JP7593095B2 - Computer program, authenticity determination method, and authenticity determination device - Google Patents

Description

The present invention relates to a computer program, an authenticity determination method, and an authenticity determination device.

Holograms are used as an anti-counterfeiting measure for items that require protection against counterfeiting, such as cash cards, credit cards, check cards, vouchers, identification cards, important documents, and brand-name goods. Anti-counterfeiting measures are also used by customs to determine whether an item infringes intellectual property.

Patent document 1 discloses an authenticity determination support device that captures an image of a hologram reproduced by an anti-counterfeiting medium attached to an object to be authenticated, and displays the captured hologram side by side with a hologram that should be reproduced by a genuine anti-counterfeiting medium.

International Publication No. 2016/190107 International Publication No. 2019/070081

However, with a device like that described in Patent Document 1, it is necessary to fully understand the characteristics of the hologram reproduced by the genuine anti-counterfeiting medium and then visually judge the difference between the two displayed holograms, which is difficult to distinguish without special skill. In particular, when the difference between the genuine and counterfeit hologram patterns is minute, there is a risk of misrecognition.

The objective of the present disclosure is to provide a computer program, an authenticity determination method, and an authenticity determination device that can easily perform authenticity determination without requiring special skills.

The computer program according to the present disclosure is a computer program for causing a computer to execute a process for determining the authenticity of an object provided with a light modulation element that generates a reconstructed image in the center of the area irradiated with light from a point light source, and causes the computer to execute a process for acquiring multiple images obtained by capturing images with the point light source at different positions relative to the light modulation element, judging the authenticity of the object based on the position of the reconstructed image in the multiple acquired images, and outputting the judgment result.

The authenticity determination method according to the present disclosure is a method for determining the authenticity of an object having a light modulation element that generates a reconstructed image in the center of the area irradiated with light from a point light source, and obtains multiple images obtained by capturing images with the point light source positioned differently relative to the light modulation element, and determines the authenticity of the object based on the position of the reconstructed image in the multiple images obtained.

The authenticity determination device according to the present disclosure is an authenticity determination device that determines the authenticity of an object having a light modulation element that generates a reconstructed image in the center of the area irradiated with light from a point light source, and includes an acquisition unit that acquires multiple images obtained by capturing images with the point light source at different positions relative to the light modulation element, a determination unit that determines the authenticity of the object based on the position of the reconstructed image in the multiple images acquired by the acquisition unit, and an output unit that outputs the determination result.

According to this disclosure, authenticity can be easily determined without requiring special skills.

1 is a block diagram showing an example of the configuration of an authenticity determining device according to a first embodiment; 1 is a cross-sectional view illustrating an example of a light modulation element according to a first embodiment. 10 is a schematic diagram showing a state in which an image of a light modulation element is captured using an authenticity determination device. FIG. FIG. 4 is a schematic diagram showing a light modulation element when it is not irradiated with light from a point light source. FIG. 2 is a schematic diagram showing a light modulation element when irradiated with light from a point light source. 4 is a flowchart showing a process for authenticity determination according to the first embodiment. 4 is an example of a display screen of an authenticity determining device that is executing an authenticity determining process according to the first embodiment. FIG. 11 is a schematic diagram showing a light modulation element according to a second embodiment attached to an object. 10A to 10C are conceptual diagrams showing a method for attaching a light modulation element according to a second embodiment. 10 is a flowchart showing a process for authenticity determination according to the second embodiment. 10 is a flowchart showing a process for authenticity determination according to the second embodiment. 13 is an example of a display screen of an authenticity determining device executing an authenticity determining process according to the second embodiment. 13 is an example of a display screen of an authenticity determining device executing an authenticity determining process according to the second embodiment. 13 is an example of a display screen of an authenticity determining device executing an authenticity determining process according to the second embodiment. 13 is an example of a display screen of an authenticity determining device executing an authenticity determining process according to the second embodiment. 13 is an example of a display screen of an authenticity determining device executing an authenticity determining process according to the second embodiment. 13 is an example of a display screen of an authenticity determining device executing an authenticity determining process according to the second embodiment. 10 is a flowchart showing a processing procedure for determining whether a predetermined condition for authenticity determination according to the second embodiment is satisfied. FIG. 11 is a conceptual diagram showing a light modulation element according to a third embodiment. 13 is a flowchart showing a processing procedure for determining whether a predetermined condition for authenticity determination according to the third embodiment is satisfied. FIG. 13 is a block diagram showing an example of the configuration of an authenticity determining device according to a fourth embodiment. FIG. 13 is a conceptual diagram showing an example of a reconstructed image DB according to the fourth embodiment. 13A to 13C are conceptual diagrams showing a method for attaching a light modulation element according to a fifth embodiment. 13A to 13C are conceptual diagrams showing a method for attaching a light modulation element according to a sixth embodiment.

A computer program, an authenticity determination method, and an authenticity determination device according to embodiments of the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, but is intended to include all modifications that are set forth in the claims and are equivalent in meaning and scope to the claims. In addition, at least some of the embodiments described below may be combined in any desired manner.

Hereinafter, the embodiment will be described in detail with reference to the drawings.
(Embodiment 1)
FIG. 1 is a block diagram showing a configuration example of an authenticity determination device 1. The authenticity determination device 1 includes a control unit 10, a storage unit 11, a light source unit 12, an imaging unit 13, a display unit 14, and an operation unit 15. The authenticity determination device 1 is a portable computer such as a smartphone, a mobile phone, a tablet terminal, a PDA (Personal Digital Assistant), or smart glasses. The authenticity determination device 1 irradiates light from an LED point light source onto a light modulation element 2 provided on an object 3 to be subjected to authenticity determination, and determines the authenticity of the object 3 by analyzing an image obtained by capturing a reproduced image 20h of a hologram generated on the light modulation element 2 (see FIG. 5).

The control unit 10 is a microcomputer having a CPU (Central Processing Unit) or MPU (Micro-Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), an input/output interface, etc. The light source unit 12, the imaging unit 13, the display unit 14, and the operation unit 15 are connected to the input/output interface of the control unit 10. The ROM stores programs necessary for the initial operation of the computer. The RAM is a memory such as a DRAM (Dynamic RAM) or an SRAM (Static RAM), and temporarily stores a computer program P (described later) read from the storage unit 11 when the control unit 10 executes the arithmetic processing, or various data generated by the arithmetic processing of the control unit 10. The CPU executes the computer program P to control the operation of each component and execute the process of determining the authenticity of the object 3. In other words, the computer equipped with the control unit 10 executes the computer program P to operate as the authenticity determination device 1 according to the present embodiment 1, and to implement the authenticity determination method according to the present embodiment 1.

The storage unit 11 is a non-volatile memory such as an EEPROM (Electrically Erasable Programmable ROM) or a flash memory, and stores a computer program P required for implementing the authenticity determination method according to the first embodiment. Note that the storage unit 11 according to the first embodiment is a built-in memory of the authenticity determination device 1, but may be an external flash memory, a hard disk, an SSD (Solid State Drive), etc.

The computer program P according to the first embodiment may be recorded in a computer-readable manner on a recording medium M. The storage unit 11 stores the computer program P read from the recording medium M by a reading device (not shown). The recording medium M is a portable semiconductor memory such as a Secure Digital (SD) card, a micro SD card, or a Compact Flash (registered trademark). The recording medium M may also be an optical disk such as a Compact Disc (CD)-ROM, a Digital Versatile Disc (DVD)-ROM, or a Blu-ray (registered trademark) Disc (BD). The recording medium M may also be a flexible disk, a magnetic disk such as a hard disk, or a magnetic optical disk. The computer program P according to the first embodiment may also be provided by an external server (not shown) connected to a communication network (not shown). The authenticity determination device 1 downloads the computer program P according to the first embodiment provided via the communication network and stores it in the storage unit 11.

The light source unit 12 is an LED light that illuminates the subject. The LED light is an example of a point light source that irradiates the light modulation element 2 with light to generate a reconstructed image 20h.

The imaging unit 13 includes a lens, an imaging element such as a CMOS or CCD that converts the image formed by the lens into an electrical signal, and an image processing unit that AD converts the electrical signal converted by the imaging element into digital image data and performs various image processing on the AD converted image data. The imaging unit 13 provides the image data obtained by imaging to the control unit 10. The imaging unit 13 can capture both moving images and still images. In this embodiment 1, the imaging unit 13 is used to capture the light modulation element 2 and the reproduced image 20h generated on the light modulation element 2. The images captured by the imaging unit 13 are stored in the memory unit 11.

The display unit 14 is a liquid crystal panel, an organic EL display, electronic paper, a plasma display, etc. The display unit 14 displays various information according to image data provided by the control unit 10.

The operation unit 15 is an interface that accepts operations by the user and outputs a control signal corresponding to the operation content to the control unit 10. The operation unit 15 is, for example, a touch sensor or a mechanical operation button provided on the surface or inside the display unit 14. The touch sensor accepts the user's operation by detecting that the user's finger has touched the display unit 14 and the position where the finger has touched, and provides the accepted operation information to the control unit 10. In other words, the control unit 10 can accept the user's operation at the operation unit 15. The operation unit 15 may also be a microphone that collects voice commands from the user.

Fig. 2 is a cross-sectional view showing a schematic example of the light modulation element 2. The light modulation element 2 according to the first embodiment is an optical element that diffracts light from a point light source to generate a reconstructed image 20h (see Fig. 5) at a central portion C of an area irradiated with the light. The reconstructed image 20h is, for example, an image showing a pattern or a symbol, an image in which the symbol is coded, or the like. In Fig. 2, the upper surface side of the light modulation element 2 is the front surface side that is imaged by the imaging unit 13, and the lower surface side is the back surface side that is adhered to the object 3.
The light modulation element 2 is configured as a hologram holder having a phase modulation type hologram structure 211 that modulates the phase of incident light (incident light) to reconstruct an optical image. The hologram structure 211 includes an element element particularly configured by a Fourier transform hologram. The Fourier transform hologram is a hologram created by recording wavefront information of a Fourier transform image of an original image, and functions as a so-called Fourier transform lens. In particular, the phase modulation type Fourier transform hologram is a hologram having a concave-convex surface 22a created by multi-valuing the phase information of the Fourier transform image and recording it as depth in a medium, and reconstructs the optical image of the original image from the incident light by utilizing the diffraction phenomenon based on the optical path length difference of the medium. Note that such a hologram can be designed using a computer based on the expected wavelength and incident direction of the incident light, as well as the shape and position of the image to be reconstructed. The hologram obtained in this manner is also called a computer generated hologram (CGH). However, the element elements of the light modulation element 2 to which the present invention can be applied are not limited to Fourier transform holograms, and the present invention can also be applied to light modulation elements 2 having holograms that reconstruct light images in other ways or other structures.
Specifically, the light modulation element 2 comprises a substrate 21, a hologram layer 22 having a reflective hologram structure 211 laminated on the back side (lower side in Figure 2) of the sheet-like substrate 21, and a reflective layer 23 formed on the back side (lower side in Figure 2) of the hologram layer 22.
The hologram structure 211 and the reflective layer 23 have an uneven surface 22a for diffracting light incident from the front side of the substrate 21 to generate a reproduced image 20h. That is, the rear surface (lower side in FIG. 2) of the hologram layer 22 forms the uneven surface 22a, and the reflective layer 23 covering this uneven surface 22a also has an uneven shape. The uneven surface 22a of the hologram structure 211 has an uneven pattern corresponding to the Fourier transform image of the original image, and has an uneven depth corresponding to each pixel of the Fourier transform image. For example, a resin (e.g., a UV-curable resin or a thermoplastic resin) constituting the hologram layer 22 is formed by coating or the like on a substrate 21 (e.g., PET: polyethylene terephthalate), and the hologram layer 22 is subjected to a UV-curing process, a heat-pressing process, and an unevenness-imparting process in which the uneven surface of an original plate is pressed against the hologram layer 22. Thereafter, a reflective layer 23 (e.g., Al, ZnS, or TiO2) is formed on the uneven surface 22a of the hologram layer 22, thereby manufacturing the hologram holder shown in Fig. 2. An adhesive, a bonding agent, a heat-sealing layer, or the like may be further formed on the reflective layer 23.

When light from a point light source is incident on such a hologram structure 211, a reproduced image 20h is generated according to the uneven pattern of the uneven surface 22a. In the following description, it is assumed that the angle of incidence of light from the light source unit 12 on the hologram structure 211 is approximately 0° (i.e., the angle along the normal direction of the incidence surface of the hologram structure 211). When light is incident on the above-described hologram structure 211, a reproduced light image 20h is reproduced in a central portion C of the area irradiated with light from the light source unit 12, which is a point light source.
Furthermore, a point light source image PL (see FIG. 5) formed by projecting a point light source from the light source unit 12 onto the light modulation element 2 stands out brightly, and the point light source image PL is projected onto the center of the reconstructed image 20h. The imaging unit 13 captures the point light source image PL together with the reconstructed image 20h.

Moreover, the surface side of the light modulation element 2 according to the first embodiment has a mark 20 that is visible by light from a non-point light source. The mark 20 is, for example, a pattern printed on the light modulation element 2, and is preferably configured to transmit light. In other words, the mark 20 is preferably configured so that light from the light source unit 12, which is a point light source, can pass through the mark 20, enter the hologram structure 211, and the diffracted light can pass through the mark 20 and exit. Furthermore, the mark 20 does not necessarily have to be a printed matter, and may be configured to be a hologram, for example a Lippmann hologram.
In addition, in the case where the reconstructed image 20h generated on the mark 20 is not to be confirmed, that is, in the case where the reconstructed image 20h generated at a position different from the mark 20 is to be confirmed, the mark 20 may be opaque.

Figure 3 is a schematic diagram showing the state in which an image of a light modulation element 2 is captured using an authenticity determination device 1. As shown in Figure 3, the light modulation element 2 is in the form of a sheet, and is attached to an object 3 to be subjected to authenticity determination. The object 3 includes, for example, contracts, cards such as cash cards, credit cards, and check cards, gift certificates, identification cards, important documents, products such as brand-name goods, and product packaging.

As shown in FIG. 3, when the light source unit 12 is placed at a position facing the surface side of the light modulation element 2 and the light source unit 12 is turned on, the light modulation element 2 generates a reproduced image 20h (see FIG. 5) centered on the central part C of the part irradiated with the light from the light source unit 12. In addition, a point light source image PL (see FIG. 5) is reflected in the central part C. Hereinafter, the light source unit 12 and the imaging unit 13 perform illumination and imaging while facing the light modulation element 2. In other words, the authenticity determination device 1 is operated so that the optical axis of the light source unit 12 and the imaging unit 13 approximately coincides with the normal direction of the light modulation element 2. Note that approximately coinciding the optical axis and the normal direction does not mean a perfect coincidence, but includes a deviation within the range in which the authenticity determination according to this embodiment 1 can be performed.

Figure 4 is a schematic diagram showing the light modulation element 2 when it is not irradiated with light from a point light source, and Figure 5 is a schematic diagram showing the light modulation element 2 when it is irradiated with light from a point light source. As shown in Figure 4, when the light source unit 12 is turned off, only the mark 20 provided on the light modulation element 2 is visible. When the light source unit 12 is turned on, as shown in Figure 5A, a reproduced image 20h is generated in the central part C by the light irradiated from the light source unit 12, which is a point light source. In Figure 5, a star indicates the point light source image PL of the light source unit 12. The position of the central part C of the part irradiated with the light from the light source unit 12 coincides with the position of the point light source image PL. In the following, the position of the central part C of the part irradiated with the light from the light source unit 12 will be appropriately described as the position of the point light source image PL.

As shown in Figures 5A and 5B, when the light source unit 12 moves in the in-plane direction of the light modulation element 2, that is, in a direction approximately parallel to the light modulation element 2, the central portion C of the area irradiated with the light of the light source unit 12 and the point light source image PL move relative to the position of the mark 20, but the reconstructed image 20h also moves following the movement of the point light source image PL, and the reconstructed image 20h is always generated at the position of the central portion C or the point light source image PL.

The authenticity determination device 1 of this embodiment 1 uses the light modulation element 2 configured in this way to determine the authenticity of the object 3. Specifically, the authenticity determination device 1 images the light modulation element 2 while changing the position of the light source unit 12 relative to the light modulation element 2, and determines the authenticity of the object 3 by analyzing the relationship between the position of the mark 20, the position of the reconstructed image 20h, and the position of the point light source image PL in the multiple images obtained by imaging.

Figure 6 is a flowchart showing the process procedure of authenticity determination according to the first embodiment. Figure 7 is an example of a display screen of the authenticity determination device 1 performing the authenticity determination process according to the first embodiment. The control unit 10 of the authenticity determination device 1 starts the imaging unit 13 (step S111), and as shown in Figure 7, displays the image captured by the imaging unit 13 on the display unit 14, as well as the aiming line image 14a and the guide display unit 14b (step S112). The aiming line image 14a is, for example, an image of a crosshair, and is for capturing the mark 20 of the light modulation element 2 at the center of the captured image. The guide display unit 14b displays information for instructing the user to perform an operation required for authenticity determination of the target object 3. For example, the guide display unit 14b displays information instructing the user to move the imaging unit 13 in the horizontal direction. In addition, as described later, the guide display unit 14b can display the result of authenticity determination of the target object 3.

After completing the process of step S112, the control unit 10 controls the light source unit 12 to blink (step S113), and uses the imaging unit 13 to capture images of the light modulation element 2 when it is turned on and when it is turned off (step S114). The control unit 10 that executes step S114 functions as an acquisition unit that acquires multiple images obtained by capturing images of the light source unit 12 (point light source) at different positions relative to the light modulation element 2. The control unit 10 then detects the movement of the light source unit 12 and the imaging device relative to the light modulation element 2 based on the multiple images captured when the light source unit 12 is turned off (step S115). For example, the control unit 10 can detect the movement of the light emitting unit and the imaging unit 13 by calculating the amount of change in the position of the image of the mark 20 included in the multiple images. Note that if the authenticity determination device 1 is equipped with an acceleration sensor, the control unit 10 may be configured to detect the movement of the light source unit 12 and the imaging unit 13 using the acceleration sensor.

Next, the control unit 10 distinguishes the image of the reconstructed image 20h and the point light source image PL included in the captured image (step S116). For example, by comparing an image obtained when the light source unit 12 is turned off with an image obtained when the light source unit 12 is turned off at substantially the same timing, the reconstructed image 20h generated by the light source unit 12, which is a point light source, can be distinguished. The control unit 10 can recognize that the images included in both the images obtained by capturing images when the light source unit 12 is turned on and when it is turned off are images of the mark 20 and other images. In addition, the control unit 10 can recognize that the images included in the images obtained by capturing images when the light source unit 12 is turned on, but not included in the images obtained by capturing images when the light source unit 12 is turned off, are the reconstructed image 20h.
On the other hand, the control unit 10 determines the point light source image PL included in the captured image. For example, the control unit 10 may determine the point light source image PL by extracting an image that has a luminance equal to or greater than a predetermined value, is located approximately in the center of the captured image, and has a size within a predetermined range, using a binarization process, a morphology process, or the like.

Next, the control unit 10 determines whether the light modulation element 2 has been imaged a predetermined number of times or more while the light source unit 12, etc. is moving relative to the light modulation element 2 (step S117). If it is determined that the number of images has been captured is less than the predetermined number of times (step S117: NO), the control unit 10 returns the process to step S113.

When it is determined that the image has been captured a predetermined number of times or more (step S117: YES), the control unit 10 determines whether or not the position of the reconstructed image 20h in the multiple images follows the movement of the light source unit 12 based on the multiple images obtained by capturing images while moving the light source unit 12 and the imaging unit 13 (step S118). Specifically, it determines whether or not the position of the point light source image PL in the multiple images matches the position of the reconstructed image 20h. The positions of the point light source image PL and the reconstructed image 20h are specified in the processing of step S115, and the control unit 10 may perform the determination of step S118 by determining whether or not the centers of the point light source image PL and the reconstructed image 20h match, or whether or not the distance between the centers is within a predetermined value.
If the position of the point light source image PL is known, the control unit 10 may determine in step S118 whether or not the reconstructed image 20h is at a predetermined position corresponding to the position of the point light source image PL. For example, if the center of the sight line image 14a corresponds to the position of the point light source image PL, the control unit 10 may determine in step S118 whether or not the reconstructed image 20h is at the center of the sight line image 14a or the center of the captured image. In this case, it is not necessary to recognize the point light source image PL in the processing of step S115.

The control unit 10 judges whether or not the object 3 to which the light modulation element 2 is attached is genuine based on the judgment result of step S118 (step S119). For example, the control unit 10 judges that the object 3 is genuine when the positions of the point light source image PL and the position of the reconstructed image 20h in the multiple images all match. Note that the control unit 10 that executes step S119 functions as a judgment unit that judges the authenticity of the object 3 based on the position of the reconstructed image 20h in the multiple acquired images.

If it is determined in step S119 that the object 3 is genuine (step S119: YES), the control unit 10 outputs information indicating that the object 3 is genuine (step S120) and ends the process. For example, the control unit 10 displays information indicating that the object 3 is genuine on the guide display unit 14b. The control unit 10 and the display unit 14 that execute step S120 function as an output unit that outputs the determination result.

In step S119, if it is determined that the image is not authentic (step S119: NO), for example, if there is an image in which the position of the point light source image PL does not match the position of the reproduced image 20h, the control unit 10 determines whether or not the image has been determined to be not authentic a predetermined number of times or more (step S121). If the number of times that the image has been determined to be not authentic is less than the predetermined number of times (step S121: NO), this may be due to an inadequate operation by the user, so the control unit 10 returns the process to step S113 and continues the authenticity determination.
The control unit 10 may display instructions on the guide display unit 14b for appropriately performing the authenticity determination. For example, when the image of the mark 20 included in the captured image is smaller than a predetermined first threshold, the control unit 10 may display information on the guide display unit 14b instructing the user to move the imaging unit 13 closer to the light modulation element 2. Conversely, when the image of the mark 20 is larger than a predetermined second threshold, the control unit 10 may display information on the guide display unit 14b instructing the user to move the imaging unit 13 away from the light modulation element. In addition, when the moving speed detected in step S115 is equal to or higher than a predetermined upper limit speed, the control unit 10 may display information on the guide display unit 14b instructing the user to move the imaging unit 13 slowly.

If it is determined that the number of times that the object 3 has been determined to be inauthentic is equal to or greater than a predetermined number (step S121: YES), the control unit 10 outputs information indicating that the object 3 is a counterfeit (step S122) and ends the process. For example, the control unit 10 displays information indicating that the object 3 is a counterfeit on the guide display unit 14b. The control unit 10 and the display unit 14 that execute step S122 function as an output unit that outputs the determination result.

As described above, the authenticity determination device 1, the authenticity determination method, and the computer program P according to the first embodiment allow a user to easily perform an authenticity determination without requiring special skills. Specifically, the authenticity of the object 3 can be determined simply by moving the point light source image PL on the light modulation element 2 while capturing an image of the sheet-like light modulation element 2.

More specifically, the control unit 10 of the authenticity determination device 1 can determine the authenticity of the object 3 by a process of determining whether the position of the reconstructed image 20h coincides with the position of the point light source image PL, regardless of the position of the point light source image PL contained in the captured image.
Furthermore, the control unit 10 of the authenticity determining device 1 can detect the movement of the light source unit 12 from the position of the mark 20 included in the captured image and the position of the point light source image PL. As described above, the control unit 10 can determine the authenticity of the object 3 by determining whether the position of the reconstructed image 20h coincides with the position of the point light source image PL, regardless of the position of the point light source image PL.

Furthermore, the control unit 10 of the authenticity determination device 1 captures an image of the light modulation element 2 while blinking the light source unit 12, thereby being able to accurately determine the reconstructed image 20h contained in the captured image, and therefore being able to more accurately determine the authenticity of the object 3.

In this embodiment 1, a portable computer such as a smartphone is exemplified as an example of the authenticity determination device 1, but it may be a multi-computer including multiple computers. The authenticity determination device 1 may also be a server-client system, a cloud server, or a virtual machine virtually constructed by software. The computer program P according to this embodiment 1 may be configured to be executed in a distributed manner on multiple computers.

In addition, in this embodiment 1, an example is described in which a sheet-shaped light modulation element 2 is attached to a flat object 3, but the object 3 and the light modulation element 2 do not need to be flat and may be curved.

Furthermore, in this embodiment 1, an example has been described in which the authenticity determination is performed by a computer, but the authenticity determination method may be configured to be partially or entirely performed by a person.

(Embodiment 2)
The authenticity determination device 1, authenticity determination method, and computer program P according to the second embodiment differ from those of the first embodiment in that the authenticity determination process has different contents, the light modulation element 2 used has a first mark 20a and a second mark 20b, and the light modulation element 2 is used like a tally seal or a seal. Since the hardware and other configurations of the authenticity determination device 1 are similar to those of the authenticity determination device 1 according to the first embodiment, the same reference numerals are used for similar parts, and detailed explanations will be omitted.

Fig. 8 is a schematic diagram showing the light modulation element 2 according to embodiment 2 attached to an object 3, and Fig. 9 is a conceptual diagram showing a method of attaching the light modulation element 2 according to embodiment 2. The object 3 to be authenticated according to embodiment 2 includes a pair of a first object half 31 and a second object half 32. The light modulation element 2 according to embodiment 2 is attached so as to straddle the first object half 31 and the second object half 32 in order to ensure that the relationship between the first object half 31 and the second object half 32 is true. The first object half 31 and the second object half 32 are, for example, two or more consecutive pages of a contract document, a contract created in two copies, etc.

The light modulation element 2 according to the second embodiment has a first mark 20a and a second mark 20b that are visible by light from a non-point light source. The first mark 20a and the second mark 20b are spaced apart. In the second embodiment, as shown in FIG. 8, the light modulation element 2 is attached to the object 3 so that the first mark 20a is located on the first object half 31 side and the second mark 20b is located on the second object half 32 side.

FIGS. 10 and 11 are flowcharts showing the steps of the authenticity determination process according to the second embodiment, and FIGS. 12 to 17 are examples of display screens of the authenticity determination device 1 executing the authenticity determination process according to the first embodiment.

The control unit 10 of the authenticity determination device 1 starts the imaging unit 13 (step S211) and, as shown in FIG. 12, displays the image captured by the imaging unit 13 on the display unit 14, as well as the aiming line image 14a and the guide display unit 14b (step S212). Then, the control unit 10 displays text information instructing the user to capture the first mark 20a at the center of the aiming line image 14a on the guide display unit 14b (step S213).

Next, the control unit 10 captures an image of the light modulation element 2 with the imaging unit 13 (step S214) and determines whether the first mark 20a is captured at the center of the sight line image 14a, in other words, whether the image of the first mark 20a is located at the center of the captured image (step S215). If it is determined that the first mark 20a is not captured at the center of the sight line image 14a (step S215: NO), the control unit 10 returns the process to step S214.

When it is determined that the first mark 20a is captured at the center of the sight line image 14a (step S215: YES), the control unit 10 turns on the light source unit 12 as shown in FIG. 13 (step S216) and captures the light modulation element 2 with the imaging unit 13 (step S217). Then, the control unit 10 distinguishes the image of the reconstructed image 20h and the image of the point light source image PL in the captured image (step S218). The method of distinguishing the reconstructed image 20h and the point light source image PL is the same as in the first embodiment. The control unit 10 temporarily stores the discrimination result of step S218. In addition, the control unit 10 may temporarily store an image captured when the first mark 20a is captured at the center of the sight line image 14a and the light source unit 12 is turned off, and an image captured when the light source unit 12 is turned on.
The image captured in step S217 corresponds to the first image obtained by capturing an image in a state in which the central portion C coincides with the first mark 20a.

Then, the control unit 10 displays text information on the guide display unit 14b instructing the user to move so that the second mark 20b is captured at the center of the sight line image 14a, as shown in FIG. 14 (step S219). Next, the control unit 10 turns off the light source unit 12 (step S220) and captures an image of the light modulation element 2 (step S221). The control unit 10 temporarily stores the captured image.

The control unit 10 determines whether the light source unit 12 has moved relative to the light modulation element 2 based on the change in the position of the first mark 20a or the second mark 20b included in the captured time-series images (step S222). If it is determined that the light source unit 12 has not moved (step S222: NO), the control unit 10 returns the process to step S221.

If it is determined that the light source unit 12 has moved (step S222: YES), the control unit 10 turns on the light source unit 12 (step S223), captures an image of the light modulation element 2 (step S224), and identifies the reconstructed image 20h and the point light source contained in the captured image (step S225).

Then, the control unit 10 judges whether the second mark 20b is captured at the center of the sight line image 14a, in other words, whether the image of the second mark 20b is located at the center of the captured image (step S226). If it is judged that the second mark 20b is not captured at the center of the sight line image 14a (step S226: NO), the control unit 10 returns the process to step S220. By repeatedly executing the processes of steps S220 to S226, the control unit 10 can distinguish or recognize the reconstructed image 20h and the point light source image PL contained in the image captured in the process of moving the point light source image PL from the first mark 20a to the second mark 20b.

When it is determined that the second mark 20b has been captured at the center of the sight line image 14a (step S226: YES), the control unit 10 determines whether or not a predetermined condition related to authenticity determination of the object 3 is satisfied (step S227).
In addition, the image captured in step S224 immediately before it is determined that the second mark 20b has been captured at the center of the aiming line image 14a corresponds to the second image obtained by capturing an image in a state where the central portion C is aligned with the second mark 20b.

If it is determined that the predetermined condition is satisfied (step S227: YES), the control unit 10 outputs information indicating that the object 3 is genuine, as shown in FIG. 15 (step S228), and ends the process. If it is determined that the predetermined condition is not satisfied (step S227: NO), the control unit 10 outputs information indicating that the object 3 is a counterfeit, as shown in FIG. 16 (step S229), and ends the process.

If the predetermined condition is not satisfied, the control unit 10 may be configured to display text information instructing the user to perform the operation again on the guide display unit 14b, as shown in FIG.
In addition, in the above authenticity determination process, an example has been described in which authenticity determination is performed when the second mark 20b is captured as the center. However, each time the point light source image PL is moved from the first mark 20a to the second mark 20b, it may be determined whether the positions of the reconstructed image 20h and the point light source image PL match, and if they do not match, or if it is determined that they have not matched a predetermined number of times or more, text information instructing the user to try the operation again may be displayed on the guide display unit 14b.

Figure 18 is a flowchart showing the process for determining whether or not a predetermined condition for authenticity determination in embodiment 2 is satisfied. In the process of step S227, the control unit 10 determines whether or not the positions of the reconstructed image 20h and the first mark 20a match based on the image captured with the first mark 20a at the center (step S251). The control unit 10 may further determine whether or not the positions of the reconstructed image 20h and the point light source image PL match.

If it is determined that the positions of the reconstructed image 20h and the first mark 20a match (step S251: YES), the control unit 10 determines whether the positions of the reconstructed image 20h and the second mark 20b match based on the image captured by capturing the second mark 20b at the center (step S252). Note that the control unit 10 may further determine whether the positions of the reconstructed image 20h and the point light source image PL match.

If it is determined that the positions of the reconstructed image 20h and the second mark 20b match (step S252: YES), the control unit 10 determines whether the position of the reconstructed image 20h included in the multiple images captured in the process of moving the point light source image PL from the first mark 20a to the second mark 20b matches the position of the point light source image PL in each image (step S253). In step S253, the control unit 10 may be configured to determine whether the position of the reconstructed image 20h matches the position of the point light source image PL for all images captured in the process of moving the point light source image PL from the first mark 20a to the second mark 20b, or to determine whether the position of the reconstructed image 20h matches the position of the point light source image PL at a predetermined rate or more.

If it is determined that the positions of the multiple reconstructed images 20h and the point light source image PL match (step S253: YES), the control unit 10 determines that the predetermined condition is satisfied (step S254) and ends the process.

If it is determined that the positions of the reconstructed image 20h and the first mark 20a do not match (step S251: NO), if it is determined that the positions of the reconstructed image 20h and the second mark 20b do not match (step S252: NO), or if it is determined that the position of the reconstructed image 20h does not match the position of the point light source image PL among the multiple reconstructed images 20h (step S253: NO), the control unit 10 determines that the predetermined condition is not satisfied (step S255) and ends the process.

As described above, according to the authenticity determination device 1, authenticity determination method, and computer program P of the second embodiment, the user can determine the authenticity of the object 3 simply by aligning the point light source image PL with the first mark 20a and then moving the point light source image PL from the first mark 20a to the second mark 20b. In particular, when the light modulation element 2 is attached to the object 3 as shown in Figures 8 and 9, the authenticity determination device 1 can determine whether the pair of the first object half 31 and the second object half 32 is authentic.

(Embodiment 3)
The authenticity determination device 1, authenticity determination method, and computer program P according to the third embodiment differ in the configuration of the light modulation element 2 used and the contents of the authenticity determination process. Since the hardware and other configurations of the authenticity determination device 1 are similar to those of the authenticity determination devices 1 and 2 according to the first embodiment, the same reference numerals are used for similar parts and detailed descriptions are omitted.

FIG. 19 is a conceptual diagram showing the light modulation element 2 according to the third embodiment. The light modulation element 2 according to the third embodiment differs from the second embodiment in that it generates a reconstructed image 20h of different sizes according to the distance between the point light source of the light source unit 12 and the light modulation element 2. Hereinafter, the distance between the light source unit 12 and the light modulation element 2 is referred to as the imaging distance. In the example of the third embodiment, as shown in FIG. 19, the larger the imaging distance, the larger the reconstructed image 20h generated. Specifically, in the center diagram of FIG. 19, the imaging distance is h1, and when the imaging distance is shortened to h2 (<h1) as shown in the left diagram of FIG. 19, the reconstructed image 20h becomes smaller. Also, when the imaging distance is lengthened to h3 (>h1) as shown in the right diagram of FIG. 19, the reconstructed image 20h becomes larger.
The relationship between the size of the reconstructed image 20h and the imaging distance is not particularly limited, but for example, the size of the reconstructed image 20h and the imaging distance are in a proportional relationship.

Figure 20 is a flowchart showing the processing procedure for determining whether or not a predetermined condition related to authenticity determination in embodiment 3 is satisfied. The processing contents of steps S351 to S353 are similar to steps S251 to S253 in embodiment 2, so detailed explanations are omitted.

If it is determined in step S353 that the positions of the multiple reconstructed images 20h and the point light source image PL match (step S353: YES), the control unit 10 determines whether the relationship between the size of the reconstructed image 20h included in the multiple images captured in the process of moving the point light source image PL from the first mark 20a to the second mark 20b and the imaging distance is a predetermined relationship (step S354). For example, in the case where the same light modulation element 2 is configured so that the relationship between the size of the reconstructed image 20h and the imaging distance is constant, the control unit 10 determines whether the relationship between the size of the reconstructed image 20h and the imaging distance is constant. In the case where the relationship between the size of the reconstructed image 20h and the imaging distance is proportional, the control unit 10 determines whether the proportionality coefficient is constant. Note that the imaging distance may be configured to be estimated from the size of the first mark 20a.

If it is determined that the relationship between the size of the reconstructed image 20h and the imaging distance satisfies a predetermined relationship (step S354: YES), the control unit 10 determines that the predetermined condition is satisfied (step S355) and ends the process.

If it is determined that the positions of the reconstructed image 20h and the first mark 20a do not match (step S351: NO), if it is determined that the positions of the reconstructed image 20h and the second mark 20b do not match (step S352: NO), if it is determined that the position of the reconstructed image 20h does not match the position of the point light source image PL among the multiple reconstructed images 20h (step S253: NO), or if it is determined that there is no predetermined relationship with the imaging distance (step S354: NO), the control unit 10 determines that the predetermined condition is not satisfied (step S356) and ends the process.

As described above, according to the authenticity determining device 1, authenticity determining method, and computer program P of the third embodiment, the point light source image PL is aligned with the first mark 20a, and then the authenticity of the object 3 is determined based on the position and size of the reconstructed image 20h in multiple images acquired in the process of moving the point light source image PL from the first mark 20a to the second mark 20b. By taking into account the position and size of the reconstructed image 20h, the authenticity of the object 3 can be determined with greater accuracy.

(Embodiment 4)
The authenticity determination device 1, authenticity determination method, and computer program P according to the fourth embodiment differ from those of the second and third embodiments in that the authenticity of the object 3 is determined using a reconstructed image database (reconstructed image DB) 416 that stores the relationship between the first mark 20a, the second mark 20b, and the reconstructed image 20h. The hardware and other configurations of the authenticity determination device 1 are similar to those of the authenticity determination devices 1 according to the first to third embodiments, and therefore similar parts are denoted by the same reference numerals and detailed description will be omitted.

FIG. 21 is a block diagram showing an example of the configuration of an authenticity determination device 1 according to embodiment 4. The storage unit 11 of the authenticity determination device 1 according to embodiment 4 includes a reconstructed image database 416.

The reconstructed image 20h generated by the light modulation element 2 is unique to that light modulation element 2. Since the light modulation element 2 attached to the object 3 to be authenticated differs for each object 3, the reconstructed image 20h reproduced by the light modulation element 2 attached to the object 3 also differs for each object 3. Therefore, the memory unit 11 of the authenticity determination device 1 stores in advance in the reconstructed image database 416 the relationship between the feature amounts of the first mark 20a and the second mark 20b of the light modulation element 2 and the feature amounts of the reconstructed image 20h.

Figure 22 is a conceptual diagram showing an example of a reconstructed image database 416 according to embodiment 4. As shown in Figure 22A, for example, the reconstructed image database 416 has a "first mark" column that stores the feature amount of the first mark 20a, a "second mark" column that stores the feature amount of the second mark 20b, and a "reconstructed image 20h" column that stores the feature amount of the reconstructed image 20h. The form of the feature amount is not particularly limited.

In another example shown in FIG. 22B, in addition to the "first mark" column, the "second mark" column, and the "reconstructed image 20h" column, there is also a "position" column that stores the position at which the reconstructed image 20h is reconstructed. The reconstructed image 20h generated by the light modulation element 2 may be changed depending on the position at which the light from the point light source is irradiated, and the reconstructed image database 416 stores the relationship between the position of the central part C of the area where the light from the point light source is illuminated and the feature amount of the reconstructed image 20h generated at that position.

In another example shown in FIG. 22C, in addition to the "first mark" column, the "second mark" column, the "position" column, and the "reconstructed image 20h" column, the relationship between the imaging distance and the size of the reconstructed image 20h is also stored.

In addition to the authenticity determination process shown in Fig. 18 of the second embodiment or the authenticity determination process shown in Fig. 20 of the third embodiment, the control unit 10 of the authenticity determination device 1 according to the fourth embodiment determines whether or not the relationship between the feature amounts of the first and second marks 20a, 20b and the feature amounts of the reconstructed image 20h to be reproduced is consistent with the relationship stored in the reconstructed image database 416 shown in Fig. 22A. If there is a consistency, the control unit 10 determines that the object 3 is authentic.
In addition, the control unit 10 may determine whether or not the relationship between the features of the first and second marks 20a, 20b, the features of the reconstructed image 20h to be reconstructed, and the position of the reconstructed image 20h is consistent with the relationship stored in the reconstructed image database 416 shown in FIG. 22B.
Furthermore, the control unit 10 may determine whether or not the relationship among the features of the first and second marks 20a, 20b, the features of the reconstructed image 20h to be reconstructed, the position of the reconstructed image 20h, and the size of the reconstructed image 20h is consistent with the relationship stored in the reconstructed image database 416 shown in FIG. 22C.

As described above, the authenticity determination device 1, the authenticity determination method, and the computer program P according to the second embodiment can determine the authenticity of the object 3 with greater accuracy.

(Embodiment 5)
23 is a conceptual diagram showing a method of attaching the light modulation element 2 according to the fifth embodiment. The object 503 according to the fifth embodiment is an ID card, and includes, for example, an ID card substrate 531 and a photograph 532 attached or printed on the ID card substrate 531, and the light modulation element 2 is attached across the ID card substrate 531 and the photograph 532. The ID card is, for example, a passport, a My Number card, a driver's license, a membership card, an employee ID card, a student ID card, a credit card, or the like.

According to the fifth embodiment, it is possible to determine the authenticity of the photograph 532 attached or printed on the ID card substrate 531.

(Embodiment 6)
24 is a conceptual diagram showing a method of attaching the light modulation element 2 according to embodiment 6. The object 603 according to embodiment 6 is, for example, an admission ticket to a facility, an annual pass for using a facility, a ballot paper, etc., and includes a main ticket 631 and a stub 632 such as a copy, and the light modulation element 2 is attached across the main ticket 631 and the stub 632.

According to embodiment 6, the authenticity of the ticket 631 and ticket stub 632 can be determined.

The embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present invention is indicated by the claims, not by the above meaning, and is intended to include all modifications within the meaning and scope of the claims.

REFERENCE SIGNS LIST 1 Authenticity determination device 2 Light modulation element 3, 503, 603 Object 10 Control unit 11 Memory unit 12 Light source unit 13 Imaging unit 14 Display unit 14a Aiming line image 14b Guide display unit 15 Operation unit 20 Mark 20a First mark 20b Second mark 20h Reconstructed image 31 First object half 32 Second object half 416 Reconstructed image database C Central portion M Recording medium P Computer program PL Point light source image

Claims (10)

A computer program for causing a computer to execute a process for determining authenticity of an object provided with a light modulation element that generates a reconstructed image at a central portion of a portion irradiated with light from a point light source, and that, when the point light source moves in an in-plane direction, causes the reconstructed image to be generated at the central portion in accordance with the movement of the central portion, the computer program comprising:
acquiring a plurality of images obtained by imaging the point light source at different positions relative to the light modulation element;
determining whether the position of the reconstructed image in the acquired multiple images coincides with the central portion, regardless of the position of the point light source , thereby determining the authenticity of the object;
A computer program for causing the computer to execute a process of outputting a result of the determination. the light modulation element has a mark visible by light from a non-point light source;
The process of determining authenticity is as follows:
and determining the authenticity of the object based on the position of the reconstructed image, the position of the image of the mark, and the position of the central portion in the acquired multiple images.
2. The computer program product of claim 1 . the light modulation element has a first mark and a second mark that are visible by light from a non-point light source;
The process of determining authenticity is as follows:
and determining the authenticity of the object based on a positional relationship between the reconstructed image and an image of the first mark in a plurality of acquired images and a positional relationship between the reconstructed image and an image of the second mark.
2. The computer program product of claim 1 . The process of acquiring the plurality of images includes:
acquiring a first image obtained by imaging a state in which at least the central portion coincides with the first mark, and acquiring a second image obtained by imaging a state in which the central portion coincides with the second mark,
The process of determining authenticity is as follows:
The process includes a process of determining whether or not a position of the reconstructed image in the acquired first image coincides with a position of the first mark or the central portion, and whether or not a position of the reconstructed image in the acquired second image coincides with a position of the second mark or the central portion.
4. A computer program according to claim 3 . The process of acquiring the plurality of images includes:
acquiring a plurality of images obtained by capturing an image while at least the central portion moves from the first mark to the second mark;
The process of determining authenticity is as follows:
and determining whether or not a position of the reconstructed image in a plurality of images obtained by capturing images during the process of moving from the first mark to the second mark coincides with a position of the central portion when each image is captured.
5. A computer program according to claim 4 . outputting an instruction to align the central portion with the first mark;
The computer program product according to claim 4 or 5 , which causes the computer to execute a process of: subsequently outputting an instruction to move the central portion from the first mark to the second mark. Repeatedly turning on and off the point light source;
7. The computer program according to claim 1, for causing the computer to execute a process of determining the reconstructed image based on an image obtained by imaging the light modulation element with the point light source turned on and an image obtained by imaging the light modulation element with the point light source turned off. the light modulation element generates the reconstructed image having a size according to a distance from the point light source,
The process of determining authenticity is as follows:
The computer program according to claim 1 , further comprising: determining whether the object is authentic or not based on a position and a size of the reconstructed image in a plurality of acquired images. 1. A method for determining authenticity of an object, the method comprising the steps of: generating a reconstructed image at a central portion of a portion irradiated with light from a point light source ; and, when the point light source moves in an in-plane direction, tracking the movement of the central portion to generate the reconstructed image at the central portion, the method comprising the steps of:
The computer includes:
acquiring a plurality of images obtained by imaging the point light source at different positions relative to the light modulation element;
The authenticity determination method determines the authenticity of the object by determining whether the position of the reconstructed image in a plurality of acquired images coincides with the central portion, regardless of the position of the point light source . 1. An authenticity determination device for determining the authenticity of an object provided with a light modulation element that generates a reconstructed image at a central portion of a portion irradiated with light from a point light source , and that, when the point light source moves in an in-plane direction, causes the reconstructed image to be generated at the central portion in accordance with the movement of the central portion,
an acquisition unit that acquires a plurality of images obtained by capturing images of the point light source at different positions relative to the light modulation element;
a determination unit that determines whether a position of the reconstructed image in the plurality of images acquired by the acquisition unit coincides with the central portion, regardless of the position of the point light source, to determine the authenticity of the object;
and an output unit that outputs the determination result.

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