JP5833689B2 - Authentication system and authentication method - Google Patents

Description

  The present invention relates to an authentication technique for authenticating the originality of an object to which all the signs, which are flat objects or three-dimensional objects to which a material constituting the color is fixed, is attached or can be regarded as a sign.

  Conventionally, various authentication technologies have been used to determine whether or not a legitimate subject is legitimate in every aspect of human activity, and more advanced authentication technologies have been demanded from the progress of computerization of the Internet and information. Yes. Classic authentication technology has been used to mark unique shapes such as seals and signatures, but due to counterfeiting, holograms, creases (watermarks), latent image patterns, pearl ink, micro characters In addition to anti-counterfeiting using technologies such as special light-emitting ink and intaglio printing, along with the progress of computerization, certain information such as passwords is currently kept secret by encrypting it. By checking, we try to prevent forgery. In addition, biometric information unique to an individual human body, such as a fingerprint, is registered in advance, and when authentication is required, various biometrics that perform authentication based on whether the biometric information matches the registered biometric information by reading the actual biometric information Authentication technology is also used (for example, Patent Document 1).

JP 2009-205393 A

  However, among the above authentication techniques, a technique using a password has a problem that since the password must be determined in advance and the user itself must be stored, the amount of information is extremely small, and theft and forgery are easy. In the technique using biological information, only a human can determine whether or not it is a legitimate object, and basically it cannot be used for other objects, animals and plants. In recent years, an act of forging the biometric information itself has also occurred, and there is a problem that it is not necessarily a completely secure authentication technique.

  Furthermore, many advanced authentication techniques often add authentication information to an object in advance physically or electronically, and processing to the object is necessary, which hinders the spread of the authentication technique. There is a problem.

  The present invention has been made in view of the above-described problems, and does not require processing for an authentication target, and specific information is obtained from image data acquired using a digital imaging device having a simple configuration for individual features of the authentication target. An object of the present invention is to provide an authentication system and an authentication method that extract and determine whether or not an authentication target is valid based on the extracted unique information.

In order to solve the above-described problem, according to one aspect of the present invention, a registration image acquisition unit that acquires a registration image that is an image to be authenticated, and a predetermined number of pixels included in the registration image are predetermined. The color information for each predetermined area that is a size area is acquired, and for each of the plurality of predetermined areas included in the registered image, the difference in the color information from one or more predetermined areas located around each predetermined area And based on the determination result, a feature point determination unit that determines a plurality of feature points indicating the feature of the authentication target from the plurality of predetermined regions included in the registered image; and In a registered image, luminance information for each predetermined region is acquired, and for each feature point, the luminance information of each feature point and the comparison result of the luminance information of one or more predetermined regions located around each feature point Indicate A luminance vector determining unit determines the luminance vector is broadcast,
For the plurality of feature points of the registered image, a storage unit that stores each feature point, a difference between the color information of each feature point, and the luminance vector of each feature point in association with each other, for authentication It is a registration device.

  According to another aspect of the present invention, there is provided an authentication image acquisition unit that acquires an authentication image that is an image to be authenticated, and a region having a predetermined size that includes one or a plurality of pixels in the authentication image. Obtaining color information for each predetermined area, determining, for each of a plurality of predetermined areas included in the authentication image, a difference of the color information with one or a plurality of predetermined areas located around each predetermined area; Based on the determination result, a feature point determination unit that determines a plurality of feature points indicating features of the authentication target from a plurality of the predetermined regions included in the authentication image; and The luminance information for each predetermined area is acquired, and for each feature point, information indicating the comparison result between the luminance information of each feature point and the luminance information of one or more predetermined areas located around each feature point. Luminance vector A brightness vector determination unit that determines a color, a storage unit in which a plurality of feature points of a specific image, color information differences of each feature point, and brightness vectors of each feature point are stored in association with each other; With reference to the difference between the color information of each feature point stored in the storage unit and the difference between the color information of the plurality of feature points of the authentication image determined by the feature point determination unit, An authentication apparatus comprising: a plurality of feature points stored in the storage unit; and a matching unit that performs matching between the plurality of feature points of the authentication image, wherein the matching unit is stored in the storage unit. When the stored brightness vector of the feature point and the brightness vector of the feature point of the authentication image do not satisfy a predetermined condition, the feature point of the authentication image is determined as the plurality of determined feature points. Excluded from An authentication device and performs ranging.

  According to another aspect of the present invention, there is provided a registration method executed by an authentication registration apparatus including a registered image acquisition unit, a feature point determination unit, a luminance vector determination unit, and a storage unit, wherein the registration method An image acquisition unit acquires a registered image that is an image to be authenticated, and the feature point determination unit is a region of a predetermined size configured of one or a plurality of pixels in the registered image. The color information for each predetermined area is acquired, and for each of the plurality of predetermined areas included in the registered image, the difference in the color information with one or a plurality of predetermined areas located around each predetermined area is determined, and this determination Based on the result, a step of determining a region to be a plurality of feature points indicating a feature of the authentication target from a plurality of the predetermined regions included in the registered image; and the luminance vector determination unit includes the registered image In Brightness information for each predetermined area is acquired, and for each feature point, a comparison result between the brightness information of each feature point and the brightness information of one or more predetermined areas located around each feature point is shown. Determining a luminance vector as information; and the storage unit for each of the plurality of feature points of the registered image, a difference between the color information of each feature point, and the luminance vector of each feature point Are stored in association with each other.

  According to another aspect of the present invention, there is provided an authentication method executed by an authentication device including an authentication image acquisition unit, a feature point determination unit, a luminance vector determination unit, and a matching unit, wherein the authentication image acquisition unit A step of acquiring an authentication image that is an image to be authenticated, and the feature point determination unit for each predetermined region that is a region of a predetermined size composed of one or a plurality of pixels in the authentication image For each of a plurality of predetermined areas included in the authentication image, a difference of the color information with one or a plurality of predetermined areas located around each predetermined area is determined, and based on the determination result Determining a region to be a plurality of feature points indicating a feature of the authentication target from a plurality of the predetermined regions included in the authentication image; and Brightness information for each predetermined area is acquired, and for each feature point, a comparison result between the brightness information of each feature point and the brightness information of one or more predetermined areas located around each feature point is shown. A step of determining a luminance vector as information, and the matching unit stores in advance a plurality of feature points of a specific image, a difference in color information of each feature point, and a luminance vector of each feature point in advance. The difference between the color information of each feature point stored in the storage unit and the color information of the plurality of feature points of the authentication image determined by the feature point determination unit are referred to the stored storage unit. And a step of matching the plurality of feature points stored in the storage unit with the plurality of feature points of the authentication image based on the difference, wherein the matching is performed. Step before When the brightness vector of the feature point stored in the storage unit and the brightness vector of the feature point of the authentication image do not satisfy a predetermined condition, the feature point of the authentication image is determined as the plurality of determined points. It is an authentication method characterized in that matching is performed by excluding the feature points.

  Moreover, the other aspect of this invention is a computer program for making a computer perform the said method.

  Another aspect of the present invention is a computer-readable recording medium storing a computer program for causing a computer to execute the above method.

It is a figure which shows an example of a structure of the authentication system which concerns on one Embodiment of this invention. It is a flowchart which shows an example of the registration process in the authentication method which concerns on one Embodiment of this invention. It is a figure which shows the specific example of the feature point extraction by the difference calculation in the registration process which concerns on one Embodiment of this invention. It is a figure which shows the image of the difference calculation process in the registration process which concerns on one Embodiment of this invention. It is a figure which shows an example of the determination of the brightness | luminance vector in the registration process which concerns on one Embodiment of this invention. It is a flowchart which shows an example of the authentication process in the authentication method which concerns on one Embodiment of this invention. It is a figure which shows an example of the functional block of the registration apparatus and authentication apparatus which concern on one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each drawing referred to in the following description, parts equivalent to those in other drawings are denoted by the same reference numerals.

(Configuration of authentication system)
The authentication system according to this embodiment includes seal stamps, signatures, trademarks, logo marks, brand marks, identification marks printed on banknotes, marks attached to solid objects by transfer paper, magnetic cards and ICs. Identification marks on cards, such as paper, wood, cloth, resin, metal, etc., or the surface of solid objects, printed or drawn with inks such as pigments and dyes, paint, etc. Authenticate objects that are subject to authentication such as flat objects or solid objects such as solid objects that are fixed in some color, such as being applied with paint or molded with resin containing color materials It is an authentication system that can.

  FIG. 1 is a diagram illustrating an example of a configuration of an authentication system 1 according to the present embodiment. An authentication system 1 shown in FIG. 1 includes a scanner 2, a computer 3, a printer 4, a display 5, and an input device 6 such as a keyboard and a mouse.

  The scanner 2 is a reading unit for reading an authentication target as color information for each mesh section. The computer 3 includes a control unit 3a including a CPU and a storage unit 3b including a storage device such as a hard disk, a ROM, and a RAM. Various programs for executing each process described later are stored in the storage unit 3b. Yes. The CPU configuring the control unit 3a reads various programs from the storage unit 3b as necessary to control the entire system.

  In the present embodiment, the authentication system 1 is configured using a computer and a scanner, but this configuration is merely an example, and the present invention is not limited to this. For example, instead of a scanner, it may be equipped with a reading means such as a digital camera, a control part such as a CPU, a storage part such as a memory or a hard disk, a display means such as a liquid crystal display, and an input means such as a keyboard, mouse or touch panel. For example, it can be realized by various computer devices typified by mobile terminals such as smartphones and PDAs, mobile phones, and the like.

  Next, an authentication method in the authentication system according to the present embodiment will be described.

(Authentication method)
In the authentication method executed by the authentication system 1, a process for registering an authentication target in advance is performed as a pre-process for authenticating an authentication target such as a sign. First, the registration process will be described below.

(registration process)
FIG. 2 is a flowchart showing an example of registration processing in the authentication method according to the present embodiment.

  First, an authentication object such as a sign to be registered (hereinafter simply referred to as “authentication object”) is set in the scanner 2 and a sign or the like as an authentication object is attached to acquire color information for each pixel. The printed surface or the like is read only once by the scanner 2 (step S102). Then, only an image such as a sign to be authenticated (hereinafter referred to as “registered image”) is obtained by trimming from the read area (step S104). Here, in the present embodiment, color information for each mesh section may be acquired as in the authentication method disclosed in Japanese Patent No. 4951564. And in each process demonstrated below, it may replace with every pixel and may perform each process for every mesh division. For example, the computer 3 acquires the color information with an optical resolution corresponding to the size of the mesh section by using the photoreactive elements partitioned by the mesh of the XY array, and stores the acquired color information in the storage unit 3b. It may be. The color material particles of the printing ink to be authenticated may be assumed to be smaller than the size of the mesh section (for example, when the scanner 2 acquires color information at a resolution of 600 dpi, the mesh section is one side. Is 42.3 μm, which is larger than the colorant particles). In this case, the color composition of some colorant particles in the mesh section is pixel-colored as a single monochrome RGB value.

  Next, the edge (contour) of the registered image acquired in step S104 is removed by image processing (step S106). The width for removing the edge may be set, for example, by a user input. The reason for removing the edge of the registered image in this step will be described later.

  Next, feature points of the registered image are extracted by calculating the difference (step S108). Feature point extraction of a registered image by difference calculation is to obtain a difference in RGB color information between each pixel constituting the registered image and its surrounding pixels, and to determine a pixel having a large difference value as a feature of this registered image (authentication target). This is a method of extracting as feature points indicating. Hereinafter, a feature point extraction method based on difference calculation will be described in detail.

(Feature point extraction by difference calculation)
FIG. 3 is a diagram illustrating a specific example of feature point extraction by difference calculation.

  The pixel that is the target of the difference calculation is a pixel P (hereinafter referred to as “target pixel”) 300, and its surrounding eight pixels are A301 (left), pixel B302 (upper), pixel C303 (right), and pixel D304 (lower), respectively. ), Pixel E305 (upper left), pixel F306 (upper right), pixel G307 (lower right), and pixel H308 (lower left), the difference in RGB color information between the pixel P and each of the pixels A to H is obtained. Here, if the upper left corner of the image is the origin (0, 0), the right direction is x, and the lower direction is y, the coordinates (x, y) of the pixel of interest P300 are the coordinates of the surrounding pixels A301 to H308. Are (x-1, y), (x, y-1), (x + 1, y), (x, y + 1), (x-1, y-1), (x + 1, y-1), (x + 1, y + 1), and (x-1, y + 1).

Further, the RGB value of the pixel of interest P300 is represented as R _P , G _P , and B _P , the RGB value of the pixel A301 is represented as R _A , G _A , B _A , and the RGB value of the pixel B 302 is represented as R _B , G _B , When the RGB values of B _B ,..., The pixel H308 are expressed as R _H , G _H , and B _H , the difference between the RGB values of the pixel of interest P and the surrounding pixels A to H is expressed by the following equation: The

Difference = | A−P | + | B−P | + | C−P | + | D−P | + | E−P | + | G−P | + | H−P |
_{= (| R A -R P |} + | G A -G P | + | B A -B P |) +
_{(| R B -R P | +} | G B -G P | + | B B -B P |) +
_{(| R C -R P | +} | G C -G P | + | B C -B P |) +
_{(| R D -R P | +} | G D -G P | + | B D -B P |) +
_{(| R E -R P | +} | G E -G P | + | B E -B P |) +
(| R _F −R _P | + | G _F −G _P | + | B _F −B _P |) +
_{(| R G -R P | +} | G G -G P | + | B G -B P |) +
_{(| R H -R P | +} | G H -G P | + | B H -B P |)

  In this example, the difference value of the RGB color information between the pixel of interest and its surrounding 8 pixels is calculated. However, some peripheral pixels are selected depending on the directionality of printing such as a sign to be authenticated. The difference may be calculated. For example, the difference between the target pixel P and the left pixel A and the upper pixel B may be calculated.

  Moreover, the calculation method of the RGB difference value by the above formula is an example, and the present invention is not limited to this. For example, the average value may be calculated by dividing the total value calculated by the above formula by the number of surrounding pixels (8 in the above example), and this may be used as the RGB difference value for each pixel of interest. That is, the RGB difference value is information that can compare a plurality of pixels in the registered image and determine which pixel has a larger (smaller) difference in RGB color information from the surrounding pixels. Good.

  As described above, when the sum of the RGB difference values between the pixel P and its surrounding pixels is calculated, the same processing is performed with the next pixel on the right as the target pixel. Then, when the processing is completed, the same processing is performed with the pixel on the right as the target pixel, and so on. The origin (x, y) = upper left of the registered image acquired in step S106 in FIG. Perform the above processing for each pixel from (0, 0) to the lower right (x, y) = (width-1, height-1) (width: image width, height: image height) (The range of x and y of the coordinates (x, y) of the pixel to be a pixel is x = 1 to width-2, y = 1 to height-2). FIG. 4 is a diagram showing an image of processing. Each time the RGB difference value is calculated for each pixel in the registered image by the process as described above, the (x, y) coordinates of the pixel P and the calculated RGB difference value are associated and stored in a format such as array data. Stored in section 3b.

  Returning to FIG. 2, after calculating the difference for all the pixels of the registered image in step S108, the top 30 to 5000 pixels of the calculated difference value are determined as final feature points of the registered image (step S110). . Then, the data (hereinafter referred to as “human decoding”) in which the feature points (the coordinates thereof) are sorted in descending order of the RGB difference values is stored. In other words, the human decoding is also data indicating a connecting line that connects the feature points in descending order of RGB difference values. Further, the human decoding may be, for example, a set of data of position vectors (positions and distances) of connecting lines. Note that the processing in step S110 is not essential, and not only the top 100 to 1000 pixels of the difference value but also all the target pixels may be stored together with the difference value to be stored as feature points. .

  Further, the number of feature points extracted in step S110 may be determined by the design of the registered image and the number of pixels. In addition, a predetermined number of feature points are not extracted, but pixels whose difference values of pixels belong to a predetermined range may be extracted as feature points. Further, a pixel whose luminance falls within a predetermined range may be determined as a feature point. Further, for example, when a plurality of determined feature points are located at a predetermined distance or less (concentrated) in the registered image, some feature points are excluded based on a rule. Also good.

  By the way, in the present embodiment, the edge of the registered image is removed in step S106 described above. This is because when the feature points are determined by the difference calculation, the difference in the edge portion of the image is remarkably large, and the edge portion is ranked higher than the subtle gradation difference of the authentication target to be originally extracted. As a result, there is a high possibility that an erroneous determination will occur during authentication of the authentication target (described later).

  Further, the continuation of the flow of FIG. 2 will be described. In step S112, the luminance vector at each feature point is determined. This process is executed to further improve the authentication accuracy. In the authentication method according to the present embodiment, the coordinates of the human decoding (the processing result of step S110) stored in advance by the registration process are collated with the coordinates of the human decoding generated by reading the authentication target in the authentication process described later. For example, the number of features whose coordinates coincide with each other or within a predetermined range is counted. When the count value satisfies a predetermined condition (for example, a predetermined ratio or more), the two are authenticated as the same. However, since the registered feature point and the feature point when reading a sign etc. at the time of authentication existed near by chance, it may be determined that the coordinates of both coincide, etc. Such feature points are called “spoofing points”). In order to eliminate this spoofing point, in the present embodiment, in the authentication process, the luminance vector is further considered for each of the pixels for which the difference of the RGB color information from the surrounding pixels is calculated as in step S108. By determining the final feature points, the authentication is made more precise. In step S112, in order to perform such processing at the time of authentication, processing for determining and storing a luminance vector for each feature point previously determined in step S110 for the registered image is executed. Here, the luminance vector at each feature point is data indicating a comparison result between the luminance of the feature point and the luminance of the surrounding pixels.

(Determination of luminance vector)
Hereinafter, a method for determining the luminance vector will be described in detail.

  As described above, the brightness vector is data indicating a comparison result between the brightness of each feature point determined in step S110 and the brightness of the surrounding pixels. The peripheral pixels for calculating the luminance may be pixels in the eight directions around each feature point, or pixels in the four directions (for example, up, down, left, and right) as in the calculation of the RGB difference values in step S108. . Further, it may be a pixel in two peripheral directions such as left and top.

  FIG. 5 is a diagram showing an image of determination of the luminance vector. In addition, in FIG. 5, the image in the case of calculating the brightness | luminance about the feature point P and the surrounding pixels AH of the surrounding 8 directions is shown as an example.

First, the brightness value of the feature point P and the brightness values of the surrounding pixels A to H are calculated. The luminance value is calculated from the RGB value of each pixel by the following formula.
Luminance value = 0.299 x R + 0.587 x G + 0.114 x B

  Then, the calculated luminance value of the feature point P is compared with the luminance values of the peripheral pixels A to H, and each comparison result is expressed as a numeric string. For example, when the luminance value of the left pixel A−the luminance value of the pixel P = a positive value (when the pixel A is brighter than the feature point P), this comparison result is indicated as “0”. When the luminance value of the left pixel A−the luminance value of the pixel P = 0 (when both luminance values are the same), this comparison result is indicated as “1”. Further, when the luminance value of the left pixel A−the luminance value of the pixel P = negative value (when the feature point P is brighter), this comparison result is indicated as “2”. Similarly, the other peripheral pixels B to H are encrypted by comparing the feature point P with the luminance value. For example, if the comparison result as shown in FIG. 5 is obtained for the feature point P, the luminance vector is determined to be “01200021”. This result is stored in association with the coordinates of the human decoding (each feature point) stored in step S110, and the registration process ends (step S114).

  In this example, the luminance vector is represented by a number string using three numbers, but is merely an example, and the present invention is not limited to this. For example, the luminance vector may be expressed by other symbols, alphanumeric characters, and the like. In the above example, the difference in luminance value between the feature point P and the surrounding pixels is classified into three (bright / dark / identical), but may be classified more finely (or roughly). For example, the difference between the two luminance values may be classified into a plurality of predetermined ranges, and different alphanumeric characters may be assigned to the difference between the luminance values depending on which range they belong to.

  Moreover, the order of the processing of step 110 and step S112 may be reversed. That is, for all the target pixels whose coordinates are stored in the storage unit 3b in step S108, the brightness vector is determined and stored in the storage unit 3b, and then the final feature point of the registered image is determined in step S110. May be.

  Further, in the authentication method according to the present embodiment, feature points are extracted in units of pixels. However, a feature point is defined with an area having a predetermined size composed of a plurality of pixels (for example, 3 × 3 pixels) as one unit. Extraction may be performed.

  Note that the authentication method according to the present embodiment is an authentication method mainly characterized by feature point extraction by difference calculation (mainly step S108) and luminance vector determination (mainly step S112). For specific methods other than these, the methods described in Japanese Patent No. 4951564 and Japanese Patent No. 5280386 can be applied. (The same applies to the authentication processing described later.)

(Authentication process)
Next, an authentication process for authenticating whether an authentication target, which is a sign or the like to which a material constituting some color is fixed, is valid will be described. FIG. 6 is a flowchart showing an example of authentication processing in the authentication method according to the present embodiment.

  The authentication process is the same as the registration process described in FIG. That is, an area including an authentication target is read by the scanner 2 only once on a printing surface with a mark or the like as an authentication target (step S202), and an authentication target image (hereinafter referred to as “authentication image”) is read from the read area. ) Only by trimming (step S204). Further, the edge of the authentication image acquired in step S204 is removed by image processing (step S206). About the width | variety etc. which remove an edge, it performs with the setting similar to the time of a registration process.

  Next, similarly to step S108 at the time of the registration process, the difference between the RGB color information is calculated for the acquired authentication image (step S208), and the top 30 to 5000 pixels of the calculated difference value are converted to the authentication image. And the human decoding is obtained (step S210). Then, similarly to step S112 during the registration process, the luminance vector at each feature point is determined (step S212).

  The human decoding data stored in the storage unit 3b of the authentication system 1 by the prior registration process and the luminance vector of each feature point constituting the human decoding are read from the storage unit 3b and acquired in step S210. And matching is performed by a technique such as vector matching (step S214). At this time, it is determined whether or not the brightness vector at each feature point such as the sign to be authenticated calculated in step S212 is the same as the brightness vector at each feature point of the human decoding read from the storage unit 3b of the authentication system 1. To do. If the two brightness vectors are not identical, it is determined that the feature point is a spoofing point, and the spoofing point is excluded from the human decoding acquired in step S210 (step S216).

  In the state where the impersonation point is excluded, matching between both human decoding is performed (step S218). As a matching method, for example, the feature points having the same coordinates or a distance within a predetermined range are counted, and if the count value is equal to or greater than a predetermined ratio, they are authenticated as the same.

(Function block)
FIG. 7 is a diagram illustrating an example of functional blocks of the registration device and the authentication device in the authentication system according to the present embodiment. In the following description, the registration device and the authentication device are shown as separate blocks. However, as in the configuration example shown in FIG. 1, both devices have a registration device and an authentication device. It may also serve as a separate device.

(1) Registration Device The registration device 100 is a device that executes processing for registering human decoding in advance (processing shown in the flowchart in FIG. 2) for authentication of an authentication target. The registration device 100 includes a registered image acquisition unit 101, a first feature point determination unit 102, a first luminance vector determination unit 103, and a storage unit 104.

  The registered image acquisition unit 101 acquires a registered image that is an image to be authenticated. The registered image acquisition unit 101 mainly executes the process of step S102 (and steps S104 and S106) in FIG.

  The first feature point determination unit 102 acquires color information for each predetermined region, which is a region having a predetermined size composed of one or a plurality of pixels, in the registered image acquired by the registered image acquisition unit 101. Then, for each of a plurality of predetermined areas included in the registered image, a difference in color information with one or a plurality of predetermined areas located around each predetermined area is determined, and the difference is included in the registered image based on the determination result. From among a plurality of predetermined regions, a region serving as a plurality of feature points indicating a feature to be authenticated is determined. The first feature point determination unit 102 mainly executes the process of step S108 (and step S110) in FIG.

  The first brightness vector determination unit 103 acquires brightness information for each predetermined area in the registered image, and for each feature point determined by the first feature point determination unit 102, the brightness information of each feature point and each feature A luminance vector that is information indicating a result of comparison with luminance information of one or more predetermined regions located around the point is determined. The first luminance vector determination unit 103 mainly executes the process of step S112 in FIG.

  The storage unit 104 stores, for each of a plurality of feature points of the registered image, each feature point, a difference in color information of each feature point, and a luminance vector of each feature point in association with each other.

(2) Authentication Device The authentication device 200 is a device that executes a process for authenticating whether the authentication target is valid (the process shown in the flowchart of FIG. 6). The authentication device 200 includes an authentication image acquisition unit 201, a second feature point determination unit 202, a second luminance vector determination unit 203, and a matching unit 204.

  The authentication image acquisition unit 201 acquires an authentication image that is an authentication target image. The authentication image acquisition unit 201 mainly executes the process of step S202 (and steps S204 and S206) of FIG.

  The second feature point determination unit 202 acquires color information for each predetermined area, which is an area of a predetermined size composed of one or a plurality of pixels, in the authentication image acquired by the authentication image acquisition unit 201. Then, for each of a plurality of predetermined areas included in the authentication image, a difference in color information from one or a plurality of predetermined areas located around each predetermined area is determined, and included in the authentication image based on the determination result From among a plurality of predetermined regions, a region serving as a plurality of feature points indicating a feature to be authenticated is determined. The second feature point determination unit 202 mainly executes the process of step S208 (and step S210) in FIG.

  The second luminance vector determination unit 203 acquires luminance information for each predetermined region in the authentication image, and for each feature point determined by the second feature determination unit 202, the luminance information of each feature point and each feature point A luminance vector that is information indicating a result of comparison with luminance information of one or more predetermined areas located around the area is determined. The second luminance vector determination unit 203 mainly executes the process of step S212 in FIG.

  The matching unit 204 refers to the storage unit 104 in which a plurality of feature points of a specific image (registered image), a difference in color information of each feature point, and a luminance vector of each feature point are stored in advance. Based on the difference between the color information of each feature point stored in the storage unit 104 and the difference between the color information of a plurality of feature points of the authentication image determined by the second feature point determination unit 202 The plurality of feature points stored in the unit 104 are matched with the plurality of feature points of the authentication image. In addition, the matching unit 204 determines the feature point of the authentication image when the brightness vector of the feature point stored in the storage unit 104 and the brightness vector of the feature point of the authentication image do not satisfy a predetermined condition. The matching is performed by excluding the determined feature points. The matching unit 204 mainly executes the processes of step S214, step S216, and step S218 in FIG.

  Each function of registration apparatus 100 and authentication apparatus 104 is realized by hardware, software, or a combination of hardware and software. For example, in the hardware configuration shown in FIG. 1, each function can be realized by the controller 3 a reading and executing various programs corresponding to each function from the storage unit 3 b.

(Summary)
According to the authentication system and the authentication method according to the present embodiment described above, the authentication target does not require any processing, and individual characteristics of the authentication target are unique from the image data acquired using the digital imaging device having a simple configuration. It is possible to extract information and determine whether the authentication target is valid based on the extracted unique information. Further, in the authentication system disclosed by Japanese Patent No. 4951564 and Japanese Patent No. 5280386, it is necessary to capture a plurality of images in order to obtain human decoding in the registration process and the authentication process. However, according to the authentication method according to the present embodiment, the feature point extraction method based on the difference calculation described above can be used to acquire the human decoding target to be authenticated by capturing only one image. This is possible and the processing load is further reduced. Furthermore, it is possible to perform authentication in consideration of the direction of printing to be authenticated.

  Up to this point, one embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and it is needless to say that the present invention may be implemented in various forms within the scope of the technical idea.

  The scope of the present invention is not limited to the illustrated and described exemplary embodiments, but includes all embodiments that provide the same effects as those intended by the present invention. Further, the scope of the invention is not limited to the combinations of features of the invention defined by the claims, but may be defined by any desired combination of particular features among all the disclosed features. .

DESCRIPTION OF SYMBOLS 1 Authentication system 2 Scanner 3 Computer 3a Control part 3b Storage part 4 Printer 5 Display 6 Input device 100 Registration apparatus 101 Registration image acquisition part 102 First feature point determination part 103 First brightness vector determination part 104 Storage part 200 Authentication apparatus 201 Authentication Image acquisition unit 202 Second feature point determination unit 203 Second luminance vector determination unit 204 Matching unit 300 Pixels of interest 301 to 308 Neighboring pixels

Claims (8)

A registered image acquisition unit for acquiring a registered image that is an image to be authenticated;
In the registered image, color information is acquired for each predetermined area that is a predetermined size area composed of one or a plurality of pixels, and each predetermined area is included in each of the predetermined areas included in the registered image. A difference of the color information with one or a plurality of predetermined areas located in the vicinity of the image, and based on the determination result, the feature of the authentication target is selected from the plurality of the predetermined areas included in the registered image. A feature point determination unit for determining a region to be a plurality of feature points to be shown;
In the registered image, the luminance information for each predetermined area is acquired, and for each feature point, the luminance information of each feature point is compared with the luminance information of one or more predetermined areas located around each feature point. A luminance vector determination unit that determines a luminance vector that is information indicating a result;
A storage unit that associates and stores each feature point, the difference of the color information of each feature point, and the luminance vector of each feature point for the plurality of feature points of the registered image;
A registration device for authentication comprising:   The registration device according to claim 1, wherein the storage unit sorts and stores the feature points based on a difference in the color information of the feature points.   The feature point extraction unit, for each of the plurality of regions included in the image, according to the print direction of the authentication target, only a part of the plurality of regions located around the region. The registration apparatus according to claim 1, wherein a difference between the color information is determined. An authentication image acquisition unit that acquires an authentication image that is an image to be authenticated;
In the authentication image, color information is acquired for each predetermined area that is an area of a predetermined size composed of one or a plurality of pixels, and each predetermined area is included in each of the predetermined areas included in the authentication image. A difference of the color information with one or a plurality of predetermined areas located in the periphery of the image, and based on the determination result, the feature of the authentication target is selected from the plurality of the predetermined areas included in the authentication image. A feature point determination unit for determining a region to be a plurality of feature points to be shown;
In the authentication image, luminance information for each predetermined region is acquired, and for each feature point, the luminance information of each feature point is compared with the luminance information of one or more predetermined regions located around each feature point. A luminance vector determination unit that determines a luminance vector that is information indicating a result;
A plurality of feature points of a specific image, a difference in color information of each feature point, and a brightness vector of each feature point are stored in advance in the storage unit with reference to a storage unit stored in association with each other. The plurality of feature points stored in the storage unit based on the difference between the color information of each feature point and the difference between the color information of the plurality of feature points of the authentication image determined by the feature point determination unit A matching unit that performs matching between the feature points and the plurality of feature points of the authentication image;
An authentication device comprising:
The matching unit determines the feature point of the authentication image when the brightness vector of the feature point stored in the storage unit and the brightness vector of the feature point of the authentication image do not satisfy a predetermined condition. An authentication apparatus that performs matching by excluding the determined plurality of feature points. A registration method executed by a registration apparatus for authentication comprising a registered image acquisition unit, a feature point determination unit, a luminance vector determination unit, and a storage unit,
The registered image acquisition unit acquiring a registered image that is an image to be authenticated;
The feature point determination unit obtains color information for each predetermined area, which is an area having a predetermined size composed of one or a plurality of pixels in the registered image, and a plurality of predetermined points included in the registered image. For each region, a difference in the color information from one or more predetermined regions located around each predetermined region is determined, and based on the determination result, a plurality of the predetermined regions included in the registered image are selected. Determining a region to be a plurality of feature points indicating the feature of the authentication target;
The brightness vector determination unit acquires brightness information for each of the predetermined areas in the registered image, and for each feature point, the brightness information of each feature point and one or a plurality of predetermined positions located around each feature point Determining a luminance vector which is information indicating a comparison result with luminance information of the region;
The storage unit stores, for each of the plurality of feature points of the registered image, each feature point, a difference between the color information of each feature point, and the luminance vector of each feature point in association with each other.
Registration method including. An authentication method executed by an authentication device including an authentication image acquisition unit, a feature point determination unit, a luminance vector determination unit, and a matching unit,
The authentication image acquisition unit acquiring an authentication image that is an image to be authenticated;
The feature point determination unit acquires color information for each predetermined area, which is an area of a predetermined size composed of one or a plurality of pixels, in the authentication image, and a plurality of predetermined points included in the authentication image For each region, a difference in the color information from one or more predetermined regions located around each predetermined region is determined, and based on the determination result, a plurality of the predetermined regions included in the authentication image are selected. Determining a region to be a plurality of feature points indicating the feature of the authentication target;
The brightness vector determination unit acquires brightness information for each of the predetermined areas in the authentication image, and for each feature point, the brightness information of each feature point and one or a plurality of predetermined positions located around each feature point Determining a luminance vector which is information indicating a comparison result with luminance information of the region;
The matching unit refers to a storage unit in which a plurality of feature points of a specific image, a difference in color information of each feature point, and a luminance vector of each feature point are stored in association with each other, Based on the difference between the color information of each feature point stored in the storage unit and the difference between the color information of the plurality of feature points of the authentication image determined by the feature point determination unit. Matching the plurality of feature points that have been performed with the plurality of feature points of the authentication image;
An authentication method including:
The matching is performed when the luminance vector of the feature point stored in the storage unit and the luminance vector of the feature point of the authentication image do not satisfy a predetermined condition. An authentication method comprising performing matching by excluding points from the plurality of determined feature points.   A computer program for causing a computer to execute the method according to claim 5.   A computer-readable recording medium storing a computer program for causing a computer to execute the method according to claim 5 or 6.