JP2024000682A - Authenticity determination device and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an authenticity determination device capable of suitably determining authenticity of an identity certificate, and the like.

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

SELECTED DRAWING: Figure 4

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to an authentication device, a program thereof, and the like.

When opening an account at a financial institution, it is necessary to verify the identity of the person using an ID card (identification card) such as a driver's license, but in order to open an account by impersonating another person for the purpose of criminal purposes such as special fraud, there are cases where a forged ID card is used to open an account. Cases of falsification, etc. are increasing.

In a typical financial institution, a user goes to the financial institution and submits an ID card, and the financial institution uses the submitted ID card to verify the user's identity face-to-face. Further, Patent Documents 1 and 2 describe an authentication device that determines the authenticity of an ID card from an image obtained by reading the face of the ID card with a reader, etc., and reads a submitted ID card with a reader, etc. It is also possible to determine the authenticity of an ID card by doing this.

Japanese Patent Application Publication No. 2011-34535 Japanese Patent Application Publication No. 2019-117549

Genuine ID cards are manufactured by printing using a predetermined printing method and ink, and by using this, it is possible to distinguish between genuine ID cards and fake ID cards. Particularly in recent years, identity verification has become stricter, and there has been a need for technology that can reliably determine the authenticity of ID cards.

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide an authentication device and the like that can suitably determine the authenticity of an identification card.

A first invention for solving the above-mentioned problems is an authenticity determination device for determining the authenticity of an identification card having a face photograph, comprising: an acquisition means for acquiring an infrared image of the identification card; Different index values are calculated from each of the image of the character part of the identification card obtained from the infrared image and the image of the face photo of the identification card obtained from the infrared image, and each index value is compared with a reference value. In this case, there is provided an authenticity determining means for determining whether the text portion and the facial photograph are genuine identification documents, and the authenticity determining means is configured to determine whether either the text portion or the facial photograph is a genuine identification card. The authentication device is characterized in that, if it is determined that the identification card is not a genuine identification card, the identification card is determined to be false.

In the present invention, a genuine identification card is manufactured by printing using a predetermined printing method and using ink, and the authenticity is determined by utilizing the appearance of its characteristics in an infrared image. For example, parts printed with ink such as carbon that absorbs infrared rays appear as low-brightness images in an infrared image, and other parts appear as high-brightness parts in an infrared image. Therefore, if there is a difference in the presence or absence of infrared absorption in the printed part between the official identification card and the ID card being judged due to differences in printing methods, inks used, etc., the identification card being judged can be faked using an infrared image. It can be determined that In addition, the present invention reliably determines authenticity by using both the text and face photo of the identification card, which often have different printing methods and ink used even within official identification cards. be able to. Furthermore, by using different index values in both determinations, the index values can be set in accordance with the differences in characteristics between the text portion and the face photograph, improving accuracy in determining authenticity.

The authenticity determining means determines an index value used in determining the text portion by an average value of the magnitude of a luminance gradient of pixels in the image of the text portion, and determines an index value used in determining the face photograph based on the average value of the luminance gradient of pixels in the image of the text portion. It is preferable to determine this based on variations in the brightness of pixels within a photographic image.
Text portions and facial photographs can be suitably determined using the respective index values described above. Each index value is based on the characteristics of the text part and the face photo. If the index values used were swapped and the average value of the luminance gradient described above for the face photo was used as the index value, the difference between the hair color and clothing of the person would be The index value may fluctuate greatly due to factors unrelated to authenticity, such as color. In addition, the number of characters, that is, the area of the characters in the image, may differ depending on the individual, such as the name or address of the text part. If we use the above-mentioned variation in brightness for the text part as an index value, there is no relationship between authenticity and authenticity depending on the number of characters. The index value may fluctuate greatly without any change.

The authenticity determining means may perform a correction in which the luminance of a pixel having a luminance higher than a predetermined threshold value in the image of the facial photograph is replaced with a luminance lower than the threshold value, before obtaining an index value to be used in determining the facial photograph. is desirable.
Thereby, it is possible to prevent holograms and the like from being present in the face photograph and becoming a high-luminance part in the infrared image, which would affect the determination result of the face photograph.

Preferably, the authenticity determining means sets the index value used in determining the character portion to 0 if the number of pixels whose brightness gradient exceeds a predetermined threshold value is less than or equal to a certain number in determining the character portion.
Thereby, it is possible to prevent a large brightness gradient from occurring in the infrared image due to the presence of minute dirt and affecting the determination result of the text portion.

A second invention is an authenticity determination device for determining the authenticity of an identification card having a face photograph, comprising: an acquisition means for acquiring an infrared image of the identification card; Different index values are calculated from each of the image of the character part of the identification card and the image of the face photo of the identification card obtained from the infrared image, and each index value is compared with a reference value to calculate the character part of the identification card. and an authenticity determining means for determining whether the character part and the face photograph are of a legitimate identification card, and the authenticity determining means determines whether either the character part or the face photograph is a genuine identity verification document. This is a program for functioning as an authenticity determination device characterized in that, if it is determined that the identity verification certificate is not a genuine one, the identity verification certificate is determined to be false.
The second invention is a program for the authentication device of the first invention.

According to the present invention, it is possible to provide an authentication device and the like that can suitably determine the authenticity of an identification card.

FIG. 1 is a diagram showing an authenticity determination system 1. FIG. FIG. 3 is a diagram showing the hardware configuration of the authenticity determination device 3. FIG. 1 is a diagram showing an ID card 10. FIG. The figure which shows the function of the authenticity determination device 3. Flowchart showing an outline of an authenticity determination method. 2 is a flowchart showing the procedure for determining the authenticity of the text portion of the ID card 10. A diagram showing a character image 100. An example of a Sobel filter. A diagram showing a brightness gradient. A diagram showing a character image 100. 10 is a flowchart showing the procedure for determining the authenticity of the face photo 18 of the ID card 10. FIG. 2 is a diagram showing a histogram in which the horizontal axis is the luminance value and the vertical axis is the number of pixels.

Hereinafter, preferred embodiments of the present invention will be described in detail based on the drawings.

(1. Authenticity determination system 1)
FIG. 1 is a diagram showing an authenticity determination system 1 having an authenticity determination device 3 according to an embodiment of the present invention. As shown in FIG. 1, the authenticity determination system 1 is configured by connecting a reading device 2 and an authenticity determination device 3 so as to be communicable by wire or wirelessly. In the authenticity determination system 1, the image of the ID card 10 is transmitted from the reading device 2 to the authenticity determination device 3, and the authenticity determination device 3 determines the authenticity of the ID card 10 from the image.

The reading device 2 photographs the ID card 10 and obtains an image thereof. In particular, in this embodiment, the reading device 2 includes an infrared camera and an infrared illumination, and the infrared camera captures an infrared image of the ID card 10 by receiving infrared rays emitted from the infrared illumination and reflected from the ID card 10.

FIG. 2 is a diagram showing the hardware configuration of the authenticity determination device 3. The authenticity determination device 3 can be realized by a computer configured by connecting a control section 31, a storage section 32, a communication section 33, a display section 34, etc. via a bus or the like. However, the present invention is not limited to this, and various configurations can be adopted as appropriate.

The control unit 31 is composed of a CPU, ROM, RAM, etc. The CPU calls a program related to the processing of the authenticity determination device 3 stored in the storage unit 32 or a storage medium such as a ROM into a work area on the RAM and executes it. ROM is a nonvolatile memory that permanently stores programs such as the boot program and BIOS, as well as data. The RAM is a volatile memory that temporarily holds programs and data loaded from the storage unit 32, ROM, etc., and also includes a work area used by the control unit 31 to perform various processes.

The storage unit 32 is a hard disk drive, a solid state drive, a flash memory, or the like, and stores programs to be executed by the authenticity determination device 3 during processing to be described later, data necessary for program execution, an OS, and the like.

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

(2. ID card 10)
The ID card 10 is an identification card that is subject to authenticity determination in this embodiment. The identity verification document is a medium used for administrative procedures and identity verification by various administrative agencies, financial institutions, mobile phone carriers, etc., and is, for example, a driver's license. However, the ID card 10 is not limited to this, and may be a My Number card, a residence card, a special permanent residence card, or the like.

FIG. 3A is a diagram schematically showing the ID card 10 (driver's license), and schematically shows an example of the face of the ID card 10. The ID card 10 includes a card holder's name 12, date of birth 13, address 14, and facial photo 18, date of issue 15, issue number 16, and expiration date 17 on a substantially rectangular card base material. etc. are printed.

The name 12, date of birth 13, address 14, date of issue 15, issue number 16, expiration date 17, etc. include on-demand information that differs depending on the individual ID card 10. The face photo 18 is also on-demand information that differs depending on each ID card 10, and this on-demand information is printed at a fixed position on the card base material using a thermal transfer printing method using a thermal head. . Characters other than the face photograph 18 are printed by a melting type thermal transfer method, and the face photograph 18 is printed by a sublimation type thermal transfer method.

On the other hand, characters such as "name", "address", "date of issue", "number", etc. that indicate the entry fields for name 12, address 14, date of issue 15, and issue number 16, as well as the ruled lines, are on each ID card 10. Commonly used. These characters and ruled lines are formed in advance at fixed positions on the card base material by a printing method such as an offset printing method or a letterpress printing method before printing the on-demand information, and are called a pre-printed portion.

FIG. 3(b) shows the pre-printed portion extracted from the ID card 10. As shown in FIG. 3(b), by printing the on-demand information on the card base material on which the pre-printed portion has been formed in advance, the ID card 10 is extracted. Card 10 is manufactured. The structure of the on-demand information and pre-printed portions differs depending on the type of ID card 10, such as a driver's license, My Number card, residence card, or special permanent resident card.

(3. Function of authenticity determination device 3)
FIG. 4 is a block diagram showing the functions of the authenticity determination device 3. The authenticity determination device 3 includes an acquisition means 301, an authenticity determination means 302, and the like.

The acquisition means 301 is for the control section 31 of the authenticity determination device 3 to receive and acquire an infrared image of the ID card 10 from the reading device 2 via the communication section 33.

The authenticity determining means 302 is for determining the authenticity of the ID card 10 by using the infrared image of the ID card 10 obtained from the reading device 2 by the control unit 31 of the authenticity determining device 3 . In this embodiment, an infrared image is used to determine whether each of the text portion and face photo 18 of the ID card 10 is true (whether or not it is a genuine ID card 10) using different indicators. However, the details will be described later.

(4. Authenticity determination method)
FIG. 5 is a flowchart showing an outline of the authenticity determination method executed by the authenticity determination system 1. S1 to S2 in FIG. 5 are processes executed by the control unit (not shown) of the reading device 2 by controlling each part of the reading device 2, and S3 to S9 are processes executed by the control unit 31 of the authenticity determining device 3. This is a process executed by controlling each part of the system.

In this embodiment, first, the user sets the ID card 10 at a predetermined position on the reading device 2, and the reading device 2 photographs the ID card 10 with an infrared camera according to the user's operation (S1).

The reading device 2 transmits an infrared image obtained by photographing the ID card 10 to the authenticity determination device 3 (S2). When the authenticity determination device 3 receives the infrared image of the ID card 10 (S3), it determines the authenticity of the ID card 10 using the infrared image from the character part (S4), and if the character part is determined to be true (S5). ;Yes), the authenticity is further determined from the face photograph 18 of the ID card 10 (S6).

As a result, if the face photo 18 is determined to be true (S7; Yes), the ID card 10 is determined to be true as a result of the final authenticity determination, and this is displayed on the display unit 34, and the process ends (S8). On the other hand, if either the text part or the face photo 18 is determined to be false (S5; No or S7; No), the ID card 10 is determined to be false as a result of the final authenticity determination, and this is displayed on the display section 34. The process ends (S9). The person in charge can take appropriate measures according to the content displayed on the display unit 34.

It should be noted that the text part of the ID card 10 and the face photo 18 may be judged first, but since the processing load on the computer is greater for the judgment of the face photo 18, as shown in FIG. The overall processing load can be reduced by performing the determination first and ending the process without determining the face photo 18 if the text portion is false.

In this embodiment, the genuine ID card 10 is manufactured by printing using a predetermined printing method and using ink, and the authenticity is determined by utilizing the appearance of its characteristics in an infrared image. Further, the specific methods of determining authenticity in S4 and S6 differ depending on the characteristics of the character portion of the ID card 10 and the facial photograph 18. The details of these authentication methods will be explained below.

(5. Authenticity determination of the text part of ID card 10)
FIG. 6 is a flowchart showing the procedure for determining the authenticity of the text portion of the ID card 10 in S4.

In this embodiment, in S4, first, a character region is extracted from the infrared image received in S3 (S401). The area is set in advance at a predetermined position within the infrared image of the ID card 10 depending on the type of ID card 10 (driver's license, My Number card, residence card, special permanent resident card, etc.).

This area includes, for example, the area for name 12, date of birth 13, address 14, issue date 15, number 16, expiration date 17, and other on-demand information in FIG. 3(a). This is an area that includes Alternatively, the area may include a pre-printed part, such as the characters "Name" indicating the column for writing the name 12 or the letters "Address" indicating the column for writing the address 14. In the case of the former (area containing on-demand information), the area should not include ruled lines, which are pre-printed parts.

Hereinafter, the image obtained by extracting the region of the text portion in S401 will be referred to as a text image. FIG. 7 shows, as an example of the character image 100, a part of the character image 100 obtained by extracting the region of the name 12. The horizontal direction of the character image 100 corresponds to the long side direction of the approximately rectangular ID card 10, and the vertical direction of the character image 100 corresponds to the short side direction of the ID card 10. In this embodiment, since the name 12, which is on-demand information, is printed using a melt-type thermal transfer method using carbon or other ink that absorbs infrared rays, if the name 12 is the character image 100 of the regular ID card 10, the character The area appears as an image with lower brightness than the surrounding area.

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

Next, the authenticity determination device 3 performs noise removal processing on the character image 100 (S404). In this embodiment, smoothing processing and opening are performed as noise removal processing.

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

In the opening, known contraction processing and expansion processing (morphological processing) are performed on the character image 100 in this order. For example, the shrinking process is a process of replacing the brightness value of the pixel of interest in the character image 100 with the minimum brightness of the pixels in a predetermined size range (for example, a range of 5 pixels vertically x 5 pixels horizontally) centered on the pixel of interest. can be performed using each pixel in the character image 100 as the pixel of interest. Further, as the expansion process, the luminance value of the pixel of interest in the character image 100 is replaced with the maximum luminance of the pixels in a predetermined size range centered on the pixel of interest. It can be done as follows. By performing the contraction process and the expansion process in this order, minute high-brightness portions (white spots) in the character image 100 are removed.

Next, the authenticity determination device 3 calculates the brightness gradient of the character image 100 (S405). The brightness gradient is a rate of change in brightness between pixels, and is calculated using a Sobel filter illustrated in FIGS. 8A and 8B in this embodiment, but is not limited thereto.

FIG. 8(a) is an example of a Sobel filter for calculating the vertical luminance gradient of the character image 100. By performing a convolution operation of the filter on the luminance value of each pixel in the character image 100, The rate of change in brightness between pixels located above and below each pixel is calculated as the value of the brightness gradient in the vertical direction of each pixel. FIG. 9A shows the magnitude (absolute value) of the brightness gradient in the vertical direction of each pixel visualized using a grayscale image, and parts with large brightness gradients are shown in white.

On the other hand, FIG. 8(b) is an example of a Sobel filter for calculating the horizontal brightness gradient of the character image 100, and the convolution operation of the filter is performed on the brightness value of each pixel in the character image 100. Then, the rate of change in brightness between pixels located on the left and right of each pixel is calculated as the value of the brightness gradient in the horizontal direction of each pixel. FIG. 9(b) is a visualization of the magnitude of the luminance gradient in the horizontal direction of each pixel, similar to FIG. 9(a).

In S405, the magnitude G of the brightness gradient of each pixel is determined by the sum of the vertical brightness gradient Gx and the horizontal brightness gradient Gy of each pixel, more specifically, as shown in equation (1) below. , is determined by the square root of the sum of the squares of Gx and Gy.
G=(Gx ² + Gy ² ) ^1/2 …(1)

The authenticity determination device 3 calculates an index value used for determination from the magnitude G of the brightness gradient of each pixel determined in S405 (S406). In S406, pixels for which the magnitude G of the luminance gradient is less than or equal to a predetermined threshold are excluded, and the average value of the magnitude G of the luminance gradient of the remaining pixels is determined, and this is used as an index value.

The above threshold value can be determined as appropriate depending on the purpose of improving determination accuracy, etc., but there is a risk that the index value may be determined by a small number of pixels with a large brightness gradient, such as minute dirt. In order to avoid this, in this embodiment, if the number of pixels in which the magnitude G of the brightness gradient exceeds the above threshold value is a certain number or less, the index value is set to 0. This constant number is obtained by multiplying the area of the character image 100 (the number of pixels of the character image 100) by a predetermined ratio. This ratio can also be determined as appropriate depending on the purpose, such as improving determination accuracy.

The authenticity determination device 3 compares the index value calculated in S406 with a predetermined reference value (S407) to determine whether the character part extracted in S401 is true (whether it is a genuine ID card 10). whether or not).

For example, if the character part extracted in S401 is printed using ink that absorbs infrared rays by the melting type thermal transfer method on the regular ID card 10 as described above, the character part is printed in the surrounding area in the character image 100. It appears as an image with lower luminance than that, and the index value calculated in S406 becomes larger. Therefore, by predetermining an appropriate value as the reference value, in S407, if the index value is greater than or equal to the reference value, the text portion can be determined to be true, and if it is less than the reference value, the text portion can be determined to be false.

How the authenticity is determined based on the comparison result between the index value and the reference value depends on the printing method, ink, etc. used to print the character portion extracted in S401 on the regular ID card 10. For example, if the character part extracted in S401 is printed on the regular ID card 10 using a different printing method and ink, the character part may have low brightness in the character image 100, as shown in FIG. In some cases, it may not appear as an image. In this case, in S407, if the index value is greater than or equal to the reference value, the text portion can be determined to be false, and if it is less than the reference value, the text portion can be determined to be true.

The same applies to the reference value, and the reference value is an appropriate value depending on the printing method, ink, etc. used to print the character part extracted in S401 on the regular ID card 10. can be determined.

If the comparison result between the index value and the reference value is a predetermined one (for example, "the designated value is greater than or equal to the reference value") (S408; Yes), the authenticity determination device 3 determines that the character part is true (S409), and if so. If not (S408; No), the character part is set to false (S410), and the process of S4 ends.

Note that a plurality of character parts may be extracted in S401 described above, and the above determination may be performed for each character image 100. Based on the determination result for each character image 100, it can be finally determined whether or not the character portion of the ID card 10 as a whole is true. The determination method is not particularly limited. For example, if at least one character image 100 is determined to be false, the final determination result of the character part may be false, and if at least one character image 100 is determined to be true If it is determined that the character part is true, the final determination result for the character part can be set as true. In addition, the final determination result of the character portion can also be determined according to the number of character images 100 determined to be false.

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

Similar to S402 to S404 described above, the authenticity determination device 3 performs resizing, grayscale conversion, and noise removal processing on the image of the area of the face photo 18 extracted in S601 (hereinafter referred to as a face image) (S602 to S604). . In this embodiment, the above-described smoothing process is performed as the noise removal process in S604.

Next, the authenticity determination device 3 performs highlight correction on the face image (S605). Depending on the type of ID card 10, a hologram may be present in the area of the face photo 18, and in such cases, the hologram may become highly bright in the infrared image, which may affect the determination result. The highlight correction in S605 is a correction performed for the purpose of excluding the influence of holograms and the like that have nothing to do with the authenticity of the ID card 10.

In S605, the brightness value of each pixel in the face image is compared with a predetermined threshold value, and pixels having brightness greater than the threshold value are determined as high-brightness pixels. Then, the brightness value of the high-brightness pixel can be replaced by a brightness lower than the threshold, more specifically, the average brightness of pixels other than the high-brightness pixel in the face image. The above-mentioned threshold value can be determined as appropriate depending on the purpose, such as improving determination accuracy.

The authenticity determination device 3 calculates an index value used for determination from the luminance value of the face image after performing the preprocessing in this way (S606). In this embodiment, this index value is used as a value representing the variation in brightness, and as shown in FIG. 12, the variance σ ² in a histogram with the brightness value on the horizontal axis and the number of pixels on the vertical axis is calculated using the following formula (2). . Then, the square root σ (standard deviation) is taken as the index value. In equation (2), N is the number of pixels in the face image, P ₁ , P ₂ , P ₃ , ..., P _N is the brightness value of each pixel in the face image, and μ is the average brightness of all pixels in the face image. It is.
σ ² =(1/N)・{(P ₁ -μ) ² +(P ₂ -μ) ² +(P ₃ -μ) ² +...+(P _N -μ) ² }...(2)

The authenticity determination device 3 compares the index value calculated in S606 with the reference value (S607) to determine whether the face photo 18 is authentic (whether it is the genuine ID card 10 or not). do.

For example, if the face photo 18 is printed on the regular ID card 10 using carbon-free ink using a dye sublimation thermal transfer method, the face image extracted in S601 will have a high overall height, similar to the example in FIG. This results in an image with small variations in brightness, and the index value calculated in S606 becomes small. Therefore, by predetermining an appropriate value as the reference value, in S607, if the index value is greater than or equal to the reference value, the face photo 18 can be determined to be false, and if it is less than the reference value, the face photo 18 can be determined to be true. .

As mentioned above, how to determine authenticity based on the comparison result between the index value and the reference value, and the value of the reference value depends on what printing method, ink, etc. It can be determined depending on the printing method used.

If the comparison result between the index value and the reference value is a predetermined one (for example, "the index value is less than the reference value") (S608; Yes), the authenticity determination device 3 determines that the face photo 18 is true (S609), and confirms that If not (S608; No), the face photo 18 is determined to be false (S610), and the process of S6 is ended.

As explained above, in this embodiment, the genuine ID card 10 is manufactured by printing using a predetermined printing method and ink, etc., and the authenticity can be determined by utilizing the characteristics appearing in the infrared image. I do. For example, parts printed with ink such as carbon that absorbs infrared rays appear as low-brightness images in an infrared image, and other parts appear as high-brightness parts in an infrared image. Therefore, if there is a difference in the presence or absence of infrared absorption in the printed part between the genuine ID card 10 and the ID card 10 to be determined due to differences in printing methods, inks used, etc., the ID card 10 to be determined can be faked using an infrared image. It can be determined that

Furthermore, in this embodiment, the authenticity can be determined reliably by using both the text part of the ID card 10 and the face photo 18, which often differ in printing method and ink used even within the regular ID card 10. can be done. Furthermore, by using different index values in both determinations, the index values can be set in accordance with the difference in characteristics between the text portion and the facial photograph 18, and the accuracy of the authenticity determination is improved.

More specifically, depending on the difference in characteristics between the text portion and the face photo 18, the average value of the luminance gradient described above is used as an index value when making a judgment from the text portion, and the above-described variation in brightness is used when making a judgment from the face photo 18. can be used as an index value. If the index values used are changed and the average value of the brightness gradient described above for the face photo 18 is used as the index value, the index value will vary greatly due to factors unrelated to authenticity, such as the color of the person's hair and clothing. There are things to do. In addition, the number of characters, that is, the area of the characters in the character image 100, may vary depending on the individual, such as the name 12 or the address 14, and if the above-mentioned variation in brightness for the character part is used as an index value, the number of characters may differ depending on the number of characters. The index value may fluctuate greatly regardless of the

Further, in this embodiment, by performing highlight correction in S605 described above, it is possible to prevent a hologram or the like from being present in the face photo 18 and resulting in high brightness, which would affect the determination result of the face photo 18. In addition, when calculating the index value used for character part determination in S406, if the number of pixels for which the magnitude G of the brightness gradient exceeds a predetermined threshold is less than a certain number, the index value is set to 0, so that the It is possible to prevent large brightness gradients from occurring in the infrared image due to the presence of dirt, which would affect the determination results of text areas.

However, the present invention is not limited to the above embodiments. For example, in this embodiment, the average value of the brightness gradient and the variation in brightness are used as the index value, but the index value may be a numerical feature that characterizes the degree to which a printed part that absorbs infrared rays appears in an infrared image. Not particularly limited.

Furthermore, the highlight correction in S605 can be omitted depending on the type of ID card 10, such as a driver's license, My Number card, residence card, or special permanent residence card. Further, the reference values used for determining the character portion and the facial photograph 18 can also be determined as appropriate depending on the type of the ID card 10.

Furthermore, the purpose of determining authenticity is not particularly limited, and can be applied to identity verification when opening an account at a financial institution, when signing a contract for a mobile terminal, and during procedures at various administrative agencies.

Although preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to such examples. It is clear that those skilled in the art can come up with various changes or modifications within the scope of the technical idea disclosed in this application, and these naturally fall within the technical scope of the present invention. Understood.

1: Authenticity determination system 2: Reading device 3: Authenticity determination device 10: ID card 301: Acquisition means 302: Authenticity determination means

Claims (5)

An authenticity determination device that determines the authenticity of an identification card having a face photo, the device comprising:
acquisition means for acquiring an infrared image of the identification card;
Different index values are calculated from each of the image of the character part of the identification card obtained from the infrared image and the image of the face photo of the identification card obtained from the infrared image, and each index value is set to a reference value. Authenticity determining means for determining whether the character part and the facial photograph are genuine identification documents by comparing the two with each other;
has
The authenticity determining device is characterized in that, when it is determined that either the text portion or the face photograph is not a genuine identity verification document, the authenticity determination means determines that the identity verification document is false. The authenticity determining means is
An index value used in determining the character part is determined by an average value of the brightness gradient of pixels in the image of the character part,
2. The authenticity determining device according to claim 1, wherein the index value used in determining the facial photograph is determined based on variations in brightness of pixels within an image of the facial photograph. The authenticity determining means may perform a correction in which the luminance of a pixel having a luminance higher than a predetermined threshold value in the image of the facial photograph is replaced with a luminance lower than the threshold value, before obtaining an index value to be used in determining the facial photograph. The authenticity determination device according to claim 2, characterized in that: The authenticity determining means is characterized in that, in determining the character portion, if the number of pixels whose brightness gradient exceeds a predetermined threshold is less than a certain number, the index value used in determining the character portion is set to 0. The authenticity determination device according to claim 2. computer,
An authenticity determination device that determines the authenticity of an identification card having a face photo, the device comprising:
acquisition means for acquiring an infrared image of the identification card;
Different index values are calculated from each of the image of the character part of the identification card obtained from the infrared image and the image of the face photo of the identification card obtained from the infrared image, and each index value is set as a reference value. Authenticity determining means for determining whether the character part and the facial photograph are genuine identification documents by comparing the two with each other;
has
The authenticity determining means functions as an authenticity determining device characterized in that when it is determined that either the text portion or the face photograph is not a genuine identity verification document, the identity verification document is determined to be false. program for.

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