JP2006178841A - Paper sheet authenticity discriminating system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To discriminate a false ticket elaborately printed by a color copier or color printer. <P>SOLUTION: The false ticket printed by the color copier or the color printer expresses deep red color by overlapping R (red ink) and B (blue ink). In that case, the color runs or runs off by a minimum unit for composition. The genuine paper sheet uses ink whose color is adjusted to the color to be expressed so that the color does not change even if the color runs or runs off. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a paper sheet authenticity determination device for determining the authenticity of paper sheets such as banknotes.

  Conventionally automatic such as ATM (Automatic Teller Machine), CD (Cash Dispenser), etc. placed at the fulcrum of financial institutions such as banks, credit unions, post offices, consumer finance companies 2. Description of the Related Art Paper transaction authenticity determination devices for determining the authenticity of securities such as banknotes are disposed in transaction apparatuses, money changers, vending machines disposed in stores and on streets, and the like. When the paper sheet discriminating apparatus discriminates the authenticity of a medium such as a banknote, an illegal medium such as a counterfeit banknote can be excluded.

As a paper sheet authenticity determination device for determining the authenticity of securities such as banknotes, for example, there is one disclosed in JP-A-4-181495. When a bill as a paper sheet is conveyed, the paper sheet authenticity discrimination device irradiates light from a light source and receives reflected light from the bill with an image sensor. Then, the true / false determination is performed from the scanning line data in the image sensor with a gray scale image, that is, 256 gray scales.
JP-A-4-181495

  By the way, in recent years, more sophisticated printing has become possible due to advances in printing technology such as color copying and color printers. With the conventional paper sheet authenticity discrimination device as described above, a counterfeit ticket is a counterfeit ticket. Sometimes it was determined as a regular ticket without being determined. Accordingly, an object of the present invention is to provide a paper sheet authenticity determination device capable of determining a counterfeit ticket printed with a color copy or a color printer.

  In order to solve the above problems, a paper sheet authenticity determination device according to the present invention includes an image information acquisition unit that captures an image of an inserted medium as image data, and a cutout unit that cuts out a predetermined area from the medium. Analyzing the combination pattern of the minimum unit of color composition determined by the color determination unit and the color determination unit capable of determining the minimum unit of color composition used for the paper sheet from the cut image data; The image processing apparatus includes an analysis unit, and a collation determination unit that determines the authenticity of the paper sheet by comparing the minimum unit of color configuration determined by the analysis unit with color data stored in advance.

  In other words, color copies and color printers are basically based on the seven colors R, G, B, C, M, Y, and K (red, green, blue, cyan, magenta, yellow, black), of which RGB or CMY One of them is used as a constituent minimum unit, and printing is performed so as to express various colors by superimposing these constituent minimum units.

  Accordingly, a fake ticket such as a color copy or a color printer is represented by overlapping R (red ink) and B (blue) ink, for example, when expressing dark red. In such a case, the color of the minimum constituent unit is blurred or protrudes. Real paper sheets are adjusted to the color expressed by the color of the ink to be printed, so the color does not change even if the color oozes or protrudes.

  By utilizing this difference, the collation determination unit 16 compares the minimum composition unit of the color appearing in the pixel unit determined by the analysis unit 15 with the color data stored in advance to check the authenticity of the paper sheet. Determine.

  According to another embodiment, an image information acquisition unit that captures an image of an inserted medium as image data, a cutout unit that cuts out a predetermined area from the medium, and a paper sheet from the cutout image data A color discriminating unit capable of discriminating the minimum unit of color used in a class on a pixel basis, a histogram creating unit for creating a histogram of average luminance of the minimum unit of color discriminated by the color discriminating unit, and the histogram A collation determining unit that compares the histogram of the average luminance of the minimum unit of color created by the creating unit with a predetermined threshold stored in advance to determine whether the paper sheet is true or false. Yes.

  That is, a real banknote is printed by adjusting the color expressed by the color of the ink itself when the character is red. However, counterfeit banknotes are often printed with color copies or color printers, and in this case, RGB ink is overprinted to produce dark red or light red. For this reason, a difference occurs in each average luminance of the RGB histogram. Using this difference, the collation determination unit 145 creates a histogram for each of the constituent colors of RGB that appear in the determined pixel unit, and shows a histogram different from the real one. By determining that it is a banknote, a counterfeit ticket is discriminate | determined with high precision with respect to the overseas banknote in foreign countries where the security of a banknote is low and circulation of a forged ticket is very much.

  According to the present invention, color copies, color printers, etc. are based on seven colors of R, G, B, C, M, Y, K (red, green, blue, cyan, magenta, yellow, black), of which RGB Printing is performed so as to express various colors by using either one of CMY and CMY as a constituent minimum unit and adjusting the overlay of the constituent minimum units. Accordingly, a fake ticket such as a color copy or a color printer represents R (red) ink and B (blue) ink in an overlapping manner when expressing dark red, for example. In such a case, the color of the minimum constituent unit is blurred or protrudes. Real paper sheets are adjusted to the color expressed by the color of the ink to be printed, so the color does not change even if the color oozes or protrudes. By utilizing this difference, the combination pattern of the minimum constituent unit of the color appearing in the pixel unit is compared with the color data stored in advance to determine the authenticity of the paper sheet.

  According to another embodiment, medium information is acquired, a histogram of average luminance for each RGB is created, and when a histogram different from the real one is shown, it is determined that the medium is a counterfeit bill.

Therefore, it is possible to discriminate counterfeit bills that have been finely printed by a color copy or a color printer.
In addition, the counterfeit ticket is discriminated with high accuracy from overseas banknotes in overseas where the security of the banknote is low and the circulation of counterfeit tickets is very large.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram showing a functional configuration of a first embodiment of the present invention, FIG. 2 is an explanatory diagram of FIG. 1 of the first embodiment of the present invention, and FIG. 3 is a first diagram of the present invention. FIG. 4 is a block diagram showing the functional configuration of the second embodiment of the present invention, FIG. 5 is an explanatory diagram of FIG. 4 of the second embodiment of the present invention, FIG. 6 is an explanatory diagram of a collation determination unit according to the second embodiment of this invention. In addition, the same code | symbol is attached | subjected about the element common to each drawing.

  In FIG. 1, reference numeral 10 denotes a paper sheet authenticity determination device according to the present embodiment, which is disposed in an automatic transaction apparatus, a money changer, a vending machine disposed in a store or on a street, and the like. Used to determine false. Here, the paper sheet 11 is, for example, a banknote, but may be a beer ticket, a gift certificate, a gift certificate such as a gift certificate, a traveler's check, a securities such as a check, a stock certificate, or a facility use ticket such as an admission ticket. It can be of any kind.

  Here, a case where the paper sheet 11 is a banknote will be described. In this case, the paper sheet authenticity determination device can determine the authenticity of the banknote 11 based on the minimum unit of color composition, but it determines the authenticity of a plurality of types of paper sheets 11. It is desirable to be able to Moreover, it is desirable that the paper sheet authenticity determination device can determine the authenticity of foreign banknotes.

  And the said paper sheet authenticity discrimination device is arrange | positioned in the banknote conveyance path | route and the banknote handling apparatus in the apparatus which receives the banknote as paper sheets like an automatic transaction apparatus, and discriminate | determines the authenticity of the received banknote. To do. In addition, the devices for receiving the banknotes are generally ATMs, CDs, etc., which are installed at sales offices such as banks, credit unions, post offices and other financial institutions, as well as store stores such as convenience stores and supermarkets. Although it is an automatic transaction device, it may be any device such as a ticket vending machine for railways, buses, etc., vending machines for beverages, cigarettes, money changers, game machines, etc. as long as it is a device for receiving banknotes. . In the present embodiment, the case where the device that receives the banknote is an automatic transaction device will be described. And the apparatus which receives the said banknote treats the banknote which the paper sheet authenticity discrimination | determination apparatus discriminate | determined as a genuine note as a genuine banknote, and the banknote which the medium authenticity discrimination | determination apparatus did not discriminate | determine as a genuine note like a forged banknote Eliminate as illegal bills.

  In the present embodiment, the paper sheet authenticity discrimination device 10 has arithmetic means such as a CPU and MPU, storage means such as a magnetic disk and a semiconductor memory, a communication interface, and the like. Whether or not there is a color that does not exist is determined as to whether it is true or false. Here, the paper sheet authenticity determination apparatus 10 includes an image information acquisition unit 12, an area cutout unit 13, a color determination unit 14, an analysis unit 15, a collation determination unit 16, and a determination threshold storage unit 17, which are controlled by a control unit. (Not shown) controls.

  The image information acquisition unit 12 acquires digital image data of the banknote 11 output from a medium image acquisition device (not shown). The image acquisition device includes, for example, a light source such as an LED (Light Emitting Diode), a lens, an imaging unit such as a CCD (Charge Coupled Device), a signal amplification unit, an A / D conversion unit, and the like. And the light which a light source emits is irradiated to the banknote 11, and reflected light is shrunk | reduced with a lens, and it images it on an imaging means. The imaging means photoelectrically converts the reflected image of the banknote 11 that has been imaged and outputs an image signal as analog image data. Further, the image signal is amplified by the signal amplification means, converted into a digital signal by the A / D conversion means, and output as digital image data.

  The area cutout unit 13 cuts out a banknote image in a necessary area determined in advance from the digital image data of the banknote 11 from the image information acquisition unit 12 as an image. Note that the inclination of the image is corrected.

  The color discriminating unit 14 discriminates the color of the minimum unit of the color for the cut out region. For example, the colors R, G, B, C, M, Y, K (red, green, blue, cyan, magenta, yellow, black) are discriminated by a color discriminating means such as a spectrophotometer.

  The analysis unit 15 detects pixels of colors that do not exist originally. For example, when making a dark red, the blue ink and the red ink are often overlaid, and in that case, the blue is oozing or protruding, as in the image 35, where the original (genuine) only dark red exists. Only the blue pixels are detected.

  Then, the collation determination unit 16 uses color thresholds such as R, G, B, C, M, Y, K (red, green, blue, cyan, magenta, yellow, black) stored in the determination threshold storage unit 17. And the analysis result of the analysis unit 15 such as R, G, B, C, M, Y, K (red, green, blue, cyan, magenta, yellow, black) Then, when a blue pixel is detected in a place where only dark red exists, the appearance is analyzed, it is determined whether the input bill 11 is genuine or a fake, and the determination result is output.

  Next, the operation of the sheet authenticity determination apparatus 10 having the above-described configuration will be described.

2 and 3 are explanatory diagrams of the embodiment of the present invention.
In FIG. 2, the inserted banknote 11 is acquired in advance by acquiring an image 22 of one banknote by the color sensor in the image information acquisition unit 12 and performing skew correction of the inserted banknote 23 from the acquired image 22. The area 24 is cut out and 25 is cut out. In this description, “People's Bank of China”, which is the character part, is defined as the cutout area.

The extracted image 25 is analyzed by the analysis unit 14 in either RGB or CMY.
Here, the analysis method of RGB, which is the three primary colors of light, is shown below using FIG.
The image 31 is a cut image 25. For explanation, an image 32 is further cut out from the image 31, and the image 32 is an image cut out from a real banknote. The character “middle” in the image 32 is cut out in red.

The image 33 is an image obtained by cutting out the same portion as the image 32 from the forged banknote. The image 37 is an enlargement of a part of the image 33, 34 indicates red, and 35 indicates blue.
When the letter is red, the real banknote is printed after being adjusted to the color represented by the color of the ink itself.

However, counterfeit bills are often printed by a printer, and in this case, RGB ink is overlaid to produce dark red or light red.
The image 33 shows the state, and in the case of making a dark red, the blue ink and the red ink are often overlaid. In this case, the blue is smeared or protrudes, as in the image 35. Then, only the pixel of blue is detected in a place where only dark red exists.

This difference is used to determine whether it is genuine or fake.
In this embodiment, the analysis unit 15 detects pixels of colors that do not exist originally. For example, when making a dark red, the blue ink and the red ink are often overlaid, and in that case, the blue is oozing or protruding, as in the image 35, where the original (genuine) only dark red exists. Then, only blue pixels are detected and their appearance patterns are analyzed.

  The matching determination unit 16 then stores the threshold values of colors such as R, G, B (red, green, blue) stored in the determination threshold storage unit 17 and the R, G, B (red, green) of the analysis unit 15. , Blue) etc., and if the blue pixel is detected in a place where only dark red originally exists, the appearance of the color is analyzed in units of that pixel, and the input banknote It is determined whether 11 is genuine or a fake and the determination result is output.

 <Second embodiment of the present invention>

A second embodiment of the present invention will be described. In addition, about the thing which has the same structure as embodiment, the description is abbreviate | omitted by providing the same code | symbol. Also, the description of the same operation and the same effect as the above embodiment is omitted.
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  In the second embodiment of the present invention, as shown in FIG. 4, the paper sheet authenticity determination apparatus 100 determines the authenticity of the paper sheet 11. Here, a case where the paper sheet 11 is a banknote will be described. In this case, the paper sheet authenticity determination device can determine the authenticity of the paper sheet 11 based on the minimum unit of color composition. It is desirable to be able to do that. Further, it is desirable that the paper sheet authenticity determination device is capable of determining the authenticity of foreign banknotes. As shown in FIG. 4, the sheet authenticity determination apparatus 100 has an image information acquisition unit 112, a region cutout unit 143, a color determination unit 144, a histogram creation unit 145, a collation determination unit 146, and a determination threshold storage unit. 147.

  In the present embodiment, the paper sheet authenticity discrimination device 100 has a computing means such as a CPU and MPU, a storage means such as a magnetic disk and a semiconductor memory, a communication interface, etc. Another histogram of average luminance is created, and authenticity determination is performed based on whether or not a histogram different from the real one is shown. Here, the paper sheet authenticity determination apparatus 100 includes an image information acquisition unit 112, an area cutout unit 143, a color determination unit 144, a histogram creation unit 145, a collation determination unit 146, and a determination threshold storage unit 147, and controls them. Control unit (not shown).

  The image information acquisition unit 12 acquires digital image data of the banknote 11 output from a medium image acquisition device (not shown). The image acquisition device includes, for example, a light source such as an LED (Light Emitting Diode), a lens, an imaging unit such as a CCD (Charge Coupled Device), a signal amplification unit, an A / D conversion unit, and the like. And the light which a light source emits is irradiated to the banknote 11, and reflected light is shrunk | reduced with a lens, and it images it on an imaging means. The imaging means photoelectrically converts the reflected image of the banknote 11 that has been imaged and outputs an image signal as analog image data. Further, the image signal is amplified by the signal amplification means, converted into a digital signal by the A / D conversion means, and output as digital image data.

  As shown in FIG. 5, the area cutout unit 1433 cuts out a banknote image of a necessary area determined in advance from the digital image data of the banknote 11 from the image information acquisition unit 12 as an image. Note that the inclination of the image is corrected.

The image 154 that has been cut out is discriminated by the color discriminating unit 144 using one of the color discriminating means such as a spectrophotometer, for example, RGB or CMY.
Here, the three primary colors of light, RGB, are discriminated.

  The histogram creation unit 145 creates a histogram of RGB colors determined by the color determination unit 144.

Reference numeral 146 denotes a collation determination unit, and a real banknote is printed after being adjusted to a color expressed by the color of the ink itself when the character is red. However, counterfeit bills are often printed by a printer, and in this case, RGB ink is overlaid to produce dark red or light red. This causes a difference in the average brightness of each RGB histogram.
The value stored in the determination threshold storage unit 147 is compared with the characteristics of the RGB color histogram acquired by the analysis unit 144, and it is determined whether the input medium is genuine or a fake, and the determination result is obtained. Output.

  The operation of the second embodiment will be described below.

  Since the operation of the image information acquisition unit 12 in FIG. 4 is the same as that of the first embodiment, it is omitted here.

  As shown in FIG. 5, the inserted banknote 11 acquires an image 152 of one banknote by the image information acquisition unit 12, and corrects the skew of the inserted banknote 11 from the acquired image 152 to cut out the banknote 153. The banknotes cut out are 154.

  The cut out banknote image 154 is subjected to RGB color discrimination by the color discrimination unit 144 by the color discrimination unit 144.

  Further, histograms are created for each of RGB, which are the three primary colors of light determined by the histogram creation unit 144. The histogram is represented by 256 gradations from 0 to 255, where 0 is dark and 255 is bright.

The collation determination unit 146 will be described with reference to the histogram diagram of FIG.
FIG. 6 is a histogram created by the histogram creation unit 145, 161 is a histogram created for each real banknote by RGB, 162 is R (red), 163 is G (green), 164 is B ( (Blue) histogram.
In this embodiment, each average luminance (r1, g1, b1) of the RGB histogram is used for the determination. In other words, the determination unit 145 calculates an average value from the histograms 162, 163, and 164 of the histogram 161, and assuming that the average values are r1, g1, and b1, as a determination condition, a predetermined determination threshold is a determination threshold storage unit 147 in advance. If the value is R threshold for R, G threshold for G, and B threshold for B,
r1> R threshold (1)
g1> G threshold (2)
b1> B threshold value (3)
When all the mathematical formulas expressed by the above formulas (1) to (3) are satisfied, it is determined to be genuine, and otherwise, it is determined to be fake.
In the case of the histogram 161, since r1, g1, and b1 all satisfy the above expressions (1) to (3) with respect to the determination threshold, it is determined to be genuine.

Further, in the histogram 165, g1 and b1 satisfy the above expressions (2) and (3) with respect to the determination threshold value, but r1 does not satisfy the expression (1), so the medium of the histogram 65 is a fake. It is determined that there is.
Moreover, you may pay attention to the difference in the appearance pattern of each average brightness | luminance of an RGB histogram.
And the result determined by the collation determination part 146 is output.

It is a block diagram which shows the function structure of the 1st Embodiment of this invention. It is explanatory drawing of FIG. 1 of the 1st Embodiment of this invention. It is explanatory drawing of the collation determination part of the 1st Embodiment of this invention. It is a block diagram which shows the function structure of the 2nd Embodiment of this invention. It is explanatory drawing of FIG. 4 of the 2nd Embodiment of this invention. It is explanatory drawing of the collation determination part of the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Medium 12 Image information acquisition part 13 Area | region extraction part 14 Color discrimination | determination means 15 Analysis part 16 Collation determination part 17 Determination threshold value storage part 144 Color discrimination means 145 Histogram creation part 146 Collation determination part 147 Determination threshold value storage part

Claims (2)

An image information acquisition unit that captures an image of the inserted medium as image data;
A cutout unit for cutting out a predetermined area from the medium;
Color discriminating means capable of discriminating the minimum unit of color used for paper sheets from the cut-out image data in pixel units;
An analysis unit for analyzing a combination pattern of the minimum unit of the color determined by the color determination unit;
A paper sheet authenticity comprising: collation determining means for determining the authenticity of the paper sheet by comparing the minimum structural unit of the color determined by the analysis unit with color data stored in advance. Discriminator. An image information acquisition unit that captures an image of the inserted medium as image data;
A cutout unit for cutting out a predetermined area from the medium;
Color discriminating means capable of discriminating the minimum unit of color used for paper sheets from the cut-out image data in pixel units;
A histogram creating unit for creating a histogram of the average luminance of the minimum unit of the color determined by the color determining unit;
Collation determination means for comparing the average luminance histogram of the minimum unit of color created by the histogram creation unit with a predetermined threshold stored in advance to determine whether the paper sheet is true or false. Characteristic paper sheet authenticity discrimination device.

Images