Authentication device, authentication method, and authentication program

Abstract

To issue an ID card with which it is possible to verify identification and authenticate validity simply and quickly at low cost, and an ID card authentication system, authentication method, and authentication program with which it is possible to authenticate the genuineness of the ID card with a simple composition.SOLUTION: In an ID card authentication system, an ID card issuing device acquires a first face image obtained by capturing the face of a person, prints an authentication image including the first face image and authentication information for authenticating validity on a card-shaped printing medium so as to output the authentication image to a printer that issues an ID card, and stores in memory a first captured image obtained by capturing the authentication image printed on the ID card by a camera. An ID card authentication device captures the authentication image printed on the ID card to be authenticated by a camera so as to acquire a second captured image, and compares the respective density characteristics of the first captured image acquired from memory and the second captured image acquired from the camera so as to authenticate the genuineness of the ID card to be authenticated.SELECTED DRAWING: Figure 1

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 technology]

[0002] Japanese Patent Application Laid-Open Publication No. 2002-007977 discloses an authentication system for authenticating the authenticity of ID (Identification Data) cards such as employee ID cards and student ID cards. The ID card described in Japanese Patent Application Laid-Open Publication No. 2002-007977 has an IC (Integrated Circuit) memory, in which an identifier, a facial photograph, and an authentication image are recorded. The authentication image is a facial photograph with digital watermark information such as a random number embedded in it. A database stores combinations of identifiers and digital watermark information. In the authentication process, if the combination of the identifier recorded on the ID card and the digital watermark information extracted from the authentication image matches the combination of the identifier and digital watermark information stored in the database, the ID card is determined to be authentic. Summary of the Invention [Problem to be solved by the invention]

[0003] In this way, the authenticity authentication system described in JP 2002-007977 A verifies the authenticity of the information recorded on the ID card by comparing authentication information such as the identifier and authentication image recorded on the ID card with authentication information previously stored in a database. In addition, since a facial photograph is recorded on the ID card, personal authentication can be performed by visual confirmation to confirm whether the ID card owner is the person in question.

[0004] In addition to personal authentication and legitimacy, authenticity is also a requirement for authentication to enhance the security of ID cards. Authenticity indicates that the ID card is not a counterfeit. The legitimacy authentication system described in JP 2002-007977 A does not mention authenticity authentication, but the ID card described in JP 2002-007977 A has an IC memory, and therefore it is possible to authenticate the authenticity by storing various information for authenticating the authenticity in the IC memory. Moreover, ID cards with IC memory are simply difficult to copy, and this difficulty in copying makes it easier to guarantee authenticity.

[0005] However, the issuance process for ID cards with IC memory takes time and simply increases costs. ID cards are not all used for long periods of time, such as employee IDs or student IDs; some ID cards are intended for short-term use, such as visitor IDs at events such as exhibitions. ID cards intended for such short-term use are not only subject to constraints on issuance costs, but also require immediate issuance at the venue on the day of the event, making the issuance process quick and simple.

[0006] When trying to realize ID cards that are low-cost, simple, and quick, it is difficult to adopt measures to increase the functionality of ID cards, such as adding IC memory. A realistic method would be to create an ID card by printing a facial photo and authentication information used to authenticate the authenticity on a card-shaped piece of paper, but such ID cards are easy to counterfeit, so the challenge was to authenticate the authenticity of ID cards with a simple configuration, assuming that counterfeiting will occur.

[0007] The technology disclosed herein aims to provide an ID card authentication system, authentication method, and authentication program that can issue ID cards that can authenticate the identity and legitimacy of users at low cost, easily, and quickly compared to conventional technologies, and that can authenticate the authenticity of ID cards with a simple configuration. [Means for solving the problem]

[0008] The ID card authentication system disclosed herein is an authentication system including an issuing device that issues ID cards and an authentication device that authenticates ID cards. The issuing device includes a first processor that acquires a first facial image by capturing an image of a person's face, outputs the authentication image to a printer that issues ID cards by printing an authentication image including the first facial image and authentication information for authenticating authenticity on a card-shaped recording medium, and stores the first captured image, captured by a camera, of the authentication image printed on the ID card in memory. The authentication device includes a second processor that acquires, as a second captured image, an image obtained by capturing the authentication image printed on the ID card to be authenticated with a camera, and authenticates the authenticity of the ID card to be authenticated by comparing the density characteristics of the first captured image acquired from the memory with those of the second captured 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 color density, which is the occurrence of density unevenness that differs from print to print, 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 differ for each print, even when the same image is printed on the same type of recording medium.

[0011] It is preferable that the second processor certify the authenticity of the ID card to be authenticated by comparing the density characteristics while taking into account changes over time in the color density of the authentication image printed on the ID card to be authenticated.

[0012] It is preferable that a portion of the authentication image includes a matching section used to compare density characteristics, and the second processor certifies the authenticity of the ID card to be authenticated by comparing the density characteristics of the matching sections of the first captured image and the second captured image.

[0013] The matching portion is preferably a solid pattern made up of a single solid color.

[0014] The printer is preferably a density modulation type printer.

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

[0016] It is preferable that the second processor acquires the face of the person who holds the ID card to be authenticated as a second facial image, and authenticates that the owner of the ID card to be authenticated is the person in question by comparing the facial features extracted from the first facial image included in the second captured image with the facial features extracted from the second facial image.

[0017] It is preferable that the first processor embeds facial features extracted from the first facial image into the authentication image, and the second processor certifies that the person is the owner of the ID card by comparing the facial features extracted from the authentication image included in the second captured image with the facial features extracted from the second facial image.

[0018] The authentication information and facial features are preferably embedded in the authentication image as a digital watermark.

[0019] The first processor and the printer are preferably housed within a single housing.

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

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

[0022] It is preferable that the second processor corrects the second captured image based on the difference in imaging performance between the camera that captures the first captured image and the camera that captures the second captured image, and uses the corrected second captured image to authenticate the authenticity of the ID card to be authenticated.

[0023] The ID card authentication method using the ID card issuing device and ID card authentication device of the present disclosure has the ID card issuing device perform a first facial image acquisition step of acquiring a first facial image obtained by capturing an image of a person's face, an output step of outputting an authentication image to a printer that issues ID cards by printing an authentication image including the first facial image and authentication information for authenticating legitimacy on a card-shaped recording medium, and a storage step of storing in memory a first captured image captured by a camera of the authentication image printed on the ID card, and has the ID card authentication device perform a second captured image acquisition step of capturing the authentication image printed on the ID card to be authenticated by the camera and acquiring it as a 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.

[0024] The ID card authentication program disclosed herein is an ID card authentication program for operating an ID card authentication system including a first computer that issues ID cards and a second computer that authenticates ID cards. The authentication program causes the first computer to function as a first facial image acquisition unit that acquires a first facial image obtained by capturing an image of a person's face, an output unit that outputs an authentication image to a printer that issues ID cards by printing an authentication image including the first facial image and authentication information for authenticating authenticity on a card-shaped recording medium, and a storage unit that stores the first captured image captured by a camera of the authentication image printed on the ID card in memory, and also causes the second computer to function as an authentication unit that acquires a second captured image by capturing the authentication image printed on the ID card to be authenticated with the camera, and 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. [Effects of the Invention]

[0025] The technology disclosed herein makes it possible to issue ID cards capable of performing identity authentication and legitimacy authentication at low cost, easily, and quickly compared to conventional technology, and also provides an ID card authentication system, authentication method, and authentication program that can authenticate the authenticity of ID cards with a simple configuration. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a schematic diagram of an authentication system. [Figure 2] FIG. 2 is a block diagram of an issuing device. [Figure 3] 10A and 10B are explanatory diagrams showing an example of processing performed by an authentication image generating unit; [Figure 4] FIG. 10 is an explanatory diagram showing an example of a method for generating an authentication image. [Figure 5] FIG. 10 is an explanatory diagram illustrating an example of processing performed by an ID card output unit. [Figure 6]4 is an explanatory diagram illustrating an example of processing performed by a first frequency characteristic acquisition unit. FIG. [Figure 7] FIG. 1 is a top view showing an example of an instant film having authenticity verification images provided in four places. [Figure 8] 10 is a graph showing an example of first frequency characteristics indicating density characteristics of four authenticity verification images. [Figure 9] 10 is a graph showing an example of a comparison between frequency characteristics of an instant method and frequency characteristics of an inkjet method. [Figure 10] 10 is a graph showing an example of a comparison between frequency characteristics of an instant method and frequency characteristics of a dye-sublimation thermal transfer method. [Figure 11] FIG. 2 is a block diagram of an authentication device. [Figure 12] FIG. 1 is a block diagram of a POS terminal. [Figure 13] FIG. 2 is an explanatory diagram showing an example of personal authentication processing performed by a personal authentication unit; [Figure 14] FIG. 10 is an explanatory diagram illustrating an example of a validity authentication process performed by a validity authentication unit. [Figure 15] FIG. 10 is an explanatory diagram showing an example of a first process of the authenticity authentication process performed by the authenticity authentication unit. [Figure 16] 10 is a graph showing an example of a change over time in color density in an authenticity verification image. [Figure 17] FIG. 10 is an explanatory diagram showing an example of a second process of the authenticity authentication process performed by the authenticity authentication unit. [Figure 18] 10 is a flowchart showing an example of the flow of an ID card issuing process. [Figure 19] 10 is a flowchart illustrating an example of the flow of an authentication process. [Figure 20] 10 is a flowchart illustrating an example of the flow of an authentication process. [Figure 21] FIG. 10 is an explanatory diagram showing another example of the first process of the authenticity authentication process performed by the authenticity authentication unit. [Figure 22] FIG. 1 is a top view illustrating an example of an ID card including multiple authenticity check images. [Figure 23] FIG. 1 is a schematic diagram showing an example of how an ID card issuing program stored in a storage medium is installed in a computer. [Figure 24] FIG. 1 is a schematic diagram showing an example of how an authentication program stored in a storage medium is installed on a computer. DETAILED DESCRIPTION OF THE INVENTION

[0027] [First embodiment] As an example, as shown in FIG. 1 , an ID card authentication system 2 includes an issuing device 4 that issues ID cards 14 and an authentication device 6 that authenticates the ID cards 14. The authentication system 2 is used, for example, at an outdoor or indoor event venue where multiple stores 16 are exhibiting. The ID cards 14 are issued to event participants 11, for example, in exchange for an admission fee to the event venue. They are used to prove that the participants 11 are legitimate attendees of the event. The ID cards 14 are participant identification cards used to identify the participants 11. For example, by authenticating the ID cards 14 at key points within the event venue, such as each store 16, it is possible to exclude unauthorized participants 11 from the event venue.

[0028] In this example, the ID card 14 also functions as a prepaid card within the event venue. Participants 11 can use the ID card 14 to pay for food and / or merchandise at each store 16. Payment information 30 for services used by participants 11 is managed through the ID card 14. The authentication system 2 is an example of an "authentication system" according to the technology of the present disclosure. The issuing device 4 is an example of an "issuing device" according to the technology of the present disclosure. The authentication device 6 is an example of an "authentication device" according to the technology of the present disclosure. The ID card 14 is an example of an "ID card" according to the technology of the present disclosure.

[0029] As an example, an ID card 14 is issued by a participant 11 using his or her own smart device 8 as follows. The issuing device 4 and authentication device 6 are installed in an administration booth 12 set up within the event venue. A participant 11 attending an event first stops by the administration booth 12. At the administration booth 12, the participant 11 uses his or her own smart device 8 to access a website for issuing ID cards. A uniform resource locator (URL) for accessing the website is provided to the participant 11, for example, in exchange for purchasing an admission ticket. The participant 11 operates the smart device 8 according to instructions on the website to capture an image of the participant 11's face, and an ID card issuance request 18 including an image 10 containing the captured face of the participant 11 is sent from the smart device 8 to the issuing device 4. This image 10 containing the face is hereinafter referred to as the original image 10 to distinguish it from a facial image, which will be described later. The issuing device 4 accepts the ID card issuance request 18 and performs an ID card issuance process in accordance with the accepted ID card issuance request 18.

[0030] In this example, the participant 11 takes an image of his or her own face using the smart device 8 owned by the participant 11, and transmits the ID card issuance request 18 from the smart device 8. This is one example of how the ID card issuance request 18 is transmitted, and in the technology disclosed herein, instead of the smart device 8 owned by the participant 11, a reception device equipped with a camera located in the management booth 12 may capture an image of the participant 11's face and transmit the ID card issuance request 18. Alternatively, a reception staff member at the event venue may use a smart device to capture an image of the participant 11's face, and the reception staff member may transmit the ID card issuance request 18 from the smart device.

[0031] The issuing device 4 has a built-in printer 20 (see FIG. 2) that can print images on 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 instant film 15 using the printer 20.

[0032] As is well known, instant film 15 is a self-developing photographic film that can develop within a few minutes after exposure. Instant film 15 is a well-known mono-sheet type and has the basic components of a mono-sheet instant film, such as a photosensitive sheet, a receiver sheet, a developer pod containing a developer solution, and a trap for absorbing excess developer solution. The photosensitive sheet contains a photosensitive material containing silver salts, which develops color when exposed to light. More specifically, in instant film 15, a latent image is photochemically formed by exposure of the photosensitive sheet. After the latent image is formed, the photosensitive sheet and receiver sheet are superimposed and pressurized while developing solution is spread between them, transferring a positive image to the receiver sheet.

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

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

[0035] Participant 11 uses ID card 14 to shop within the event venue. When participant 11 pays at a store 16 within the event venue, he / she presents ID card 14 to cashier 17 of each store 16. When cashier 17 operates the ID card 14, authentication request 22 is sent from POS (point of sale) terminal 19 of each store 16 to authentication device 6. Authentication device 6 accepts authentication request 22 and performs authentication processing in accordance with the accepted authentication request 22.

[0036] Although described in more detail below, the authentication process includes an identity authentication process that verifies that the owner of the ID card 14 to be authenticated is the creator of the ID card 14, a validity authentication process that verifies that the ID card 14 to be authenticated has legitimate access rights to the authentication system 2, and an authenticity authentication process that verifies that the ID card 14 to be authenticated is not a counterfeit card. If the authentication device 6 authenticates the ID card 14 to be authenticated after the authentication process, payment information 30 of the participant 11 is sent to the authentication device 6. The payment information 30 is data including the name of the store 16 and the payment amount. As a result, the payment amount is deducted from the charge balance 28 charged to the ID card 14 to be authenticated. Note that if the authentication device 6 does not authenticate the ID card 14 to be authenticated, the payment information 30 is not sent, and the charge balance 28 is not deducted.

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

[0038] 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 into a single housing. The computer 32 includes a central processing unit (CPU) 32A, a non-volatile memory (NVM) 32B, a random access memory (RAM) 32C, and a communication interface (I / F) 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 one another via a bus 36.

[0039] The CPU 32A controls the entire issuing device 4. The NVM 32B is a non-volatile memory. Here, an EEPROM (electrically erasable programmable read-only memory) is used as an example of the NVM 32B, but it is not limited to this and may be a flash memory or a combination of multiple 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, for example, a device having an FPGA (field-programmable gate array). The communication I / F 32D is connected to the database 24 and controls the exchange of various information between the CPU 32A and the database 24. The communication I / F 32D is also 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 controls 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 instant film 15 as a recording medium. The printer 20 includes, for example, an LCD (Liquid Crystal Display) as an exposure device. Within the printer 20, the exposure device is positioned so that the image display surface that displays the 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 using a photosensitive material containing silver halide. Furthermore, because the printer 20 uses instant film 15 as a recording medium, it is naturally a density modulation printer that forms images by changing the color density of the photosensitive material depending on the amount of exposure.

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

[0043] An ID card issuance program 38 is stored in NVM 32B. CPU 32A reads out ID card issuance program 38 from NVM 32B and executes the read ID card issuance program 38 on 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 an ID card issuance process. The authentication image generation unit 40, the ID card output unit 42, and the first frequency characteristic acquisition unit 44 are examples of a "first processor" according to the technology of the present disclosure.

[0044] An example of the ID card issuing process performed by the issuing device 4 will be specifically described below with reference to FIGS.

[0045] As an example, as shown in FIG. 3, when the authentication image generation unit 40 receives an ID card issuance request 18 including an original image 10 from the smart device 8, the authentication image generation unit 40 uses a known facial recognition technology to extract a first facial image 45 representing a person's face from the original image 10. The first facial image 45 can be extracted using known facial recognition technologies, such as a method of extracting contours by performing edge detection or other processing on the original image 10, identifying a facial contour from the extracted contours by pattern matching, and extracting the area within the identified facial contour as a facial image, as well as a method using machine learning. The first facial image 45 is an example of a "first facial image" according to the technology of the present disclosure.

[0046] The authentication image generation unit 40 acquires the serial number 27 and the validity authentication information 48. The serial number 27 is, for example, an identification number of the participant 11 assigned to each participant 11 in the order in which the participant 11 is registered. In the example shown in FIG. 3, four-digit numbers ranging from "0001" to "0101" are assigned to the participants 11. In addition, in FIG. 3, the serial number 27 "0101" enclosed in a dotted circle is the serial number 27 assigned to the participant 11 who sent the latest ID card issuance 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 below. In the example shown in FIG. 3, a combination of letters and numbers, "oi3fzq," is assigned as the validity authentication information 48 to the participant 11 whose serial number 27 is "0101." The authentication image generation unit 40 associates the acquired serial number 27 and validity authentication information 48 with the original image 10 and the extracted first face image 45, and stores them in the database 24 as participant data 26. The validity authentication information 48 is an example of "authentication information" according to the technology of the present disclosure.

[0048] The authentication image generation unit 40 performs image analysis on the first facial image 45 to extract first facial feature values ​​47 (see FIG. 4 ) that indicate the feature values ​​of the first facial image 45. As facial feature values ​​used for the first facial feature values ​​47, for example, known feature values ​​such as Haar-like feature values, Histograms of Oriented Gradients (HOG) feature values, Scale Invariant Feature Transform (SIFT) feature values, and Local Binary Pattern (LBP) feature values ​​can be appropriately used. As a feature extraction method, for example, known feature extraction techniques can be used, such as a method using a trained model that is trained in advance to output feature values ​​using training facial images, and that takes facial images as input and outputs feature values. The first facial feature values ​​47 are data used in the personal authentication process described below. The first facial feature values ​​47 are an example of a “facial feature value” according to the technology disclosed herein.

[0049] The authentication image generation unit 40 generates a watermarked image 49 (see FIG. 4) by digitally watermarking the first facial feature 47 and the authenticity authentication information 48 and embedding the watermarked image in the original image 10. The authentication image generation unit 40 further generates the authentication image 21 by combining an authenticity verification pattern 50 and an area mark 51 read from the database 24 with the watermarked image 49. 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 in the database 24.

[0050] More specifically, as shown in Fig. 4 as an example, the authentication image generation unit 40 generates a digital watermark-embedded image 49 in which a first facial feature 47 and validity authentication information 48 are embedded in the original image 10 in an invisible manner by calculation using a specific algorithm. In the example shown in Fig. 4, the first facial feature 47 and the validity authentication information 48 are embedded as a digital watermark 52 in the digital watermark-embedded image 49. The digital watermark 52 is data that cannot be seen with the naked eye but can be detected by applying specific calculation processing to the digital 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, plain pattern having a square shape with sides of several mm (millimeters). The area mark 51 is a cross-shaped mark measuring several mm to several tens of mm. As will be described in more detail later, the area mark 51 is a mark that indicates where in the authentication image 21 the digital watermark 52 and the authenticity verification pattern 50 are recorded.

[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 digital watermark-embedded image 49 and four area marks 51 on the four corners of the digital watermark-embedded image 49. In this example, the digital watermark 52 and the authentication image 21 are approximately the same size, so by placing the area marks 51 on the four corners of the digital watermark-embedded image 49, the four corners of the digital watermark 52 can be indicated. These four area marks 51 indicate the recording position of the digital watermark 52. Furthermore, since the authenticity verification pattern 50 is placed in the lower right corner of the digital 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. 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 an area for capturing the digital 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] 5, the ID card output unit 42 controls the printer 20 built into the issuing device 4 to print the authentication image 21 input from the authentication image generation unit 40. Under the control of the ID card output unit 42, the printer 20 prints the authentication image 21 on an instant film 15. The printed instant film 15 is ejected from the printer 20.

[0054] Here, the portion of the authentication image 21 printed on the instant film 15 that corresponds to the authenticity verification pattern 50 is referred to as the authenticity verification image 57 to distinguish it from the authenticity verification pattern 50. The authenticity verification image 57 is an image showing a portion of the first captured image 46, and is an image obtained by printing the authenticity verification pattern 50 included in the authentication image 21 using the printer 20. In other words, the authenticity verification pattern 50 is image data that constitutes a portion of the authentication image 21 when the authentication image 21 exists as image data, and the authenticity verification image 57 is an image that is printed on the instant film 15 and constitutes a portion of the authentication image 21 as a printed image. With the technology disclosed herein, the authenticity of the ID card 14 is authenticated by utilizing the fact that the density characteristics of the authenticity verification image 57 change with each print. In contrast, because the authenticity verification pattern 50 is image data, the density characteristics do not change with each print. As such, the authenticity verification image 57 and the authenticity verification pattern 50 differ in that they are a printed image and image data, respectively, and since it is necessary to distinguish between these two in order to explain the principles of authenticity authentication, we will explain them separately here.

[0055] In the issuing device 4, the authentication image 21 of the ejected instant film 15 is placed within the shooting range of the camera 34. The instant film 15 may be placed automatically or manually by a staff member or other person. Examples of automatic placement include a method of setting the camera 34 so that the instant film 15 ejected from the printer 20 is within its shooting range, or a method of transporting the ejected instant film 15 to the position of the camera 34 using a transport mechanism.

[0056] The ID card output unit 42 controls the camera 34 to capture an image of the authentication image 21 printed on the instant film 15. Specifically, the ID card output unit 42 operates the camera 34 to capture an image of the instant film 15 and detects area marks 51 arranged at the four corners of the authentication image 21 from the captured image. The ID card output unit 42 cuts out the area surrounded by the area marks 51 from the captured image and obtains the cut-out image as the first captured image 46. As described above, the area surrounded by the four area marks 51 in the authentication image 21 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 capturing time 54, which is the time when the instant film 15 was captured by the camera 34, in the database 24 in association with the serial number 27, the authenticity authentication information 48, the original image 10, and the first facial image 45. After the image is captured by the camera 34, the instant film 15 on which the authentication image 21 is printed is discharged from the issuing device 4 to the outside as the ID card 14.

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

[0059] The first frequency characteristic acquisition unit 44 acquires a first frequency characteristic 56 from the extracted authenticity verification image 57. The first frequency characteristic 56 is a frequency characteristic that indicates 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 refers to the fact that even when the same image is printed on the same type of recording medium, the occurrence of density unevenness varies from print to print. For example, even when a solid, solid-color pattern is recorded on the same type of recording medium, density unevenness occurs in the printed image. The technology disclosed herein utilizes this uncertainty in the color density to authenticate the authenticity of the ID card 14.

[0060] One reason for the uncertainty in color density in instant film 15 is that the distribution of the developer spread across the recording surface during the development process is not uniform across the entire recording surface. Another reason is that the distribution of the photosensitive material, which is the color-producing material, is also uneven across the entire recording surface. Thus, even within a single instant film 15, unevenness in the developer and photosensitive material occurs across the recording surface.

[0061] Therefore, as shown in FIG. 7, even if four authenticity verification images 57A, 57B, 57C, and 57D are provided on an instant film 15 based on a single authenticity verification pattern 50, the four authenticity verification images 57A, 57B, 57C, and 57D exhibit different density characteristics. The graph shown in FIG. 8 illustrates first frequency characteristics 56A, 56B, 56C, and 56D, which represent the density characteristics of the four authenticity verification images 57A, 57B, 57C, and 57D. Each of the first frequency characteristics 56A, 56B, 56C, and 56D is derived by Fourier analysis of each of the authenticity verification images 57A, 57B, 57C, and 57D. In FIG. 8, the horizontal axis represents frequency, the vertical axis represents power, and the first frequency characteristics 56A, 56B, 56C, and 56D are frequency spectra that indicate the degree of density unevenness at each frequency. Overall, there is a tendency for density unevenness to be relatively greater in the low frequency region and relatively less in the high frequency region, but there are subtle differences between the four first frequency characteristics 56A, 56B, 56C, and 56D.

[0062] In this way, density characteristics vary depending on the location even on a single instant film 15. Therefore, if the instant film 15 is different, the density characteristics of the same authenticity verification image 57 printed in the same location will also change. Therefore, for example, even if an ID card 14 is counterfeited by printing the same facial image on the instant film 15, it is possible to identify whether the ID card 14 is genuine or counterfeit by using the authenticity verification image 57.

[0063] The technology disclosed herein authenticates the authenticity of the ID card 14 by utilizing the uncertainty of color density, which is the difference in the occurrence of density unevenness between prints, even when the same image is printed on the same type of recording medium. The occurrence of density unevenness is manifested as the frequency characteristics of the color density of the image. Therefore, the technology disclosed herein authenticates the authenticity of the ID card 14 by utilizing the difference in the frequency characteristics of the color density of the image between prints, even when the same image is printed on the same type of recording medium.

[0064] Furthermore, the difference in density characteristics becomes more pronounced when the printing method is different. Figures 9 and 10 are graphs showing the difference in density characteristics due to different printing methods. Figure 9 shows the frequency characteristics DP-INST of an instant printing method that uses instant film 15 and the frequency characteristics DP-INK of an inkjet printing method that records images by spraying ink onto plain paper. Comparing the two, as shown in Figure 9, the frequency characteristics DP-INST of the instant printing method have more density unevenness in the low-frequency range and less density unevenness in the high-frequency range compared to the frequency characteristics DP-INK of the inkjet printing method. The instant printing method uses a density modulation method, while the inkjet printing method uses an area modulation method that changes gradation depending on the dot density. As shown in Figure 9, the inkjet printing method has relatively more density unevenness in the high-frequency range, which indicates that images printed using the inkjet printing method have a relatively stronger graininess.

[0065] Figure 10 is a graph showing the frequency characteristics DP-INST of the instant printer and DP-THR of the dye-sublimation thermal printer. The dye-sublimation thermal printer uses a thermal head to heat sublimation dye ink applied to an ink ribbon, melting the ink and transferring it to specially coated paper, such as polyester-based resin. Both the instant printer and the dye-sublimation thermal printer use density modulation. However, as shown in Figure 10, there are differences in the density characteristics of the two printers, with the dye-sublimation thermal printer showing more density unevenness in the frequency range circled by the dashed line than the instant printer.

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

[0067] 11 , the authentication device 6 includes a computer 60, an accepting 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 accepting device 70, and the display 72 are connected to one another via a bus 74.

[0068] The CPU 60A controls the entire authentication device 6. The NVM 60B is a non-volatile memory. Here, an EEPROM is used as an example of the NVM 32B, but it is not limited to this and may be a flash memory or a combination of multiple 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, for example, a device having an FPGA. The communication I / F 60D is connected to the database 24 by wire, and controls the exchange of various information between the CPU 60A and the database 24. The communication I / F 60D is also connected to a plurality of POS terminals 19 via LAN cables or the like, and controls 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 mouse receive instructions for the authentication apparatus 6 in response to operations by an attendant. The display 72 is used to display various information under the control of the CPU 60A.

[0071] An 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 a personal authentication unit 64, a validity authentication unit 66, and an 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 executed when the authentication device 6 receives an authentication request 76 from at least one of the multiple POS terminals 19. The personal authentication unit 64, the validity authentication unit 66, and the authenticity authentication unit 68 are examples of a "second processor" according to the technology of the present disclosure.

[0072] An example of the authentication process performed by the authentication device 6 will be specifically described below with reference to FIGS.

[0073] 12 , the POS terminal 19 includes a computer 78, an accepting 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 accepting device 86, the video camera 80, the display 82, and the printer 84 are connected to one another via a bus 85.

[0074] The CPU 78A controls the entire POS terminal 19. The NVM 78B is a non-volatile memory. Here, an EEPROM is used as an example of the NVM 78B, but it is not limited to this and may be a flash memory or a combination of multiple non-volatile memories. The NVM 78B stores various programs as well as sales data processed by the POS terminal 19. 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 accepting device 86 includes a camera 86A, a barcode reader 86B, and input keys 86C. The camera 86A has the same imaging capabilities, i.e., lens performance, filter performance, and imaging element performance, as the camera 34 built into the issuing device 4. The camera 86A captures 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 such as the product name and price of each product. The input keys 86C include a numeric keypad and are used to manually input information such as information about each product into the POS terminal 19. The camera 86A is an example of a "camera" according to the technology of the present disclosure.

[0076] The display 82, under the control of the CPU 78A, is used to present the purchase amount to the participant 11. The printer 84 prints a receipt showing the contents of the purchase.

[0077] When participant 11 goes shopping at store 16, for example, cashier 17 at store 16 has barcode reader 86B read the barcode attached to the product that participant 11 is purchasing. CPU 78A calculates the purchase amount based on the product information contained in the barcode read by barcode reader 86B.

[0078] When paying at a store 16, a participant 11 presents their ID card 14, i.e., the ID card 14 to be authenticated, to a cashier 17. When the cashier 17 brings the presented ID card 14 close to the camera 86A, the camera 86A, under the control of the CPU 78A, captures an authentication image 21 included in the ID card 14 to be authenticated. The CPU 78A detects area marks 51 arranged at the four corners of the authentication image 21 from the image captured by the camera 86A, and cuts out the area surrounded by the area marks 51 to acquire it as a second captured image 88. Also, under the control of the CPU 78A, the video camera 80 captures an image of the participant 11 standing in front of the POS terminal 19 for one to several seconds, thereby acquiring a video 90 including several dozen frame images. The POS terminal 19 then transmits an authentication request 76 to the authentication device 6, including the second captured image 88, the video 90, and a second capture time 89 indicating the time when the camera 86A captured the authentication image 21 included in the ID card 14. The second captured image 88 is an example of the "second captured image" according to the technique of the present disclosure.

[0079] 13 as an example, the personal authentication unit 64 performs personal authentication processing when receiving an authentication request 76 from the POS terminal 19. Specifically, the personal authentication unit 64 acquires a second captured image 88 included in the authentication request 76. The personal authentication unit 64 performs specific arithmetic processing on the acquired second captured image 88 to extract, from the second captured image 88, the first facial feature value 47 embedded as a digital watermark 52 in the authentication image 21.

[0080] The personal authentication unit 64 extracts a second facial image 92 representing a person's face from a frame image included in the video 90. The second facial image 92 can be extracted using a known facial recognition technique similar to the extraction method for the first facial image 45 described above. The personal authentication unit 64 extracts, for example, the face of the person extracted first from the faces of people extracted from the multiple frame images included in the video 90 as the second facial image 92. The personal authentication unit 64 extracts a second facial feature amount 94 from the extracted second facial image 92. The second facial feature amount 94 is similar to the first facial feature amount 47, and can be extracted using the same known feature extraction technique as the first facial feature amount 47.

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

[0082] 14 , the validity authentication unit 66 performs a validity authentication process when receiving an authenticated signal from the identity authentication unit 64. Specifically, the validity authentication unit 66 extracts, from the second captured image 88, the validity authentication information 48 embedded as a digital watermark 52 in the authentication image 21 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 or not there is validity authentication information 48 matching the validity authentication information 48 extracted from the second captured image 88. If the validity authentication information 48 matching the validity authentication information 48 extracted from the second captured image 88 is present in the participant data 26, the validity authentication unit 66 determines that the ID card 14 has valid access rights to the authentication system 2. In this case, the validity authentication unit 66 outputs to the authenticity authentication unit 68 a signal indicating that the validity has been authenticated (hereinafter referred to as a "validity authenticated signal").

[0083] As an example, as shown in FIG. 15 , when the authenticity verifying unit 68 receives an authenticated signal from the authenticity verifying unit 66, the authenticity verifying unit 68 performs an authenticity verifying process. The authenticity verifying process includes a first process for verifying authenticity by utilizing uncertainty in the color density of the authenticity verifying image 57, and a second process for verifying authenticity by utilizing changes over time in the color density of the authenticity verifying image 57. First, in the first process, the authenticity verifying unit 68 acquires the second captured image 88 included in the authentication request 76. The authenticity verifying unit 68 extracts the authenticity verifying image 57 from the acquired second captured image 88 by, for example, pattern matching. The authenticity verifying unit 68 optically scans the extracted authenticity verifying image 57 to acquire the color density characteristics of the authenticity verifying image 57, i.e., a second frequency characteristic 96 indicating density unevenness.

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

[0085] In the second process, the authenticity verifying unit 68 verifies the authenticity by comparing the color density characteristics while taking into account the change in color density of the authenticity verification image 57 over time. As shown in FIG. 16 as an example, it is known that the color density of an image printed on an instant film 15 changes over time. The change in color density over time varies depending on the printed color. The graph shown in FIG. 16 shows, for example, the change in color density over time of the authenticity verification image 57 from the first image capture time 54. In FIG. 16, 0 minutes indicates the time when the authentication image 21 is printed on the instant film 15 by the printer 20, and the first image capture time 54 indicates the time when the authentication image 21 printed on the instant film 15 is captured by the camera 34. The first image capture time 54 is the time several to several tens of seconds after the authentication image 21 is printed on the instant film 15.

[0086] In Figure 16, the vertical axis represents brightness; the higher the brightness, the lower the density, and the lower the brightness, the higher the density. As Figure 16 shows, color development on instant film 15 progresses rapidly within a short period of time (approximately 3 minutes) immediately after printing, resulting in a rapid increase in density (decrease in brightness) during this period. The density increase thereafter is gradual. The change in color density of instant film 15 over time follows the trend shown in Figure 16, making it possible to predict the color density of instant film 15 at any given time based on the amount of time that has passed since printing.

[0087] The database 24 stores in advance a density change table 98 that indicates the change over time in the color density of the authenticity verification image 57. Here, the change over time in the color density is a value derived, for example, by testing using an actual device and / or computer simulation. Note that instead of the density change table 98, an arithmetic expression may be used in which the elapsed time from the first image capture time 54 is the independent variable and the color density is the dependent variable.

[0088] 17 as an example, in the second process, the authenticity verifying unit 68 reads from the database 24 the first image capture time 54 stored in the participant data 26 in association with the authenticity verification information 48 searched for by the authenticity verification unit 66 in the authenticity verification process shown in FIG. 14. The authenticity verifying unit 68 calculates the elapsed time from the first image capture time 54 to the second image capture time 89 by taking the difference between the second image capture time 89 included in the authentication request 76 and the first image capture time 54. The authenticity verifying unit 68 uses a 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 verifying 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 verifying 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 verifying unit 68 determines that the ID card 14 is not a counterfeit. In this case, the authenticity verifying unit 68 transmits an authentication signal to the POS terminal 19 indicating that the ID card 14 has been authenticated.

[0091] Next, the operation of the authentication system 2 according to this embodiment will be described with reference to Fig. 18 to Fig. 20. 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 process shown in Fig. 19 to Fig. 20 is realized by the CPU 60A of the authentication device 6 executing the authentication program 62.

[0092] 18 is started 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 facial 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 or not the first facial image 45 has been extracted from the original image 10. If the first facial image 45 has been extracted in step ST101, the determination is affirmative, and the ID card issuance process proceeds to step ST102. If the first facial image 45 has not been extracted, the determination is negative, and the ID card issuance process ends.

[0093] In step ST102, the authentication image generating unit 40 acquires the new serial number 27 and the validity authentication information 48 corresponding to the accepted ID card issuance request 18. After that, the ID card issuance process proceeds to step ST103.

[0094] In step ST103, the authentication image generating unit 40 associates the acquired serial number 27 and validity authentication information 48 with the original image 10 and the first facial 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 generating unit 40 extracts the first facial feature amount 47 from the first facial image 45. After that, the ID card issuance process proceeds to step ST105.

[0096] In step ST105, the authentication image generation unit 40 digitally watermarks the extracted first facial feature amount 47 and the acquired validity authentication information 48 and embeds the watermarked image 49 in the original image 10. After that, the ID card issuance process proceeds to step ST106.

[0097] In step ST106, the authentication image generating unit 40 reads out 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 the authentication image 21 by combining the read authenticity verification pattern 50 and area mark 51 with the generated digital watermark embedded 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. As a result, the printer 20 prints the authentication image 21 on the instant film 15. After that, the ID card issuance process proceeds to step ST109.

[0100] In step ST109, the ID card output unit 42 controls the camera 34 to capture an image of the instant film 15 on which the authentication image 21 is printed. As a result, the camera 34 captures the authentication image 21 printed on the instant film 15, and the ID card output unit 42 acquires the image captured by the camera 34 as a first captured image 46. After the image is captured by the camera 34, the instant film 15 on which the authentication image 21 is printed is discharged outside the issuing device 4 as an 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 capturing time 54 indicating the time when the first captured image 46 was captured in the database 24 in association with the serial number 27, the authenticity authentication information 48, the original image 10, and the first facial 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, from the first captured image 46, the authenticity verification image 57 located in the lower right corner of 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, from the extracted authenticity check image 57, the first frequency characteristic 56 indicating density unevenness in the authenticity check image 57. After that, 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 association with the first captured image 46 in the database 24. After this, the ID card issuance process ends.

[0105] 19 and 20 is started when the personal authentication unit 64 receives an authentication request 76 from the POS terminal 19. The authentication process includes personal authentication process shown in steps ST201 to ST205, validity authentication process shown in steps ST206 and ST207, and authenticity authentication process shown in steps ST208 to ST216. The authenticity authentication process is broadly divided 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 the first facial feature 47 embedded as the digital 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 facial feature 47 has been extracted from the digital watermark 52 included in the second captured image 88. If the first facial feature 47 has been extracted in step ST201, the determination is affirmative, and the personal authentication process proceeds to step ST202. If the first facial feature 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 facial image 92 from the video 90 included in the authentication request 76. In step ST202, the personal authentication unit 64 determines whether or not the second facial image 92 has been extracted from the video 90. If the second facial image 92 has been extracted in step ST202, the determination is affirmative, and the personal authentication process proceeds to step ST204. If the second facial image 92 has not been extracted, the determination is negative, and the personal authentication process proceeds to step ST203.

[0108] If the second facial image 92 is not extracted from the video 90, in step ST203, the personal authentication unit 64 causes the CPU 78A of the POS terminal 19 to operate the video camera 80 and retransmit the video 90 captured by the video camera 80. After this, the personal authentication process proceeds to step ST202.

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

[0110] In step ST205, the personal authentication unit 64 determines whether or not the difference between the extracted first facial feature amount 47 and the second facial feature amount 94 is within a predetermined range. If the difference between the first facial feature amount 47 and the second facial 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 and ST207. If the difference between the first facial feature amount 47 and the second facial 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 authentication process, first, the authenticity authentication unit 66 extracts the authenticity authentication information 48 from the digital watermark 52 included in the second captured image 88. In step ST206, the authenticity authentication unit 66 determines whether or not the authenticity authentication information 48 has been extracted from the digital watermark 52 included in the second captured image 88. If the authenticity authentication information 48 has been extracted in step ST206, the determination is affirmative, and the authenticity authentication process proceeds to step ST207. If the authenticity authentication information 48 has not been extracted, the determination is negative, and the authentication process proceeds to step ST218.

[0112] The authenticity authentication unit 66 searches the extracted authenticity authentication information 48 within the participant data 26 of the database 24. In step ST207, the authenticity authentication unit 66 determines whether or not the extracted authenticity authentication information 48 exists in the participant data 26 of the database 24. If the authenticity authentication information 48 exists in the participant data 26 in step ST207, the determination is affirmative, and the authenticity authentication process proceeds to the authenticity authentication process shown in steps ST208 to ST216. If the authenticity authentication 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 step of the authenticity authentication process, first, in step ST208, the authenticity authentication unit 68 acquires the first frequency characteristic 56 stored in the participant data 26 in association with the authenticity authentication information 48 extracted in the authenticity authentication process. After this, the authenticity authentication process proceeds to step ST209.

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

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

[0116] In step ST211, the authenticity verifying unit 68 determines whether or not the difference between the first frequency characteristic 56 and the second frequency characteristic 96 is within a predetermined range. 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 verifying process proceeds to a 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 step of the authenticity authentication process, first, in step ST212, the authenticity authentication unit 68 acquires the first image capture time 54 stored in the participant data 26 of the database 24 in association with the authenticity authentication information 48 extracted in the authenticity authentication process. After this, the authenticity authentication process proceeds to step ST213.

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

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

[0120] In step ST215, the authenticity verifying section 68 measures the color density 100 of the authenticity check image 57 extracted from the second captured image 88. After this, the authenticity verifying 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. If the difference between the color density 100 and the predicted color density 99 is within the predetermined range in step ST216, the determination is affirmative, 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 negative, 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 through the personal authentication process, the validity authentication process, and the authenticity authentication process, from the authentication device 6 to the POS terminal 19 that is the sender 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 one of the personal authentication process, the validity authentication process, and the authenticity authentication process, from the authentication device 6 to the POS terminal 19 that is the sender 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 generation unit 40 of the issuing device 4 acquires a first facial image 45 from the original image 10 capturing an image of the face of the participant 11. The authentication image generation unit 40 generates an authentication image 21 including the first facial image 45 and 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 generation unit 40 on the instant film 15. The ID card output unit 42 acquires a 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 as an ID card 14 to the outside.

[0125] Therefore, with this configuration, the ID card 14 can be created by printing the authentication image 21 on the instant film 15. The authentication device 6's authenticity verifying unit 68 acquires, as a second captured image 88, an image obtained by capturing the authentication image 21 printed on the ID card 14 to be authenticated using the camera 86A. 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 acquired from the database 24 with those of the second captured image 88. Comparing image density characteristics is a relatively common technique in the image processing field. Therefore, with this configuration, it is possible to provide an authentication system 2 capable of issuing ID cards 14 that can perform identity authentication and legitimacy authentication easily and quickly at low cost and with a simple configuration, compared to, for example, providing an IC memory in the ID card to achieve identity authentication, legitimacy authentication, and legitimacy authentication.

[0126] Furthermore, according to this embodiment, the authenticity verifying unit 68 verifies the authenticity of the ID card 14 by utilizing the uncertainty of color density, which is the difference in density unevenness that occurs with each print, even when the same image is printed on the same type of instant film 15. Therefore, according to this configuration, the authenticity of the ID card 14 can be verified with a simple configuration and at low cost by using a relatively common technique in the image processing field, which is to compare differences in density unevenness between images.

[0127] Furthermore, according to this embodiment, the authenticity verifying unit 68 verifies the authenticity of the ID card 14 to be authenticated by utilizing the fact that the frequency characteristics of the color density of each image differ even when the same image is printed on the same type of instant film 15. Therefore, according to this configuration, the authenticity of the ID card 14 can be verified with a simple configuration and at low cost by using a relatively common technique in the image processing field that compares the differences in the frequency characteristics of the color density of each image.

[0128] Furthermore, according to this embodiment, the authenticity verifying unit 68 verifies the authenticity of the ID card 14 by comparing the density characteristics while taking into account changes over time in the color density 100 of the authentication image 21 printed on the ID card 14 to be authenticated. Therefore, according to this configuration, even if the color density 100 of the ID card 14 to be authenticated changes over time, more accurate authenticity verification can be performed than when the change over time is not taken into account.

[0129] Furthermore, according to this embodiment, a portion of the authentication image 21 includes an authenticity verification pattern 50 used for comparing density characteristics. The authenticity verifying unit 68 verifies the authenticity of the ID card 14 by comparing the density characteristics of an authenticity verification image 57 showing the authenticity verification pattern 50 in the first captured image 46 with an authenticity verification image 57 showing the authenticity verification pattern 50 in the second captured image 88. Therefore, according to this configuration, since only the authenticity verification image 57 is compared, compared to comparing the density characteristics of the entire first captured image 46 and the second captured image 88, the processing load on the authentication device 6 required for authenticity verification can be reduced.

[0130] In addition, in this embodiment, the authenticity verification pattern 50 is a solid pattern consisting of a single solid color. Therefore, this configuration makes it easier to compare the density characteristics of the authenticity verification image 57 between the first captured image 46 and the second captured image 88 than when using a verification pattern that includes multiple colors.

[0131] Furthermore, according to this embodiment, the printer 20 is a density modulation printer. Images printed using a density modulation printer have different frequency characteristics and color reproducibility than images printed using an area modulation printer, such as an inkjet printer. Therefore, this configuration makes it possible to provide an authentication system 2 that can easily detect counterfeit ID cards 14 that have been counterfeited using an area modulation printer by utilizing the differences in frequency characteristics and color reproducibility between the area modulation printer and the image printed using a density modulation printer.

[0132] Furthermore, according to this embodiment, the printer 20 is an instant photo printer that uses instant film 15, which develops color using a photosensitive material containing silver halide, as the recording medium. Therefore, this configuration allows for the instant issuance of ID cards 14 by using an instant photo printer as the printer 20. Furthermore, instant film 15 has non-uniformity in the photosensitive material and non-uniformity in the developer on the recording surface. Therefore, even if the same image is recorded in the same location on multiple instant film 15, the density characteristics will differ. By utilizing these characteristics of instant film 15, even if an ID card 14 is counterfeited using the same type of instant film 15 as a legitimate ID card 14, the authenticity of the ID card 14 can be verified 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 facial image 92. The identity authentication unit 64 compares the first facial feature amount 47 extracted from the first facial image 45 included in the second captured image 88 with the second facial feature amount 94 extracted from the second facial image 92, thereby authenticating that the owner of the ID card 14 to be authenticated is the creator of the ID card 14. Therefore, according to this configuration, compared to visually comparing the first facial image 45 included in the ID card 14 to be authenticated with the face of the owner of the ID card 14 to be authenticated, an administrator is not required to perform the comparison, and the accuracy of identity authentication is improved.

[0134] Furthermore, according to this embodiment, the authentication image generation unit 40 embeds the first facial feature 47 extracted from the first facial image 45 into the authentication image 21. The personal authentication unit 64 compares the first facial feature 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 94 extracted from the second facial image 92, thereby authenticating that the person is the owner of the ID card 14. Therefore, according to this configuration, the first facial feature 47 is embedded in the authentication image 21, and personal authentication is performed based on the first facial feature 47 extracted from the authentication image 21. Compared to extracting the first facial feature 47 from the first facial image 45 each 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 it is possible to provide a highly secure ID card 14.

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

[0137] Furthermore, according to this embodiment, the camera 34 that acquires 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 generation unit 40, the ID card output unit 42, the first frequency characteristic acquisition unit 44, the printer 20, and the camera 34 are provided in separate housings.

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

[0139] In the above embodiment, the camera 34 capturing the first captured image 46 and the camera 86A capturing the second captured image 88 have the same imaging capabilities. However, the technology of the present disclosure is not limited to this. The camera 34 capturing the first captured image 46 and the camera 86A capturing the second captured image 88 may have different imaging capabilities. In this case, as shown in FIG. 21 as an example, the authenticity verification unit 68 may correct the second captured image 88 based on the difference in imaging capabilities between the camera 34 and the camera 86A, and verify the authenticity of the ID card 14 using the corrected second captured image 88. Therefore, this configuration improves the accuracy of authenticity verification compared to when the second captured image 88 captured by the camera 86A, which has different imaging capabilities from the camera 34, is used for authenticity verification as is.

[0140] Furthermore, in the above embodiment, an example in which the printer 20 is an instant photo printer has been described, but the technology of the present disclosure is not limited to this. The printer 20 may be, for example, a dye-sublimation printer using the dye-sublimation thermal transfer method described above. Furthermore, a dye-sublimation printer can also use a plastic card as a recording medium instead of dedicated coated paper. When using a dye-sublimation printer, the ID card 14 may be created by printing the authentication image 21 on a plastic card. Furthermore, the printer 20 may also be an inkjet printer using an inkjet method. As shown in FIGS. 9 and 10 , density characteristics differ depending on the printing method. Therefore, even when 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 using a different printing method.

[0141] Similarly to instant photo printers, dye-sublimation printers other than instant photo printers also experience uncertainty in color density, as density variations vary from print to print when printing the same image on the same type of recording medium. For example, dye-sublimation printers experience thermal fluctuations due to heat generation and heat accumulation in the thermal head, resulting in density variations from print to print, even when printing the same image on the same type of recording medium. Inkjet printers also experience variations in the dot landing position, resulting in density variations from print to print, even when printing the same image 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-uniformities in the photosensitive material and developer, so issuing ID cards 14 with an instant photo printer makes it easier to utilize the uncertainty of color density in authenticating ID cards 14 than issuing ID cards 14 with a dye-sublimation printer or inkjet printer. Therefore, an instant photo printer is preferable to a dye-sublimation printer or inkjet printer as printer 20.

[0143] Instant film 15 also differs from dye-sublimation printers and inkjet printers, which use subtractive color-mixing methods that produce Y (yellow), M (magenta), and C (cyan) in that it uses an additive color-mixing method that uses photosensitive materials that produce B (blue), G (green), and R (red). Because there is a large difference in density characteristics between additive and subtractive color-mixing methods, using an instant photo printer as printer 20 to issue ID cards 14 makes it easier to detect counterfeit ID cards 14 made with dye-sublimation printers and inkjet printers.

[0144] As mentioned 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 density unevenness in inkjet printers is caused by fluctuations in the landing position of dots, which are controlled by mechanical position control of the inkjet head. The cause of density unevenness in density modulation printers is nonuniformity between the photosensitive material and the developer in instant photo printers, and thermal fluctuations due to heat generation and heat accumulation in the thermal head in dye-sublimation printers. This is because controlling nonuniformity between the photosensitive material and the developer or thermal fluctuations in the thermal head is more difficult than controlling the mechanical position of the inkjet head.

[0145] The technology disclosed herein utilizes the uncertainty of the printer's color density to authenticate the authenticity, so the greater the uncertainty of the color density, the more preferable the printer for use with the technology disclosed herein. Therefore, density gradation printers such as instant photo printers and dye-sublimation printers are more preferable than area gradation printers such as inkjet printers.

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

[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 require higher reading accuracy because they have less uncertainty in color density compared to instant film 15. 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 higher reading accuracy.

[0148] In addition, in the above embodiment, an example is described in which the issuing device 4 has a built-in camera 34 and printer 20, but the technology disclosed herein 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. However, 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 housed in the same housing, or at least two of the issuing device 4, the authentication device 6, and the database 24 may be housed in the same housing. When the issuing device 4 and the authentication device 6 are housed in the same housing, a single computer may function as both the computer 32 and the computer 60.

[0150] Furthermore, in the above embodiment, an example of an embodiment in which the authentication system 2 is used at an event where eating and drinking and / or merchandise are sold has been described, but the technology of the present disclosure is not limited to this, and the authentication system 2 may be used in commercial facilities where payments are made at multiple locations, including shopping malls, shopping streets, hotels, inns, etc. Furthermore, in the above embodiment, an example of an embodiment in which the authentication system 2 manages payment information 30 for each participant 11 has been described, but the technology of the present disclosure is not limited to this, and the authentication system 2 may be used to manage the entrance and exit of participants 11 at, for example, highly confidential facilities, member-only facilities, and private events such as weddings.

[0151] In the above embodiment, an example of the authentication process being performed in the order of identity authentication process, validity authentication process, and authenticity authentication process has been described, but the technology of the present disclosure is not limited to this, and the order in which identity authentication process, validity authentication process, and authenticity authentication process are performed can be changed as appropriate. Furthermore, identity authentication process, validity authentication process, and authenticity authentication process can also be performed in parallel.

[0152] In the above embodiment, the authenticity verification process includes a first process that utilizes the uncertainty of the color density of the authenticity verification image 57 and a second process that utilizes the change over time in the color density of the authenticity verification image 57. However, the technology of the present disclosure is not limited to this. The authenticity verification 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 they may be performed in parallel.

[0153] Furthermore, in the above embodiment, an example in which the authenticity verification pattern 50 is 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 verification pattern 50 may be placed anywhere in the authentication image 21. Furthermore, the authenticity verification pattern 50 may be placed in a location other than the digital watermark embedded image 49. Furthermore, the number of authenticity verification patterns 50 is not limited to one, and multiple authenticity verification patterns 50 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 covers 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 verification process using a plurality of authenticity verification images 57, the accuracy of the authenticity verification process can be improved compared to when the authenticity verification process is performed using a single authenticity verification image 57. This is because there are more targets for comparing density characteristics.

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

[0157] Furthermore, printing a plurality of authenticity verification images 57 increases the resistance to reading errors of the authenticity verification images 57 caused by disturbances such as dirt, improving robustness.

[0158] Furthermore, two-dimensional codes 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. Two-dimensional codes such as a QR code (registered trademark) are composed of solid pattern blocks of several millimeters square, so it is possible to use part of the two-dimensional code as the authenticity verification pattern 50 and the authenticity verification image 57. Furthermore, using a two-dimensional code makes it easy to use existing software such as a two-dimensional code reader to read the authenticity verification image 57.

[0159] The authenticity verification 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 square, and may be other shapes such as a circle, a polygon, a rectangle, or a strip.

[0160] As mentioned above, the size of the authenticity verification image 57 only needs to be a few millimeters square. This size allows the density characteristics necessary for comparison to be obtained by scanning the image at a resolution of, for example, about 600 dpi (dots per inch). Because the authenticity verification image 57 is relatively small, it is easy to provide multiple images on the ID card 14.

[0161] Furthermore, 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 capture the audio of the participant 11. The captured audio information is then registered in the database 24. A URL that allows access to the audio information is recorded on the ID card 14. The audio information thus registered is used as authentication information for identity authentication or authenticity authentication.

[0162] Furthermore, in the above embodiment, the computers 32, 60, and 78 are exemplified, but the technology of the present disclosure is not limited to this. For example, devices including an ASIC (application specific integrated circuit), an FPGA, and / or a PLD (programmable logic device) may be applied instead of the computers 32, 60, or 78. Furthermore, a combination of hardware and software configurations may be used instead of the computers 32, 60, or 78.

[0163] In the above embodiment, an example in which the ID card issuance process is executed by the CPU 32A of the issuing device 4 has been described, but the technology of the present disclosure is not limited to this. Instead of the CPU 32A, a GPU (graphics processing unit) or multiple CPUs may be used. Furthermore, various processes may be executed by a single processor or multiple physically separated processors.

[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) or multiple CPUs may be used. Furthermore, various processes may be executed by a single processor or multiple processors that are physically separated from each other.

[0165] Furthermore, 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. For 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] Alternatively, the ID card issuance program 38 may be stored in a program memory of another computer or 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] Furthermore, 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. For 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 authentication processing in accordance with the installed authentication program 62.

[0168] Alternatively, the authentication program 62 may be stored in a 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] The hardware resources that execute the ID card issuance process and authentication process can be various processors, as listed below. As a processor, for example, as mentioned above, there is a CPU, which is a general-purpose processor that functions as a hardware resource that executes data processing according to software, i.e., a program.

[0170] Other processors include dedicated electrical circuits, which are processors having circuit configurations specifically designed to perform specific processes, such as FPGAs, PLDs, or ASICs. All processors have built-in or connected memory, and all processors perform data processing by using the memory.

[0171] The hardware resource that executes data processing may be configured with one of these various processors, or may be configured with a combination of two or more processors of the same or different types (for example, a combination of multiple FPGAs, or a combination of a CPU and an FPGA). Also, the hardware resource that executes data processing may be a single processor.

[0172] Examples of systems configured with a single processor include, first, a system in which one processor is configured with a combination of one or more CPUs and software, as typified by client and server computers, and this processor functions as a hardware resource that executes data processing. Second, a system in which a processor is used to implement the functions of an entire system, including multiple hardware resources that execute data processing, on a single IC chip, as typified by SoCs (system-on-a-chips). In this way, data processing is implemented using one or more of the above-mentioned various processors as hardware resources.

[0173] Furthermore, more specifically, the hardware structure of these various processors can be an electric circuit that combines circuit elements such as semiconductor elements.

[0174] Furthermore, the data processing described above is merely an example, and it goes without saying that unnecessary steps may be deleted, new steps may be added, or the processing order may be changed, without departing from the spirit of the invention.

[0175] The above-described description and illustrations are a detailed explanation of the parts related to the technology of the present disclosure and are merely an example of the technology of the present disclosure. For example, the above description of the configuration, functions, actions, and effects is an explanation of an example of the configuration, functions, actions, and effects of the parts related to the technology of the present disclosure. Therefore, it goes without saying that unnecessary parts may be deleted, new elements may be added, or replacements may be made to the above-described description and illustrations within the scope of the gist of the technology of the present disclosure. Furthermore, to avoid confusion and facilitate understanding of the parts related to the technology of the present disclosure, the above-described description and illustrations omit explanations of common technical knowledge that do not require particular explanation to enable the implementation of the technology of the present disclosure.

[0176] In this specification, "A and / or B" is synonymous with "at least one of A and B." In other words, "A and / or B" means that it may be only A, only B, or a combination of A and B. Furthermore, in this specification, the same concept as "A and / or B" is also applied when three or more things are expressed connected by "and / or."

[0177] All publications, patent applications, and technical standards mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, or technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. An ID card authentication system including an issuing device that issues an ID card and an authentication device that authenticates the ID card, the issuing device includes a first processor; The first processor acquiring a first face image capturing a face of a person; outputting 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 authenticity on a card-shaped recording medium; a first captured image obtained by capturing the authentication image printed on the ID card with a camera is stored in a memory; the authentication device includes a second processor; The second processor an image obtained by capturing an authentication image printed on the ID card to be authenticated with a camera is acquired as a second captured image; The authenticity of the ID card to be authenticated is verified 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 system.

2. The ID card authentication system described in claim 1, wherein the second processor authenticates the authenticity of the ID card to be authenticated by utilizing the uncertainty of color density, which is the occurrence of density unevenness that differs from print to print, even when the same image is printed on the same type of recording medium.

3. The ID card authentication system described in 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 differ for each print, even when the same image is printed on the same type of recording medium.

4. An ID card authentication system described in any one of claims 1 to 3, wherein the second processor certifies the authenticity of the ID card to be authenticated by comparing the density characteristics while taking into account changes over time in the color density of the authentication image printed on the ID card to be authenticated.

5. a part of the authentication image includes a matching portion used for comparing density characteristics; The second processor verifies the authenticity of the ID card by comparing density characteristics of the matching portion of the first captured image and the second captured image.

5. An ID card authentication system according to claim 1.

6. 6. The ID card authentication system according to claim 5, wherein the matching portion is a solid pattern made up of a single solid color.

7. 7. The ID card authentication system according to claim 1, wherein the printer is a density modulation type printer.

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

9. The second processor acquiring a second face image of the face of the person who holds the ID card to be authenticated; By comparing the facial feature amount extracted from the first facial image included in the second captured image with the facial feature amount extracted from the second facial image, the owner of the ID card to be authenticated is authenticated.

9. The ID card authentication system according to claim 1.

10. The first processor Embedding facial features extracted from the first face image into the authentication image; The second processor 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 person is authenticated as the owner of the ID card. The ID card authentication system according to claim 9.

11. 11. The ID card authentication system according to claim 10, wherein the authentication information and the facial feature amount are embedded in the authentication image as a digital watermark.

12. 12. The ID card authentication system according to claim 1, wherein the first processor and the printer are built into a single housing.

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

14. The ID card authentication system according to claim 1 , wherein the first captured image and the second captured image are acquired by cameras having the same imaging performance.

15. The second processor correcting the second captured image based on a difference in imaging performance between a camera that captures the first captured image and a camera that captures the second captured image; The corrected second captured image is used to authenticate the authenticity of the ID card to be authenticated.

15. An ID card authentication system according to any one of claims 1 to 14.

16. An ID card authentication method using an ID card issuing device and an ID card authentication device, comprising: a first face image acquisition step of acquiring a first face image obtained by capturing an image of a person's face; an output step of printing an authentication image including the first face image and authentication information for authenticating authenticity on a card-shaped recording medium, and outputting the authentication image to a printer that issues ID cards; a storage step of storing a first captured image of the authentication image printed on the ID card in a memory, the first captured image being captured by a camera; a second captured image acquisition step of capturing an authentication image printed on an ID card to be authenticated by a camera to acquire the second captured image; and an authentication step of authenticating the authenticity of the ID card to be authenticated by comparing density characteristics of the first captured image acquired from the memory and the second captured image acquired from the camera. ID card authentication method.

17. An ID card authentication program for operating an ID card authentication system including a first computer that issues ID cards and a second computer that authenticates ID cards, a first face image acquisition unit that acquires a first face image obtained by capturing an image of a person's face; an output unit that outputs an authentication image including the first facial image and authentication information for authenticating authenticity to a printer that issues an ID card by printing the authentication image on a card-shaped recording medium; The first computer is configured to function as a storage unit that stores a first captured image of the authentication image printed on the ID card by a camera in a memory, and a second captured image acquisition unit that acquires an authentication image printed on an ID card to be authenticated as a second captured image by using a camera; and causing the second computer to function as an authentication unit that authenticates the authenticity of the ID card to be authenticated by comparing 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