Authenticity determination system, authenticity determination device, computer program and authenticity determination method

Abstract

To provide an authenticity determination system, an authenticity determination device, a computer program, and an authenticity determination method that can improve accuracy of authenticity determination by photographing a target medium under more appropriate photographing conditions.SOLUTION: An authenticity determination system includes an authenticity determination device and a terminal device having a light-emitting unit and an imaging unit. The terminal device transmits time-series images obtained by photographing a target medium to the authenticity determination device. The authenticity determination device determines whether or not the target medium was photographed under a photographing condition that allows a hologram image to be identified based on the time-series images, and transmits update information for updating the photographing condition to the terminal device if it was not photographed under the photographing condition that allows the hologram image to be identified. The terminal device transmits time-series images obtained by photographing the target medium using the update information to the authenticity determination device.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a genuine / fake determination system, a genuine / fake determination device, a computer program, and a genuine / fake determination method.

Background Art

[0002] For credit cards, banknotes, stock certificates, gift certificates, luxury brand products, etc., media on which information for preventing duplication and forgery is recorded are used. For such media, security technologies such as holograms that are difficult to duplicate are utilized.

[0003] In recent years, portable terminals such as high-performance cameras capable of taking flash photos and high-quality photos and smartphones equipped with advanced image processing functions have become widely popular. Even without special skills or expertise, it is reasonable to perform genuine / fake determination of media by using the functions provided by such portable terminals.

[0004] Patent Document 1 discloses a genuine / fake determination system that captures and reads an electronic watermark code marked on an object with a camera provided in an information terminal, transmits the read code information to a server, and the server analyzes the read log data stored in a database to determine the genuineness of the object.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In a system such as Patent Document 1, since an image captured by a camera is transmitted to a server, if the shooting conditions of the camera are not appropriate, the server will perform authenticity determination based on the inappropriate image, and the accuracy of the authenticity determination may decrease. Also, when the shooting conditions vary during shooting with a camera, the accuracy of the authenticity determination may decrease until shooting is performed under optimal shooting conditions.

[0007] The present invention has been made in view of such circumstances, and an object thereof is to provide an authenticity determination system, an authenticity determination device, a computer program, and an authenticity determination method capable of improving the accuracy of authenticity determination by shooting a target medium under more appropriate shooting conditions.

Means for Solving the Problems

[0008] The authenticity determination system of the present embodiment includes an authenticity determination device and a terminal device having a light emitting unit and an imaging unit. The terminal device transmits time-series images of a target medium captured to the authenticity determination device. The authenticity determination device determines whether the target medium is captured under shooting conditions that can specify a hologram image based on the time-series images. When the target medium is not captured under shooting conditions that can specify a hologram image, the authenticity determination device transmits update information for updating the shooting conditions to the terminal device. The terminal device transmits time-series images of the target medium captured using the update information to the authenticity determination device.

[0009] The authenticity determination device of the present embodiment includes a control unit. The control unit receives time-series images of a target medium from a terminal device, determines whether the target medium is captured under shooting conditions that can specify a hologram image based on the received time-series images, and when the target medium is not captured under shooting conditions that can specify a hologram image, transmits update information for updating the shooting conditions to the terminal device.

[0010] The computer program of this embodiment causes a computer to execute a process of receiving, from a terminal device, time-series images of a target medium that has been photographed, determining whether the target medium has been photographed under imaging conditions that enable identification of a hologram image based on the received time-series images, and transmitting, to the terminal device, update information for updating the imaging conditions when the target medium has not been photographed under imaging conditions that enable identification of the hologram image.

[0011] In the authenticity determination method of this embodiment, the terminal device transmits time-series images of a target medium to an authenticity determination device, the authenticity determination device determines whether the target medium has been photographed under imaging conditions that enable identification of a hologram image based on the time-series images, when the target medium has not been photographed under imaging conditions that enable identification of the hologram image, the authenticity determination device transmits, to the terminal device, update information for updating the imaging conditions, and the terminal device transmits, to the authenticity determination device, time-series images of the target medium photographed using the update information.

Advantages of the Invention

[0012] According to the present invention, it is possible to photograph a target medium under more appropriate imaging conditions and improve the accuracy of authenticity determination.

Brief Description of the Drawings

[0013]

Figure 1

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Embodiments for Carrying Out the Invention

[0014] Hereinafter, the present invention will be described based on the drawings showing its embodiments. FIG. 1 is a diagram showing an example of the configuration of an authenticity determination system. The authenticity determination system includes an authenticity determination device 50 and a terminal device 10. The terminal device 10 and the authenticity determination device 50 are connected via a communication network N. The authenticity determination device 50 can access a determination threshold value DB 70. There may be a plurality of terminal devices 10.

[0015] The terminal device 10 is composed of a portable device such as a smartphone, a tablet terminal, a personal computer, etc., and is carried by a user. The terminal device 10 includes a control unit 11 for controlling the entire device, a light emitting unit 12, an imaging unit 13, a display unit 14, an operation unit 15, a communication unit 16, a memory 17, and a storage unit 18.

[0016] The memory unit 18 can be configured by, for example, a semiconductor memory or the like, and can store the computer program 20 and required information. The computer program 20 operates on the terminal device 10.

[0017] The control unit 11 is configured by incorporating a required number of CPUs (Central Processing Units), MPUs (Micro-Processing Units), GPUs (Graphics Processing Units), etc. The control unit 11 can execute the processing defined by the computer program 20. That is, the processing by the control unit 11 is also the processing by the computer program 20. A recording medium (a non-temporary recording medium readable by a computer) on which the computer program 20 is recorded may be read by a recording medium reading device (for example, a computer, etc.), and the read computer program 20 may be downloaded via the communication unit 16 and stored in the memory unit 18.

[0018] The light emitting unit 12 includes a light emitting element such as an LED. As the LED, for example, a white LED or the like can be used. The light emitting unit 12 irradiates reference light onto the target medium. The target medium is an object for authenticity determination, and is, for example, a medium such as a credit card, banknote, stock certificate, gift certificate, or high-class brand product on which information for preventing duplication, forgery, etc. is recorded. In the present embodiment, the target medium uses holography (hologram).

[0019] Holography is a technique of interfering the amplitude and phase (object light) of the light wave to be recorded with a reference light, recording it as an interference fringe on a medium, and reproducing the recorded light wave using the diffraction phenomenon. In the present invention, the medium on which the interference fringe is recorded is called a hologram. Holograms are roughly classified into relief type holograms in which interference fringes are recorded as unevenness and volume type holograms. In the present invention, the hologram is expressed including both the meanings of the relief type and the volume type.

[0020] The imaging unit 13 is equipped with a camera. The imaging unit 13 can acquire time-series images of the target medium being photographed. Specifically, the imaging unit 13 acquires time-series images (first images) of the target medium as still images or moving images under the condition that the light from the light-emitting unit 12 irradiates the target medium (also referred to as "LED on"), and at the same time, acquires time-series images (second images) of the target medium as still images or moving images under the condition that the light from the light-emitting unit 12 does not irradiate the target medium (also referred to as "LED off").

[0021] The display unit 14 includes a liquid crystal display panel, an organic EL display panel, etc., and can display the determination result by the authenticity determination device 50 and the like.

[0022] The operation unit 15 is composed of a touch panel or the like, and can perform a character input operation on the display unit 14, and can also perform operations on icons, images, characters, etc. displayed on the display unit 14.

[0023] The communication unit 16 includes, for example, a communication module, and has a communication function with the authenticity determination device 50 and other external devices via the communication network N. Under the control of the control unit 11, the communication unit 16 transmits the first image and the second image photographed by the imaging unit 13 to the authenticity determination device 50.

[0024] The memory 17 can be composed of semiconductor memories such as SRAM (Static Random Access Memory), DRAM (Dynamic Random Access Memory), and flash memory. By expanding the computer program 20 in the memory 17, the control unit 11 can execute the computer program 20.

[0025] The control unit 11 (computer program 20, authenticity determination application) can control the operations of the light-emitting unit 12 and the imaging unit 13, and can update (adjust) the imaging conditions related to the light-emitting unit 12 and the imaging unit 13 based on the update information for updating the imaging conditions transmitted from the authenticity determination device 50.

[0026] The genuine / fake determination device 50 includes a control unit 51 that controls the entire device, a communication unit 52, a memory 53, and a storage unit 54. The genuine / fake determination device 50 is configured by, for example, a personal computer or the like. A determination threshold value DB70 is connected to the genuine / fake determination device 50. The similarity threshold value used for genuine / fake determination is stored in the determination threshold value DB70.

[0027] The storage unit 54 can be configured by, for example, a hard disk or a semiconductor memory, and can store a computer program 60, correct answer information 61, and required information. The computer program 60 operates on the genuine / fake determination device 50. The correct answer information 61 includes a correct answer character string and a correct answer image, which will be described later.

[0028] The control unit 51 is configured by incorporating a required number of CPUs (Central Processing Units), MPUs (Micro-Processing Units), GPUs (Graphics Processing Units), etc. The control unit 51 can execute the processing defined by the computer program 60. That is, the processing by the control unit 51 is also the processing by the computer program 60. A recording medium (a non-temporary recording medium readable by a computer) on which the computer program 60 is recorded may be read by a recording medium reading device (for example, a computer), and the read computer program 60 may be stored in the storage unit 54.

[0029] The communication unit 52 includes, for example, a communication module and has a communication function with the terminal device 10 via the communication network N. The control unit 51 can receive and acquire the time-series images (the first image and the second image) captured and transmitted by the terminal device 10 via the communication unit 52.

[0030] The memory 53 can be composed of semiconductor memories such as SRAM (Static Random Access Memory), DRAM (Dynamic Random Access Memory), and flash memory. By deploying the computer program 60 in the memory 53, the control unit 51 can execute the computer program 60.

[0031] The control unit 51 (computer program 60) has a function of determining whether the target medium is photographed under shooting conditions that can identify the hologram image based on the acquired time-series images. Further, when the target medium is not photographed under shooting conditions that can identify the hologram image, the control unit 51 transmits update information for updating the shooting conditions to the terminal device 10.

[0032] When the target medium is photographed under shooting conditions that can identify the hologram image, the control unit 51 identifies the hologram image based on the acquired time-series images (the first image and the second image), and determines the authenticity of the target medium based on the identified hologram image. Further, the control unit 51 transmits the authenticity determination result to the terminal device 10 via the communication unit 52.

[0033] FIG. 2 is a diagram showing an example of the transmission form of time-series images between the terminal device 10 and the authenticity determination device 50. Let the shooting times of the time-series images of the target medium photographed by the terminal device 10 be..., t(n - 1), t(n), t(n + 1),.... Here, the time-series images refer to each image for each shooting time in a still image or a moving image, or both the entire continuous images of each image for each shooting time in a still image or a moving image. A moving image is a continuous image of one image, and photographing the target medium with the terminal device 10 includes both the meaning of shooting with a still image and shooting with a moving image. The terminal device 10 (control unit 11) transmits the difference image Δt(n) between the image at the shooting time t(n) and the image at the shooting time t(n - 1) to the authenticity determination device 50. Similarly, the terminal device 10 transmits the difference image Δt(n + 1) between the image at the shooting time t(n + 1) and the image at the shooting time t(n) to the authenticity determination device 50. Similarly for other shooting times, the terminal device 10 transmits only the difference images to the authenticity determination device 50 instead of the time-series images.

[0034] The genuine / fake determination device 50 (control unit 51) generates an image at the shooting time point t(n) by performing an addition operation on the image at the shooting time point t(n - 1) and the received differential image Δt(n). Similarly, the genuine / fake determination device 50 generates an image at the shooting time point t(n + 1) by performing an addition operation on the image at the shooting time point t(n) and the received differential image Δt(n + 1). Images at other shooting time points can be generated in the same way.

[0035] As described above, the terminal device 10 transmits a differential image between an image at the first time point when the target medium is photographed and an image at the second time point after the first time point to the genuine / fake determination device 50. The genuine / fake determination device 50 can generate the image at the second time point based on the image and the differential image at the first time point. The genuine / fake determination device 50 can identify a hologram image based on the generated image at the second time point.

[0036] As in the above configuration, when the terminal device 10 transmits differential images only at each shooting time point to the genuine / fake determination device 50 as compared with the case of transmitting each image in time series to the genuine / fake determination device 50, the amount of data to be transmitted can be reduced, the processing related to communication is reduced, and the communication delay between the terminal device 10 and the genuine / fake determination device 50 can be reduced.

[0037] Figure 3 is a diagram showing an overview of holography. Holography is a technique of recording the amplitude and phase (object light) of a light wave to be recorded by interfering it with a reference light as interference fringes on a medium and reproducing the recorded light wave using the diffraction phenomenon. An object on which interference fringes are recorded is called a hologram. As shown in Figure 3, when the object light and the reference light are interfered, interference fringes are recorded on the medium. If the target medium is genuine, since interference fringes are recorded, when the reference light is irradiated on the target medium, the amplitude and phase of the recorded light wave are reproduced as the object light. On the other hand, for example, on a replicated medium (fake) such as a color copy of the medium, since interference fringes are not recorded, the object light is not reproduced.

[0038] FIG. 4 is a diagram showing an example of normal diffracted light due to ambient light. In the example of FIG. 4, the target medium is real. Since the LED is in the off state, only the ambient light is irradiated onto the target medium as the reference light. When the real target medium is irradiated with the ambient light as the reference light, it reproduces a normal diffracted light pattern (also referred to as a "diffracted light pattern". In the example of FIG. 4A, the pattern of a tiara). In the determination area, the first hologram is recorded so that normal diffracted light is reproduced by the ambient light. The normal diffracted light pattern is the diffracted light of the first hologram.

[0039] As shown in FIG. 4B, when the relative positions of the reference light and the camera are changed, a normal diffracted light pattern such as a pattern of an animal is reproduced. In the determination area, the first hologram is recorded so that normal diffracted light is reproduced by the ambient light. Note that the first hologram may be able to reproduce a plurality of types of normal diffracted light patterns according to the relative position of the camera as shown in FIG. 4, or may be able to reproduce only one type of normal diffracted light pattern.

[0040] FIG. 5 is a diagram showing an example of a special diffracted light pattern that appears centered on the zero-order diffracted light when irradiated with a point light source. In the example of FIG. 5, the target medium is real. Since the LED is in the on state, in addition to the ambient light, the LED light is irradiated onto the target medium as the reference light. When the real target medium is irradiated with the LED light (the light of a light source that can be regarded as a point light source) as the reference light, it reproduces a special diffracted light pattern (unique bright spot pattern) around the zero-order diffracted light (specular reflection). In the determination area, the second hologram is recorded so that a special diffracted light pattern (unique bright spot pattern) is reproduced by the LED light. The special diffracted light pattern is the diffracted light of the second hologram. That is, two types of holograms, the first hologram described in FIG. 4 and the second hologram shown in FIG. 5, are recorded on the real target medium.

[0041] In the example of FIG. 5, in the determination area, a special diffraction light pattern including a bright spot pattern like the letter "O" on the upper side and a bright spot pattern like the letter "K" on the lower side is reproduced centering on the zero-order diffracted light. Note that the example of the hologram is just an example and is not limited to the letters "O" or "K".

[0042] The zero-order diffracted light is total reflection light in a state where the light intensity of all RGB color components is irradiated above the detection limit of the camera sensor (saturated state or a state close to the saturated state), and is a strong white bright spot. The zero-order diffracted light has a shape such as a circle or a rectangle, for example, and is an area where continuous bright spots are gathered.

[0043] The brightness of the special diffraction light pattern (unique bright spot pattern) is lower than that of the zero-order diffracted light but stronger than that of the normal diffraction light pattern. The special diffraction light pattern has non-uniform RGB color components and does not form a white bright spot like the zero-order diffracted light.

[0044] FIG. 6 is a diagram showing an example in the determination area when the target medium is a counterfeit. When the target medium is a counterfeit (for example, printed forgery, etc.), there is no hologram in the determination area of the target medium. FIG. 6A shows the case where the target medium is photographed with the LED of the terminal device 10 turned off. Since the LED is in the off state, only the ambient light irradiates the target medium as the reference light. However, since there is no hologram in the determination area, the diffracted light is not reproduced and the reflected light returns to the camera.

[0045] FIG. 6B shows the case where the target medium is photographed with the LED of the terminal device 10 turned on. Since the LED is in the on state, in addition to the ambient light, the LED light irradiates the target medium as the reference light. In this case, bright spots due to the LED light are detected in the determination area, and the direct reflected light of the LED light returns to the camera. Since there is no hologram in the determination area, the above-mentioned special diffraction light pattern cannot be seen.

[0046] FIG. 7 is a diagram showing the difference between a normal diffraction light pattern and a special diffraction light pattern. FIGS. 7A and 7B show the case where the image is taken with the LED off. As shown in FIG. 7A, a normal diffraction light pattern (a tiara pattern in the example of the figure) is reproduced in the determination area. As shown in FIG. 7B, even when the terminal device 10 (for example, a smartphone) is moved in the direction of the arrow with respect to the determination area, the position of the normal diffraction light pattern reproduced in the determination area does not change.

[0047] FIGS. 7C and 7D show the case where the image is taken with the LED on. As shown in FIG. 7C, a special diffraction light pattern (the patterns of the characters "O" and "K" around the zero-order diffracted light in the example of FIG. 7) is reproduced in the determination area. As shown in FIG. 7D, when the terminal device 10 (for example, a smartphone) is moved in the direction of the arrow with respect to the determination area, the position of the special diffraction light pattern in the determination area moves following the positions of the camera and the LED light source together with the zero-order diffracted light. This is because the incident point of the LED light incident on the determination area moves.

[0048] Next, the method for detecting (1) the bright point pattern (special diffraction light pattern) and (2) calculating the relative positions of the detected bright point patterns, which are necessary as a premise for authenticity determination of the target medium, will be described.

[0049] FIG. 8 is a diagram showing an example of a method for detecting a bright point pattern. The control unit 51 acquires an image (first image) of the target medium taken with the LED on, and identifies a bright point area based on the acquired image. The bright point area is an area where the zero-order diffracted light appears.

[0050] Specifically, the control unit 51 can perform a filtering process on the acquired image to identify an area with a predetermined brightness or higher as a bright spot area. In the filtering process shown in FIG. 8, among the bright spots in the image, only the strong white bright spots that are saturated or nearly saturated are left to identify the bright spot area. The control unit 51 performs a zero-order diffracted light detection process on the bright spot area to detect the coordinates of the zero-order diffracted light. The zero-order diffracted light detection process includes, for example, (1) a determination process for strong white bright spots where all RGB color components are saturated or nearly saturated, (2) a process for calculating the shape and area of the zero-order diffracted light based on the number of pixels in an area where saturated bright spots or bright spots close to saturation are continuous, (3) a process for calculating the coordinates of the center point, etc.

[0051] The control unit 51 performs a detection process for the bright spot pattern. Specifically, the control unit 51 detects the bright spot pattern (special diffracted light pattern) in the peripheral area of the zero-order diffracted light. Although the brightness of the bright spot pattern is lower than that of the zero-order diffracted light, it is stronger than the normal diffracted light pattern, so it is only necessary to detect the bright spots within a predetermined brightness value range. In the example of FIG. 8, the pattern A of the character "O" and the pattern B of the character "K" are detected.

[0052] FIG. 9 is a diagram showing an example of a method for calculating the relative positions of the detected bright spot patterns. As described above, the detected bright spot patterns are set as pattern A (character "O") and pattern B (character "K"). Identify the rectangle surrounding pattern A and the rectangle surrounding pattern B. One point among the four corners of each rectangle (in the example of the figure, the upper left corner) is set as the detection position of the pattern. Let the coordinates of the detection position A1 of pattern A be (ax, ay), and the coordinates of the detection position B1 of pattern B be (bx, by). Let the coordinates of the center position O of the zero-order diffracted light be (u, v).

[0053] If the coordinates of the relative position of pattern A are (Iax, Iay), they can be calculated as Iax = ax - u and Iay = ay - v. Also, if the coordinates of the relative position of pattern B are (Ibx, Iby), they can be calculated as Ibx = bx - u and Iby = by - v.

[0054] In the above example, the detection position of the bright spot pattern is set to the upper left corner of the rectangle, but it is not limited to this, and it may be other corners of the four corners, or the center position of the rectangle.

[0055] FIG. 10 is a diagram showing an example of authenticity determination using a special diffraction light pattern. The control unit 51 calculates the similarity between the bright spot pattern (the first hologram image), which is a special diffraction light pattern in the peripheral region of the zero-order diffracted light, and a predetermined bright spot pattern (the first correct image), and determines the authenticity (the first authenticity) of the target medium based on the calculated similarity and the first similarity threshold. For calculating the similarity, for example, a template matching method as follows can be used. That is, the mean squared error of the luminance values for each corresponding pixel between the bright spot pattern and the predetermined bright spot pattern is calculated, the mean squared error calculated for each pixel is added, and the reciprocal of the added value can be used as the similarity. In this case, since the similarity is a value corresponding to the reciprocal of the value calculated based on the mean squared error, the greater the similarity, the more similar the bright spot pattern and the predetermined bright spot pattern are. Note that the calculation of the similarity is not limited to the template matching method.

[0056] Further, the control unit 51 may specify the relative position between the predetermined position of the bright spot pattern in the peripheral region of the zero-order diffracted light and the position of the zero-order diffracted light (bright spot region), and determine the authenticity of the target medium based on the specified relative position and the relative position threshold. The predetermined position of the bright spot pattern can be the detection position of the bright spot pattern, and the position of the zero-order diffracted light can be the center position of the zero-order diffracted light (see FIG. 9).

[0057] In the example of FIG. 10, the control unit 51 first performs authenticity determination of the target medium based on pattern A. As shown in FIG. 10, the authenticity determination conditions can be that (1) the similarity between pattern A and the correct bright point pattern is equal to or greater than the similarity threshold Sa, and (2) the difference (Δx, Δy) between the relative position (Iax, Iay) of pattern A and the relative position threshold (Tax, Tay) is within a predetermined range (for example, within ±5% of the size of the captured image). When the authenticity determination conditions are satisfied, the target medium is determined to be genuine. When the authenticity determination conditions are not satisfied, the target medium can be determined to be a fake.

[0058] Further, the control unit 51 performs authenticity determination of the target medium based on pattern B. As shown in FIG. 10, the authenticity determination conditions can be that (1) the similarity between pattern B and the correct bright point pattern is equal to or greater than the similarity threshold Sb, and (2) the difference (Δx, Δy) between the relative position (Ibx, Iby) of pattern B and the relative position threshold (Tbx, Tby) is within a predetermined range (for example, it can be within ±5% of the size of the captured image, but is not limited to ±5%). When the authenticity determination conditions are satisfied, the target medium is determined to be genuine. When the authenticity determination conditions are not satisfied, the target medium can be determined to be a fake.

[0059] Then, when the control unit 51 can determine that the target medium is genuine based on at least one of the detected bright point patterns (pattern A and pattern B), the control unit 51 can determine (first authenticity determination) that the target medium is genuine. The control unit 51 outputs the result of the first authenticity determination.

[0060] FIG. 11 is a diagram showing an example of authenticity determination using a normal diffraction light pattern. The control unit 51 acquires an image (second image) of the target medium taken without irradiating the target medium with light from the light emitting unit 12, and performs diffraction light pattern detection processing on the acquired image to identify a normal diffraction light pattern (second hologram image).

[0061] The control unit 51 calculates the similarity between the identified normal diffraction pattern and one or more second correct images included in the correct information 61 by performing a similarity calculation process. For calculating the similarity, for example, the following template matching method can be used. That is, the mean square error of the luminance values for each corresponding pixel is calculated between the detected normal diffraction pattern and the correct image, the mean square errors calculated for each pixel are added, and the reciprocal of the added value can be used as the similarity. In this case, since the similarity corresponds to the reciprocal of the value calculated based on the mean square error, the greater the similarity, the more similar the normal diffraction pattern and the correct image are. Note that the calculation of the similarity is not limited to the template matching method.

[0062] The control unit 51 performs a authenticity determination process and outputs a second authenticity determination result based on the calculated similarity. The second authenticity determination result can be determined as "genuine" when the calculated similarity is equal to or greater than a predetermined second similarity threshold, and can be determined as "fake" when the calculated similarity is less than the second similarity threshold.

[0063] The control unit 51 can determine the authenticity of the target medium based on the first authenticity determination result and the second authenticity determination result. For example, when the first authenticity determination result is "genuine" and the second authenticity determination result is "genuine", the target medium can be determined to be genuine, and when either the first authenticity determination result or the second authenticity determination result is "fake", the target medium can be determined to be fake. Note that when both the first authenticity determination result and the second authenticity determination result are "fake", the target medium may be determined to be fake.

[0064] Next, a process of determining whether or not the terminal device 10 is photographing the target medium under imaging conditions that enable identification of the hologram image will be described.

[0065] FIG. 12 is a diagram showing an example of the determination process of the shooting conditions of the terminal device 10 by the authenticity determination device 50. The terminal device 10 (control unit 11) shoots the target medium (S11). When shooting the target medium in step S11, the terminal device 10 can appropriately switch between the LED-on state and the LED-off state, and may repeat the switching process as necessary. The terminal device 10 transmits a difference image from the most recent frame image (the captured image at the most recent shooting time) to the authenticity determination device 50 (S12).

[0066] The authenticity determination device 50 (control unit 51) generates a frame image (the captured image at the shooting time next to the most recent shooting time) based on the most recent frame image and the difference image transmitted from the terminal device 10 (S13). For details of steps S12 and S13, refer to FIG. 2. The authenticity determination device 50 determines whether the target medium is shot under shooting conditions that can identify the hologram image (the first hologram image and the second hologram image) (S14).

[0067] If the target medium is not shot under shooting conditions that can identify the hologram image (NO in S14), the authenticity determination device 50 transmits update information for updating the shooting conditions to the terminal device 10 (S15). Whether the target medium is shot under shooting conditions that can identify the hologram image and specific examples of the update information will be described later.

[0068] The terminal device 10 determines whether a predetermined time (for example, 10 seconds, 20 seconds, 30 seconds, etc.) has elapsed since the start of shooting the target medium (S16). If the predetermined time has not elapsed (NO in S16), the terminal device 10 updates the shooting conditions based on the update information (S17) and continues the processes after step S11. If the predetermined time has elapsed (YES in S16), the terminal device 10 outputs a timeout (S18) and ends the process.

[0069] If the target medium is shot under shooting conditions that can identify the hologram image (YES in S14), the authenticity determination device 50 executes the authenticity determination process (S19) and ends the process.

[0070] FIG. 13 is a diagram showing an example of update processing of shooting conditions in the terminal device 10 by the authenticity determination system. The terminal device 10 turns off the LED (light emitting unit 12) (S31), and the authenticity determination device 50 recognizes the target medium photographed by the imaging unit 13 (S32). Regarding S31 to S32, the terminal device 10 transmits a difference image between frames in which the target medium is photographed to the authenticity determination device 50, and the authenticity determination device 50 generates a frame image using the difference image and recognizes the target medium based on the generated frame image. The recognition of the target medium is, for example, a process of checking whether a hologram image appears in the generated image.

[0071] The terminal device 10 controls an optical system such as a lens included in the imaging unit 13 to adjust the focus of the lens (S33). In S33, as a result of the authenticity determination device 50 recognizing the target medium, if it is determined that the focus needs to be changed, update information is generated to update the focus, and the generated update information is transmitted to the terminal device 10.

[0072] After the terminal device 10 adjusts the focus, it transmits a difference image between frames in which the target medium is photographed to the authenticity determination device 50, and the authenticity determination device 50 generates a frame image using the difference image and recognizes a second hologram image based on the generated frame image (S34). When the authenticity determination device 50 determines that the position of the second hologram image is shifted, in order to adjust the position of the second hologram image (S35), update information for controlling the shift from the optical axis of the lens is generated, and the generated update information is transmitted to the terminal device 10.

[0073] After the terminal device 10 adjusts the position of the second hologram image, it transmits a difference image between frames in which the target medium is photographed to the authenticity determination device 50, and the authenticity determination device 50 generates a frame image using the difference image. When it is determined that the position of the second hologram image is at the correct position based on the generated frame image, the authenticity determination device 50 generates update information for turning on the LED and transmits the generated update information to the terminal device 10.

[0074] The terminal device 10 turns on the LED (S36), captures a differential image between frames of the target medium, and transmits it to the authenticity determination device 50. The authenticity determination device 50 generates a frame image using the differential image and recognizes a first hologram image based on the generated frame image (S37). In step S35, since the focus and position for specifying the second hologram image have been adjusted, the first hologram image can be specified while maintaining the position.

[0075] The processes in steps S32 to S35 may be repeated a plurality of times as necessary.

[0076] As described above, the update information includes information for adjusting the focus of the imaging unit 13. Also, the update information includes information for controlling the on / off of the light emitting unit 12. Further, the update information includes information for controlling the deviation from the optical axis of the imaging unit 13.

[0077] As described above, the terminal device 10 (control unit 11) transmits a time-series of images of the target medium to the authenticity determination device 50. The authenticity determination device 50 (control unit 51) determines whether the target medium has been photographed under imaging conditions that enable the identification of a hologram image based on the time-series of images. If the target medium has been photographed under imaging conditions that enable the identification of a hologram image, the authenticity determination device 50 identifies a hologram image based on the acquired time-series of images and determines the authenticity of the target medium based on the identified hologram image. On the other hand, if the target medium has not been photographed under imaging conditions that enable the identification of a hologram image, the authenticity determination device 50 transmits update information for updating the imaging conditions to the terminal device 10. The terminal device 10 (control unit 11) transmits a time-series of images of the target medium to the authenticity determination device 50 using the update information. The authenticity determination device 50 (control unit 51) can repeat the same process based on the time-series of images of the target medium photographed using the update information.

[0078] As described above, in the authenticity determination system of the present embodiment, before determining the authenticity of the target medium based on the image of the target medium, it is determined whether the target medium is photographed under imaging conditions that can identify the hologram image based on the image in units of frames. If the target medium is not photographed under imaging conditions that can identify the hologram image, the authenticity determination device 50 transmits update information for updating the imaging conditions to the terminal device 10. Therefore, the target medium can be photographed under more appropriate imaging conditions to improve the accuracy of authenticity determination. Further, for each image in units of frames, it is determined whether the target medium is photographed under imaging conditions that can identify the hologram image. Therefore, it is possible to shorten the time until appropriate imaging conditions are obtained, improve the processing speed of authenticity determination, and shorten the time during which the accuracy of authenticity determination decreases.

[0079] FIG. 14 is a diagram showing an example of the procedure of the authenticity determination process by the authenticity determination device 50 of the present embodiment. The control unit 51 acquires an image (first image) of the target medium under the condition that the LED is on (S41), and detects the position of the zero-order diffracted light based on the acquired image (S42). The control unit 51 identifies a first hologram image (special diffracted light pattern) in the peripheral region of the zero-order diffracted light (S43). The control unit 51 calculates the similarity between the identified first hologram image and the correct image (S44), and performs a first authenticity determination based on the calculated similarity (S45).

[0080] The control unit 51 acquires an image (second image) of the target medium under the condition that the LED is off (S46), identifies a second hologram image (normal diffracted light pattern) based on the acquired image (S47), and calculates the similarity between the identified second hologram image and the correct image (S48). The control unit 51 performs a second authenticity determination based on the calculated similarity (S49).

[0081] The control unit 51 can repeat the processes of steps S42 to S45 for the required number of times until the first authenticity determination result is obtained. Also, the control unit 51 can repeat the processes of steps S46 to S49 for the required number of times until the second authenticity determination result is obtained. The control unit 51 determines the authenticity of the target medium based on the first and second authenticity determination results (S50). The control unit 51 outputs the determination result of the authenticity determination (S51) and ends the process.

[0082] FIG. 15 is a diagram showing an example of a display screen at the time of authenticity determination. The display screen shown in FIG. 15 is displayed on the display unit 14. FIG. 15A shows the display screen when the target medium is determined to be genuine in the authenticity determination, and FIG. 15B shows the display screen when it is determined to be a fake. When the user activates the authenticity determination application, the terminal device 10 acquires a second image obtained by photographing the target medium with the LED in the off state, and transmits the acquired second image to the authenticity determination device 50. The authenticity determination device 50 identifies a second hologram image based on the received second image and performs a second authenticity determination. The authenticity determination device 50 transmits a command to turn on the LED to the terminal device 10. The terminal device 10 acquires a first image obtained by photographing the target medium with the LED in the on state, and transmits the acquired first image to the authenticity determination device 50. The authenticity determination device 50 identifies a first hologram image based on the received first image and performs a first authenticity determination. When the authenticity determination device 50 transmits the authenticity determination result that the target medium is genuine to the terminal device 10, the terminal device 10 can display a message such as "The hologram has been recognized" to notify the user that the target object is genuine.

[0083] On the other hand, as shown in FIG. 15B, when the authenticity determination device 50 transmits the authenticity determination result that the target medium is a fake to the terminal device 10, the terminal device 10 can display a message such as "Timed out" to notify the user that the target object is a fake.

[0084] (Appendix 1) The authenticity determination system includes an authenticity determination device and a terminal device having a light emitting unit and an imaging unit. The terminal device transmits time-series images of a target medium to the authenticity determination device. The authenticity determination device determines whether the target medium is photographed under imaging conditions that can identify a hologram image based on the time-series images. If the target medium is not photographed under imaging conditions that can identify a hologram image, the authenticity determination device transmits update information for updating the imaging conditions to the terminal device. The terminal device transmits time-series images of the target medium photographed using the update information to the authenticity determination device.

[0085] (Appendix 2) In the authenticity determination system according to Appendix 1, when the target medium is photographed under imaging conditions that can identify a hologram image, the authenticity determination device identifies the hologram image based on the time-series images and determines the authenticity of the target medium based on the identified hologram image.

[0086] (Appendix 3) In the authenticity determination system according to Appendix 1 or Appendix 2, the update information includes information for adjusting the focus of the imaging unit.

[0087] (Appendix 4) In the authenticity determination system according to any one of Appendices 1 to 3, the update information includes information for controlling the on / off of the light emitting unit.

[0088] (Appendix 5) In the authenticity determination system according to any one of Appendices 1 to 4, the update information includes information for controlling the deviation from the optical axis of the imaging unit.

[0089] (Appendix 6) In the authenticity determination system according to any one of Appendices 2 to 5, the terminal device transmits a difference image between an image at a first time point when the target medium is photographed and an image at a second time point after the first time point to the authenticity determination device. The authenticity determination device generates the image at the second time point based on the image at the first time point and the difference image, and identifies a hologram image based on the generated image at the second time point.

[0090] (Appendix 7) In any one of Appendices 2 to 6, the authenticity determination system is such that the authenticity determination device identifies a first hologram image based on a first image taken while irradiating the target medium with light from the light emitting unit of the terminal device, calculates the similarity between the identified first hologram image and a first correct image, and determines the first authenticity of the target medium based on the calculated similarity and a first similarity threshold value.

[0091] (Appendix 8) In Appendix 7, the authenticity determination system is such that the authenticity determination device identifies a second hologram image based on a second image taken without irradiating the target medium with light from the light emitting unit of the terminal device, calculates the similarity between the identified second hologram image and a second correct image, and determines the second authenticity of the target medium based on the calculated similarity and a second similarity threshold value.

[0092] (Appendix 9) In Appendix 8, the authenticity determination system is such that the authenticity determination device determines the authenticity of the target medium based on the determination result of the first authenticity and the determination result of the second authenticity.

[0093] (Appendix 10) The authenticity determination device includes a control unit. The control unit receives time-series images of the target medium from the terminal device, determines whether the target medium is photographed under imaging conditions that enable identification of a hologram image based on the received time-series images, and if the target medium is not photographed under imaging conditions that enable identification of a hologram image, transmits update information for updating the imaging conditions to the terminal device.

[0094] (Appendix 11) A computer program causes a computer to execute a process of receiving time-series images of the target medium from the terminal device, determining whether the target medium is photographed under imaging conditions that enable identification of a hologram image based on the received time-series images, and if the target medium is not photographed under imaging conditions that enable identification of a hologram image, transmitting update information for updating the imaging conditions to the terminal device.

[0095] (Appendix 12) In the authenticity determination method, the terminal device transmits time-series images of the target medium to the authenticity determination device, and the authenticity determination device determines whether the target medium has been photographed under shooting conditions that enable identification of the hologram image based on the time-series images. If the target medium has not been photographed under shooting conditions that enable identification of the hologram image, the authenticity determination device transmits update information for updating the shooting conditions to the terminal device, and the terminal device transmits time-series images of the target medium photographed using the update information to the authenticity determination device.

[0096] The matters described in each embodiment can be combined with each other. Also, the independent claims and dependent claims described in the claims can be combined with each other in all possible combinations regardless of the citation format. Further, although the claims use a format (multi-claim format) in which a claim that cites two or more other claims is described, it is not limited to this. A format in which a multi-claim (multi-multi-claim) that cites at least one multi-claim may be described.

Description of Reference Numerals

[0097] 10 Terminal device 11 Control unit 12 Light-emitting unit 13 Imaging unit 14 Display unit 15 Operation unit 16 Communication unit 17 Memory 18 Storage unit 20 Computer program 50 Authenticity determination device 51 Control unit 52 Communication unit 53 Memory 54 Storage unit 60 Computer program 61 Correct answer information 70 Decision threshold DB

Claims

1. A authenticity determination device and a terminal device having a light emitting unit and an imaging unit, The terminal device transmits time-series images of a target medium to the authenticity determination device, The authenticity determination device determines whether the target medium is photographed under imaging conditions capable of specifying a hologram image based on the time-series images, when the target medium is not photographed under imaging conditions capable of specifying a hologram image, transmits update information for updating the imaging conditions to the terminal device, The terminal device transmits time-series images of the target medium photographed using the update information to the authenticity determination device. An authenticity determination system.

2. The authenticity determination device when the target medium is photographed under imaging conditions capable of specifying a hologram image, specifies a hologram image based on the time-series images, determines the authenticity of the target medium based on the specified hologram image. The authenticity determination system according to claim 1.

3. The update information includes information for adjusting the focus of the imaging unit. The authenticity determination system according to claim 1.

4. The update information includes information for controlling the on / off of the light emitting unit. The authenticity determination system according to claim 1.

5. The update information includes information for controlling the deviation from the optical axis of the imaging unit. The authenticity determination system according to claim 1.

6. The terminal device Transmit a difference image between an image at a first time point when the target medium is photographed and an image at a second time point after the first time point to the authenticity determination device. The authenticity determination device generates the image at the second time point based on the image at the first time point and the difference image. identifies a hologram image based on the generated image at the second time point. The authenticity determination system according to any one of claims 2 to 5.

7. The authenticity determination device identifies a first hologram image based on a first image photographed in a state where the target medium is irradiated with light from a light emitting unit of the terminal device, calculates a similarity between the identified first hologram image and a first correct image, and determines the first authenticity of the target medium based on the calculated similarity and a first similarity threshold. The authenticity determination system according to any one of claims 2 to 5.

8. The authenticity determination device identifies a second hologram image based on a second image photographed in a state where the target medium is not irradiated with light from a light emitting unit of the terminal device, calculates a similarity between the identified second hologram image and a second correct image, and determines the second authenticity of the target medium based on the calculated similarity and a second similarity threshold. The authenticity determination system according to claim 7.

9. The authenticity determination device determines the authenticity of the target medium based on the determination result of the first authenticity and the determination result of the second authenticity. The authenticity determination system according to claim 8.

10. includes a control unit, and the control unit receives time-series images of the target medium photographed from the terminal device, Determine whether the target medium is photographed under imaging conditions that enable identification of a hologram image based on the received time-series images, if the target medium is not photographed under imaging conditions that enable identification of a hologram image, transmit update information for updating the imaging conditions to the terminal device, A genuine / fake determination device.

11. Receive time-series images of the target medium from a terminal device, Determine whether the target medium is photographed under imaging conditions that enable identification of a hologram image based on the received time-series images, if the target medium is not photographed under imaging conditions that enable identification of a hologram image, transmit update information for updating the imaging conditions to the terminal device, A computer program for causing a computer to execute the processing.

12. The terminal device transmits time-series images of the target medium to the genuine / fake determination device, the genuine / fake determination device determines whether the target medium is photographed under imaging conditions that enable identification of a hologram image based on the time-series images, if the target medium is not photographed under imaging conditions that enable identification of a hologram image, the genuine / fake determination device transmits update information for updating the imaging conditions to the terminal device, the terminal device transmits time-series images of the target medium photographed using the update information to the genuine / fake determination device, A genuine / fake determination method.

Images