding to S208 in Fig. 14 can be applied to each of the different types of ID cards 10.

[0089] As explained above, the configuration of the face of the ID card 10 (the position of face information, etc.) differs depending on the type of ID card 10, but in this embodiment, a common algorithm can be effectively applied based on the type identification information of the ID card 10, and authenticity is determined from images of inspection areas a and b at different positions depending on the type of ID card 10. As a result, in this embodiment, authenticity determination of multiple types of ID cards 10 can be suitably performed without switching algorithms for each type of ID card 10.

[0090] An example of a common algorithm is the flow of S109 to S111 in Fig. 10. In this embodiment, if the ID card 10 is falsified by attaching a piece of paper or the like on which false face information is printed to the ID card 10 or by scratching off the face information from the ID card 10 and then writing back the false face information, a step will be created on the ID card 10 due to the attachment trace or scratching trace, and the step will appear as a light area or a dark area when the ID card 10 is photographed with the light source 22 located on one side of the ID card 10 turned on. This fact can be utilized to determine the authenticity of the ID card 10. In addition, a pair of step detection images are obtained by photographing the ID card 10 with the light sources 22 on both sides of the ID card 10 turned on, and by calculating the difference between these images, only the area where the step has occurred can be extracted as a difference image 140, allowing for optimal authentication.

[0091] Another example of a common algorithm is S208 in FIG. 14. In this embodiment, a genuine ID card 10 is manufactured by printing each area of ​​the card surface using a predetermined printing method. Authenticity can be determined by utilizing the fact that the shading of these areas differs between a comparison image (visible light image) and an infrared image depending on the ink used. For example, a portion printed with ink containing an infrared-absorbing component, such as carbon, appears as a dark area (high density area) in both the comparison image and the infrared image. However, a portion printed with ink that does not absorb infrared appears as a dark area in the comparison image and a light area (low density area) in the infrared image. This makes it possible to effectively detect cases of counterfeiting or alteration using ink with different infrared absorption characteristics from the ink used in the genuine ID card 10.

[0092] In this embodiment, the accuracy of authenticity determination by each algorithm can be improved by setting multiple inspection areas a and b for each of multiple types of ID cards 10. Furthermore, by using the above two algorithms in combination, a wide range of methods for counterfeiting and altering ID cards 10 can be addressed.

[0093] However, the present invention is not limited to the above embodiments. For example, the present invention can also determine the authenticity of the ID card 10 based on the presence or absence of an IC chip. In this case, if the reader 2 cannot read the IC chip in S1, it transmits information indicating that the IC chip could not be read to the authenticity determination device 3 in S3. Upon receiving this information, the authenticity determination device 3 determines that the ID card 10 is a counterfeit.

[0094] The authenticity determination device 3 may also display on the display unit 34 the inspection areas a and b that caused the ID card 10 to be determined to be not authentic, i.e., the inspection area a having the continuous range C where the determination value exceeds the threshold value 313 in S111, or the inspection area b determined to be not authentic in S208. This allows the person in charge to check the area and visually detect any erroneous determination due to dust or the like, or to show the area to the holder of the ID card 10 and explain the determination result. The inspection areas a and b may be displayed together with the card image, or only the inspection areas a and b may be enlarged and displayed.

[0095] Furthermore, the common algorithm is not limited to the above, and may be one that determines whether or not there is a contradiction in the character information obtained by performing OCR on an image of an inspection area on an ID card, such as the date of birth, using the method described in paragraphs

[0043] to

[0045] of JP 2019-209603 A.

[0096] Furthermore, the purpose of authenticity determination is not particularly limited, and the present invention can be applied not only when opening an account at a financial institution, but also when signing a contract for a mobile device, when verifying identity during procedures at various administrative agencies, and when creating documents using the ID card 10, and the cards to which the present invention is applicable are not limited to the ID card 10. The present invention can also be applied to identity verification when making various applications or issuing media using an ID photo machine.

[0097] In this embodiment, the type identification information of the ID card 10 is obtained from the IC chip of the ID card 10, but as described above, the configuration of the face of the ID card 10 differs depending on the type of ID card 10, so the type identification information of the ID card 10 can also be obtained from a photographed image of the ID card 10. Alternatively, the user may input the type identification information of the ID card 10 to the authenticity determination device 3, and the authenticity determination device 3 may acquire the type identification information input by the user. These methods make it possible to apply the present invention to cards without IC chips.

[0098] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to these examples. It is clear that those skilled in the art can conceive of various modifications or alterations within the scope of the technical ideas disclosed herein, and it is understood that these modifications also fall within the technical scope of the present invention. [Explanation of symbols]

[0099] 1: Authenticity determination system 2: Reading device 3: Authenticity determination device 10: ID card 301: Acquisition method 302: Authenticity determination means

Claims

1. An authenticity determination device that determines the authenticity of a card from an image of an inspection area of ​​the card, an acquisition means for acquiring a photographed image of the card and type identification information that can identify the type of the card; an authenticity determination means for obtaining images of an inspection area at different positions depending on the type of card based on the photographed image and the type identification information, and determining the authenticity of the plurality of types of cards from the images of the inspection area using a common algorithm; Equipped with The photographed images of the card are a pair of photographed images taken by lighting up light sources provided on both sides of the card, one on each side, the image of the inspection area is an image in a difference image created by taking a difference in gradation values ​​of the image of the card obtained from each of the pair of captured images, The authenticity determination device is characterized in that the common algorithm determines a judgment value based on the number of bright points in the image of the inspection area and compares the judgment value with a threshold value.

2. An authenticity determination device that determines the authenticity of a card from an image of an inspection area of ​​the card, an acquisition means for acquiring a photographed image of the card and type identification information that can identify the type of the card; an authenticity determination means for obtaining images of an inspection area at different positions depending on the type of card based on the photographed image and the type identification information, and determining the authenticity of the plurality of types of cards from the images of the inspection area using a common algorithm; Equipped with the captured image of the card is a visible light image and an infrared image of the card; The common algorithm is: An authenticity determination device characterized by calculating the number of pixels within the inspection area whose shading in the visible light image and the infrared image meets a predetermined standard as a discrimination value, and determining whether the inspection area is genuine or not based on the results of comparing the discrimination value with a threshold value.

3. 3. The authenticity determination device according to claim 1, wherein a plurality of the inspection areas are set for each of a plurality of types of the card.

4. Computer, An authenticity determination device that determines the authenticity of a card from an image of an inspection area of ​​the card, an acquisition means for acquiring a photographed image of the card and type identification information that can identify the type of the card; an authenticity determination means for obtaining images of an inspection area at different positions depending on the type of card based on the photographed image and the type identification information, and determining the authenticity of the plurality of types of cards from the images of the inspection area using a common algorithm; Equipped with The photographed images of the card are a pair of photographed images taken by lighting up light sources provided on both sides of the card, one on each side, the image of the inspection area is an image in a difference image created by taking a difference in gradation values ​​of the image of the card obtained from each of the pair of captured images, A program for functioning as an authenticity determination device, characterized in that the common algorithm determines a judgment value based on the number of bright points in the image of the inspection area and compares the judgment value with a threshold value.

5. Computer, An authenticity determination device that determines the authenticity of a card from an image of an inspection area of ​​the card, an acquisition means for acquiring a photographed image of the card and type identification information that can identify the type of the card; an authenticity determination means for obtaining images of an inspection area at different positions depending on the type of card based on the photographed image and the type identification information, and determining the authenticity of the plurality of types of cards from the images of the inspection area using a common algorithm; Equipped with the captured image of the card is a visible light image and an infrared image of the card; The common algorithm is: A program for functioning as an authenticity determination device, characterized in that it calculates a discrimination value as the number of pixels within the inspection area whose shading in the visible light image and the infrared image meets a predetermined standard, and determines whether the inspection area is genuine or not based on the comparison result between the discrimination value and a threshold value.

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