Authenticity determination device and program

Abstract

To provide an authenticity determination device capable of suitably determining authenticity of an identity certificate, and the like.SOLUTION: An authenticity determination device 3 determines the authenticity of an ID card 10 including a face photo. The authenticity determination device 3 comprises acquisition means 301 for acquiring an infrared image of the ID card 10, and authenticity determination means 302 for calculating index values different from each other from each of an image of a character portion of the ID card 10 obtained from the infrared image and an image of a face photo of the ID card 10 obtained from the infrared image and determining whether the character portion and the face photo are those of the normal ID card 10 by comparing each index value with a reference value. The authenticity determination means 302 determines the ID card 10 as false when the character portion or the face photo is not that of the normal ID card 10.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] When opening an account at a financial institution, identification is required using an ID card (personal identification) such as a driver's license. However, there has been an increase in cases where ID cards are forged or altered in order to open accounts under the guise of a different person for criminal purposes such as special fraud.

[0003] At ordinary financial institutions, it is common for a user to go to the financial institution and submit an ID card, and the financial institution will verify the user's identity in person using the submitted ID card. Patent documents 1 and 2 describe an authenticity determination device that determines the authenticity of an ID card from an image obtained by reading the face of the ID card with a reader or the like, and it is also possible to determine the authenticity of an ID card by reading a submitted ID card with a reader or the like. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-34535 [Patent Document 2] Japanese Patent Application Publication No. 2019-117549 Summary of the Invention [Problem to be solved by the invention]

[0005] Genuine ID cards are manufactured using a specific printing method and ink, and by utilizing this, it is possible to distinguish between genuine and counterfeit ID cards. In particular, with the trend in recent years toward stricter identity verification, there has been a demand for technology that can reliably distinguish between genuine and counterfeit ID cards.

[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 that can suitably determine the authenticity of an identification card. [Means for solving the problem]

[0007] A first invention for solving the above-mentioned problems is an authenticity determination device for determining the authenticity of an identification card having a facial photograph, comprising: an acquisition means for acquiring an infrared image of the identification card; and an authenticity determination means for calculating different index values ​​from an image of a text portion of the identification card obtained from the infrared image and an image of a facial photograph of the identification card obtained from the infrared image, and for determining whether the text portion and the facial photograph are genuine identification cards by comparing each index value with a reference value; and when it is determined that either the text portion or the facial photograph is not genuine identification cards, the authenticity determination means determines that the identification card is fake. The index value used in determining the character portion is calculated based on the average value of the magnitude of the luminance gradient of the pixels in the image of the character portion. The authenticity determination device is characterized by the above.

[0008] In the present invention, authenticity is determined by utilizing the fact that genuine identification cards are produced by printing using a predetermined printing method, ink, etc., and that these characteristics appear in infrared images. For example, portions printed with infrared-absorbing ink, such as carbon, appear as low-intensity images in infrared images, while other portions appear as high-intensity areas in infrared images. Therefore, if the infrared absorption of the printed portion of a genuine identification card and the identification card being evaluated differs due to differences in printing method, ink, etc., the identification card being evaluated can be determined as fake using the infrared image. Furthermore, in the present invention, authenticity can be reliably determined by performing an evaluation using both the text portion and the facial photograph of the identification card, which often differ in printing method, ink, etc., even within genuine identification cards. Furthermore, by using different index values ​​for both evaluations, index values ​​can be determined that correspond to the differences in the characteristics of the text portion and the facial photograph, improving the accuracy of authenticity determination.

[0009] The authenticity determining means beforeIt is desirable that the index value used in determining the facial photograph is calculated based on the variation in brightness of pixels within the facial photograph image. The text portion and facial photograph can be suitably judged using the respective index values ​​described above. Each index value is based on the characteristics of the text portion and facial photograph, and if the index values ​​used were interchanged and the average value of the brightness gradient described above were used as the index value for the facial photograph, the index value could fluctuate significantly due to factors unrelated to authenticity, such as the person's hair color or clothing color. Furthermore, the number of characters in the text portion, i.e., the area of ​​the characters in the image, such as names and addresses, may differ from person to person, and if the brightness variation described above for the text portion were used as the index value, the index value could fluctuate significantly depending on the number of characters, regardless of authenticity.

[0010] It is desirable that the authenticity determination means, before calculating the index value used in determining the facial photograph, perform a correction in the image of the facial photograph to replace the brightness of pixels that have a brightness greater than a predetermined threshold with a brightness lower than the threshold. This prevents the presence of a hologram or the like in a facial photograph from becoming a high-brightness area in the infrared image and affecting the facial photograph determination result.

[0011] It is desirable that the authenticity determining means sets the index value used in determining the character portion to 0 if the number of pixels whose brightness gradient exceeds a predetermined threshold is equal to or less than a certain number. This prevents the presence of minute stains from creating a large brightness gradient in the infrared image, which can affect the determination results for the character portion.

[0012] A second invention is an authenticity determination device for determining the authenticity of an identification card having a facial photograph, the authenticity determination device comprising: an acquisition means for acquiring an infrared image of the identification card; and an authenticity determination means for calculating different index values ​​from an image of a text portion of the identification card obtained from the infrared image and an image of a facial photograph of the identification card obtained from the infrared image, and for determining whether the text portion and the facial photograph are genuine identification cards by comparing each index value with a reference value. When it is determined that either the text portion or the facial photograph is not genuine identification cards, the authenticity determination means determines that the identification card is fake. The index value used in determining the character portion is calculated based on the average value of the magnitude of the luminance gradient of the pixels in the image of the character portion. The program is for causing the device to function as an authenticity determination device characterized by: A second invention is a program for the authenticity determination device of the first invention. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide an authenticity determination device and the like that can suitably determine the authenticity of an identification card. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram showing an authenticity determination system 1. [Figure 2] FIG. 2 is a diagram showing the hardware configuration of the authenticity determination device 3. [Figure 3] 1 is a diagram showing an ID card 10. FIG. [Figure 4] FIG. 2 is a diagram showing the function of the authenticity determination device 3. [Figure 5] 1 is a flowchart showing an outline of an authenticity determination method. [Figure 6] 10 is a flowchart showing the procedure for determining the authenticity of the text portion of the ID card 10. [Figure 7] FIG. 1 shows a character image 100. [Figure 8] An example of a Sobel filter. [Figure 9] FIG. [Figure 10] FIG. 1 shows a character image 100. [Figure 11]1 is a flowchart showing the procedure for determining the authenticity of a facial photograph 18 on an ID card 10. [Figure 12] FIG. 10 is a diagram showing a histogram in which the horizontal axis represents luminance values ​​and the vertical axis represents the number of pixels. DETAILED DESCRIPTION OF THE INVENTION

[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 wire or wirelessly. In the authenticity determination system 1, an 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 image.

[0017] The reading device 2 photographs the ID card 10 and acquires the image. In particular, in this embodiment, the reading device 2 is equipped with an infrared camera and an infrared illuminator, and captures an infrared image of the ID card 10 by receiving infrared light emitted from the infrared illuminator and reflected from the ID card 10 with the infrared camera.

[0018] 2 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.

[0019] 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.

[0020] 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.

[0021] The communication unit 33 is a communication interface that mediates communication with the reading device 2. The display unit 34 is a liquid crystal display or the like, and displays various information related to the authenticity determination process of this embodiment.

[0022] (2. ID Card 10) In this embodiment, the ID card 10 is an identification card that is the subject of authentication. The identification card is a medium used for administrative procedures and identity verification by various government agencies, financial institutions, mobile phone carriers, etc., and may be, for example, a driver's license. However, the ID card 10 is not limited to this, and may also be a My Number card, a residence card, a special permanent resident card, etc.

[0023] 3(a) is a diagram showing an outline of an ID card 10 (driver's license), and is a schematic illustration of an example of the face of the ID card 10. The ID card 10 is a roughly rectangular card substrate on which the card holder's name 12, date of birth 13, address 14, and photograph 18, as well as the date of issue 15 of the ID card 10, issue number 16, expiration date 17, etc. are printed.

[0024] Name 12, date of birth 13, address 14, date of issue 15, issue number 16, expiration date 17, etc. contain on-demand information that differs for each individual ID card 10. Facial photograph 18 is also on-demand information that differs for each individual ID card 10, and this on-demand information is printed in a predetermined position on the card substrate by a thermal transfer printing method using a thermal head. Text other than the facial photograph 18 is printed by a melt-type thermal transfer method, and the facial photograph 18 is printed by a dye-sublimation thermal transfer method.

[0025] Meanwhile, characters such as "Name," "Address," "Date of Issue," and "Number" that indicate the entry fields for Name 12, Address 14, Date of Issue 15, and Issue Number 16, as well as ruled lines, are used in common on each ID card 10. These characters and ruled lines are formed in advance in predetermined positions on the card substrate using a printing method such as offset printing or letterpress printing before the on-demand information is printed, and are called pre-printed portions.

[0026] Figure 3(b) shows the pre-printed portion extracted from ID card 10, and ID card 10 is manufactured by printing the on-demand information on a card substrate on which a pre-printed portion has been formed in advance, as shown in Figure 3(b). The configuration of the on-demand information and pre-printed portion varies depending on the type of ID card 10, such as a driver's license, My Number card, residence card, or special permanent resident card.

[0027] (3. Functions of the Authentication Device 3) 4 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 by which the control unit 31 of the authenticity determination device 3 receives and acquires an infrared image of the ID card 10 from the reading device 2 via the communication unit 33.

[0029] The authenticity determination means 302 determines the authenticity of the ID card 10 using an infrared image of the ID card 10 acquired by the control unit 31 of the authenticity determination device 3 from the reading device 2. In this embodiment, the infrared image is used to determine whether the text portion and the facial photograph 18 of the ID card 10 are authentic (whether the ID card 10 is genuine) using different indicators, the details of which will be described later.

[0030] (4. Authenticity determination method) Fig. 5 is a flowchart showing an outline of the authenticity determination method executed by the authenticity determination system 1. S1 to S2 in Fig. 5 are processes executed by a control unit (not shown) of the reading device 2 by controlling each unit of the reading device 2, and S3 to S9 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, first, the user sets the ID card 10 in a predetermined position on the reading device 2, and the reading device 2 takes a picture of the ID card 10 with an infrared camera in response to the user's operation (S1).

[0032] The reader 2 photographs the ID card 10 and transmits the infrared image obtained to the authenticity determination device 3 (S2). The authenticity determination device 3 receives the infrared image of the ID card 10 (S3), and then determines the authenticity of the ID card 10 based on the text portion of the ID card 10 using the infrared image (S4). If the text portion is determined to be authentic (S5; Yes), the authenticity is further determined based on the facial photograph 18 on the ID card 10 (S6).

[0033] As a result, if the facial photograph 18 is determined to be authentic (S7; Yes), the ID card 10 is determined to be authentic as the final result of the authenticity determination, which is displayed on the display unit 34, and the process ends (S8). On the other hand, if either the text portion or the facial photograph 18 is determined to be false (S5; No or S7; No), the ID card 10 is determined to be false as the final result of the authenticity determination, which is displayed on the display unit 34, and the process ends (S9). The person in charge can take appropriate action depending on the content displayed on the display unit 34.

[0034] It is possible to judge either the text portion of the ID card 10 or the facial photograph 18 first, but since judging the facial photograph 18 places a greater processing load on the computer, the overall processing load can be reduced by judging the text portion first, as shown in Figure 5, and if the text portion is false, judging the facial photograph 18 is not performed and the process is terminated.

[0035] In this embodiment, a genuine ID card 10 is manufactured by printing using a predetermined printing method and ink, and its characteristics appear in an infrared image, which is used to determine its authenticity. The specific methods for determining authenticity in S4 and S6 differ depending on the characteristics of the text portion and facial photograph 18 of the ID card 10. These methods for determining authenticity are described in detail below.

[0036] (5. Determining the authenticity of the text on ID card 10) FIG. 6 is a flowchart showing the procedure for determining the authenticity of the text portion of the ID card 10 in S4.

[0037] In this embodiment, in S4, first, a text area is extracted from the infrared image received in S3 (S401). The area is set in advance at a predetermined position in the infrared image of the ID card 10 according to the type of ID card 10 (driver's license, My Number card, residence card, special permanent resident card, etc.).

[0038] This area is an area containing on-demand information, such as the area for name 12, the area for date of birth 13, the area for address 14, the area for date of issue 15, the area for number 16, and the area for expiration date 17 in Figure 3(a). Alternatively, it may be an area containing pre-printed portions, such as the characters "name" indicating the entry field for name 12 or the characters "address" indicating the entry field for address 14. In the former case (an area containing on-demand information), the area is made so that the ruled lines that are pre-printed portions are not included.

[0039] Hereinafter, the image obtained by extracting the character portion area in S401 will be referred to as a character image. Fig. 7 shows a portion of character image 100 obtained by extracting the area of ​​name 12 as an example of character image 100. The horizontal direction of character image 100 corresponds to the long side direction of the approximately rectangular ID card 10, and the vertical direction of character image 100 corresponds to the short side direction of ID card 10. In this embodiment, name 12, which is on-demand information, is printed by a melt-type thermal transfer method using ink that absorbs infrared rays, such as carbon, so that if the character image 100 is on a genuine ID card 10, the character portion will appear as an image with lower brightness than the surrounding area.

[0040] The authenticity determination device 3 resizes the character image 100 to reduce it to a predetermined size (S402) and performs grayscale conversion (S403). This speeds up subsequent processing. The specific method of grayscale conversion is not particularly important. The pixel values ​​of the character image 100 after grayscale conversion are values ​​that indicate the magnitude of brightness, with bright pixels having large pixel values ​​and dark pixels having small pixel values. Hereinafter, these pixel values ​​will be referred to as brightness values.

[0041] Next, the authenticity determination device 3 performs noise removal processing on the character image 100 (S404). In this embodiment, the noise removal processing includes smoothing processing and opening.

[0042] The smoothing process is a process for removing high frequency components in the character image 100, and can be performed by performing a convolution operation of various filters (coefficient matrices) on the luminance value of each pixel in the character image 100. The filter, for example, replaces the luminance value of a pixel of interest with the average luminance of pixels in a range of a predetermined size centered on the pixel of interest, but is not limited to this.

[0043] Opening involves performing known erosion and dilation (morphological processing) processes on the character image 100 in this order. For example, the erosion process can replace the luminance value of a pixel of interest in the character image 100 with the minimum luminance of pixels in a range of a predetermined size (e.g., a range of 5 pixels vertically and 5 pixels horizontally) centered on the pixel of interest, with each pixel in the character image 100 being the target pixel. The dilation process can replace the luminance value of a pixel of interest in the character image 100 with the maximum luminance of pixels in a range of a predetermined size centered on the pixel of interest, with each pixel in the character image 100 being the target pixel. By performing the erosion and dilation processes in this order, tiny high-luminance areas (white dots) in the character image 100 are removed.

[0044] Next, the authenticity determination device 3 calculates the luminance gradient of the character image 100 (S405). The luminance gradient is the rate of change in luminance between pixels, and in this embodiment, is calculated using a Sobel filter as shown in FIGS. 8(a) and 8(b), but is not limited to this.

[0045] Fig. 8(a) is an example of a Sobel filter for calculating the vertical brightness gradient of a character image 100. By performing a convolution operation of this filter on the brightness value of each pixel in the character image 100, the brightness change rate between the pixels located above and below each pixel is calculated as the vertical brightness gradient value of each pixel. Fig. 9(a) visualizes the magnitude (absolute value) of the vertical brightness gradient of each pixel using a grayscale image, with areas with a large brightness gradient shown in white.

[0046] On the other hand, Fig. 8(b) is an example of a Sobel filter for calculating the horizontal brightness gradient of the character image 100. By performing a convolution operation of this filter on the brightness value of each pixel in the character image 100, the brightness change rate between the pixels located to the left and right of each pixel is calculated as the value of the horizontal brightness gradient of each pixel. Fig. 9(b) visualizes the magnitude of the horizontal brightness gradient of each pixel in the same way as Fig. 9(a).

[0047] In S405, the magnitude G of the luminance gradient of each pixel is calculated as the combined value of the vertical luminance gradient Gx and the horizontal luminance gradient Gy of each pixel, more specifically, the square root of the sum of the squares of Gx and Gy, as shown in the following equation (1). G=(Gx 2 +Gy 2 ) 1 / 2 …(1)

[0048] The authenticity determination device 3 calculates an index value to be used for the determination from the magnitude G of the brightness gradient of each pixel calculated in S405 (S406). In S406, pixels whose brightness gradient magnitude G is equal to or smaller than a predetermined threshold are excluded, and the average value of the brightness gradient magnitude G of the remaining pixels is calculated and used as the index value.

[0049] The above threshold value can be set appropriately depending on the purpose, such as improving the accuracy of the determination, but there is a risk that the index value will be determined by a small number of pixels with a large brightness gradient, such as a small stain. To avoid this, in this embodiment, if the number of pixels whose brightness gradient magnitude G exceeds the above threshold is equal to or less than a certain number, the index value is set to 0. This certain number is calculated by multiplying the area of ​​the character image 100 (the number of pixels in the character image 100) by a predetermined ratio. This ratio can also be set appropriately depending on the purpose, such as improving the accuracy of the determination.

[0050] The authenticity determination device 3 compares the index value calculated in S406 with a predetermined reference value (S407) to determine whether the character portion extracted in S401 is authentic (whether it is from a legitimate ID card 10).

[0051] For example, if the character portion extracted in S401 is printed on the genuine ID card 10 by a fusion thermal transfer method using ink that absorbs infrared rays, as described above, the character portion will appear as an image with lower brightness than the surrounding area in the character image 100, and the index value calculated in S406 will be large. Therefore, by predetermining an appropriate reference value, the character portion can be determined to be true if the index value in S407 is equal to or greater than the reference value, and can be determined to be false if the index value is less than the reference value.

[0052] How to determine authenticity from the comparison result between the index value and the reference value depends on the printing method, ink, etc. used to print the character portion extracted in S401 on the genuine ID card 10. For example, if the character portion extracted in S401 is printed using a different printing method, ink, etc. from the genuine ID card 10, the character portion may not appear as a low-brightness image in the character image 100, as shown in Fig. 10. In this case, if the index value in S407 is equal to or greater than the reference value, the character portion can be determined to be false, and if it is less than the reference value, the character portion can be determined to be authentic.

[0053] The same applies to the reference value, which can be set to an appropriate value depending on the printing method, ink used, etc., with which the character portion extracted in S401 is printed on the genuine ID card 10.

[0054] If the comparison result between the index value and the reference value is predetermined (for example, "the specified value is equal to or greater than the reference value") (S408; Yes), the authenticity determination device 3 determines the character portion to be true (S409); otherwise (S408; No), it determines the character portion to be false (S410), and ends the processing of S4.

[0055] It is also possible to extract multiple character portions in the above-mentioned S401 and perform the above determination for each character image 100. Whether the character portion of the ID card 10 as a whole is true or not can be finally determined based on the determination result for each character image 100. The method for this determination is not particularly limited, and for example, if at least one character image 100 is determined to be false, the final determination result for the character portion can be determined to be false, or if at least one character image 100 is determined to be true, the final determination result for the character portion can be determined to be true. Alternatively, the final determination result for the character portion can be determined depending on the number of character images 100 determined to be false.

[0056] (6. Determining the authenticity of the face photo 18 on the ID card 10) 11 is a flowchart showing the procedure for determining the authenticity of the facial photograph 18 on the ID card 10 in S6 of Fig. 5. In this embodiment, in S6, first, the area of ​​the facial photograph 18 is extracted from the infrared image received in S3 (S601). This area is also set in advance at a predetermined position in the infrared image of the ID card 10 depending on the type of ID card 10, and is an area that does not include elements other than the facial photograph 18, such as characters or lines.

[0057] The authenticity determination device 3 performs resizing, grayscale conversion, and noise reduction processing on the image of the region of the facial photograph 18 extracted in S601 (hereinafter referred to as the facial image) in the same manner as in S402 to S404 (S602 to S604). In this embodiment, the noise reduction processing in S604 is performed by performing the smoothing processing described above.

[0058] Next, the authenticity determination device 3 performs highlight correction on the facial image (S605). Depending on the type of ID card 10, a hologram may exist in the facial photograph 18 area. In such cases, the hologram may appear bright in the infrared image and affect the determination result. The highlight correction in S605 is performed to remove the influence of holograms and other elements that are not related to the authenticity of the ID card 10.

[0059] In S605, the luminance value of each pixel in the facial image is compared with a predetermined threshold, and pixels having a luminance greater than the threshold are designated as high-luminance pixels. The luminance value of the high-luminance pixel can then be replaced with a luminance value lower than the threshold, more specifically, the average luminance of pixels other than the high-luminance pixels in the facial image. The threshold can be appropriately determined depending on the purpose, such as improving the accuracy of the determination.

[0060] The authenticity determination device 3 calculates an index value to be used for determination from the brightness value of the face image after the preprocessing (S606). In this embodiment, this index value is a value that represents the brightness variation, and as shown in FIG. 12, the variance σ 2is calculated using the following formula (2). The square root σ (standard deviation) is used as the index value. In formula (2), N is the number of pixels in the face image, P1, P2, P3, ..., P N is the brightness value of each pixel in the face image, and μ is the average brightness of all pixels in the face image. σ 2 =(1 / N)·{(P1-μ) 2 +(P2-μ) 2 +(P3-μ) 2 +…+(P N -μ) 2}…(2)

[0061] The authenticity determination device 3 compares the index value calculated in S606 with a reference value (S607) to determine whether the facial photograph 18 is authentic (whether it is from a legitimate ID card 10).

[0062] For example, if the facial photograph 18 is printed on a genuine ID card 10 using a dye-sublimation thermal transfer method with ink that does not contain carbon, the facial image extracted in S601 will be an image with high overall brightness and little brightness variation, as in the example of Fig. 10, and the index value calculated in S606 will be small. Therefore, by setting an appropriate value as the reference value in advance, the facial photograph 18 can be determined to be false if the index value in S607 is equal to or greater than the reference value, and can be determined to be authentic if the index value is less than the reference value.

[0063] As mentioned above, how to determine authenticity based on the comparison result between the index value and the reference value, and the value of the reference value, will differ depending on the printing method, ink used, etc., used to print the facial photograph 18 on the genuine ID card 10, and can be determined according to the printing method.

[0064] If the comparison result between the index value and the reference value is a predetermined one (for example, "the index value is less than the reference value") (S608; Yes), the authenticity determination device 3 determines that the facial photograph 18 is genuine (S609); otherwise (S608; No), the authenticity determination device 3 determines that the facial photograph 18 is false (S610), and ends the processing of S6.

[0065] As described above, in this embodiment, a genuine ID card 10 is manufactured by printing using a predetermined printing method, ink, etc., and its authenticity is determined by utilizing the characteristics that appear in an infrared image. For example, portions printed with ink that absorbs infrared rays, such as carbon, appear as low-intensity images in an infrared image, while other portions appear as high-intensity images in an infrared image. Therefore, if the presence or absence of infrared absorption in the printed portions differs between the genuine ID card 10 and the ID card 10 to be judged due to differences in printing method, ink, etc., the ID card 10 to be judged can be determined to be fake based on the infrared image.

[0066] Furthermore, in this embodiment, authenticity can be reliably determined by using both the text portion of the ID card 10 and the facial photograph 18, which often have different printing methods and inks used even within genuine ID cards 10. Furthermore, by using different index values ​​for both determinations, index values ​​can be set that correspond to the differences in the characteristics of the text portion and the facial photograph 18, improving the accuracy of authenticity determination.

[0067] More specifically, depending on the differences in the characteristics of the text portion and the facial photograph 18, the average value of the brightness gradient described above can be used as the index value when making a judgment based on the text portion, and the brightness variation described above can be used as the index value when making a judgment based on the facial photograph 18. If the index values ​​used were switched and the average value of the brightness gradient described above were used as the index value for the facial photograph 18, the index value could fluctuate significantly due to factors unrelated to authenticity, such as the person's hair color or clothing color. Furthermore, the number of characters in the text portion, such as the name 12 or address 14, i.e., the character area in the text image 100, can vary from person to person, and if the brightness variation described above for the text portion is used as the index value, the index value could fluctuate significantly depending on the number of characters, regardless of authenticity.

[0068] Furthermore, in this embodiment, by performing highlight correction in S605, it is possible to prevent the presence of holograms or the like in the facial photograph 18, which cause high brightness, from affecting the determination results of the facial photograph 18. Furthermore, when calculating the index value used to determine the text portion in S406, if the number of pixels whose brightness gradient magnitude G exceeds a predetermined threshold is equal to or less than a certain number, the index value is set to 0, thereby preventing the presence of minute stains from creating a large brightness gradient in the infrared image and affecting the determination results of the text portion.

[0069] However, the present invention is not limited to the above embodiment. For example, in this embodiment, the average value of the brightness gradient and the brightness variation are used as the index value, but the index value is not particularly limited as long as it is a numerical value that characterizes the degree to which a printed portion that absorbs infrared light appears in an infrared image.

[0070] Furthermore, the highlight correction in S605 may be omitted depending on the type of ID card 10, such as a driver's license, My Number card, residence card, special permanent resident card, etc. The reference values ​​used to determine the text portion and the facial photograph 18 may also be appropriately determined depending on the type of ID card 10.

[0071] Furthermore, the purpose of authenticity determination is not particularly limited, and it can be applied to opening an account at a financial institution, signing a contract for a mobile device, and verifying the identity of a person when carrying out procedures at various government agencies.

[0072] 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]

[0073] 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 for determining the authenticity of an identification card having a facial photograph, an acquisition means for acquiring an infrared image of the identification card; an authenticity determination means for calculating different index values ​​from an image of the character portion of the identification card obtained from the infrared image and an image of the face photograph of the identification card obtained from the infrared image, and for determining whether the character portion and the face photograph are genuine identification cards by comparing each index value with a reference value; and The authenticity determination means determines that the identification card is fake if it is determined that either the text portion or the facial photograph is not that of a genuine identification card, and calculates the index value used to determine the text portion by calculating the average value of the brightness gradient of the pixels in the image of the text portion.

2. The authenticity determining means 2. The authenticity determination device according to claim 1, wherein the index value used in determining the facial photograph is determined based on the variation in brightness of pixels within the facial photograph image.

3. The authenticity determination device according to claim 2, characterized in that, before calculating the index value used in determining the facial photograph, the authenticity determination means performs a correction in which the brightness of pixels in the facial photograph image that are brighter than a predetermined threshold value are replaced with brightness that is lower than the threshold value.

4. The authenticity determination device according to claim 2, characterized in that, when determining the character portion, if the number of pixels whose brightness gradient exceeds a predetermined threshold is equal to or less than a certain number, the authenticity determination means sets the index value used in determining the character portion to 0.

5. Computer, An authenticity determination device for determining the authenticity of an identification card having a facial photograph, an acquisition means for acquiring an infrared image of the identification card; an authenticity determination means for calculating different index values ​​from an image of the character portion of the identification card obtained from the infrared image and an image of the face photograph of the identification card obtained from the infrared image, and for determining whether the character portion and the face photograph are genuine identification cards by comparing each index value with a reference value; and The authenticity determination means determines that the identification card is fake if it is determined that either the text portion or the facial photograph is not that of a genuine identification card, and calculates the index value used to determine the text portion by calculating the average value of the brightness gradient of the pixels in the image of the text portion.

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