JP2024092962A - Game machine, game card authenticity determination method, computer program, and game card - Google Patents

Abstract

To provide a game machine, a game card authenticity determination method, a computer program, and a game card.SOLUTION: A game device includes: an acquisition unit that acquires a capture image of a game card including an information code and a pattern formed by ink that absorbs or reflects special light; a determination unit that determines the authenticity of the game card on the basis of the pattern included in the acquired capture image; and an output unit that outputs information that the game card is a counterfeit if the determination unit determines the game card to be a counterfeit.SELECTED DRAWING: Figure 1

Description

The present invention relates to a game machine, a method for determining the authenticity of a game card, a computer program, and a game card.

In recent years, arcade-type game machines have been installed in game arcades and other locations that read information codes printed on game cards and make specific characters appear or progress through specific scenarios depending on the information read from the information codes.

Such game machines are equipped with a code reading device. Code reading devices include code readers that read one-dimensional codes such as barcodes, and code readers that read two-dimensional codes such as QR codes (registered trademark). Code readers have an optical sensor (such as an image sensor) that acquires optical information from information codes such as one-dimensional codes and two-dimensional codes, convert the electrical signal (analog signal) output from the optical sensor into a digital signal, and decode the digital signal to read the information code.

Game cards that are obtained by playing games on game consoles are valuable due to their rarity and as collectibles, and counterfeiting them has become a problem.

Patent document 1 discloses a method of providing a game card with a hologram as an authenticity identification mark and determining the authenticity of the game card from an image of the hologram.

JP 2013-022739 A

However, the method disclosed in Patent Document 1 requires that the game machine be equipped with imaging means capable of capturing images from two directions simultaneously with a predetermined parallax angle. If the imaging direction is limited to one direction, it becomes impossible to distinguish between genuine and counterfeit game cards. In addition, it is necessary to attach a hologram that allows two different images to be seen when viewed from two different directions, which poses the problem of high unit costs for game cards that are generally manufactured only by printing.

The present invention was made in consideration of the above circumstances, and aims to provide a game machine, a method for determining the authenticity of a game card, a computer program, and a game card that can determine the authenticity of a game card based on the pattern printed on the game card.

A game machine according to one embodiment of the present invention includes an acquisition unit that acquires an image of a game card including an information code and a pattern formed by ink that absorbs or reflects special light, a determination unit that determines whether the game card is genuine or counterfeit based on the pattern included in the acquired image, and an output unit that outputs information indicating that the game card is counterfeit if the determination unit determines that the game card is counterfeit.

According to this application, authenticity can be determined based on the pattern printed on the game card.

10 is an explanatory diagram illustrating an overview of an information code reading process executed in the game machine according to the embodiment; FIG. FIG. 2 is a block diagram illustrating the configuration of the game machine. FIG. 2 is an explanatory diagram illustrating the configuration of a game card. 10 is a flowchart showing a procedure for reading a game card in the first embodiment. 13 is a flowchart showing a procedure for reading a game card in the second embodiment. FIG. 2 is a schematic diagram showing an example of a Fourier transform image. 13 is a graph showing the calculation results of average values. 13 is a graph showing the calculation results of the difference. FIG. 13 is an explanatory diagram illustrating the configuration of a game card in embodiment 3.

Hereinafter, the present invention will be described in detail with reference to the drawings showing embodiments thereof.
(Embodiment 1)
FIG. 1 is an explanatory diagram for explaining an outline of an information code reading process executed in a game machine 10 according to an embodiment. The game machine 10 according to an embodiment is, for example, an arcade-type game machine installed in a game parlor or the like. A game card GC is used in the game machine 10. Game content is printed on the first side of the game card GC, and an information code CD is printed on the second side. The game machine 10 captures an image of the second side of the game card GC set by the player using the imaging unit 17, and obtains an image including the information code CD. A plurality of game cards GC may be set in the game machine 10. In this case, the game machine 10 captures an image of the plurality of game cards GC at once using the imaging unit 17, and obtains an image including the information code CD printed on each game card GC. The game machine 10 reads information indicated by one or more information codes CD from the captured image, and progresses a predetermined scenario (game play) based on the read information. After the game play ends, the game machine 10 ejects a new game card GC according to the progress of the scenario, etc., and provides it to the player.

The information code CD is a two-dimensional code such as a QR code (registered trademark). Alternatively, the information code CD may be a one-dimensional code such as a barcode. In this embodiment, the information code CD is offset printed on the second surface of the game card GC with transparent IR (Infrared) absorbing ink. The information code CD includes attribute information of the characters that will appear in the game, information that defines the game scenario, and the like.

Since the game card GC contains an information code CD, for example, each game card GC can have various attributes depending on the design (character) drawn on the first side. In general, the release rate of game cards GC is adjusted so that the more valuable an attribute is in game play, the more rare the card will be.

Game Card GCs are collectible items and can be highly valuable. For this reason, duplicating a Game Card GC leads to a loss of income that would have been necessary to obtain that card. Furthermore, if Game Card GCs are copied and used unlimitedly, the balance and ranking system within the game will no longer function, raising concerns that legitimate players will stop playing.

The game machine 10 according to this embodiment uses an authenticity determination pattern PT to determine the authenticity of the game card GC. The authenticity determination pattern PT is offset printed around the information code CD using, for example, transparent IR absorbing ink.

When capturing an image of the information code CD of the game card GC, the game machine 10 captures the pattern PT arranged around it as well, and obtains a captured image including the information code CD and the pattern PT. The game machine 10 cuts out the pattern PT from the captured image and determines the authenticity of the game card GC based on the cut-out pattern PT. If the game card GC is determined to be authentic, the game machine 10 continues game play based on information obtained by reading the information code CD. On the other hand, if the game card GC is determined to be counterfeit, the game machine 10 stops game play. At this time, the game machine 10 may output a warning to the player.

Figure 2 is a block diagram explaining the configuration of the gaming machine 10. The gaming machine 10 includes a control unit 11, a memory unit 12, an operation unit 13, a display unit 14, a deposit acceptance unit 15, a card issuing unit 16, an imaging unit 17, an information code reading unit 18, and a communication unit 19.

The control unit 11 includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The ROM included in the control unit 11 stores control programs that control the operation of each piece of hardware included in the game console 10, as well as data necessary for control. The CPU in the control unit 11 executes the control programs stored in the ROM and controls the operation of each piece of hardware. The RAM included in the control unit 11 temporarily stores various data generated during execution of control.

The memory unit 12 is composed of a storage device such as a flash memory. The memory unit 12 stores various computer programs and data used in the game machine 10. The computer programs stored in the memory unit 12 include a program for causing the control unit 11 to progress the game scenario. The data stored in the memory unit 12 includes attribute information of characters that appear in the game. Character attribute information includes information such as the character's name, design, rarity, strength, and skills.

The operation unit 13 has various buttons, and outputs information corresponding to a pressed button to the control unit 11. The buttons on the operation unit 13 include, for example, a start button for starting the game, and a selection button for accepting a selection operation by the player. The buttons on the operation unit 13 are designed appropriately depending on the model and game scenario. The operation unit 13 may further include a touch panel. If the operation unit 13 has a touch panel, the operation unit 13 outputs information input from the touch panel to the control unit 11.

The display unit 14 is equipped with a display device such as an LCD monitor or an organic EL (Electro-Luminescence) monitor, and displays a selection screen for accepting selection operations by the player in response to instructions from the control unit 11, a game screen showing the progress of the game, and the like.

The deposit acceptance unit 15 includes an input port for inserting coins, an identification device for identifying the inserted coins, a storage section for storing the inserted coins, and an outlet for discharging change. The deposit acceptance unit 15 identifies coins inserted into the input port using the identification device, stores the identified coins in the storage section, and outputs information on the identified amount (amount information) to the control unit 11. The deposit acceptance unit 15 discharges coins (change) in an amount equal to the identified amount minus the game play fee, to the outlet. The deposit acceptance unit 15 may be configured to only accept fixed-amount coins so that no change is generated. In this case, the deposit acceptance unit 15 may not be provided with an outlet. The deposit acceptance unit 15 may also be configured to accept deposits by credit card, prepaid card, postpaid card, or electronic payment.

The card issuing unit 16 includes a storage section that stores multiple game cards GC with game content printed on the first side and an information code CD and pattern PT printed on the second side, an ejection mechanism that ejects the game cards GC to be provided to the player depending on the game play, and an ejection port that ejects the game cards GC ejected by the ejection mechanism.

The imaging unit 17 includes a platform on which the game card GC is placed, and an imaging device that images the game card GC placed on the platform. One or more game cards GC are placed on the platform. In this embodiment, the imaging device included in the imaging unit 17 is an IR camera. The imaging unit 17 irradiates IR light onto the area of the game card GC on which the information code CD and pattern PT are printed, and obtains an image including the information code CD and pattern PT by forming an image of the light reflected from the surface of the game card GC on an imaging element. When multiple game cards GC are placed on the platform, the imaging device may image multiple game cards GC at once.

For the imaging unit 17, a camera with sufficient performance to read the information code CD printed on a medium such as a game card GC is selected. In addition, there are size restrictions due to the space inside the housing of the game machine 10, and the price of the camera itself must be kept low. For this reason, cameras with a resolution of about 640 x 360 pixels (about 200,000 pixels) to 1920 x 1080 pixels (about 2 million pixels) that are inexpensive, small, and commonly available for industrial use are generally used for the camera mounted on the imaging unit 17. Similarly, from the perspective of the space inside the housing, the shooting distance from the medium on which the information code CD is printed to the camera is assumed to be about 10 to 600 mm, and the vertical and horizontal dimensions of the information code CD printed on a medium such as a game card GC are assumed to be 10 to 50 mm, and the reading device is configured so that the shooting distance is sufficient to read the size of the printed information code CD as described above.

The information code reading unit 18 is configured as a processing circuit that includes, for example, a CPU and a memory, detects the information code CD from the captured image input by the imaging unit 17, and reads the information indicated by the detected information code CD. The information code reading unit 18 also detects the pattern PT included in the captured image, and determines the authenticity of the game card GC based on the detected pattern PT.

The memory provided in the information code reading unit 18 stores an authenticity determination program PG1 and a reading process program PG2 for causing the CPU to execute the information code reading process. The programs such as the authenticity determination program PG1 and the reading process program PG2 stored in the memory are provided by a recording medium RM on which these programs are recorded in a readable manner. The recording medium RM is, for example, a portable recording medium such as an SD (Secure Digital) card, a micro SD card, or a Compact Flash (registered trademark). The control unit 11 reads the programs from the recording medium RM using a reading device (not shown) and stores the read programs in the memory of the information code reading unit 18. The programs such as the authenticity determination program PG1 and the reading process program PG2 may also be provided by communication. In this case, the control unit 11 obtains the programs provided by communication and stores the obtained programs in the memory.

The configuration of the information code reader 18 is not limited to the above, and may be one or more processing circuits or arithmetic circuits including a multi-core CPU, a GPU (Graphics Processing Unit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), an ASIC (Application Specific Integrated Circuit) for image processing, a microcomputer, a volatile or non-volatile memory, etc. The information code reader 18 may also include a clock that outputs date and time information, a timer that measures the elapsed time from when a measurement start instruction is given to when a measurement end instruction is given, a counter that counts numbers, etc.

The CPU of the information code reading unit 18 executes an authenticity determination program PG1 stored in memory to determine the authenticity of the game card GC set on the placement table of the imaging unit 17. The CPU of the information code reading unit 18 also executes a reading process program PG2 stored in memory to perform an information code reading process. In this embodiment, the authenticity determination program PG1 and the reading process program PG2 are described as two separate programs, but they may be configured as a single computer program.

The communication unit 19 has a communication interface for communicating with an external device. The communication interface of the communication unit 19 is, for example, a communication interface such as WiFi (registered trademark), LAN (Local Area Network), Bluetooth (registered trademark), ZigBee (registered trademark), 3G, 4G, 5G, or LTE (Long Term Evolution). The communication unit 19 transmits various data to be notified to the external device and receives various data transmitted from the external device. The external device communicatively connected to the communication unit 19 is, for example, a server device (not shown) that comprehensively manages multiple game machines 10 installed in each gaming facility.

Figure 3 is an explanatory diagram explaining the structure of a game card GC. The example in Figure 3 shows a game card GC on which an information code CD is printed in the lower center of the second side, and a pattern PT for determining authenticity is printed on both the left and right sides of the information code CD. The information code CD and pattern PT are printed with transparent IR absorbing ink. The transparent IR absorbing ink is made by mixing an infrared absorbing material with a dilution ink. For the infrared absorbing material, a material with a maximum absorption wavelength in the range of 850 nm to 950 nm is used, for example.

The information code CD and pattern PT are printed with transparent IR-absorbing ink, so it is difficult to visually confirm the information code CD and pattern PT under normal indoor or outdoor ambient light (visible light). On the other hand, when IR light is irradiated onto the information code CD and pattern PT, the IR light is absorbed in the areas printed with IR-absorbing ink and reflected in other areas, creating a contrast between the areas where the IR light is absorbed and the areas where it is not absorbed (the reflected areas), which becomes apparent as an image. The IR camera provided in the imaging unit 17 focuses the image on an imaging element and outputs it as an image including the information code CD and pattern PT.

The game content (such as the game name and game characters) is printed in normal ink on the first side of the game card GC. Information to be presented to the player, such as character attribute information, may be printed in normal ink on the second side of the game card GC. The content printed in normal ink is information that is visible under normal ambient light, indoors or outdoors.

In the example of FIG. 3, the information code CD and pattern PT are printed in one location on the game card GC (the lower center of the second side), but they may be printed in multiple locations on the game card GC, such as the lower center and upper center of the second side. Also, in the example of FIG. 3, the pattern PT is printed on both the left and right sides of the information code CD, but the pattern PT may be printed so as to surround the periphery of the information code CD. In the game card GC, the positional relationship between the information code CD and the pattern PT is known, and information on this positional relationship is stored in a memory provided in the information code reading unit 18.

As shown in the partially enlarged view of FIG. 3, the pattern PT is a concentric pattern in which image lines and non-image lines are alternately arranged on a plane as concentric circles with a common center point. The image line width and non-image line width are selected in the range of 0.2 mm to 5 mm. If the image line width is too thin for the resolution of the IR camera, the lines may be crushed and not be detectable, so it is preferable that the image line width and non-image line width selected are detectable values according to the shooting conditions. The ratio of the image line width and non-image line width is selected, for example, in the range of 25:1 to 1:25, and more preferably, in the range of 1:1 to 1:2. The center points of the concentric circles are within the arrangement area of the pattern PT. The pattern PT may include other concentric patterns with different center points, image line widths, and non-image line widths. Furthermore, these concentric patterns may overlap each other.

Assuming a counterfeit game card GC is a casual copy in which an image captured by an IR camera is printed and then processed to game card size. With such counterfeits, the contrast is reduced when the image is captured and printed, and there is a high possibility that some of the lines that make up the pattern PT (concentric circles) will disappear. Assuming a counterfeit game card GC is a casual copy in which only the information code CD is extracted from an image captured by an IR camera, printed, and then processed to game card size. Such counterfeits include the information code CD but not the pattern PT.

Figure 4 is a flow chart showing the procedure for reading a game card GC in embodiment 1. The imaging unit 17 of the game machine 10 captures an image of the game card GC set on the mounting table, and outputs the captured image to the information code reading unit 18. The information code reading unit 18 acquires the captured image output from the imaging unit 17 (step S101).

There may be multiple game cards GC set on the placement table. In this case, the imaging unit 17 captures an image of the multiple game cards GC at once and outputs the captured image including the multiple game cards GC to the information code reading unit 18.

The information code reading unit 18 performs a process of detecting the information code CD from the captured image and judges whether the information code CD has been successfully detected (step S102). When the information code CD is a QR code, the information code reading unit 18 detects the information code CD by finding the finder pattern arranged at the three vertices of the QR code. The finder pattern is composed of a black square and a black outer frame surrounding the square, and is designed so that the ratio of black cells to white cells is 1:1:3:1:1 regardless of whether the square is scanned from the vertical, horizontal, or diagonal direction. The information code reading unit 18 can detect the information code CD by finding a pattern (finder pattern) in which the ratio of black cells to white cells is a predetermined ratio. If the information code CD is a code other than a QR code, the information code CD may be detected according to a detection method specified for the code. If the captured image contains multiple information codes CD, the information code reading unit 18 may perform a process of detecting each of the multiple information codes CD in step S102.

If detection of the information code CD fails (S102: NO), the information code reading unit 18 returns the process to step S101.

If the information code CD is successfully detected (S102: YES), the information code reading unit 18 executes a process of reading information indicated by the detected information code CD from the information code CD (step S103). Existing technology is used to read the information code CD. For example, when reading a code consisting of white cells and black cells, the information code reading unit 18 recognizes the horizontal and vertical directions of the code from a finder pattern or the like included in the information code CD, and recognizes the white and black cells in the code along the recognized horizontal and/or vertical directions. The information code reading unit 18 rearranges the recognized white cells into a data string of 0 and the black cells into a data string of 1, and performs a decoding process to convert them into character information. The information code reading unit 18 can read the information code CD by using a reading method determined according to the code, not limited to the above-mentioned method. The process from step S103 to steps S104 to S107 described below is performed the same number of times as the number of information codes CD detected in step S102.

The information code reading unit 18 calculates the pattern area based on the information code CD (step S104). Since the positional relationship between the information code CD and the pattern PT is known in the game card GC, the information code reading unit 18 calculates the area in which the pattern PT is located based on the information on that positional relationship. In addition, if the position in the imaging area in which the pattern PT is captured is fixed, the information code reading unit 18 may determine a predetermined area as the area in which the pattern PT is located.

The information code reading unit 18 executes pre-processing and cut-out processing (step S105). Specifically, the information code reading unit 18 performs perspective transformation and lens distortion correction to convert the area including the pattern PT so that it has the same shape as when the game card GC is faced directly, and cuts out the converted area. The information code reading unit 18 may also perform edge enhancement processing, sharpening processing, etc. on the captured image that is out of focus due to the placement position.

Next, the information code reading unit 18 calculates a judgment value used for authenticity determination from the pattern PT included in the cut-out area (step S106). The information code reading unit 18 calculates a judgment value that indicates the size of the feature from the pattern PT included in the area cut out in step S105. For example, the information code reading unit 18 may calculate the ratio of the line drawing width and the non-line drawing width in the concentric pattern PT as a feature and use it as the judgment value. The information code reading unit 18 may also perform frequency analysis on the concentric pattern PT and determine the judgment value based on the obtained frequency spectrum. The method of calculating the judgment value is arbitrary, and the information code reading unit 18 may calculate the feature appearing in the concentric pattern PT and determine the judgment value used for authenticity determination based on the calculated feature.

The information code reading unit 18 compares the judgment value calculated in step S106 with a threshold value to determine the authenticity of the game card GC (step S107). For example, if the calculated judgment value is equal to or greater than the threshold value, the information code reading unit 18 determines that the game card GC is authentic, and if the judgment value is less than the threshold value, the information code reading unit 18 determines that the game card GC is counterfeit.

The threshold for the judgment value depends on the shape of the pattern PT, the imaging environment, the counterfeiting accuracy, etc. For this reason, it is preferable to find a threshold in advance according to the usage environment and maximize the judgment accuracy. For example, multiple images are taken of both the genuine product and the counterfeit product, a judgment value is calculated from each captured image, and the median between the average judgment value calculated from the genuine product and the average judgment value calculated from the counterfeit product is set as the threshold.

The information code reading unit 18 then outputs the result of the authenticity determination in step S107 to the control unit 11 of the game machine 10 (step S108). If the information code reading unit 18 determines that the game card GC is genuine, it outputs information to that effect to the control unit 11 of the game machine 10. If multiple game cards GC are set in the game machine 10, it is only necessary to output information to the control unit 11 that the game card GC is genuine if all of the game cards GC are genuine. The information code reading unit 18 also outputs information indicated by the information code CD read in step S103 to the control unit 11.

When the control unit 11 acquires from the information code reading unit 18 information indicating that the game card GC is true and information indicated by the information code CD, the control unit 11 continues game play. For example, the control unit 11 determines attribute information of a character to be made to appear in the game based on the information indicated by the information code CD, and performs processing to progress game play by making a character having that attribute information appear in the game.

On the other hand, if the information code reading unit 18 determines that the game card GC is counterfeit, it outputs information to that effect to the control unit 11 of the game machine 10. If multiple game cards GC are set in the game machine 10, and one or more of the multiple game cards GC set are counterfeit, it outputs information to the control unit 11 that the game card GC is counterfeit. If the control unit 11 obtains information that the game card GC is counterfeit from the information code reading unit 18, it stops game play. The control unit 11 may also display an error on the display unit 14 to inform the player that the game card GC is an unusable card.

As described above, in the first embodiment, the authenticity of a game card GC can be determined using the pattern PT printed with IR absorbing ink. In counterfeit products made by casual copying of genuine products, it is highly likely that some of the lines that make up the pattern PT will have disappeared (deteriorated), and the determination value calculated in step S106 is highly likely to differ from that of genuine products. Therefore, by comparing this determination value with a threshold value, it is possible to identify counterfeit products, and if a counterfeit product is identified, the continuation of game play can be halted.

In this embodiment, a game card GC on which both the information code CD and the pattern PT are printed with IR absorbing ink has been described, but a game card GC on which the information code CD is printed with normal ink and the pattern PT is printed with IR absorbing ink may also be used. In this case, even if a counterfeit product is created using an image captured with a normal camera or scanner, the counterfeit product will not contain the pattern PT, and therefore can be determined to be a counterfeit (fake) by authenticity determination performed by the information code reading unit 18.

In this embodiment, the pattern PT is printed using IR absorbing ink, but the pattern PT may also be printed using ink that absorbs or reflects light in a specific wavelength range, such as UV absorbing ink or UV reflective ink. Light in a specific wavelength range is also called special light in contrast to normal ambient light (visible light).

(Embodiment 2)
In the second embodiment, a configuration for calculating a judgment value from a pattern PT using frequency analysis will be described.
The internal structure of the game machine 10 and the structure of the game card GC are the same as those in the first embodiment, and therefore the description thereof will be omitted.

Figure 5 is a flowchart showing the procedure for reading a game card GC in embodiment 2. The information code reading unit 18 calculates a pattern area from the captured image using the same procedure as in embodiment 1, and performs pre-processing and extraction processing on the pattern area (steps S201 to S205).

The information code reading unit 18 performs a Fourier transform on the image of the cut-out pattern region to generate a Fourier transform image (step S206). FIG. 6 is a schematic diagram showing an example of a Fourier transform image. A Fourier transform image is an image in which the spatial frequency appearing in the pattern PT is expressed by the pixel value of each pixel. In the Fourier transform image, the distance d from the image center c to the pixel P corresponds to the height of the spatial frequency, and the direction (directional angle) α of the line segment connecting the image center c and the pixel P corresponds to the direction of the wave. The Fourier transform image is a grayscale image in which the pixel value of each pixel P is expressed as a value between 0 and 1 according to the strength of the spatial frequency (power spectrum). In the example of FIG. 6, a line corresponding to the height of the spatial frequency appears at a position distance d from the image center c.

The information code reading unit 18 performs low-pass filter processing on the generated Fourier transform image (step S207). Low-pass filter processing is a known process, but in this embodiment, the pixel value of the pixel of interest is determined by averaging the top seven pixel values of the pixel values of the pixel of interest and its surrounding eight pixels, and this process is performed across the entire image while changing the position of the pixel of interest. The low-pass filter processing reduces the effects of noise that appears as dark areas in the image. The above process is one example, and the number of pixels used as surrounding pixels and the number of pixels used to calculate the average can be set arbitrarily.

If multiple pattern areas are cut out in step S205, the information code reading unit 18 generates a Fourier transform image from the image of each pattern area, performs low-pass filter processing, and then generates a Fourier transform image by integrating them.

The information code reading unit 18 performs a masking process on the Fourier transform image after the low-pass filter process (step S208). In the Fourier transform image, pixel values may be large near the x-axis and y-axis due to the influence of a background pattern (not shown), which may reduce the accuracy of the authenticity determination. For this reason, in step S208, a process is performed to replace the pixel values of pixels included in a predetermined region including the x-axis and y-axis with the average pixel value in the low-frequency region (near the central axis).

The information code reading unit 18 performs a normalization process on the Fourier transform image after the mask process (step S209). If the pixel value range is changed when integrating multiple Fourier transform images, the pixel value range is converted to the range from 0 to 1 by the normalization process.

The information code reading unit 18 calculates a judgment value used for authenticity judgment from the Fourier transform image after normalization processing (step S210). The information code reading unit calculates the average value PM of the pixel values NPf of pixels P at positions M that are a distance d away from the image center c of the Fourier transform image for each distance d. The area where the mask processing has been performed is excluded from the calculation of the average value PM. Since the concentric pattern PT does not have directionality as a geometric characteristic, the average value PM may be calculated only from the pixels in the first or second quadrant.

Figure 7 is a graph showing the calculation results of the average value PM. In Figure 7, the horizontal axis is distance d from the image center c, the vertical axis is average value PM, and the value PM(d) of the average value PM for each distance d is shown by a solid line. PM(d) can be calculated only for distance d in the target range. Distance d is a natural number, and the target range can be determined as appropriate.

The information code reader 18 can determine whether the game card GC has a specified pattern PT based on the value of PM(d). In other words, if the value of PM(d) is high at a distance d that corresponds to the distance (spatial frequency) between the inner and outer circles in the specified concentric pattern PT, it can be determined that the game card GC has the specified pattern PT.

However, in Fourier transform images, there is a general tendency for pixel values to decrease as you move from the center of the image to the periphery. In this embodiment, processing is performed to prevent this tendency from affecting the judgment, thereby improving the accuracy of authenticity judgment.

The information code reader 18 first calculates dmin+1, the average of multiple distances (dmin, dmin+1, dmin+2) near the lower limit (=dmin) of the target range, and calculates the average avePMmin of PM(d) calculated for these multiple distances. The information code reader 18 also calculates dmax-1, the average of multiple distances (dmax-2, dmax-1, dmax) near the upper limit (=dmax) of the target range, and calculates the average avePMmax of PM(d) calculated for these multiple distances.

As shown in FIG. 7, the information code reading unit 18 creates an equation L(d) for the straight line connecting the two points (dmin+1, avePMmin) and (dmax-1, avePMmax) as an equation that indicates the decreasing trend of the pixel value NPf according to the distance d, and calculates the difference ΔR(d) by subtracting the value of L(d) from the value of PM(d) for each distance d between dmin and dmax. This makes it possible to prevent the decreasing trend of the pixel value NPf in the Fourier transform image from affecting the judgment.

Fig. 8 is a graph showing the calculation result of the difference ΔR(d). Fig. 8 is a graph showing the value of ΔR(d) for each distance d, with the horizontal axis representing the distance d from the image center c and the vertical axis representing ΔR(d). The information code reading unit 18, for example, determines the value of ΔR(dn) for each of a plurality of target distances dn (d1 to d7 in the example of Fig. 8) located between dmin and dmax, and calculates a weighted sum Rs with Wn (=W1 to W7) as a weighting coefficient, as shown in the following formula.
Rs = W1ΔR(d1) + W2ΔR(d2) + ... + W7ΔR(d7)

The target distances dn and their number for which the weighted sum Rs is calculated are determined to include the distance d corresponding to the distance (spatial frequency) between the inner and outer circles in the concentric pattern PT. The weighted sum Wn is determined to have a larger value the closer it is to the distance d.

The information code reading unit 18 calculates a judgment value (defined as R) from the weighted sum Rs by R = 10/(Rs + 0.1). Here, the maximum value of R is 1000, and if Rs + 0.1 is smaller than 0.01, R = 1000. Note that the method of calculating the judgment value is not limited to the above, and the weighted sum Rs itself may be used as the judgment value.

The procedure after calculating the judgment value is the same as in embodiment 1. That is, the information code reading unit 18 performs a process of judging the authenticity of the game card GC by comparing the judgment value calculated in step S210 with a threshold value (step S211), and outputs the judgment result to the control unit 11 of the game machine 10 (step S212).

As for the threshold value, similarly to the first embodiment, images of both genuine and counterfeit products may be captured multiple times, a judgment value may be calculated from each captured image, and the median value between the average judgment value calculated from genuine products and the average judgment value calculated from counterfeit products may be set as the threshold value.

As described above, in the second embodiment, whether or not a game card GC has a predetermined pattern PT (whether or not the game card GC is true) is determined by Fourier analysis, thereby improving the accuracy of the determination.

In this embodiment, a counterfeit game card GC is assumed to be a casual copy created using a 300-600 dpi IR scanner and a 600-6000 dpi printer for printing scanned images, which are within the range available to individual users. In embodiment 2, a significant difference appears in the judgment value for the casual copy due to the deterioration of characteristics during counterfeiting, and the judgment value can be used to distinguish and identify counterfeits from genuine products.

(Embodiment 3)
In the third embodiment, a configuration will be described in which a pattern PT obtained by inverse Fourier transform is arranged on a game card GC.
The internal configuration of the game machine 10 is the same as that of the first embodiment, and therefore the description thereof will be omitted.

Figure 9 is an explanatory diagram explaining the structure of a game card GC in embodiment 3. The game card GC in embodiment 3 is similar to that shown in embodiments 1 and 2, with game content printed on the first side and an information code CD and a pattern PT for authenticity determination printed on the second side. In the example of Figure 9, the information code CD is placed in the center of the second side, and multiple patterns PT for authenticity determination are placed around it. As in embodiments 1 and 2, the information code CD and the pattern PT for authenticity determination are printed with transparent IR absorbing ink, so they are difficult to see under visible light, but the game machine 10 can read the content of the information indicated by the information code CD and the pattern PT for authenticity determination by capturing an image using an IR camera mounted on the imaging unit 10.

The arrangement of the information code CD and pattern PT shown in FIG. 9 is an example and can be designed as appropriate. At least one information code CD and one pattern PT need to be arranged on either the first or second side of the game card GC.

The pattern PT in the third embodiment is a pattern obtained by performing an inverse Fourier transform on the image for which the judgment value is calculated as described above. Here, the image for which the judgment value is calculated is an image drawn in a spatial frequency domain in which the vicinity of the center has low frequency components and the frequency components become higher as the distance from the center increases. As the image for which the judgment value is calculated, for example, an image in which a line corresponding to the height of the spatial frequency (i.e., pattern PT1 which is a single circle in the spatial frequency domain) is drawn at a position at a certain distance from the center of the image can be used. When such an image is used, the information code reading unit 18 can calculate the judgment value R by using the method described in the second embodiment.

When pattern PT1, which is a single circle in the spatial frequency domain, is inverse Fourier transformed, pattern PT2 shown in the center of Figure 9 is obtained. In embodiment 3, pattern PT2 obtained by inverse Fourier transform is used as pattern PT for authenticity determination. Pattern PT for authenticity determination may be the entire pattern PT2 obtained by inverse Fourier transform, or a part of pattern PT2 obtained by trimming. The example in Figure 9 shows an example in which multiple patterns PT for authenticity determination obtained by trimming a part (near the center) of pattern PT2 are arranged on a panel.

When a concentric circle pattern is used as the pattern PT for authenticity determination, it is possible to read characteristics such as the circle radius, line width, and non-line width by pattern analysis, but when the pattern PT for authenticity determination is formed using an inverse Fourier transform, the pattern PT can be configured as a complex design, making pattern analysis difficult. As a result, it is possible to make the pattern PT difficult to counterfeit or alter.

The procedure for determining the authenticity of a game card GC is exactly the same as in embodiment 2. The information code reading unit 18 captures an image of the second side of the game card GC using the imaging unit 17, cuts out the pattern PT area from the obtained image, and performs a Fourier transform on the image of the cut-out pattern area to generate a Fourier transform image. For example, when a Fourier transform image is generated from the image of pattern PT2 in FIG. 9, an image containing pattern PT1, which is a single circle in the spatial frequency domain, is obtained. The information code reading unit 18 can calculate a determination value R by executing S207 to S211 of the flowchart described in FIG. 5, and can determine the authenticity of the game card GC based on the determination value R.

As described above, in the third embodiment, a pattern obtained by performing an inverse Fourier transform on the image from which the judgment value R is calculated is used as the pattern PT for authenticity determination, making pattern analysis difficult and making it difficult to counterfeit or alter the pattern PT.

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

For example, the game card GC may be made by printing game content on a first surface of a backing, and printing an information code CD and a pattern PT for authenticity determination on a second surface. Alternatively, the game card GC may be made by attaching a sticker paper on which the game content is printed to a first surface of a plastic plate, and attaching a sticker paper on which the information code CD and a pattern PT for authenticity determination are printed to a second surface. The shape, size, and material of the game card GC may be designed as appropriate.

The following notes are provided regarding this embodiment:

(1) The game machine disclosed herein includes an acquisition unit that acquires an image of a game card that includes an information code and a pattern formed with ink that absorbs or reflects special light, a determination unit that determines whether the game card is genuine or counterfeit based on the pattern included in the acquired image, and an output unit that outputs information that the game card is counterfeit when the determination unit determines that the game card is counterfeit.

(2) In the game machine described in (1) above, the pattern is arranged at a position specified based on the information code.

(3) In the game machine described in (1) or (2) above, the pattern is a concentric pattern.

(4) In the game machine described in any one of (1) to (3) above, the information code is formed with ink that absorbs or reflects the special light.

(5) In the gaming machine described in any one of (1) to (4) above, the determination unit calculates a determination value from the feature amount of the pattern and compares the calculated determination value with a threshold value to determine the authenticity of the game card.

(6) In the game machine described in (5) above, the determination unit calculates the determination value by performing frequency analysis on the captured image.

(7) In the game machine described in (5) or (6) above, the judgment unit generates a Fourier transform image from the captured image in which the pixel value of each pixel is the strength of the spatial frequency, the distance from the image center to the pixel of interest is the height of the spatial frequency, and the direction of the line segment connecting the image center and the pixel of interest is the direction of the wave, calculates the average value of pixel values for pixels equidistant from the image center of the generated Fourier transform image, derives an equation showing the tendency of the average value to decrease according to the distance, calculates the difference between the average value calculated for each distance and the equation, and calculates the judgment value based on the calculated difference.

(8) In the game machine described in (6) or (7) above, the pattern is obtained by inverse Fourier transforming an image in the spatial frequency domain from which the judgment value is calculated by the frequency analysis.

(9) In the gaming machine described in any one of (5) to (8) above, the judgment unit calculates judgment values from multiple captured images obtained by capturing multiple images of genuine and counterfeit game cards, and sets the threshold value based on the average value of the judgment values calculated for genuine game cards and the average value of the judgment values calculated for counterfeit game cards.

(10) In the gaming machine described in any one of (1) to (9) above, the acquisition unit acquires an image obtained by capturing an image of multiple game cards at once, and the determination unit determines the authenticity of each game card based on the pattern formed on each game card.

(11) The method of determining the authenticity of a game card disclosed herein acquires an image of a game card including an information code and a pattern formed by ink that absorbs or reflects special light, determines the authenticity of the game card based on the pattern included in the acquired image, and, if the game card is determined to be a counterfeit, executes a process by a computer to output information that the game card is a counterfeit.

(12) The computer program disclosed herein is a computer program for causing a computer to execute a process of acquiring an image of a game card including an information code and a pattern formed by ink that absorbs or reflects special light, determining whether the game card is genuine based on the pattern included in the acquired image, and outputting information that the game card is a fake if the game card is determined to be fake.

(13) A game card disclosed herein has game content printed on a first side and an information code and a pattern printed on a second side, the pattern being printed around the information code using ink that absorbs or reflects special light, and is used in a game machine equipped with an imaging unit that images the information code and the pattern.

REFERENCE SIGNS LIST 10 Game machine 11 Control unit 12 Memory unit 13 Operation unit 14 Display unit 15 Deposit acceptance unit 16 Card issuing unit 17 Imaging unit 18 Information code reading unit 19 Communication unit PG1 Authenticity determination program PG2 Reading processing program RM Recording medium

Claims (13)

an acquisition unit that acquires a captured image of a game card including an information code and a pattern formed by ink that absorbs or reflects special light;
a determination unit that determines the authenticity of the game card based on a pattern included in the acquired captured image;
and an output unit that outputs information that the game card is a counterfeit when the determination unit determines that the game card is a counterfeit. The game machine according to claim 1 , wherein the pattern is arranged at a position specified based on the information code. The gaming machine according to claim 1 , wherein the pattern is a concentric circular pattern. 2. The game machine according to claim 1, wherein the information code is formed with ink that absorbs or reflects the special light. The determination unit is
A judgment value is calculated from the feature amount of the pattern;
The gaming machine according to claim 1 , wherein the authenticity of the game card is determined by comparing the calculated determination value with a threshold value. The determination unit is
The game machine according to claim 5 , wherein the judgment value is calculated by subjecting the captured image to frequency analysis. The determination unit is
A Fourier transform image is generated from the captured image, with the pixel value of each pixel being the strength of the spatial frequency, the distance from the center of the image to the pixel of interest being the height of the spatial frequency, and the direction of the line segment connecting the center of the image and the pixel of interest being the direction of the wave.
Calculating an average value of pixel values of pixels equidistant from the center of the generated Fourier transform image;
Deriving an equation showing a decreasing tendency of the average value according to the distance;
Calculating a difference between the average value calculated for each distance and the formula;
The game machine according to claim 6 , wherein the determination value is calculated based on the calculated difference. 8. The gaming machine according to claim 6, wherein the pattern is a pattern obtained by performing an inverse Fourier transform on an image in a spatial frequency domain from which the judgment value is calculated by the frequency analysis. The determination unit is
Calculating a judgment value from a plurality of captured images obtained by capturing images of the genuine game card and the counterfeit game card multiple times;
The gaming machine according to claim 5 , wherein the threshold value is set based on an average value of the determination values calculated for genuine game cards and an average value of the determination values calculated for counterfeit game cards. the acquiring unit acquires captured images obtained by capturing images of a plurality of game cards at once;
The gaming machine according to claim 1 , wherein the determination unit determines the authenticity of each game card based on a pattern formed on each game card. Acquire a captured image of a game card including an information code and a pattern formed by ink that absorbs or reflects special light;
determining the authenticity of the game card based on a pattern included in the acquired captured image;
When the game card is determined to be a counterfeit, information indicating that the game card is a counterfeit is output. Acquire a captured image of a game card including an information code and a pattern formed by ink that absorbs or reflects special light;
determining the authenticity of the game card based on a pattern included in the acquired captured image;
If the game card is determined to be a counterfeit, outputting information indicating that the game card is a counterfeit. Game content is printed on the first side, and information code and patterns are printed on the second side.
the pattern is printed around the information code using ink that absorbs or reflects special light,
A game card used in a game machine equipped with an imaging device for imaging the information code and the pattern.

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