WO2012139354A1

WO2012139354A1 - Paper money identifying method and device

Info

Publication number: WO2012139354A1
Application number: PCT/CN2011/078794
Authority: WO
Inventors: 陈新; 李蒙; 唐辉; 成和建; 鲍东山
Original assignee: 北京新岸线软件科技有限公司
Priority date: 2011-04-11
Filing date: 2011-08-23
Publication date: 2012-10-18
Also published as: CN102737435A

Abstract

A paper money identifying method and device are provided. The transmission image of the region transmitted by light beam is collected. In the region, there is windowed security thread impression feature on paper money. The impression feature in the image is analyzed and identified. Thus, a determination is made whether the paper money is true. The paper money identifying method and device have the advantage of good adaptability to money type, low hardware cost, high detection and identification ratio, and stable and reliable performance.

Description

Technical field

The invention belongs to the field of optoelectronic technology, and in particular relates to a banknote authentication method and device. Background technique

The core issue in the field of financial instruments is the authentication of banknotes. A safety line (secur i ty thread) is a linear or ribbon-shaped additive that is continuously placed in the paper and parallel to the paper surface, and has an anti-counterfeiting function. The earliest safety thread in the world was made by natural hemp or silk spinning, and was continuously added to the paper during papermaking. Currently, security threads are often based on PET (polyester), which is loaded with a variety of visible, optically variable and machine readable anti-counterfeiting features. The current banknote security line is generally 20-40 μ ηι thick and l-4 mm wide, and the length is the same as the width of the cut single banknote. The safety line is generally divided into a fully buried safety line and a window-opening safety line to the extent that the embedded paper is covered by the fiber. Both sides of the safety line are covered with paper fibers called a fully buried safety line. Under the reflected light, the security line is generally not obvious. When you see it in the light, you can see the continuous security line shadow and the hollow text on it or the dark text on the light color line. Another type of safety thread is that one side is completely covered by paper fibers, and the other side is intermittently covered with fibers. The area that does not cover the fibers is like an open small window, which exposes the safety line for a period of time, so it is called window-opening safety. line. The window-opening safety line is more difficult to deploy than the full-buried safety line; the window-opening wide safety line can load more visible information, and it is more difficult to cast, making it more difficult to forge. Therefore, the window-opening safety line is one of the fastest growing types of anti-counterfeiting technology for banknotes.

However, the prior art for the detection of the safety line is for the detection of the security feature of the security line itself; due to the window-opening safety line application process, visible light and dark lines can be seen on both sides of the security line during transmission. The indentation pattern, and the counterfeit currency cannot be copied because there is no corresponding process equipment. In this way, a feature with strong anti-counterfeiting capability is produced: a window-opening safety line indentation feature.

Summary of the invention

In view of the above, the present invention provides a banknote authentication method and apparatus for a banknote window-type security line indentation feature. In order to have a basic understanding of some aspects of the disclosed embodiments, A simple summary. This generalization is not a general comment, nor is it intended to identify key/critical constituent elements or to describe the scope of protection of these embodiments. Its sole purpose is to present some concepts in the form of a

In order to achieve the object of the present invention, in one aspect, the present invention provides a method for authenticating a banknote, comprising: obtaining a transmission image of a region in which a window-type security line indentation feature is transmitted by a light beam; and analyzing and identifying a pressure in the image Trace features to determine the authenticity of the banknote.

In some optional embodiments, the beam of light is infrared light, ultraviolet light, or white light.

In some optional embodiments, the analyzing the indentation features in the image comprises: pre-processing the image of the region where the indentation feature is located, and analyzing the pre-processed image.

In some optional embodiments, the pre-processing of the image of the region in which the indentation feature is located includes:

Positioning the security line in the image, binarizing the image of the region where the indentation feature is located; performing denoising on the binarized image.

In some optional embodiments, the analyzing the preprocessed image comprises: analyzing the indentation features on both sides of the security line in the preprocessed image by a gray value projection map, respectively.

In some optional embodiments, the X-axis coordinate of the grayscale projection map is a pixel value of the banknote width; the y-axis coordinate is a grayscale value.

In some optional embodiments, the analyzing by the gray value projection map comprises: calculating an X-axis coordinate difference between the rising edge and the falling edge by detecting a rising edge and a falling edge in the gray value projection map Value, the peak width is obtained;

When the peak width satisfies the set range, it is an indentation feature of the genuine coin.

In some optional embodiments, the peak width is the width of the open line. Another aspect of the present invention provides a banknote authentication device, including:

The light source and the image sensor are respectively disposed on the upper and lower sides of the banknote passage;

The image sensor obtains a transmission image of the area where the indentation feature of the window-opening safety line on the banknote is transmitted by the light beam;

The master control circuit analyzes and identifies the indentation features in the image to determine the authenticity of the banknote.

In some optional embodiments, the light source is an infrared source, an ultraviolet source, or a common source. In some optional embodiments, the image sensor is a contact image sensor CIS. In some optional embodiments, the total control circuit includes: a pre-processing module that preprocesses an image of an area in which the indentation feature is located;

The identification module analyzes the preprocessed image.

In some optional embodiments, the pre-processing module is configured to:

In some optional embodiments, the identification module analyzes the indentation features on both sides of the security line in the preprocessed image by a gray value projection map.

In some optional embodiments, the identification module is configured to:

By detecting the rising edge and the falling edge of the gray value projection map, calculating the X-axis coordinate difference corresponding to the rising edge and the falling edge, and obtaining the peak width;

In some optional embodiments, the peak width is the width of the open line. For the above and related purposes, one or more embodiments include the features that are described in detail below and particularly pointed out in the claims. The following description, as well as the drawings, are in the drawing Equivalent. It belongs to the general security point. The light and dark stripes are changed due to the density of the paper fiber when making the window-opening security thread. This feature has extremely hidden security features. The _ coins that are in circulation are all opened in the security line, and the security line is magnetically imitation on the high simulation currency. This indentation feature cannot be prevented due to the manufacturing process of the window-opening safety thread lacking genuine coins. Since the feature is a light-dark interlace interval under the transmission of the light beam, and the counterfeit currency has no such pattern, the method of authenticity is simple and the stability is high. The invention proposes a method and device for authenticating the indentation feature of a window-opening safety line based on beam transmission by analyzing the principle of the real problem and the starting point of the fraud. Compared with the traditional image recognition based on reflection imaging, the invention has the advantages of being difficult to crack, strong adaptability of currency types, and low hardware cost.

The detection method and device provided by the invention are less affected by the banknotes in the mechanical banknotes, and the effect of obtaining the indentation features can also be ensured. Second, for different currencies, safety line indentation Features Even if the positions of the banknotes are different, the detection of banknotes of different currencies can be completed by a single set of equipment. When a new version of a banknote is issued, the device upgrade can be completed only through a software upgrade. When the mechanical part is designed, the structure can be made more compact and the equipment assembly is more convenient. Effectively save hardware costs. Since the conventional reflective image collection device needs to perform image recognition in the up, down, left, and right directions, at least two sets of collection devices are required to complete all the collection work. The anti-counterfeiting device provided by the invention can solve the problem of different images brought by different positions of the upper and lower sides of the banknote by distinguishing the up-and-down direction by the algorithm. Therefore, only one light source and imaging device is needed to complete the image acquisition process. The detection method and device provided by the invention have high detection rate and stable and reliable performance.

Instruction sheet

1 is a structural diagram of a security device provided by the present invention;

Figure 2 is a real coin image;

Figure 3 is an image of a coin;

Figure 4 is a flow chart of the detection scheme of the present invention;

Figure 5 is an indentation feature image of a genuine coin;

Figure 6 is an indentation feature image of the counterfeit currency;

Figure 7 is a projection of the gray value of the true and counterfeit indentation features. detailed description

The detailed description of the embodiments of the invention are set forth in the description Other embodiments may include structural, logical, electrical, process, and other changes. The examples represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operations can vary. Portions and features of some embodiments may be included or substituted for parts and features of other embodiments. The scope of the embodiments of the invention includes the full scope of the claims, and all equivalents of the claims. These embodiments of the invention may be referred to herein individually or collectively by the term "invention," for convenience only, and if more than one invention is disclosed, it is not intended to automatically limit the application. The scope is any single invention or inventive concept.

In order to achieve the object of the present invention, in one aspect, the present invention provides a method for authenticating a banknote, comprising: Acquiring a transmission image of the area where the indentation feature of the window-opening safety line on the banknote is transmitted by the light beam; analyzing and identifying the indentation feature in the image to determine the authenticity of the banknote.

In some optional embodiments, the light source is an infrared source, an ultraviolet source, or a common source. In some alternative embodiments, the image sensor is a contact image sensor CIS. In some optional embodiments, the total control circuit includes:

a pre-processing module that preprocesses an image of an area in which the indentation feature is located;

The identification module analyzes the preprocessed image.

In some optional embodiments, the pre-processing module is configured to:

Positioning the security line in the image, and binarizing the image of the area where the indentation feature is located; Denoising the image after binarization.

In some optional embodiments, the identification module is configured to:

In some optional embodiments, the peak width is the width of the open line. FIG. 1 is a schematic structural view of a security device according to the present invention. 1 is the image sensor CIS, 2 is the light source, 3 is the banknote channel, 4 is the entrance of the banknote channel, and 5 is the exit of the banknote channel. When the system is started, the banknote passes through the banknote channel entrance 4, passes through the banknote channel 3, and when entering the channel between the image sensor 1 and the light source 2, after the tube is triggered, the image sensor 1 starts to collect images, and the image is collected. When the identification module (not shown) starts to recognize, the banknote is stopped or dispensed according to the recognition result, and the banknote is finally transported out from the banknote exit 5. Good results can be obtained when the light source 2 uses an infrared or ultraviolet light source.

The indentation features of true and counterfeit coins can be clearly seen from Fig. 2 and Fig. 3, and Fig. 2 is an image of the real currency reflected by the image beam, and Fig. 3 is an image of the counterfeit currency. It can be seen that the counterfeit currency has no indentation pattern around the security line. In contrast, the real currency has obvious strip-shaped indentation patterns. Through edge processing, related information extraction, feature analysis, counterfeit currency can be used. Detected.

4 is a flow chart of the technical solution of the present invention. After the image sensor is used to obtain the transmission image of the area where the indentation feature of the window-opening security line on the banknote is transmitted by the light beam, the identification module analyzes the image. First, locate the position of the safety line in the image. Then, in the detection method shown in the figure, after positioning to the position of the safety line, first detect whether there is light and dark stripes in the area near the safety line on the left side. The detection method is image binarization by dynamic multi-threshold, and image extraction is performed. Then, the denoising process is performed by an etching method, and finally the projection is based on the number of peaks to detect the indentation features on both sides of the security line, and if both have the indentation feature, it is judged to be a genuine coin; Judgment is 4 coins, stop or divide the banknotes.

Figures 5 and 6 are images obtained by binarizing and denoising the real and counterfeit images, respectively. According to the solution provided by the present invention, after the binarization and denoising processing of the banknote image collected by the cockroach, the indentation feature on the side of the security line is analyzed by the gradation value projection image, and then the indentation feature on the other side is passed. Gray value projection map analysis; Gray value projection map is shown in Figure 7; the X-axis coordinate of the gray value projection map is the pixel value of the banknote width; the y-axis coordinate is the gray value. The peak width is calculated by detecting the difference between the X-axis coordinates of the corresponding rising edge and the falling edge, and the width corresponds to the width of the open grain. The edge detecting the change of the amplitude can determine whether the start and end of the peak in the projected image exist. , the indentation feature of the real currency exists in both the start and the end and the width satisfies a certain range. In Fig. 7, after the feature image of the real coin is projected in the y-axis direction, a projection map of the indentation feature of the stripe can be obtained, and the real coin has an obvious fluctuation of the peak trough, and the counterfeit currency has no streak, so the projection curve does not have a certain The law. It can be seen from the projection curve that the real currency has obvious peaks and troughs and has a certain width, while the counterfeit currency has no such characteristics, and is mostly a sharp pulse. Therefore, by detecting the edge of a certain amplitude, the existence of the peak can be determined, and the X-axis coordinate difference corresponding to the rising edge and the falling edge is detected, and the peak width is calculated. Those that meet this condition are legal peaks (clear lines in light and dark stripes), so that true and false judgments are made based on the number of peaks. It belongs to the general security point. The light and dark stripes are caused by the change of the paper fiber density when making the window-opening security thread, so that the absorption characteristics of infrared or ultraviolet light during transmission are different, resulting in bright and dark changes of the image. Extremely hidden security features. The circulating counterfeit coins are all opened in the security line to open the window, and the safety line magnetic imitation is high on the simulation coin. The indentation feature cannot be prevented due to the manufacturing process of the window-opening safety thread lacking genuine coins. Since the feature is a light-dark stripe spacing under the transmission of the light beam, and the counterfeit currency has no such pattern, the method of authenticity is simple and the stability is high. The invention proposes an indentation feature judging method and device for a window-opening safety line based on beam transmission by analyzing the principle of the real problem and the starting point of the fraud. Compared with the traditional image recognition based on reflection imaging, the invention has the advantages of being difficult to crack, strong adaptability of currency types, and low hardware cost.

The detection method and device provided by the invention are affected by the banknotes in the mechanical banknote pocket Small, the effect of obtaining indentation features is also guaranteed. Secondly, for different currency types, the security line indentation features can be detected in different currency types even if the positions of the banknotes are different. When a new version of a banknote is issued, the device upgrade can be completed only through a software upgrade. When the mechanical part is designed, the structure can be made more compact and the equipment assembly is more convenient. Effectively save hardware costs. Since the conventional reflective image collection device needs to perform image recognition in the up, down, left, and right directions, at least two sets of collection devices are required to complete all the collection work. The anti-counterfeiting device provided by the invention can solve the problem of different images brought by different positions of the upper and lower sides of the banknote by distinguishing the up-and-down direction by the algorithm. Therefore, only one light source and imaging device is needed to complete the image acquisition process. The detection method and device provided by the invention have high detection rate and stable and reliable performance.

Unless specifically stated otherwise, terms such as processing, computing, computing, determining, displaying, etc. may refer to actions and/or processes of one or more processing or computing systems, or similar devices, which are represented as The physical (e.g., electronic) amount of data manipulation and conversion within the registers or memory of the processing system is similarly represented as memory, registers, or other such information of the processing system to store, transmit, or otherwise display other quantities of data within the device. Information and signals can be represented using any of a variety of different techniques and methods. For example, the data, instructions, commands, information, signals, bits, symbols, and chips referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.

It is understood that the specific order or hierarchy of steps in the process disclosed is an example of an exemplary method. Based on a design preference, it is understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of the disclosure. The appended method claims set forth the elements of the various steps, and are not intended to

In the above Detailed Description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting the intent that the embodiments of the claimed subject matter require more features than those set forth in the claims. Rather, as the following claims reflect, the invention is in a <RTIgt; Therefore, the following claims are hereby expressly incorporated into the claims

Various illustrative logical blocks, modules, circuits, and method steps described in connection with the embodiments herein can be implemented as electronic hardware, computer software, or combinations thereof. To clearly illustrate the interchangeability between hardware and software, various illustrative components, blocks, Modules, circuits, and steps are generally described around their function. Whether such functionality is implemented as hardware or as software depends on the particular application and design constraints imposed on the overall system. Skilled artisans are capable of <Desc/Clms Page number>></RTI><RTIgt;</RTI><RTIgt;</RTI><RTIgt;</RTI><RTIgt;

General purpose processor, digital signal processor (DSP), application specific integrated circuit (ASIC), field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete for performing the functions described herein The various illustrative logical block diagrams, modules, and circuits described in connection with the embodiments herein can be implemented or executed in hardware components or any combination thereof. The general purpose processor may be a microprocessor, or the processor may be any conventional processor, controller, microcontroller or state machine. The processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, a combination of one or more microprocessors and a DSP core, or any other such structure.

The steps of a method or method described in connection with the embodiments herein may be embodied as hardware, a software module executed by a processor, or a combination thereof. The software module can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor to enable the processor to read information from, and write information to, the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and storage media can be located in an ASIC. The ASIC can be located in the user terminal. Of course, the processor and the storage medium can also exist as discrete components in the user terminal.

The disclosed embodiments have been described above in order to enable any person skilled in the art to make or use the invention. The various modifications of the embodiments are obvious to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the spirit and scope of the disclosure. Therefore, the present disclosure is not limited to the embodiments presented herein, but is in accordance with the broadest scope of the principles and novel features disclosed herein.

For software implementations, the techniques described in this application can be implemented with modules (e.g., procedures, functions, etc.) that perform the functions described herein. These software codes can be stored in a memory unit and executed by the processor. The memory unit can be implemented within the processor or external to the processor. In the latter case, it is communicatively coupled to the processor via various means, which are well known in the art.

Moreover, various aspects or features described herein can be used as standard programming and/or Engineering methods, devices or articles are implemented. The term "article of manufacture" as used herein is intended to include a computer program that can be accessed from any computer-readable device, carrier, or media. For example, a computer readable medium can include, but is not limited to, a magnetic storage device (eg, a hard disk, a floppy disk, a magnetic tape, etc.), an optical disk (eg, a compact compact disk (CD), a digital versatile disk (DVD), etc.), a smart card, and flash storage. Equipment (eg EPROM, card, stick, key drive, etc.). Furthermore, various storage media described herein are represented as one or more devices and/or other machine-readable media for storing information. The term "machine-readable medium" includes, but is not limited to, wireless channels and various other mediums capable of storing, containing, and/or carrying instructions and/or data.

The above description includes examples of one or more embodiments. Of course, it is not possible to describe all possible combinations of components or methods for the purpose of describing the above-described embodiments, but one of ordinary skill in the art will recognize that the various embodiments can be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such modifications, modifications and variations as fall within the scope of the appended claims. Furthermore, the term "comprising", as used in the specification or the claims, is intended to be inclusive of the term "comprising" as used in the claims. Moreover, any term "or" used in the specification of the claims is intended to mean "non-exclusive or".

Claims

Rights request

A method for authenticating banknotes, comprising:

Acquiring a transmission image of the area where the indentation feature of the window-opening safety line on the banknote is transmitted by the light beam; analyzing and identifying the indentation feature in the image to determine the authenticity of the banknote.

2. The method according to claim 1, wherein the light beam is infrared light, ultraviolet light or white light.

3. The method according to claim 1, wherein the analyzing the indentation features in the image comprises: preprocessing an image of an area in which the indentation feature is located, and dividing the preprocessed image.

4. The method of claim 3, wherein the pre-processing the image of the region in which the indentation feature is located comprises:

The method according to claim 3, wherein the analyzing the preprocessed image comprises: respectively performing indentation features on both sides of the security line in the preprocessed image by using a gray value projection image analysis.

6. The method according to claim 5, wherein the X-axis coordinate of the gradation value projection map is a pixel value of a banknote width; and the y-axis coordinate is a gradation value.

7. The method according to claim 5, wherein the analyzing by the gray value projection map comprises:

By detecting the rising edge and the falling edge of the gray value projection map, calculating the X-axis coordinate difference between the corresponding rising edge and the falling edge, and obtaining the peak width;

8. The method of claim 7, wherein the peak width is the width of the open line.

A banknote counterfeiting device, comprising:

10. Apparatus according to claim 9, wherein said light source is an infrared source, an ultraviolet source or a common source.

11. Apparatus according to claim 9 wherein said image sensor is a contact image sensor CIS.

12. The device according to claim 9, wherein the total control circuit comprises: a pre-processing module for pre-processing an image of an area where the indentation feature is located;

The identification module analyzes the preprocessed image.

The device according to claim 12, wherein the pre-processing module is configured to: position a security line in the image, perform binarization processing on the image of the region where the indentation feature is located; The subsequent image is denoised.

14. The apparatus according to claim 12, wherein the identification module analyzes the indentation features on both sides of the security line in the preprocessed image by a gray value projection map.

15. The apparatus according to claim 14, wherein the X-axis coordinate of the gradation value projection map is a pixel value of a banknote width; and the y-axis coordinate is a gradation value.

The device according to claim 14, wherein the identification module is configured to: calculate an X axis corresponding to the rising edge and the falling edge by detecting a rising edge and a falling edge in the gray value projection map The coordinate difference, the peak width is obtained;

17. Apparatus according to claim 16 wherein said peak width is the width of the open line.