ID Card Authentication System and Authentication Program

Abstract

This ID card authentication system comprises an ID card issuing device and an ID card authentication device. A first process of the issuing device acquires a first face image obtained by imaging the face of a person, outputs an authentication image, which includes the first face image and authentication information for authenticating validity, to a printer which issues an ID card by printing the authentication image on a card-like recording medium, and stores, to a memory, a first captured image obtained by imaging the authentication image printed on the ID card by means of a camera. A second processor of the authentication device acquires, as a second captured image, an image obtained by imaging the authentication image printed on the ID card of a subject to be authenticated, and authenticates the validity of the ID card to be authenticated by comparing respective concentration characteristics of the first captured image acquired from the memory and a second captured image acquired from the camera.

Description

Technical Field

[0001] The technology of the present disclosure relates to an ID card authentication system, an authentication method, and an authentication program.

Background Art

[0002] Japanese Patent Application Laid-Open No. 2002-007977 discloses a validity authentication system for authenticating the validity of ID (Identification Data) cards such as employee cards and student cards. The ID card described in Japanese Patent Application Laid-Open No. 2002-007977 has an IC (Integrated Circuit) memory, and an identifier, a face photo, and an authentication image are recorded in the IC memory. The authentication image is obtained by embedding electronic watermark information such as a random number in the face photo. In the database, a combination of an identifier and electronic watermark information is stored. In the authentication process, when the combination of the identifier recorded on the ID card and the electronic watermark information extracted from the authentication image matches the combination of the identifier and the electronic watermark information stored in the database, this ID card is determined to be valid.

Summary of the Invention

Problems to be Solved by the Invention

[0003] Thus, in the validity authentication system described in Japanese Patent Application Laid-Open No. 2002-007977, by collating authentication information such as the identifier and the authentication image recorded on the ID card with the authentication information stored in the database in advance, the information recorded on the ID card is determined to be valid. by In addition, since a face photo is recorded on the ID card, it is possible to perform personal authentication to confirm whether the owner of the ID card is the person himself / herself by visual confirmation or the like.

[0004] As requirements for authentication to enhance the security of ID cards, in addition to identity verification and legitimacy, authenticity is also required. Authenticity indicates that the ID card is not a forged one. In the legitimacy authentication system described in Japanese Patent Application Laid-Open No. 2002-007977, there is no description regarding the authentication of authenticity. However, since the ID card described in Japanese Patent Application Laid-Open No. 2002-007977 has an IC memory, it is possible to authenticate authenticity by storing various information for authenticating authenticity in the IC memory. Moreover, an ID card with an IC memory is difficult to simply duplicate, and it is easy to guarantee authenticity due to the difficulty of duplication.

[0005] However, an ID card with an IC memory not only takes time for the issuance procedure but also simply increases costs. ID cards are not only those used for a long time such as employee ID cards and student ID cards. Among ID cards, there are also ID cards assumed to be used for a short period, such as ID cards used as admission tickets at events such as exhibitions. For such ID cards assumed to be used for a short period, in addition to there being restrictions on the issuance cost, there is also a need to immediately issue them at the venue on the day of the event, and the simplicity and speed of the issuance procedure are required.

[0006] When trying to realize an ID card at low cost and simply and quickly, it is difficult to adopt measures to enhance the functionality of the ID card such as providing an IC memory. As a practical method, for example, a method of creating an ID card by printing a face photo and authentication information used for legitimacy authentication on a card-shaped piece of paper can be considered. However, since such ID cards are easy to forge, on the premise that forgery occurs, it has been an issue to authenticate the authenticity of the ID card with a simple configuration.

[0007] The technology of the present disclosure aims to provide an ID card authentication system, an authentication method, and an authentication program that can issue an ID card capable of performing identity verification and legitimacy verification at low cost and simply and quickly compared with the prior art, and can authenticate the authenticity of the ID card with a simple configuration.

Means for Solving the Problems

[0008] The authentication system for the ID card of the present disclosure is an authentication system including an issuing device for issuing an ID card and an authentication device for authenticating the ID card. The issuing device includes a first processor. The first processor acquires a first face image obtained by imaging a person's face, and outputs an authentication image including the first face image and authentication information for authenticating validity to a printer that issues an ID card by printing the authentication image on a card-shaped recording medium. The first imaging image obtained by imaging the authentication image printed on the ID card by a camera is stored in a memory. The authentication device includes a second processor. The second processor acquires, as a second imaging image, an image obtained by imaging the authentication image printed on the ID card to be authenticated by a camera, and authenticates the authenticity of the ID card to be authenticated by comparing the density characteristics of the first imaging image acquired from the memory and the second imaging image acquired from the camera.

[0009] It is preferable that the second processor authenticates the authenticity of the ID card to be authenticated by utilizing the uncertainty of the color density in which the occurrence state of density unevenness is different for each printing even when the same image is printed on the same type of recording medium.

[0010] It is preferable that the second processor authenticates the authenticity of the ID card to be authenticated by utilizing the fact that the frequency characteristics of the color density of the image are different for each printing even when the same image is printed on the same type of recording medium.

[0011] It is preferable that the second processor authenticates the authenticity of the ID card to be authenticated by comparing the density characteristics in consideration of the change over time of the color density of the authentication image printed on the ID card to be authenticated.

[0012] A collation part used for comparing density characteristics is included in a part of the authentication image. It is preferable that the second processor authenticates the authenticity of the ID card to be authenticated by comparing the density characteristics of the collation parts of the first imaging image and the second imaging image.

[0013] The matching part is preferably a solid pattern composed of a single color without any pattern.

[0014] The printer is preferably a printer using a density modulation method.

[0015] The printer is preferably an instant photo printer that uses, as a recording medium, an instant film that develops color with a photosensitive material containing silver salts.

[0016] The second processor preferably acquires the face of the person who is the owner of the ID card to be authenticated as a second face image, and authenticates that the owner of the ID card to be authenticated is the person himself / herself by comparing the face feature amount extracted from the first face image included in the second captured image with the face feature amount extracted from the second face image.

[0017] The first processor embeds the face feature amount extracted from the first face image into the authentication image, and the second processor preferably authenticates that the person is the owner of the ID card himself / herself by comparing the face feature amount extracted from the authentication image included in the second captured image with the face feature amount extracted from the second face image.

[0018] The authentication information and the face feature amount are preferably embedded in the authentication image as an electronic watermark.

[0019] The first processor and the printer are preferably built into one housing.

[0020] It is preferable that a camera for acquiring the first captured image is built into the housing.

[0021] The first captured image and the second captured image are preferably acquired by cameras with the same imaging performance.

[0022] The second processor preferably corrects the second captured image based on the difference in imaging performance between the camera that acquires the first captured image and the camera that acquires the second captured image, and authenticates the authenticity of the ID card to be authenticated using the corrected second captured image.

[0023] The ID card authentication method using the ID card issuing device and the ID card authentication device of the present disclosure includes a first face image acquisition step of acquiring a first face image obtained by imaging a person's face, and an output step of outputting an authentication image including the first face image and authentication information for authenticating validity to a printer that issues an ID card by printing the authentication image on a card-shaped recording medium. The ID card issuing device is caused to execute a storage step of storing, in a memory, a first captured image obtained by imaging the authentication image printed on the ID card with a camera. By imaging the authentication image printed on the ID card to be authenticated with a camera, the obtained image a second captured image acquisition step of acquiring a second captured image as the second captured image, and an authentication step of authenticating the authenticity of the ID card to be authenticated by comparing the density characteristics of the first captured image acquired from the memory and the second captured image acquired from the camera are executed by the ID card authentication device.

[0024] The ID card authentication program of the present disclosure is an ID card authentication program for operating an ID card authentication system including a first computer that issues an ID card and a second computer that authenticates the ID card. The authentication program functions the first computer as a first face image acquisition unit that acquires a first face image obtained by imaging a person's face, an output unit that outputs an authentication image including the first face image and authentication information for authenticating validity to a printer that issues an ID card by printing the authentication image on a card-shaped recording medium, and a storage unit that stores, in a memory, a first captured image obtained by imaging the authentication image printed on the ID card with a camera. By imaging the authentication image printed on the ID card to be authenticated with a camera, the obtained imageAn ID card authentication program for causing a second computer to function as a second imaging image acquisition unit that acquires a second imaging image, and an authentication unit that authenticates the authenticity of an ID card to be authenticated by comparing the density characteristics of the first imaging image acquired from the memory and the second imaging image acquired from the camera.

Advantages of the Invention

[0025] According to the technology of the present disclosure, it is possible to issue an ID card that can perform personal authentication and authenticity authentication at low cost, simply and quickly, compared with the prior art, and it is possible to authenticate the authenticity of the ID card with a simple configuration. An ID card authentication system, authentication method, and authentication program can be provided.

Brief Description of the Drawings

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Mode for Carrying Out the Invention

[0027] [First Embodiment] As an example, as shown in FIG. 1, the ID card authentication system 2 includes an issuing device 4 that issues an ID card 14 and an authentication device 6 that authenticates the ID card 14. The authentication system 2 is used, for example, in an outdoor or indoor event venue where a plurality of stores 16 are exhibiting. The ID card 14 is issued to the event participants 11, for example, in exchange for the entrance fee to the event venue. It is used to prove that the participant 11 is a legitimate attendee of the event. The ID card 14 is a participant card for identifying the participant 11. As an example, by authenticating the ID card 14 at key points such as each store 16 within the event venue, it becomes possible to exclude unauthorized participants 11 from entering the event venue.

[0028] Also, in this example, the ID card 14 also functions as a prepaid card within the event venue. The participant 11 can use the ID card 14 for payments such as dining and / or shopping at each store 16. The payment information 30 for services etc. used by the participant 11 is managed through the ID card 14. Note that the authentication system 2 is an example of the "authentication system" according to the technology of the present disclosure. The issuing device 4 is an example of the "issuing device" according to the technology of the present disclosure. The authentication device 6 is an example of the "authentication device" according to the technology of the present disclosure. The ID card 14 is an example of the "ID card" according to the technology of the present disclosure.

[0029] As an example, the issuance of the ID card 14 is performed by the participant 11 using their smart device 8 as follows. The issuing device 4 and the authentication device 6 are installed in the management booth 12 provided inside the event venue. The participant 11 who participates in the event first stops by the management booth 12. At the management booth 12, the participant 11 uses the smart device 8 they own to access the website for ID card issuance. The URL (Uniform Resource Locator) for accessing the website is provided to the participant 11, for example, in exchange for purchasing the admission ticket. By operating the smart device 8 according to the instructions described on the website, the participant 11 captures an image of their face, and an ID card issuance request 18 including an image 10 including the face of the participant 11 obtained by the imaging is transmitted from the smart device 8 to the issuing device 4. This image 10 including the face is hereinafter referred to as the original image 10 in order to distinguish it from the face image described later. The issuing device 4 receives the ID card issuance request 18 and performs an ID card issuance process in response to the received ID card issuance request 18.

[0030] In this example, an example is described in which the participant 11 uses the smart device 8 they own to capture their own face and transmit the ID card issuance request 18 from the smart device 8. This is an example of the transmission form of the ID card issuance request 18. In the technology of the present disclosure, instead of the smart device 8 owned by the participant 11, a reception device with a camera arranged in the management booth 12 may capture the face of the participant 11 and transmit the ID card issuance request 18. Further, a reception staff member inside the event venue may use a smart device to capture the face of the participant 11 and the reception staff member may transmit the ID card issuance request 18 from the smart device.

[0031] The issuing device 4 incorporates a printer 20 (see FIG. 2) capable of printing an image on the instant film 15. In the ID card issuance process, the issuing device 4 generates an authentication image 21 based on the original image 10 included in the ID card issuance request 18 and prints the authentication image 21 on the instant film 15 using the printer 20.

[0032] As is well known, the instant film 15 is a self-developing type photographic film that can be developed within several minutes after the image is exposed. As the instant film 15, a well-known monosheet type is used, and it has the basic components of a well-known monosheet type instant film, such as a photosensitive sheet, an image receiving sheet, a developing pod containing a developing processing solution, and a trap portion for absorbing excess developing solution. The photosensitive sheet has a light-sensitive material containing silver salts, and the light-sensitive material develops color when exposed. More specifically, in the instant film 15, a latent image is formed photochemically by exposing the photosensitive sheet. After the latent image is formed, with the photosensitive sheet and the image receiving sheet overlapped, the two sheets are pressed while developing the developing processing solution between them, whereby a positive image is transferred to the image receiving sheet.

[0033] In the instant film 15, for example, characters of "Tokyo XX Festival" indicating the event name are pre-printed in the margin outside the exposure area where the image is exposed, and a mark indicating that the instant film 15 is used in the event is displayed. The printer 20 issues the ID card 14 by printing the authentication image 21 on the instant film 15. Note that the printer 20 is an example of the "printer" according to the technology of the present disclosure. The authentication image 21 is an example of the "authentication image" according to the technology of the present disclosure. The instant film 15 is an example of the "card-shaped recording medium" according to the technology of the present disclosure.

[0034] In this example, since the ID card 14 functions as a prepaid card, the participant 11 can charge an arbitrary amount to the ID card 14. The participant 11 can charge an arbitrary amount to the issued ID card 14, for example, using a charging device (not shown) installed at the management booth 12.

[0035] Participant 11 shops within the event venue using ID card 14. Each time Participant 11 presents ID card 14 to cashier 17 at store 16 within the event venue for checkout, upon the operation of cashier 17, authentication request 22 is sent from the POS (point of sale) terminal 19 of each store 16 to authentication device 6. Authentication device 6 receives authentication request 22 and performs authentication processing in response to the received authentication request 22.

[0036] As will be described in detail later, the authentication processing includes an identity authentication process for authenticating that the owner of the ID card 14 to be authenticated is the person who created ID card 14, a validity authentication process for authenticating that the ID card 14 to be authenticated is a card with a legitimate access right to authentication system 2, and an authenticity authentication process for authenticating that the ID card 14 to be authenticated is not a counterfeit card. When authentication device 6 authenticates the ID card 14 to be authenticated through the authentication process, the payment information 30 of Participant 11 is sent to authentication device 6. Payment information 30 is data including the store name of store 16 and the payment amount. Thereby, the payment amount is deducted from the remaining charge balance 28 charged to the ID card 14 to be authenticated. Note that when authentication device 6 does not authenticate the ID card 14 to be authenticated, payment information 30 is not sent and no deduction is made from the remaining charge balance 28.

[0037] Issuing device 4 and authentication device 6 are connected to database 24. Participant data 26 is stored in database 24. In participant data 26, a sorting number 27 assigned to each participant 11, the original image 10 included in the ID card issuance request 18, the remaining charge balance 28 charged to ID card 14, and the payment information 30 sent from store 16 are stored for each participant 11. Each time payment information 30 is sent from POS terminal 19 to authentication device 6, the sent payment information 30 is accumulated in database 24, and the remaining charge balance 28 of Participant 11 is updated by subtracting the amount corresponding to payment information 30. Note that instead of charging an arbitrary amount to ID card 14 in advance, Participant 11 may pay the total payment amount later according to the payment information 30 accumulated in database 24.

[0038] As an example, as shown in FIG. 2, the issuing device 4 includes a computer 32, a camera 34, and a printer 20. The computer 32, the camera 34, and the printer 20 are built in one housing. The computer 32 includes a CPU (Central Processing Unit) 32A, an NVM (Non-Volatile Memory) 32B, a RAM (Random Access Memory) 32C, and a communication I / F (interface) 32D. The CPU 32A, the NVM 32B, the RAM 32C, the communication I / F 32D, the camera 34, and the printer 20 are connected to each other via a bus 36.

[0039] The CPU 32A controls the entire issuing device 4. The NVM 32B is a non-volatile memory. Here, as an example of the NVM 32B, an EEPROM (electrically erasable programmable read-only memory) is adopted, but it is not limited to this, and it may be a flash memory or the like, or a combination of a plurality of non-volatile memories. The RAM 32C is a volatile memory. The RAM 32C is used as a work memory by the CPU 32A.

[0040] The communication I / F 32D is realized by a device having, for example, an FPGA (field-programmable gate array). The communication I / F 32D is connected to the database 24 and manages the exchange of various information between the CPU 32A and the database 24. Further, the communication I / F 32D is connected to the smart device 8 of the participant 11 via a communication network such as a wireless LAN (Local Area Network) or a wireless WAN (Wide Area Network), and manages the exchange of various information between the CPU 32A and the smart device 8.

[0041] In this example, the printer 20 is an instant photo printer that uses the instant film 15 as a recording medium. The printer 20 includes, for example, an LCD (Liquid Crystal Display) as an exposure device. Inside the printer 20, the exposure device is arranged in a posture where the image display surface for displaying an image faces the photosensitive surface of the instant film 15. The printer 20 exposes the photosensitive material of the instant film 15 by displaying the image to be printed on the exposure device. As described above, the instant film 15 is a film that develops color with a photosensitive material containing silver salts. Also, since the printer 20 uses the instant film 15 as a recording medium, it is naturally a printer that forms an image by changing the color density of the photosensitive material according to the exposure amount, that is, a density modulation type printer.

[0042] Under the control of the CPU 32A, the printer 20 prints the authentication image 21 generated based on the original image 10 included in the ID card issuance request 18 on the instant film 15 (see FIG. 1), and outputs the printed instant film 15 as the ID card 14 (see FIG. 1). The camera 34, which will be described in detail later, acquires the first captured image 46 (see FIG. 5) by imaging the ID card 14 output from the printer 20. Note that the camera 34 is an example of the "camera" according to the technology of the present disclosure. The first captured image 46 is an example of the "first captured image" according to the technology of the present disclosure.

[0043] The NVM 32B stores an ID card issuance program 38. The CPU 32A reads the ID card issuance program 38 from the NVM 32B and executes the read ID card issuance program 38 on the RAM 32C, thereby operating as an authentication image generation unit 40, an ID card output unit 42, and a first frequency characteristic acquisition unit 44. The authentication image generation unit 40, the ID card output unit 42, and the first frequency characteristic acquisition unit 44 cooperate to perform the ID card issuance process. Note that the authentication image generation unit 40, the ID card output unit 42, and the first frequency characteristic acquisition unit 44 are an example of the "first processor" according to the technology of the present disclosure.

[0044] With reference to FIGS. 3 to 10, an example of the ID card issuing process performed by the issuing device 4 will be specifically described below.

[0045] As an example, as shown in FIG. 3, when the authentication image generation unit 40 receives an ID card issuing request 18 including the original image 10 from the smart device 8, it uses a well-known face recognition technology to extract a first face image 45 showing the face of a person from the original image 10. As a method for extracting the first face image 45, for example, contour extraction is performed by applying processing such as edge detection to the original image 10, the face contour is specified by pattern matching from the extracted contours, and the area within the specified face contour is extracted as the face image. In addition, known face recognition technologies such as a method using machine learning can be used. Note that the first face image 45 is an example of the "first face image" according to the technology of the present disclosure.

[0046] The authentication image generation unit 40 acquires the sorting number 27 and the validity authentication information 48. The sorting number 27 is, for example, an identification number of the participant 11 assigned to each participant 11 in the registration order of the participants 11. In the example shown in FIG. 3, four-digit numbers from "0001" to "0101" are assigned to the participants 11. Also, in FIG. 3, the sorting number 27 of "0101" surrounded by a dotted round frame is the sorting number 27 assigned to the participant 11 who sent the latest ID card issuing request 18 in FIG. 3.

[0047] The validity authentication information 48 is, for example, a random number assigned to each participant 11 and functions as a password for accessing the authentication device 6. The validity authentication information 48 is data used in the validity authentication process described later. In the example shown in FIG. 3, for the participant 11 whose sorting number 27 is "0101", a combination of letters and numbers "oi3fzq" is assigned as the validity authentication information 48. The authentication image generation unit 40 associates the acquired sorting number 27 and validity authentication information 48, the original image 10, and the extracted first face image 45, and stores them in the database 24 as participant data 26. Note that the validity authentication information 48 is an example of the "authentication information" according to the technology of the present disclosure.

[0048] The authentication image generation unit 40 extracts a first face feature amount 47 (see FIG. 4) indicating the feature amount of the first face image 45 by performing image analysis on the first face image 45. As the feature amount of the face image used for the first face feature amount 47 and the like, for example, known feature amounts such as Haar-like feature amounts, HOG (Histograms of Oriented Gradients) feature amounts, SIFT (Scale Invariant Feature Transform), and LBP (Local Binary Pattern) feature amounts can be appropriately used. As a feature amount extraction method, for example, a known feature amount extraction technique such as a method using a learned model that is pre-learned to output a feature amount using a face image for learning, takes the face image as an input, and outputs the feature amount can be used. The first face feature amount 47 is data used for the personal authentication process described later. Note that the first face feature amount 47 is an example of the "face feature amount" according to the technology of the present disclosure.

[0049] The authentication image generation unit 40 generates an electronically watermarked image 49 (see FIG. 4) by electronically watermarking the first face feature amount 47 and the authenticity authentication information 48 and embedding them in the original image 10. The authentication image generation unit 40 further generates the authentication image 21 by synthesizing the authenticity verification pattern 50 and the area mark 51 read from the database 24 into the electronically watermarked image 49. Note that the authenticity verification pattern 50 and the area mark 51 may be stored in the NVM 32B as additional information of the ID card issuance program 38 instead of the database 24.

[0050] Specifically, as an example, as shown in FIG. 4, the authentication image generation unit 40 generates an electronic watermark-embedded image 49 in which the first face feature amount 47 and the authenticity authentication information 48 are embedded in the original image 10 in a mode where they are not visually recognizable by performing an operation using a specific algorithm. In the example shown in FIG. 4, the first face feature amount 47 and the authenticity authentication information 48 are embedded in the electronic watermark-embedded image 49 as an electronic watermark 52. The electronic watermark 52 refers to data that is not visually recognizable, but can be detected by performing specific arithmetic processing on the electronic watermark-embedded image 49 using detection software or the like.

[0051] The authentication image generation unit 40 reads out the authenticity verification pattern 50 and the area mark 51 from the database 24. The authenticity verification pattern 50 is, for example, a solid-color plain pattern having a square with a side length of several millimeters (mm). The area mark 51 is a cross-shaped mark of several mm to a dozen or so mm. Although it will be described in detail later, the area mark 51 is a mark for indicating where the electronic watermark 52 and the authenticity verification pattern 50 are recorded in the authentication image 21.

[0052] The authentication image generation unit 40 generates the authentication image 21 by superimposing the authenticity verification pattern 50 on the lower right corner of the watermark-embedded image 49 and superimposing four area marks 51 on the four corners of the watermark-embedded image 49. In this example, since the watermark 52 and the authentication image 21 are approximately the same size, by arranging the area marks 51 at the four corners of the watermark-embedded image 49, the four corners of the watermark 52 can be indicated. The recording position of the watermark 52 is indicated by these four area marks 51. Also, since the authenticity verification pattern 50 is arranged at the lower right corner of the watermark-embedded image 49, the recording position of the authenticity verification pattern 50 is indicated by the area mark 51 at the lower right corner. Further, as will be described later, the authentication image 21 is captured by the camera 34, and the area mark 51 is also used as a mark indicating the cutout area for cutting out the watermark-embedded image 49 from the first captured image 46, which is the authentication image 21 captured by the camera 34. The authentication image generation unit 40 outputs the generated authentication image 21 to the printer 20.

[0053] As an example, as shown in FIG. 5, the ID card output unit 42 controls the printer 20 built in the issuing device 4 to print the authentication image 21 input from the authentication image generation unit 40. The printer 20 prints the authentication image 21 on the instant film 15 under the control of the ID card output unit 42. The printed instant film 15 is discharged from the printer 20.

[0054] Here, in the authentication image 21 printed on the instant film 15, the portion corresponding to the authenticity verification pattern 50 is called the authenticity verification image 57, distinguished from the authenticity verification pattern 50. The authenticity verification image 57 is an image showing a part of the first captured image 46, and is an image obtained by printing the authenticity verification pattern 50 included in the authentication image 21 with the printer 20. That is, the authenticity verification pattern 50 is image data constituting a part of the authentication image 21 when the authentication image 21 exists as image data, and the authenticity verification image 57 is an image constituting a part of the authentication image 21 as a printed image printed on the instant film 15. In the technology of the present disclosure, the authenticity authentication of the ID card 14 is performed by utilizing the fact that the density characteristics of the authenticity verification image 57 change for each print. On the other hand, since the authenticity verification pattern 50 is image data, there is no change in the density characteristics for each print. Thus, there is a difference between the authenticity verification image 57 and the authenticity verification pattern 50 in terms of printed image and image data, and these distinctions are necessary to explain the principle of authenticity authentication. Therefore, they are distinguished and explained here.

[0055] In the issuing device 4, the authentication image 21 of the discharged instant film 15 is disposed within the shooting range of the camera 34. The arrangement of the instant film 15 may be performed automatically or by a person such as a staff member. Examples of automatic arrangement include a method of installing the camera 34 so that the instant film 15 discharged from the printer 20 enters the shooting range, or a method of transporting the discharged instant film 15 to the position of the camera 34 by a transport mechanism.

[0056] The ID card output unit 42 controls the camera 34 to capture the authentication image 21 printed on the instant film 15. Specifically, the ID card output unit 42 operates the camera 34 to capture the instant film 15, and detects the area marks 51 arranged at the four corners of the authentication image 21 from the image obtained by the capture. The ID card output unit 42 cuts out the area surrounded by the area marks 51 from the image obtained by the capture, and acquires the cut-out image as the first captured image 46. As described above, in the authentication image 21, the area surrounded by the four area marks 51 includes the digital watermark 52 and the authenticity verification image 57 corresponding to the authenticity verification pattern 50. Therefore, the first captured image 46 also includes the digital watermark 52 and the authenticity verification image 57 (see also FIG. 6).

[0057] The ID card output unit 42 stores the acquired first captured image 46 and the first capture time 54, which is the time when the instant film 15 is captured by the camera 34, in the database 24 in association with the sorting number 27, the validity authentication information 48, the original image 10, and the first face image 45. After the capture by the camera 34, the instant film 15 on which the authentication image 21 is printed is discharged to the outside as the ID card 14 from the issuing device 4.

[0058] As shown in FIG. 6 as an example, the first frequency characteristic acquisition unit 44 reads out the first captured image 46 from the database 24, and extracts the authenticity verification image 57 located at the lower right corner of the read first captured image 46. The recording position of the authenticity verification image 57 is specified by detecting the area mark 51 at the lower right corner. The authenticity verification image 57 is used for the authenticity authentication processing described later. Note that the authenticity verification image 57 is an example of the "verification unit" according to the technology of the present disclosure.

[0059] The first frequency characteristic acquisition unit 44 acquires the first frequency characteristic 56 from the extracted authenticity verification image 57. The first frequency characteristic 56 is a frequency characteristic indicating the density characteristic in the authenticity verification image 57. When an image is recorded on a recording medium, there is uncertainty in the color density. The uncertainty in the color density means that even when the same image is printed on the same type of recording medium, the occurrence state of density unevenness is different for each print. For example, even when a solid single-color solid pattern is recorded on the same type of recording medium, density unevenness occurs in the printed image. The technology of the present disclosure authenticates the authenticity of the ID card 14 by utilizing such uncertainty in the color density.

[0060] In the instant film 15, one reason for the occurrence of uncertainty in the color density is that the distribution of the developing solution developed on the recording surface in the developing process does not become uniform over the entire recording surface. Another reason is that the distribution of the light-sensitive material, which is the coloring material that develops color, also becomes non-uniform over the entire recording surface. Thus, even in a single instant film 15, non-uniformities such as the developing solution and the light-sensitive material occur on the recording surface.

[0061] Therefore, as shown in FIG. 7, in the instant film 15, even when authenticity verification images 57A, 57B, 57C, and 57D are provided at four locations based on one authenticity verification pattern 50, the four authenticity verification images 57A, 57B, 57C, and 57D show different density characteristics. The graph shown in FIG. 8 is a graph of the first frequency characteristics 56A, 56B, 56C, and 56D indicating the density characteristics of the four authenticity verification images 57A, 57B, 57C, and 57D, respectively. Each of the first frequency characteristics 56A, 56B, 56C, and 56D is derived by performing Fourier analysis on each authenticity verification image 57A, 57B, 57C, and 57D. In FIG. 8, the horizontal axis is the frequency, the vertical axis is the power, and the first frequency characteristics 56A, 56B, 56C, and 56D are frequency spectra indicating the degree of occurrence of density unevenness for each frequency. As a whole, there is a tendency that the density unevenness in the low-frequency region is relatively large and the density unevenness in the high-frequency region is relatively small, but there are slight differences in the four first frequency characteristics 56A, 56B, 56C, and 56D.

[0062] Thus, even in a single instant film 15, there are differences in density characteristics depending on the location. Therefore, if the instant films 15 are different, the density characteristics of the same authenticity verification images 57 printed at the same location will also change. Therefore, for example, even when the same face image is printed on the instant film 15 and the ID card 14 is forged, it is possible to identify whether the ID card 14 is genuine or forged by using the authenticity verification image 57.

[0063] The technology of the present disclosure authenticates the authenticity of the ID card 14 by utilizing the uncertainty of the color density in which the occurrence situation of density unevenness is different for each printing even when the same image is printed on the same type of recording medium in this way. And the occurrence situation of density unevenness appears as the frequency characteristics of the color density of the image. Therefore, the technology of the present disclosure authenticates the authenticity of the ID card 14 by utilizing the fact that the frequency characteristics of the color density of the image are different for each printing even when the same image is printed on the same type of recording medium.

[0064] Also, if the printing method is different, the difference in density characteristics becomes more prominent. FIGS. 9 and 10 are graphs showing the difference in density characteristics due to the difference in the printing method. FIG. 9 shows the frequency characteristics DP-INST of the instant method using the instant film 15 and the frequency characteristics DP-INK of the inkjet method that records an image by ejecting ink onto plain paper. As shown in FIG. 9, when comparing the two, the frequency characteristics DP-INST of the instant method have more density unevenness in the low-frequency region and less density unevenness in the high-frequency region compared to the frequency characteristics DP-INK of the inkjet method. The instant method is a density modulation method, whereas the inkjet method is an area modulation method that changes the gradation depending on the dot density. As shown in FIG. 9, the fact that the inkjet method has relatively more density unevenness in the high-frequency region indicates that the image recorded by the inkjet method has a relatively stronger grainy feeling.

[0065] FIG. 10 is a graph showing the frequency characteristics DP-INST of the instant method and the frequency characteristics DP-THR of the sublimation thermal transfer method. The sublimation thermal transfer method is a method of heating sublimable dye ink applied to an ink ribbon with a thermal head and transferring the melted ink to a dedicated coated paper coated with, for example, a polyester-based resin. Both the instant method and the sublimation thermal transfer method are density modulation methods. However, as shown in FIG. 10, there are also differences in the density characteristics of the two, and the density unevenness in the frequency region surrounded by the broken-line circle is more in the sublimation thermal transfer method than in the instant method.

[0066] The first frequency characteristic acquisition unit 44 acquires the occurrence state of density unevenness of the authenticity verification image 57 as the first frequency characteristic 56, and stores the acquired first frequency characteristic 56 in the database 24 in association with the first captured image 46. The acquired first frequency characteristic 56 shows a unique waveform for each instant film 15. The first frequency characteristic 56 is used for the authenticity verification process described later.

[0067] As shown in FIG. 11 as an example, the authentication device 6 includes a computer 60, a reception device 70, and a display 72. The computer 60 includes a CPU 60A, an NVM 60B, a RAM 60C, and a communication I / F 60D. The CPU 60A, the NVM 60B, the RAM 60C, the communication I / F 60D, the reception device 70, and the display 72 are connected to each other via a bus 74.

[0068] The CPU 60A controls the entire authentication device 6. The NVM 60B is a non-volatile memory. Here, as an example of the NVM 60 B, an EEPROM is adopted, but it is not limited to this, and it may be a flash memory or the like, or a combination of a plurality of non-volatile memories. The RAM 60C is a volatile memory. The RAM 60C is used as a work memory by the CPU 60A.

[0069] The communication I / F 60D is realized by a device having, for example, an FPGA. The communication I / F 60D is connected to the database 24 by wire and is in charge of the exchange of various information between the CPU 60A and the database 24. Also, the communication I / F 60D is connected to a plurality of POS terminals 19 via a LAN cable or the like and is in charge of the exchange of various information between the CPU 60A and the POS terminals 19.

[0070] The reception device 70 includes a keyboard and a mouse. The keyboard and the mouse receive an instruction for the authentication device 6 according to an operation by an attendant. The display 72 is used to display various information under the control of the CPU 60A.

[0071] The authentication program 62 is stored in the NVM 60B. The CPU 60A reads the authentication program 62 from the NVM 60B and executes the read authentication program 62 on the RAM 60C, thereby operating as the personal authentication unit 64, the validity authentication unit 66, and the authenticity authentication unit 68. The personal authentication unit 64, the validity authentication unit 66, and the authenticity authentication unit 68 cooperate to perform authentication processing. The authentication processing is a process executed when the authentication device 6 receives an authentication request 76 from at least one of the plurality of POS terminals 19. Note that the personal authentication unit 64, the validity authentication unit 66, and the authenticity authentication unit 68 are an example of the "second processor" according to the technology of the present disclosure.

[0072] With reference to FIGS. 12 to 17, an example of the authentication processing performed by the authentication device 6 will be specifically described below.

[0073] As shown in FIG. 12 as an example, the POS terminal 19 includes a computer 78, a reception device 86, a video camera 80, a display 82, and a printer 84. The computer 78 includes a CPU 78A, an NVM 78B, a RAM 78C, and a communication I / F 78D. The CPU 78A, the NVM 78B, the RAM 78C, the communication I / F 78D, the reception device 86, the video camera 80, the display 82, and the printer 84 are connected to each other via a bus 85.

[0074] The CPU 78A controls the entire POS terminal 19. The NVM 78B is a non-volatile memory. Here, as an example of the NVM 78B, an EEPROM is adopted, but it is not limited to this, and it may be a flash memory or the like, or a combination of a plurality of non-volatile memories. In the NVM 78B, in addition to various programs, the sales data processed by the POS terminal 19 is stored. The RAM 78C is a volatile memory. The RAM 78C is used as a work memory by the CPU 78A. The communication I / F 78D controls the exchange of various information between the CPU 78A and the authentication device 6.

[0075] The reception device 86 includes a camera 86A, a barcode reader 86B, and an input key 86C. The camera 86A has the same imaging performance as the camera 34 built in the issuing device 4, that is, lens performance, filter performance, and imaging element performance. The camera 86A images the authentication image 21 included in the ID card 14 to be authenticated. The barcode reader 86B reads the barcode pre-attached to each product. The barcode contains information regarding the product name and price of each product. The input key 86C includes a numeric keypad and is a key that enables manual input of information regarding each product into the POS terminal 19. Note that the camera 86A is an example of the "camera" according to the technology of the present disclosure.

[0076] The display 82 is used to present the shopping amount to the participant 11 under the control of the CPU 78A. The printer 84 prints a receipt indicating the details of the shopping.

[0077] When the participant 11 shops at the store 16, for example, the cashier 17 of the store 16 causes the barcode reader 86B to read the barcode attached to the product purchased by the participant 11. The CPU 78A calculates the shopping amount based on the product information included in the barcode read by the barcode reader 86B.

[0078] Participant 11 presents the ID card 14 he / she holds, i.e., the ID card 14 to be authenticated, to the cashier 17 during checkout at store 16. When the cashier 17 brings the presented ID card 14 close to the camera 86A, the camera 86A captures the authentication image 21 included in the ID card 14 to be authenticated under the control of the CPU 78A. The CPU 78A detects the area marks 51 arranged at the four corners of the authentication image 21 from the image obtained by the imaging of the camera 86A, cuts out the area surrounded by the area marks 51, and acquires it as the second captured image 88. Also, the video camera 80 acquires a video 90 including frame images for dozens of frames by imaging Participant 11 in front of the POS terminal 19 for 1 to several seconds under the control of the CPU 78A. The POS terminal 19 transmits an authentication request 76 including the second captured image 88, the video 90, and the second imaging time 89 indicating the time when the camera 86A captured the authentication image 21 included in the ID card 14 to the authentication device 6. Note that the second captured image 88 is an example of the "second captured image" according to the technology of the present disclosure.

[0079] As shown in FIG. 13 as an example, when the personal authentication unit 64 receives the authentication request 76 from the POS terminal 19, it performs a personal authentication process. Specifically, the personal authentication unit 64 acquires the second captured image 88 included in the authentication request 76. The personal authentication unit 64 performs a specific arithmetic process on the acquired second captured image 88 to extract the first face feature amount 47 embedded as an electronic watermark 52 in the authentication image 21 from the second captured image 88.

[0080] The personal authentication unit 64 extracts a second face image 92 showing the face of a person from the frame images included in the video 90. As the method for extracting the second face image 92, a known face recognition technology similar to the method for extracting the first face image 45 described above can be used. The personal authentication unit 64 extracts, as the second face image 92, the face of the person extracted first, for example, from the faces of the persons extracted from the plurality of frame images included in the video 90. The personal authentication unit 64 extracts a second face feature amount 94 from the extracted second face image 92. The second face feature amount 94 is the same as the first face feature amount 47, and can be extracted using a known feature amount extraction technology similar to the first face feature amount 47.

[0081] The personal authentication unit 64 compares the first face feature amount 47 extracted from the second captured image 88 with the second face feature amount 94 extracted from the second face image 92 included in the moving image 90. When the difference between the first face feature amount 47 and the second face feature amount 94 is within a predetermined range, the personal authentication unit 64 determines that the person shown in the authentication image 21 of the ID card 14 to be authenticated and the person in front of the POS terminal 19 are the same person. In this case, the personal authentication unit 64 outputs a signal indicating that the personal authentication has been completed (hereinafter referred to as the "personal authentication completed signal") to the validity authentication unit 66. Note that the second face image 92 is an example of the "second face image" according to the technology of the present disclosure. The first face feature amount 47 is an example of the "face feature amount extracted from the first face image" according to the technology of the present disclosure, and the second face feature amount 94 is an example of the "face feature amount extracted from the second face image" according to the technology of the present disclosure.

[0082] As an example, as shown in FIG. 14, when the validity authentication unit 66 receives the personal authentication completed signal from the personal authentication unit 64, the validity authentication unit 66 performs a validity authentication process. Specifically, the validity authentication unit 66 extracts the validity authentication information 48 embedded as the digital watermark 52 in the authentication image 21 from the second captured image 88 by performing a specific arithmetic process on the second captured image 88. The validity authentication unit 66 searches the participant data 26 stored in the database 24 to determine whether there is validity authentication information 48 that matches the validity authentication information 48 extracted from the second captured image 88. When there is validity authentication information 48 that matches the validity authentication information 48 extracted from the second captured image 88 in the participant data 26, the validity authentication unit 66 determines that the ID card 14 is a card having a legitimate access right to the authentication system 2. In this case, the validity authentication unit 66 outputs a signal indicating that the validity authentication has been completed (hereinafter referred to as the "validity authentication completed signal") to the authenticity authentication unit 68.

[0083] As an example, as shown in FIG. 15, when the authenticity verification unit 68 receives an authenticity-verified signal from the validity verification unit 66, it performs authenticity verification processing. The authenticity verification processing includes a first process of verifying authenticity using the uncertainty of the color density of the authenticity verification image 57, and a second process of verifying authenticity using the change over time of the color density of the authenticity verification image 57. First, in the first process, the authenticity verification unit 68 acquires the second captured image 88 included in the authentication request 76. The authenticity verification unit 68 extracts the authenticity verification image 57 from the acquired second captured image 88 using, for example, pattern matching. The authenticity verification unit 68 optically scans the extracted authenticity verification image 57 to acquire the color density characteristics in the authenticity verification image 57, that is, the second frequency characteristics 96 indicating density unevenness.

[0084] The authenticity verification unit 68 reads out the first frequency characteristics 56 stored in the participant data 26 in association with the validity verification information 48 searched by the validity verification unit 66 in the validity verification process shown in FIG. 14 from the database 24. That is, in the example shown in FIG. 15, the authenticity verification unit 68 reads out the first frequency characteristics 56 "A0101" stored in the participant data 26 in association with the validity verification information 48 "oi3fzq" searched by the validity verification unit 66 from the database 24. The authenticity verification unit 68 compares the first frequency characteristics 56 read out from the database 24 with the second frequency characteristics 96 of the authenticity verification image 57 extracted from the second captured image 88. When the difference between the first frequency characteristics 56 and the second frequency characteristics 96 is within a predetermined range, the authenticity verification unit 68 executes the second process.

[0085] In the second process, the authenticity verification unit 68 performs authenticity verification by comparing the color density characteristics, taking into account the change over time in the color density of the authenticity verification image 57. As shown in FIG. 16 as an example, it is known that the color density of an image printed on the instant film 15 changes over time. The characteristics of the change over time in color density differ for each printed color. The graph shown in FIG. 16 shows, for example, the change over time in color density from the first imaging time 54 of the authenticity verification image 57. In FIG. 16, 0 minutes indicates the time when the authentication image 21 was printed on the instant film 15 by the printer 20, and the first imaging time 54 indicates the time when the authentication image 21 printed on the instant film 15 was imaged by the camera 34. The first imaging time 54 is a time when several seconds to several tens of seconds have elapsed since the time when the authentication image 21 was printed on the instant film 15.

[0086] In FIG. 16, the vertical axis represents the luminance value. The higher the luminance value, the lower the density, and the lower the luminance value, the higher the density. As shown in FIG. 16, in the instant film 15, since the color development progresses rapidly in a short time (about 3 minutes) immediately after printing, the density increase (drop in luminance value) during this period is rapid. The subsequent density increase is gradual. Since the change over time in the color density of the instant film 15 shows a tendency as shown in FIG. 16, it is possible to predict the color density of the instant film 15 at that point from the elapsed time after printing.

[0087] The database 24 stores in advance a density change table 98 showing the change over time in the color density of the authenticity verification image 57. Here, the change over time in color density is a value derived, for example, by tests using actual machines and / or computer simulations. Instead of the density change table 98, an arithmetic expression with the elapsed time from the first imaging time 54 as the independent variable and the color density as the dependent variable may be used.

[0088] As an example, as shown in FIG. 17, in the second process, the authenticity verification unit 68 reads out the first imaging time 54 stored in the participant data 26 in association with the authenticity verification information 48 searched by the authenticity verification unit 66 in the authenticity verification process shown in FIG. 14 from the database 24. The authenticity verification unit 68 calculates the elapsed time from the first imaging time 54 to the second imaging time 89 by taking the difference between the second imaging time 89 included in the authentication request 76 and the first imaging time 54. The authenticity verification unit 68 uses the density change table 98 to derive a predicted color density 99, which is a predicted value of the color density of the authenticity verification image 57, based on the elapsed time.

[0089] The authenticity verification unit 68 measures the color density 100 of the authenticity verification image 57 extracted from the second captured image 88. The color density 100 is the luminance value of the authenticity verification image 57.

[0090] The authenticity verification unit 68 compares the color density 100 of the authenticity verification image 57 obtained by measurement with the predicted color density 99 derived using the density change table 98. If the difference between the predicted color density 99 and the color density 100 is within a predetermined range, the authenticity verification unit 68 determines that the ID card 14 is not forged. In this case, the authenticity verification unit 68 transmits an authentication signal indicating that the ID card 14 has been authenticated to the POS terminal 19.

[0091] Next, the operation of the authentication system 2 according to the present embodiment will be described with reference to FIGS. 18 to 20. Note that the ID card issuance process shown in FIG. 18 is realized by the CPU 32A of the issuing device 4 executing the ID card issuance program 38. The authentication processes shown in FIGS. 19 to 20 are realized by the CPU 60A of the authentication device 6 executing the authentication program 62.

[0092] The ID card issuance process shown in FIG. 18 starts when the authentication image generation unit 40 receives an ID card issuance request 18 from the smart device 8. In the ID card issuance process, first, the authentication image generation unit 40 extracts a first face image 45 from the original image 10 included in the received ID card issuance request 18. In step ST101, the authentication image generation unit 40 determines whether the first face image 45 has been extracted from the original image 10. In step ST101, if the first face image 45 has been extracted, the determination is affirmative, and the ID card issuance process proceeds to step ST102. If the first face image 45 has not been extracted, the determination is negative, and the ID card issuance process ends.

[0093] In step ST102, the authentication image generation unit 40 acquires a new sorting number 27 and authenticity verification information 48 corresponding to the received ID card issuance request 18. After that, the ID card issuance process proceeds to step ST103.

[0094] In step ST103, the authentication image generation unit 40 associates the acquired sorting number 27 and authenticity verification information 48, the original image 10, and the first face image 45 and stores them in the database 24. After that, the ID card issuance process proceeds to step ST104.

[0095] In step ST104, the authentication image generation unit 40 extracts a first face feature amount 47 from the first face image 45. After that, the ID card issuance process proceeds to step ST105.

[0096] In step ST105, the authentication image generation unit 40 generates an embedded watermark image 49 by electronically watermarking the extracted first face feature amount 47 and the acquired authenticity verification information 48 and embedding them in the original image 10. After that, the ID card issuance process proceeds to step ST106.

[0097] In step ST106, the authentication image generation unit 40 reads the authenticity verification pattern 50 and the area mark 51 from the database 24. After that, the ID card issuance process proceeds to step ST107.

[0098] In step ST107, the authentication image generation unit 40 generates an authentication image 21 by synthesizing the read authenticity verification pattern 50 and area mark 51 into the generated embedded watermark image 49. The authentication image generation unit 40 outputs the generated authentication image 21 to the printer 20. After this, the ID card issuance process proceeds to step ST108.

[0099] In step ST108, the ID card output unit 42 controls the printer 20 to print the authentication image 21 input from the authentication image generation unit 40. Thereby, the printer 20 prints the authentication image 21 on the instant film 15. After this, the ID card issuance process proceeds to step ST109.

[0100] In step ST109, the ID card output unit 42 controls the camera 34 to image the instant film 15 on which the authentication image 21 is printed. Thereby, the camera 34 images the authentication image 21 printed on the instant film 15, and the ID card output unit 42 acquires the image imaged by the camera 34 as the first captured image 46. After imaging by the camera 34, the instant film 15 on which the authentication image 21 is printed is discharged outside the issuing device 4 as the ID card 14. After this, the ID card issuance process proceeds to step ST110.

[0101] In step ST110, the ID card output unit 42 stores the acquired first captured image 46 and the first capture time 54 indicating the time when the first captured image 46 was captured in the database 24 in association with the collation number 27, authenticity verification information 48, original image 10, and first face image 45. After this, the ID card issuance process proceeds to step ST111.

[0102] In step ST111, the first frequency characteristic acquisition unit 44 extracts the authenticity verification image 57 located at the lower right corner of the first captured image 46 from the first captured image 46. After this, the ID card issuance process proceeds to step ST112.

[0103] In step ST112, the first frequency characteristic acquisition unit 44 acquires a first frequency characteristic 56 indicating density unevenness in the authenticity verification image 57 from the extracted authenticity verification image 57. After this, the ID card issuance process proceeds to step ST113.

[0104] In step ST113, the first frequency characteristic acquisition unit 44 stores the acquired first frequency characteristic 56 in the database 24 in association with the first captured image 46. After this, the ID card issuance process ends.

[0105] The authentication process shown in FIGS. 19 to 20 is started when the personal authentication unit 64 receives an authentication request 76 from the POS terminal 19. The authentication process includes the personal authentication process shown in steps ST201 to ST205, the validity authentication process shown in steps ST206 to ST207, and the authenticity authentication process shown in steps ST208 to ST216. Further, the authenticity authentication process is roughly classified into a first process shown in steps ST208 to ST211 and a second process shown in steps ST212 to ST216.

[0106] In the personal authentication process, first, the personal authentication unit 64 extracts a first face feature amount 47 embedded as an electronic watermark 52 from the second captured image 88 included in the received authentication request 76. In step ST201, the personal authentication unit 64 determines whether or not the first face feature amount 47 has been extracted from the electronic watermark 52 included in the second captured image 88. In step ST201, if the first face feature amount 47 has been extracted, the determination is affirmative and the personal authentication process proceeds to step ST202. If the first face feature amount 47 has not been extracted, the determination is negative and the authentication process proceeds to step ST218.

[0107] The personal authentication unit 64 extracts the second face image 92 from the video 90 included in the authentication request 76. In step ST202, the personal authentication unit 64 determines whether the second face image 92 has been extracted from the video 90. In step ST202, if the second face image 92 has been extracted, the determination is affirmative and the personal authentication process proceeds to step ST204. If the second face image 92 has not been extracted, the determination is negative and the personal authentication process proceeds to step ST203.

[0108] If the second face image 92 has not been extracted from the video 90, in step ST203, the personal authentication unit 64 operates the video camera 80 on the CPU 78A of the POS terminal 19 and causes the video 90 obtained by imaging with the video camera 80 to be resent. After that, the personal authentication process proceeds to step ST202.

[0109] If the second face image 92 has been extracted from the video 90, in step ST204, the personal authentication unit 64 extracts the second face feature amount 94 from the second face image 92. After that, the personal authentication process proceeds to step ST205.

[0110] In step ST205, the personal authentication unit 64 determines whether the difference between the extracted first face feature amount 47 and the second face feature amount 94 is within a predetermined range. In step ST205, if the difference between the first face feature amount 47 and the second face feature amount 94 is within the predetermined range, the determination is affirmative and the personal authentication process proceeds to the validity authentication process shown in steps ST206 to ST207. If the difference between the first face feature amount 47 and the second face feature amount 94 is not within the predetermined range, the determination is negative and the authentication process proceeds to step ST218.

[0111] In the authenticity verification process, first, the authenticity verification unit 66 extracts the authenticity verification information 48 from the digital watermark 52 included in the second captured image 88. In step ST206, the authenticity verification unit 66 determines whether the authenticity verification information 48 has been extracted from the digital watermark 52 included in the second captured image 88. In step ST206, if the authenticity verification information 48 has been extracted, the determination is affirmative, and the authenticity verification process proceeds to step ST207. If the authenticity verification information 48 has not been extracted, the determination is negative, and the authentication process proceeds to step ST218.

[0112] The authenticity verification unit 66 searches for the extracted authenticity verification information 48 within the participant data 26 of the database 24. In step ST207, the authenticity verification unit 66 determines whether the extracted authenticity verification information 48 exists in the participant data 26 of the database 24. In step ST207, if the authenticity verification information 48 exists in the participant data 26, the determination is affirmative, and the authenticity verification process proceeds to the authenticity verification process shown in steps ST208 to ST216. If the authenticity verification information 48 does not exist in the participant data 26, the determination is negative, and the authentication process proceeds to step ST218.

[0113] In the first process of the authenticity verification process, first, in step ST208, the authenticity verification unit 68 acquires the first frequency characteristic 56 stored in the participant data 26 in association with the authenticity verification information 48 extracted in the authenticity verification process. Thereafter, the authenticity verification process proceeds to step ST209.

[0114] The authenticity verification unit 68 extracts the authenticity comparison image 57 from the second captured image 88. In step ST209, the authenticity verification unit 68 determines whether the authenticity comparison image 57 has been extracted from the second captured image 88. In step ST209, if the authenticity comparison image 57 has been extracted, the determination is affirmative, and the authenticity verification process proceeds to step ST210. If the authenticity comparison image 57 has not been extracted, the determination is negative, and the authentication process proceeds to step ST218.

[0115] In step ST210, the authenticity verification unit 68 extracts the second frequency characteristic 96 from the authenticity verification image 57. After that, the authenticity verification process proceeds to step ST211.

[0116] In step ST211, the authenticity verification unit 68 determines whether the difference between the first frequency characteristic 56 and the second frequency characteristic 96 is within a predetermined range. In step ST211, if the difference between the first frequency characteristic 56 and the second frequency characteristic 96 is within the predetermined range, the determination is affirmative, and the authenticity verification process proceeds to the second process shown in steps ST212 to ST216. If the difference between the first frequency characteristic 56 and the second frequency characteristic 96 is not within the predetermined range, the determination is negative, and the authentication process proceeds to step ST218.

[0117] In the second process of the authenticity verification process, first, in step ST212, the authenticity verification unit 68 acquires the first imaging time 54 stored in the participant data 26 of the database 24 in association with the authenticity verification information 48 extracted in the validity verification process. After that, the authenticity verification process proceeds to step ST213.

[0118] In step ST213, the authenticity verification unit 68 derives the elapsed time from the first imaging time 54 to the second imaging time 89 by obtaining the difference between the first imaging time 54 acquired from the database 24 and the second imaging time 89 included in the authentication request 76. After that, the authenticity verification process proceeds to step ST214.

[0119] In step ST214, the authenticity verification unit 68 derives the predicted color density 99 based on the derived elapsed time and the density change table 98 stored in the database 24. After that, the authenticity verification process proceeds to step ST215.

[0120] In step ST215, the authenticity verification unit 68 measures the color density 100 of the authenticity verification image 57 extracted from the second captured image 88. After that, the authenticity verification process proceeds to step ST216.

[0121] In step ST216, the authenticity verification unit 68 determines whether the difference between the measured color density 100 and the derived predicted color density 99 is within a predetermined range. In step ST216, if the difference between the color density 100 and the predicted color density 99 is within the predetermined range, the determination is affirmed, and the authentication process proceeds to step ST217. If the difference between the color density 100 and the predicted color density 99 is not within the predetermined range, the determination is negated, and the authentication process proceeds to step ST218.

[0122] In step ST217, the CPU 60A of the authentication device 6 transmits an authentication signal indicating that the ID card 14 to be authenticated has been authenticated by the personal authentication process, the validity authentication process, and the authenticity verification process from the authentication device 6 to the POS terminal 19 which is the source of the authentication request 76. After this, the authentication process ends.

[0123] In step ST218, the CPU 60A of the authentication device 6 transmits an unauthenticated signal indicating that the ID card 14 to be authenticated has not been authenticated by any of the personal authentication process, the validity authentication process, and the authenticity verification process from the authentication device 6 to the POS terminal 19 which is the source of the authentication request 76. After this, the authentication process ends.

[0124] As described above, according to this embodiment, the authentication system 2 includes the issuing device 4 that issues the ID card 14, and the authentication device 6 that authenticates the ID card 14. The authentication image generating unit 40 of the issuing device 4 acquires the first face image 45 from the original image 10 that captures the face of the participant 11. The authentication image generating unit 40 generates the authentication image 21 including the first face image 45 and the validity authentication information 48, and outputs the generated authentication image 21 to the printer 20 built in the issuing device 4. The ID card output unit 42 of the issuing device 4 causes the printer 20 to print the authentication image 21 output from the authentication image generating unit 40 on the instant film 15. The ID card output unit 42 acquires the first captured image 46 by causing the camera 34 to capture the authentication image 21 printed on the instant film 15, and stores the acquired first captured image 46 in the database 24. Thereafter, the ID card output unit 42 outputs the instant film 15 on which the authentication image 21 is printed to the outside as the ID card 14.

[0125] Therefore, according to this configuration, the ID card 14 can be created by printing the authentication image 21 on the instant film 15. The authenticity verifying unit 68 of the authentication device 6 obtains an image obtained by capturing the authentication image 21 printed on the ID card 14 to be authenticated by the camera 86A as the second captured image 88. The authenticity verifying unit 68 verifies the authenticity of the ID card 14 to be authenticated by comparing the density characteristics of the first captured image 46 obtained from the database 24 with the second captured image 88. In the field of image processing, the comparison of density characteristics of images is a relatively general technique. Therefore, according to this configuration, it is possible to provide an authentication system 2 capable of issuing an ID card 14 that can perform identity authentication and authenticity authentication easily and quickly at low cost and with a simple configuration, as compared with a case in which an IC memory is provided in the ID card to realize identity authentication, authenticity authentication, and authenticity authentication.

[0126] Also, according to the present embodiment, the authenticity authentication unit 68 authenticates the authenticity of the ID card 14 by utilizing the uncertainty of the color density in which the occurrence state of density unevenness is different for each printing even when the same image is printed on the same type of instant film 15. Therefore, according to this configuration, it is possible to authenticate the authenticity of the ID card 14 with a simple configuration and at low cost by using a relatively general-purpose technique in the field of image processing for comparing the differences in density unevenness between images.

[0127] Also, according to the present embodiment, the authenticity authentication unit 68 authenticates the authenticity of the ID card 14 to be authenticated by utilizing the fact that the frequency characteristics of the color density of the image are different for each printing even when the same image is printed on the same type of instant film 15. Therefore, according to this configuration, it is possible to authenticate the authenticity of the ID card 14 with a simple configuration and at low cost by using a relatively general-purpose technique in the field of image processing for comparing the differences in the frequency characteristics of the color density between images.

[0128] Also, according to the present embodiment, the authenticity authentication unit 68 authenticates the authenticity of the ID card 14 by comparing the density characteristics in consideration of the change over time of the color density 100 of the authentication image 21 printed on the ID card 14 to be authenticated. Therefore, according to this configuration, even when the color density 100 in the ID card 14 to be authenticated changes over time, it is possible to perform more accurate authenticity authentication compared to the case where the change over time is not considered.

[0129] Also, according to the present embodiment, a part of the authentication image 21 includes an authenticity verification pattern 50 used for comparing density characteristics. The authenticity authentication unit 68 authenticates the authenticity of the ID card 14 by comparing the density characteristics between the authenticity verification image 57 showing the authenticity verification pattern 50 in the first captured image 46 and the authenticity verification image 57 showing the authenticity verification pattern 50 in the second captured image 88. Therefore, according to this configuration, compared to the case of comparing the overall density characteristics between the first captured image 46 and the second captured image 88, only the authenticity verification image 57 is compared, so that the processing load on the authentication device 6 required for authenticity authentication can be reduced.

[0130] According to the present embodiment, the authenticity verification pattern 50 is a solid pattern made up of a single solid color. Therefore, according to this configuration, it is easier to compare the density characteristics in the authenticity verification image 57 between the first captured image 46 and the second captured image 88, compared to the case where a verification pattern including multiple colors is used.

[0131] According to the present embodiment, the printer 20 is a density modulation printer. Images printed using a density modulation printer have different frequency characteristics and color reproducibility from images printed using an area modulation printer, such as an inkjet printer. Therefore, according to this configuration, by utilizing the difference in frequency characteristics and color reproducibility with respect to an area modulation printer, it is possible to provide an authentication system 2 that can easily detect counterfeiting when an ID card 14 is counterfeited using an area modulation printer.

[0132] Furthermore, according to this embodiment, the printer 20 is an instant photo printer that uses, as a recording medium, an instant film 15 that develops color due to a photosensitive material containing silver salt. Therefore, according to this configuration, by using an instant photo printer as the printer 20, it becomes possible to instantly issue an ID card 14. Also, the instant film 15 has non-uniformity in the photosensitive material and non-uniformity in the developing solution on the recording surface. Therefore, by recording the same image in the same place on each of a plurality of instant films 15, also becomes darker By utilizing these characteristics of the instant film 15, even if the ID card 14 is counterfeited using the same type of instant film 15 as the genuine ID card 14, the authenticity of the ID card 14 can be authenticated by comparing the density characteristics.

[0133] Furthermore, according to this embodiment, the identity authentication unit 64 acquires the face of the owner of the ID card 14 to be authenticated as the second face image 92. The identity authentication unit 64 certifies that the owner of the ID card 14 to be authenticated is the creator of the ID card 14 by comparing the first face feature amount 47 extracted from the first face image 45 included in the second captured image 88 with the second face feature amount 94 extracted from the second face image 92. Therefore, according to this configuration, compared to a case where the first face image 45 included in the ID card 14 to be authenticated is compared with the face of the owner of the ID card 14 to be authenticated by visual inspection, an administrator who performs the comparison is not required, and the accuracy of identity authentication is improved.

[0134] Further, according to the present embodiment, the authentication image generating unit 40 embeds the first facial feature amount 47 extracted from the first facial image 45 in the authentication image 21. The personal authentication unit 64 certifies that the person is the owner of the ID card 14 by comparing the first facial feature amount 47 extracted from the authentication image 21 included in the second captured image 88 obtained by capturing an image of the ID card 14 to be authenticated with the second facial feature amount 94 extracted from the second facial image 92. Therefore, according to this configuration, the first facial feature amount 47 is embedded in the authentication image 21, and personal authentication is performed based on the first facial feature amount 47 extracted from the authentication image 21. Compared to the case where the first facial feature amount 47 is extracted from the first facial image 45 every time personal authentication is performed, the processing load for personal authentication in the authentication system 2 is reduced and the processing time is shortened.

[0135] Furthermore, according to this embodiment, the validity authentication information 48 and the first facial feature amount 47 are embedded in the authentication image 21 as a digital watermark 52. Therefore, according to this configuration, it is more difficult to forge the validity authentication information 48 and the first facial feature amount 47 than when the validity authentication information 48 and the first facial feature amount 47 are embedded directly in the authentication image 21, so that a highly secure ID card 14 can be provided.

[0136] Furthermore, according to this embodiment, the authentication image generating unit 40, the ID card output unit 42, the first frequency characteristic acquiring unit 44, and the printer 20 are built into one housing. Therefore, according to this configuration, the authentication system 2 can be arranged in a smaller space than when the authentication image generating unit 40, the ID card output unit 42, the first frequency characteristic acquiring unit 44, and the printer 20 have separate housings.

[0137] Furthermore, according to this embodiment, the camera 34 that captures the first captured image 46 is built into the housing. Therefore, according to this configuration, the authentication system 2 can be arranged in a smaller space than when the authentication image generating unit 40, the ID card output unit 42, the first frequency characteristic acquiring unit 44, the printer 20, and the camera 34 have separate housings.

[0138] Furthermore, according to this embodiment, the first captured image 46 and the second captured image 88 are captured by the cameras 34 and 86A, which have the same imaging performance. Therefore, according to this configuration, the influence of density characteristics caused by the difference in imaging performance between the cameras 34 and 86A is reduced, and therefore it is easier to compare the density characteristics of the first captured image 46 and the second captured image 88 compared to the case where the first captured image 46 and the second captured image 88 are captured by cameras with different imaging performance.

[0139] In the above embodiment, the camera 34 that acquires the first captured image 46 and the camera 86A that acquires the second captured image 88 have the same imaging performance, but the technology of the present disclosure is not limited to this. The camera 34 that acquires the first captured image 46 and the camera 86A that acquires the second captured image 88 may have different imaging performance. In this case, as shown in FIG. 21 as an example, the authenticity authentication unit 68 may correct the second captured image 88 based on the difference in imaging performance between the camera 34 and the camera 86A, and authenticate the authenticity of the ID card 14 using the corrected second captured image 88. Therefore, according to this configuration, the authentication accuracy of the authenticity can be improved compared to the case where the second captured image 88 acquired by the camera 86A having imaging performance different from that of the camera 34 is used for authenticity authentication as it is.

[0140] In the above embodiment, the printer 20 is an instant photo printer, but the technology of the present disclosure is not limited to this. The printer 20 may be, for example, a dye-sublimation printer of the above-mentioned dye-sublimation thermal transfer method. The dye-sublimation printer may also use a plastic card as a recording medium instead of a dedicated coated paper. When a dye-sublimation printer is used, the ID card 14 may be created by printing the authentication image 21 on a plastic card. The printer 20 may also be an inkjet printer of an inkjet method. As shown in FIG. 9 and FIG. 10, the density characteristics differ depending on the printing method. Therefore, even if a printer other than an instant photo printer is used, it is possible to authenticate the authenticity of an ID card 14 counterfeited by a printer with a different printing method.

[0141] In addition, in dye-sublimation printers other than instant photo printers, as in the case of instant photo printers, when the same image is printed on the same type of recording medium, there is a certain degree of uncertainty in the color density, as the occurrence of density unevenness varies from print to print. For example, dye-sublimation printers experience thermal fluctuations due to heat generation and heat storage in the thermal head, so density unevenness occurs from print to print, even when the same image is printed on the same type of recording medium. In addition, inkjet printers also experience fluctuations in the landing position of dots, so density unevenness occurs from print to print, even when the same image is printed on the same type of recording medium. Therefore, even when dye-sublimation printers other than instant photo printers are used, it is possible to authenticate the authenticity of ID cards 14 counterfeited using the same type of printer.

[0142] However, as mentioned above, instant film 15 has non-uniformity in the photosensitive material and developer, so it is easier to utilize the uncertainty of color density in authenticating ID card 14 issued by an instant photo printer than by a dye-sublimation printer or inkjet printer. Therefore, an instant photo printer is more preferable than a dye-sublimation printer or inkjet printer as printer 20.

[0143] Instant film 15 also differs in printing method from dye-sublimation printers and inkjet printers, which are subtractive color mixing methods that produce colors Y (yellow), M (magenta), and C (cyan), in that the instant film 15 is an additive color mixing method that uses photosensitive material that produces colors B (blue), G (green), and R (red). Since there is a large difference in density characteristics between additive color mixing and subtractive color mixing, by using an instant photo printer as printer 20 that issues ID cards 14, it is easy to detect counterfeit ID cards 14 produced by dye-sublimation printers and inkjet printers.

[0144] As described above, instant photo printers and dye-sublimation printers are density modulation printers, while inkjet printers are area modulation printers. Compared to area modulation printers, density modulation printers have greater uncertainty in color density. This is because the density unevenness of inkjet printers is caused by fluctuations in the landing positions of dots, but the landing positions of dots are controlled by mechanical position control of the inkjet head. The cause of density unevenness in density modulation is nonuniformity between the photosensitive material and the developing solution in the case of instant photo printers, and thermal fluctuations due to heat generation and heat accumulation in the thermal head in the case of dye-sublimation printers. This is because it is more difficult to control nonuniformity between the photosensitive material and the developing solution or thermal fluctuations in the thermal head compared to mechanical position control of the inkjet head.

[0145] The technology disclosed herein utilizes the uncertainty of the color density of a printer to authenticate the authenticity, so the greater the uncertainty of the color density, the more preferable the printer to be used with the technology disclosed herein. modulation Compared to printers using the dye-sublimation method, instant photo printers and dye-sublimation printers have a higher density. modulation A printer using this method is preferred.

[0146] Furthermore, as a printer to be used with the technology of the present disclosure, an instant photo printer, which has a greater degree of uncertainty in color density compared to a dye-sublimation printer, is preferable.

[0147] When a dye-sublimation printer or inkjet printer is used as the printer 20, it is preferable to increase the reading resolution for reading the authenticity verification image 57 compared to when an instant photo printer is used. This is because dye-sublimation printers use the same density modulation method as instant photo printers, but have less uncertainty in color density compared to instant film 15, so more accurate reading is required. Also, as shown in Figure 9, inkjet printers have more density unevenness in the high frequency range compared to instant photo printers, so they also require more accurate reading.

[0148] In addition, in the above embodiment, an example of an embodiment in which the issuing device 4 has a built-in camera 34 and printer 20 has been described, but the technology of the present disclosure is not limited to this, and the camera 34 and / or printer 20 may have a housing separate from the issuing device 4.

[0149] In the above embodiment, the issuing device 4, the authentication device 6, and the database 24 are each housed in a separate housing, but the technology of the present disclosure is not limited to this. The issuing device 4, the authentication device 6, and the database 24 may be built into the same housing, or at least two of the issuing device 4, the authentication device 6, and the database 24 may be built into the same housing. When the issuing device 4 and the authentication device 6 are built into the same housing, a single computer may function as both the computer 32 and the computer 60.

[0150] In addition, in the above embodiment, an example of the authentication system 2 being used at an event where eating and drinking and / or merchandise sales are performed has been described, but the technology of the present disclosure is not limited thereto, and the authentication system 2 may be used, for example, in a commercial facility where payments are made at a plurality of locations including a shopping mall, a shopping street, a hotel, an inn, etc. In addition, in the above embodiment, an example of the authentication system 2 managing the payment information 30 for each participant 11 has been described, but the technology of the present disclosure is not limited thereto, and the authentication system 2 may be used, for example, to manage the entrance and exit of participants 11 at highly confidential facilities, member-only facilities, and private events such as weddings.

[0151] In the above embodiment, an example of the authentication process is described in which the authentication process is performed in the order of the identity authentication process, the validity authentication process, and the authenticity authentication process, but the technology disclosed herein is not limited to this, and the order in which the identity authentication process, the validity authentication process, and the authenticity authentication process are performed can be changed as appropriate. Also, the identity authentication process, the validity authentication process, and the authenticity authentication process can be performed in parallel.

[0152] In the above embodiment, the authenticity authentication process includes a first process that uses the uncertainty of the color density of the authenticity check image 57 and a second process that uses the change over time in the color density of the authenticity check image 57, but the technology of the present disclosure is not limited to this. The authenticity authentication process may include at least one of the first process and the second process. The order in which the first process and the second process are performed may be changed, or the first process and the second process may be performed in parallel.

[0153] Furthermore, in the above embodiment, an example of the authenticity matching pattern 50 being placed in the lower right corner of the authentication image 21 has been described, but the technology of the present disclosure is not limited to this, and the authenticity matching pattern 50 may be placed anywhere in the authentication image 21. Furthermore, the authenticity matching pattern 50 may be placed in a location other than the digital watermark embedded image 49. Furthermore, the number of authenticity matching patterns 50 is not limited to one, and multiple authenticity matching patterns may be placed.

[0154] The example shown in Fig. 22 is an example in which authenticity verification images 57 corresponding to authenticity verification patterns 50 are printed in multiple locations on an ID card 14. In the example shown in Fig. 22, the authentication image 21 is the entire area of ​​the ID card 14, including the digital watermark embedded image 49. The authenticity verification images 57 are printed at the four corners of the digital watermark embedded image 49. The authenticity verification images 57 are also printed in areas other than the digital watermark embedded image 49.

[0155] According to this configuration, by performing the authenticity authentication process using a plurality of authenticity verification images 57, it is possible to improve the accuracy of the authenticity authentication process compared to performing the authenticity authentication process using a single authenticity verification image 57. This is because the number of objects to compare the density characteristics increases.

[0156] This effect is particularly noticeable when instant film 15 is used. As shown in Figures 7 and 8, the instant film 15 has non-uniformity in the photosensitive material and developer on the recording surface. In this case, multiple authenticity verification images 57 printed on one instant film 15 using the same authenticity verification pattern 50 are likely to have varying density characteristics depending on the location. Therefore, in an instant film 15, the more authenticity verification images 57 there are, the more comparison targets with different density characteristics there are. occurs.

[0157] Furthermore, by printing a plurality of authenticity check images 57, the resistance to reading errors of the authenticity check images 57 caused by disturbances such as dirt is increased, and robustness is improved.

[0158] Furthermore, a two-dimensional code such as a QR (Quick Response) code (registered trademark) may be used as the authenticity verification pattern 50 and the authenticity verification image 57 on which the authenticity verification pattern 50 is printed. Since a two-dimensional code such as a QR code (registered trademark) is composed of elements each consisting of a solid pattern block of several millimeters square, it is possible to use a part of the two-dimensional code as the authenticity verification pattern 50 and the authenticity verification image 57. Furthermore, by using a two-dimensional code, it is easy to use existing software such as a two-dimensional code reader to read the authenticity verification image 57.

[0159] The authenticity checking image 57 may be a pattern other than a solid color, or may be a striped pattern of two or more colors. The shape does not have to be a square, and may be a circle, a polygon, a rectangle, a strip, or any other shape.

[0160] As described above, the size of the authenticity verification image 57 only needs to be a few millimeters square. This is because, with this size, it is possible to obtain the density characteristics required for comparison by reading the image at a resolution of, for example, about 600 dpi (dots per inch). Since the authenticity verification image 57 is relatively small, it is easy to provide multiple images on the ID card 14.

[0161] In the above embodiment, an example was described in which only images were used as authentication information, but audio may also be used in addition to images. For example, when the original image 10 is photographed with the smart device 8, the audio recording function of the smart device 8 is used to obtain the audio of the participant 11. The obtained audio information is then registered in the database 24. A URL that allows access to the audio information is recorded in the ID card 14. The audio information registered in this manner is used as authentication information for identity authentication or authenticity authentication.

[0162] In the above embodiment, the computers 32, 60, and 78 are illustrated, but the technology of the present disclosure is not limited thereto. For example, a device including an application specific integrated circuit (ASIC), an FPGA, and / or a programmable logic device (PLD) may be applied instead of the computer 32, 60, or 78. Also, a combination of a hardware configuration and a software configuration may be used instead of the computer 32, 60, or 78.

[0163] In the above embodiment, the ID card issuing process is executed by the CPU 32A of the issuing device 4, but the technology of the present disclosure is not limited to this. Instead of the CPU 32A, a GPU (graphics processing unit) may be used, or multiple CPUs may be used. Furthermore, various processes may be executed by one processor or multiple processors that are physically separated from each other.

[0164] In the above embodiment, the authentication process is executed by the CPU 60A of the authentication device 6, but the technology of the present disclosure is not limited to this. Instead of the CPU 60A, a GPU (graphics processing unit) may be used, or multiple CPUs may be used. Furthermore, various processes may be executed by one processor or multiple processors that are physically separated from each other.

[0165] In the above embodiment, an example in which the ID card issuance program 38 is stored in the NVM 32B has been described, but the technology of the present disclosure is not limited to this. As an example, as shown in FIG. 23, the ID card issuance program 38 may be stored in a portable storage medium 200. The storage medium 200 is a non-transitory storage medium. Examples of the storage medium 200 include an SSD and a USB memory. The ID card issuance program 38 stored in the storage medium 200 is installed in the computer 32, and the CPU 32A executes the ID card issuance process in accordance with the installed ID card issuance program 38.

[0166] Also, the ID card issuance program 38 may be stored in a program memory of another computer or a server device connected to the computer 32 via a communication network (not shown), and the ID card issuance program 38 may be downloaded to the issuing device 4 in response to a request from the issuing device 4. In this case, the ID card issuance process based on the downloaded ID card issuance program 38 is executed by the CPU 32A of the computer 32.

[0167] In the above embodiment, an example in which the authentication program 62 is stored in the NVM 60B has been described, but the technology of the present disclosure is not limited to this. As an example, as shown in FIG. 24, the authentication program 62 may be stored in a portable storage medium 201. The storage medium 201 is a non-transitory storage medium. Examples of the storage medium 201 include an SSD and a USB memory. The authentication program 62 stored in the storage medium 201 is installed in the computer 60, and the CPU 60A executes the authentication process in accordance with the installed authentication program 62.

[0168] Alternatively, an authentication program 62 may be stored in the program memory of another computer or server device connected to the computer 60 via a communication network (not shown), and the authentication program 62 may be downloaded to the authentication device 6 in response to a request from the authentication device 6. In this case, the authentication process based on the downloaded authentication program 62 is executed by the CPU 60A of the computer 60.

[0169] As hardware resources for executing the ID card issuance process and the authentication process, the following various processors can be used. As a processor, for example, as described above, a general-purpose processor, i.e., a CPU, which functions as a hardware resource for executing data processing according to software, i.e., a program, can be mentioned.

[0170] Also, as other processors, for example, a dedicated electric circuit, which is a processor having a circuit configuration dedicated to executing specific processing such as an FPGA, a PLD, or an ASIC, can be mentioned. A memory is built in or connected to any of the processors, and any of the processors executes data processing by using the memory.

[0171] The hardware resources for executing data processing may be configured by one of these various processors, or may be configured by a combination of two or more processors of the same type or different types (for example, a combination of a plurality of FPGAs, or a combination of a CPU and an FPGA). Also, the hardware resources for executing data processing may be a single processor.

[0172] As an example of a configuration consisting of one processor, first, as represented by computers such as clients and servers, one processor is configured by a combination of one or more CPUs and software, and this processor functions as a hardware resource for executing data processing. Second, as represented by a system-on-a-chip (SoC) or the like, there is a form in which a processor that realizes the functions of an entire system including a plurality of hardware resources for executing data processing is used in one IC chip. Thus, data processing is realized as a hardware resource using one or more of the above various processors.

[0173] Furthermore, as a hardware structure of these various processors, more specifically, an electric circuit combining circuit elements such as semiconductor elements can be used.

[0174] Also, the data processing described above is merely an example. Therefore, it goes without saying that unnecessary steps may be deleted, new steps may be added, or the processing order may be changed within the scope of not departing from the gist.

[0175] The description and illustration shown above are detailed explanations of the part related to the technology of the present disclosure and are merely examples of the technology of the present disclosure. For example, the explanations regarding the above configuration, functions, actions, and effects are explanations regarding an example of the configuration, functions, actions, and effects of the part related to the technology of the present disclosure. Therefore, it goes without saying that within the scope of not departing from the gist of the technology of the present disclosure, the description and illustration shown above may be modified by deleting unnecessary parts, adding new elements, or replacing them. Also, in order to avoid complication and facilitate the understanding of the part related to the technology of the present disclosure, the description of common technical knowledge that does not particularly require explanation for implementing the technology of the present disclosure is omitted in the description and illustration shown above.

[0176] As used herein, "A and / or B" is synonymous with "at least one of A and B". That is, "A and / or B" means that it may be only A, only B, or a combination of A and B. Further, in this specification, when expressing three or more matters connected by "and / or", the same concept as "A and / or B" is applied.

[0177] All documents, patent applications, and technical standards described in this specification are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually indicated to be incorporated by reference.

Claims

1. An ID card authentication system comprising an issuing device for issuing an ID card and an authentication device for authenticating the ID card, wherein the issuing device includes a first processor, and the first processor, obtains a first face image obtained by imaging a person's face, outputs the authentication image to a printer that issues an ID card by printing the authentication image including the first face image and authentication information for authenticating legitimacy on a card-shaped recording medium, stores, in a memory, a first captured image obtained by imaging the authentication image printed on the ID card with a camera, the authentication device includes a second processor, and the second processor, obtains, as a second captured image, an image obtained by imaging the authentication image printed on the ID card to be authenticated with a camera, authenticates the authenticity of the ID card to be authenticated by comparing the density characteristics of the first captured image obtained from the memory and the second captured image obtained from the camera. An ID card authentication system.

2. The ID card authentication system according to claim 1, wherein the second processor authenticates the authenticity of the ID card to be authenticated by utilizing the uncertainty of the color density in which the occurrence state of density unevenness is different for each printing even when the same image is printed on the same type of recording medium.

3. The ID card authentication system according to claim 1 or claim 2, wherein the second processor authenticates the authenticity of the ID card to be authenticated by utilizing the fact that the frequency characteristics of the color density of the image are different for each printing even when the same image is printed on the same type of recording medium.

4. The ID card authentication system according to any one of claims 1 to 3, wherein the second processor authenticates the authenticity of the ID card to be authenticated by comparing the density characteristics in consideration of the change over time of the color density of the authentication image printed on the ID card to be authenticated.

5. A collation part used for comparing density characteristics is included in a part of the authentication image, and the second processor authenticates the authenticity of the ID card by comparing the density characteristics of the collation parts of the first captured image and the second captured image. The ID card authentication system according to any one of claims 1 to 4.

6. The ID card authentication system according to claim 5, wherein the collation part is a solid pattern composed of a single solid color.

7. The printer is the ID card authentication system according to any one of claims 1 to 6, which is a printer using a density modulation method.

8. The printer is the ID card authentication system according to claim 7, which is an instant photo printer using an instant film that develops color with a photosensitive material containing silver salt as the recording medium.

9. The second processor acquires the face of the person who is the owner of the ID card to be authenticated as a second face image, and authenticates that the owner of the ID card to be authenticated is the person himself / herself by comparing the facial feature amount extracted from the first face image included in the second captured image with the facial feature amount extracted from the second face image. The ID card authentication system according to any one of claims 1 to 8.

10. The first processor embeds the facial feature amount extracted from the first face image into the authentication image, The second processor authenticates that the person is the owner of the ID card himself / herself by comparing the facial feature amount extracted from the authentication image included in the second captured image with the facial feature amount extracted from the second face image. The ID card authentication system according to claim 9.

11. The authentication information and the facial feature amount are embedded in the authentication image as an electronic watermark in the ID card authentication system according to claim 10.

12. The ID card authentication system according to any one of claims 1 to 11, wherein the first processor and the printer are built in one housing.

13. The ID card authentication system according to claim 12, wherein a camera for acquiring the first captured image is built in the housing.

14. The ID card authentication system according to any one of claims 1 to 13, wherein the first captured image and the second captured image are acquired by cameras with the same imaging performance.

15. The second processor corrects the second captured image based on the difference in imaging performance between the camera for acquiring the first captured image and the camera for acquiring the second captured image, and authenticates the authenticity of the ID card to be authenticated using the corrected second captured image. The ID card authentication system according to any one of claims 1 to 14.

16. An ID card authentication program for operating an ID card authentication system including a first computer that issues an ID card and a second computer that authenticates the ID card, a first face image acquisition unit that acquires a first face image obtained by imaging a person's face, an output unit that outputs the authentication image to a printer that issues an ID card by printing an authentication image including the first face image and authentication information for authenticating validity on a card-shaped recording medium, functioning the first computer as a storage unit that stores, in a memory, a first captured image obtained by imaging the authentication image printed on the ID card with a camera, and a second captured image acquisition unit that acquires, as a second captured image, an authentication image printed on an ID card to be authenticated by imaging with a camera, for functioning the second computer as an authentication unit that authenticates the authenticity of the ID card to be authenticated by comparing the density characteristics of the first captured image acquired from the memory and the second captured image acquired from the camera ID card authentication program.

Images