JP3818988B2 - Image processing apparatus and copy stop method for copy prohibited original - Google Patents

Description

  The present invention relates to an image processing apparatus such as a copying machine having a function of preventing forgery of paper sheets such as banknotes, securities, and various types of cash vouchers.

  Hard copy such as a copying machine, which is one of the image processing apparatuses that have been widely used in the past, has been developed for the purpose of forming a faithful image on an original. Color copiers that can form reproduced images that are indistinguishable from images are also commercially available.

If a reproduced image very close to the original image is obtained, it may be misused for counterfeiting of banknotes and securities. Conventionally, in order to prevent such forgery, it is determined by feature extraction whether the input image signal is an image signal of banknotes or securities prohibited from being copied, and the image signal is prohibited from being copied. If it is judged, the copy is easily recognized as a counterfeit by starting a copy prevention function that stops the output image or performs a conversion process such as reduction processing or mirror image reversal and then reproduces the image. Thus, a method for preventing forgery (see, for example, Patent Document 1) has been taken.
JP-A-1-316683

  However, in the conventional copying machine described as one of the image processing apparatuses as described above, forgery of copy-prohibited manuscripts can be found only after sufficient copies of copy-prohibited manuscripts such as banknotes and securities are in circulation. It cannot be quickly discovered as a counterfeit before it is fully available. In addition, even if a counterfeit copy of a copy-prohibited manuscript is found, there is a problem that it is difficult to reliably obtain the evidence data such as what and how the copy machine has copied. .

  The present invention solves the above-mentioned conventional problems, and can quickly find counterfeit copies of copy-prohibited manuscripts before they are fully available to the public. The present invention provides an image processing apparatus and a method for stopping copying of a copy-prohibited manuscript that can easily and reliably obtain evidence data such as whether the copy has been made.

In order to solve the above problems, an image processing apparatus of the present invention is registered in advance with feature extraction means for extracting a predetermined image pattern or a predetermined color distribution as a feature from an image signal for each original of a plurality of originals . Correlation means for calculating a correlation value for identifying a copy-prohibited original for each original from a predetermined comparative image pattern or predetermined comparative color distribution data and the predetermined image pattern or predetermined color distribution. And a storage means for storing the correlation value for each original; and a cumulative value obtained by accumulating the correlation value stored for each original, and when the cumulative value is a predetermined value or more, a normal duplication function And replication stop means for stopping the system.

As described above, for the copied counterfeit, it is possible to reliably leave evidence data such as what model and what was copied, and the accumulated value of the correlation value calculated with each copy-prohibited document. Therefore, it is possible to quickly find counterfeit copy-prohibited manuscripts before they are fully available.

As described above, according to the present invention, it is possible to easily and surely obtain evidence data such as what and how the model was copied with respect to the copied counterfeit and calculated for each manuscript. Since the fraud is determined based on the cumulative value obtained by accumulating the correlation values with the copy-prohibited manuscripts, it is possible to quickly find counterfeit copies of the copy-prohibited manuscripts before they become fully available. As a result, easy forgery of copy-prohibited manuscripts can be suppressed.

Below, an image processing apparatus and replication method of stopping duplication-inhibited original illustrating one embodiment of the present invention, a copying apparatus as an example will be specifically described with reference to the drawings.

  FIG. 1 is a block diagram showing the configuration of a copying apparatus as an image processing apparatus according to an embodiment of the present invention. In FIG. 1, an image reading unit 1 reads an image of a document and outputs an electrical color image signal p. The image processing unit 2 to which the image reading unit 1 is connected is connected to the image output unit 3, which processes the image signal p from the image reading unit 1 and outputs it as a necessary image forming signal q to the image output unit 3. Then, the image output unit 3 forms a color image on the recording paper.

  The feature extracting unit 4 to which the image reading unit 1 is connected is connected to the history creating unit 5, and the feature extracting unit 4 extracts a specific feature of the image signal p from the image reading unit 1 and sends it to the history creating unit 5. The feature data signal s is output. The history creating means 5 to which the feature extracting means 4, the operation panel 6 and the image reading unit 1 are connected is connected to the storage means 7, and the feature data signal s of the feature correlation value data of the copy original and the ID from the operation panel 6 are connected. A description file t composed of the date and time, the number of copies, and the image data p from the image reading unit 1 is created, and the description file t is stored in the storage means 7 as history information. Note that when the feature data signal s of the feature correlation value data is small, the image data p may be deleted.

  FIG. 2 is a block diagram showing the internal configuration of the feature extraction means 4 in the copying apparatus of FIG. In FIG. 2, a color distribution coefficient generation circuit 8 is connected to an image discrimination circuit 9, and each of the signals R, G, and B shown in FIG. Generate a histogram. From the generated histogram, an approximate expression (Equation 1) of each signal R, G, B is obtained based on the least square method, and the color distribution coefficients a to o are obtained from the approximate expression (Equation 1).

この色分布係数ａ〜ｏは係数信号ｕとして色分布係数発生回路８から画像判別回路９に出力される。また、パターン検出回路１０は画像判別回路９に接続され、入力される画像読取部１からのＲデータ、Ｇデータ、Ｂデータにより、原稿の特徴パターンの検出を行ってパターン信号ｖをパターン検出回路１０から画像判別回路９に出力する。これら色分布係数発生回路８およびパターン検出回路１０が接続される画像判別回路９は画像特徴パターンデータ１１および画像色分布係数データ１２に接続され、パターン信号ｖとパターンデータ信号ｗ、および係数信号ｕと係数データ信号ｘとの相関度合を計算し、その相関値を特徴データ信号ｓとして履歴作成手段５に出力する。

The color distribution coefficients a to o are output from the color distribution coefficient generation circuit 8 to the image discrimination circuit 9 as a coefficient signal u. Further, the pattern detection circuit 10 is connected to the image discrimination circuit 9 and detects the feature pattern of the original document based on the input R data, G data, and B data from the image reading unit 1 and outputs the pattern signal v to the pattern detection circuit. 10 to the image discrimination circuit 9. The image discrimination circuit 9 to which the color distribution coefficient generation circuit 8 and the pattern detection circuit 10 are connected is connected to the image feature pattern data 11 and the image color distribution coefficient data 12, and the pattern signal v, the pattern data signal w, and the coefficient signal u. And the coefficient data signal x are calculated, and the correlation value is output to the history creating means 5 as the feature data signal s.

  This image color distribution coefficient data is constituted by feature coefficients A to O of functions approximated by a quartic equation, and the correlation value here is a value obtained by normalizing the least square sum for each coefficient. These characteristic coefficients A to O correspond to the color distribution coefficients a to o, respectively. For example, the correlation between image patterns is performed by comparing the density distributions of image patterns viewed from a plurality of angles with feature functions in the same manner as the color distribution coefficients, and the correlation value is the minimum square sum for each coefficient. Is a normalized value. The two normalized values are combined by the set mixing ratio and become the final correlation value. The feature extraction of the image pattern may use a template matching method.

  The operation of the above configuration will be described below. First, the image reading unit 1 reads a document to be copied, and outputs R data, G data, and B data to the image processing unit 2 as color image signals p. The image processing unit 2 receives the color image signal p and outputs Y data, M data, C data, and K data to the generated image output unit 3 as an image forming signal q necessary for the image output unit 3. The image output unit 3 forms a color image on the recording paper by the input image forming signal q.

  Further, a specific feature of the document is extracted by the feature extraction unit 4 based on the image pattern of the image signal p from the image reading unit 1, and the feature data signal s is output to the history creation unit 5. Here, the operation of the feature extraction unit 4 will be described. As shown in FIG. 2, the color distribution coefficient generation circuit 8 is supplied with the R data, G data, and B data from the image reading unit 1 as shown in FIG. A histogram of each signal R, G, B shown is generated. From the generated histogram, the approximate expression (Equation 1) of each of the above signals R, G, B is obtained based on the least square method, and the color distribution coefficients a to o are obtained. The color distribution coefficients a to o are output to the image discrimination circuit 9 as a coefficient signal u. Further, the pattern detection circuit 10 detects the feature pattern of the document from the input R data, G data, and B data from the image reading unit 1 and outputs a pattern signal v to the image determination circuit 9. The image discriminating circuit 9 calculates the degree of correlation between the pattern signal v and the pattern data signal w, and the coefficient signal u and the coefficient data signal x, and uses the correlation value as the feature data signal s from the feature extraction means 4 to the history creation means 5. Output to.

  The history creating means 5 is a description file composed of a feature data signal s of feature correlation value data for a copied document, an ID from the operation panel 6, date and time, the number of copies, and image data p from the image reading unit 1. t is created, and the description file t is stored in the storage means 7 as history information as evidence data. Note that the image data p may be deleted when the feature data signal s of the feature correlation value data is small.

  Therefore, a specific feature of the image signal p from the image reading unit 1 is extracted by the feature extraction unit 4, and the history information of the document created by the history creation unit 5 from the output of the feature extraction unit 4 and the output of the image reading unit 1 is obtained. Since it is stored in the storage means 7, if the feature extraction means 4 performs a specific feature extraction such as a manuscript whose copying is prohibited, such as banknotes and securities, a particular manuscript such as a copy-prohibited manuscript is used and who is what. Evidence data such as whether it has been copied to the storage means 7 surely remains in the storage means 7, and if the history information in the storage means 7 is regularly checked during maintenance, etc. Evidence data such as who copied how on the machine is clear. This also prevents easy forgery of copy-prohibited manuscripts.

  FIG. 4 is a block diagram showing a configuration of a copying apparatus as an image processing apparatus according to another embodiment of the present invention. In FIG. 4, an image reading unit 21 reads an image of a document and outputs an electrical color image signal P. The image processing unit 22 to which the image reading unit 21 is connected is connected to the image output unit 23, processes the image signal P from the image reading unit 21, and outputs the processed image forming signal Q to the image output unit 23. Then, the image output unit 23 forms a color image on the recording paper. The image reading unit 21, the image processing unit 22, and the image output unit 23 constitute an image forming unit 24.

  The image processing means 22 is connected to the history creating means 25, and the reduced image signal E is output from the image processing means 22 to the history creating means 25. The feature extraction unit 26 to which the image reading unit 21 is connected is configured in the same manner as the feature extraction unit 4 in FIG. 1, extracts a specific feature of the image signal P from the image reading unit 21, and outputs a feature data signal S. Output to the history creation means 25. The history creation means 25 to which the image processing unit 22 and the feature extraction means 26 are connected is connected to the storage means 27 and also connected to the operation panel 29 via the bus 28, and the reduced image signal E and the feature correlation value data. A description file T is created based on the feature data signal S, the ID from the operation panel 29, the date and time, and the number of copies, and history information as evidence data is stored in the storage means 27.

  Here, FIG. 5 shows a file configuration diagram of an example of the description file T. As shown in FIG. 5, the first block is a header of the description file T, and describes size information of each block used in the description file T, validity / invalidity of the block, and the like. There is no information written in the invalid block, but there is a block size. The second block is the history number, the third block is the ID of the person who used it, the fifth block is the number of copies, and the sixth block is the copy date and time. Enter. Further, a feature data signal S is input to the fourth block with a correlation value between the specific image feature registered in advance and the feature of the copy original, and a copy original from the image processing unit 22 is input to the seventh block. The reduced image signal E is input. If the feature data signal S that is a correlation value signal is small, the reduced image data E of the seventh block may be deleted.

  Further, the copy prevention unit 30 is connected to the storage unit 27 and the control unit 31 via the bus 28, and the control unit 31 is connected to the image forming unit 24 via the bus 28 and stored in the history information stored in the storage unit 27. The cumulative value of the correlation value with the feature of the copy-prohibited document is calculated from the image forming unit 24 via the control unit 31 when the cumulative value is a predetermined value or more or the correlation value is a predetermined value or more. The normal copying function is stopped. Further, this control unit 31 is connected to the communication means 32 and the storage means 27 via the bus 28, and when the copy prevention means 30 is operated, the operation state of the copy prevention function is transmitted to the external line via the communication means 32. At the same time, the history information stored in the storage means 27 is transmitted.

  Further, the release means 33 is connected to the copy prevention means 30 and releases the copy prevention means 30 by a release signal Y from the release means 33. The control unit 31 to which the copy prevention unit 30 is connected is connected to the image forming unit 24 and the storage unit 28. The released copy prevention unit 30 outputs a stop release signal to the control unit 31, and the control unit 31 is the image forming unit. The 24 stop state is canceled and the storage means 27 is initialized. The communication unit 32 is connected to the release unit 33 via the bus 28 and receives an operation signal from an external line to enable or disable the release unit 33. The control unit 31 includes a CPU, a ROM for storing programs, a RAM for work registers, and the like. The control unit 31 is controlled by operations from the operation panel 29, the copy prevention unit 30, the communication unit 32, and the release unit 33. Is a configuration for performing a corresponding control operation.

  Further, the second storage means 34 as an external storage means is constituted by a manufacturer's floppy (registered trademark) or an IC card, and the second storage means 34 is operated by operating the operation panel 29. 27 can be re-saved, and the copy preventing means 30 is released via the releasing means 33 by this re-saving.

  The operation of the above configuration will be described below. First, a document to be copied is read by the image reading unit 21, and R data, G data, and B data are output to the image processing unit 22 as color image signals P. The image processing unit 22 receives the color image signal P, generates Y data, M data, C data, and K data as an image forming signal Q necessary for the image output unit 23. The Y data, M data, The C data and K data are output to the image output unit 23. The image output unit 23 forms a color image on the recording paper using the input image forming signal Q.

  Further, the reduced image signal E is output from the image processing means 22 to the history creating means 25. Here, the reduced image signal E output from the image processing means 22 will be described. In the image processing means 22, a monochrome image Mono is generated from the image signal P, the image is enlarged / reduced, and the image is binarized. This single color image Mono is generated by Mono = (R + 2G + B) / 4, and the generated single color image Mono is binarized with a preset threshold value. For example, the monochromatic signal is 8-bit data from 0 to FF (HEX). If the threshold value is 7F (HEX), the data is “1” if the data is greater than 7F (HEX). If the data is 7F (HEX) or less, it is “0”. As a result, the monochromatic image data Mono is a binary image expressed by data “0” and “1”. The binarized binary image is enlarged or reduced using, for example, an n-division method, a logical sum method, a nearest neighbor method, a projection method, or an inverse distance proportional method. The image signal E reduced by the image processing means 22 is output to the history creating means 25.

  Further, the feature extraction unit 26 extracts a specific feature of the document based on the image pattern of the image signal P from the image reading unit 21 and outputs a feature data signal S to the history creation unit 25. Then, the history creation means 25 includes a feature data signal S of feature correlation value data from the feature extraction means 26 of the copied document, a reduced image signal E from the image processing unit 22, an ID from the operation panel 29, a date and time. A description file T composed of the number of copies is created, and this description file T is stored in the storage means 27 as history information.

  Further, the copy preventing means 30 examines the history of the fourth block indicating the characteristic correlation value with the document whose copying is prohibited from the history information of the plurality of description file data stored in the storage means 28, and stores the history information. Calculate the cumulative correlation value. When the accumulated value is equal to or greater than a predetermined value or the correlation value is greater than or equal to a predetermined value, that is, the accumulated value calculated by the copy preventing means 30 is greater than a preset value, and the credibility of the copy-prohibited document is increased. Or when it is determined that a document that is clearly prohibited has been copied, a copy function stop signal is output to the control unit 31 via the bus 28, and the control unit 31 outputs the image forming unit 24. The normal copying function is stopped.

  As a result, compared to the conventional method of starting the copy prevention function for stopping the output image directly from the feature extraction means 26, the frequency of malfunctions with respect to copy-prohibited originals can be reduced, and determination as to whether or not a copy-prohibited original is made. Thus, it is possible to reliably prevent a large number of copy-prohibited originals from being copied. In this case, the normal copying function is stopped by stopping the operations of the image reading unit 21 and the image output unit 23. However, the image processing unit 22 changes the color or eliminates the color. Alternatively, processing such as enlargement / reduction of an image, such as a copy being found to be counterfeit at first glance, may be performed.

  In addition, the control unit 31 generates an operation signal for notifying the communication unit 32 that the copy preventing unit 30 has been operated, and further reads out the description file data from the storage unit 27 and sends it to the communication unit 32. The communication means 32 transmits this to the manufacturer or the like via the external line. On the other hand, the manufacturer can immediately check the status of the copier, the read manuscript, the copying status, etc. from a remote location by reporting information from the copier, and can quickly detect the circulation of counterfeit bills. Model identification can be performed quickly. Therefore, history information can be easily and quickly managed on the manufacturer side.

  Further, the copy prevention operation of the copy prevention means 30 can be canceled by the release signal Y output from the release means 33 to the copy prevention means 30, and the released copy prevention means 30 releases the stop state of the copy function to the control unit 31. Generate a stop release signal. In response to the stop cancellation signal, the control unit 31 cancels the stopped state of the image forming unit 24 and initializes the description file T stored in the storage unit 27 via the bus 28. As a result, the copying apparatus can perform the copying operation again, and the required storage capacity of the storage means 27 can be set smaller. Further, the communication means 32 receives an operation signal transmitted from a manufacturer or the like through an external line, and sends a release control signal for enabling or disabling the release function to the release means 33. If the manufacturer determines from the reduced image data of the description file T that a document that is clearly prohibited has been copied, the release means 33 is disabled and the copy prevention means 30 cannot be released. If the document is not prohibited, it is validated and the copy preventing means 30 can be canceled by an operation signal from the manufacturer. As a result, it is possible to immediately cope with the copying machine from a remote place.

  Further, the control unit 31 identifies, for example, a floppy (registered trademark) having a specific encryption key, an IC card having a specific encryption key, or the like on the manufacturer side by an operation from the operation panel 29, and these specific floppy (registered trademark) or The release means 33 can also be made effective by re-saving the description file T of the storage means 27 in the second storage means 34 such as a specific IC card or a medium capable of storing information. As described above, the copy prevention means 30 transmits the description file T stored in the storage means 27 to the manufacturer side, or the second storage means such as a specific floppy (registered trademark) or a specific IC card on the manufacturer side. It cannot be canceled unless it is saved again in 34.

  The image processing apparatus of the present invention has a forgery prevention function, and can be applied to a copying machine having a forgery prevention function for paper sheets that are prohibited from being copied, such as banknotes, securities, or various types of cash vouchers.

1 is a block diagram showing a configuration of a copying apparatus as an image processing apparatus according to an embodiment of the present invention. 1 is a block diagram showing the internal configuration of feature extraction means 4 in the copying apparatus of FIG. The histogram of each signal R, G, B from the image reading unit 1 in the copying apparatus of FIG. FIG. 3 is a block diagram showing the configuration of a copying apparatus as an image processing apparatus according to another embodiment of the present invention. 4 is a file configuration diagram showing an example of a description file T stored in the storage means 27 in the copying apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 21 Image reading part 2, 22 Image processing part 4, 26 Feature extraction means 5, 25 History creation means 7, 27 Storage means 8 Color distribution coefficient generation circuit 9 Image discrimination circuit 10 Pattern detection circuit 11 Image feature pattern data 12 Image Color distribution coefficient data 24 Image forming means 30 Copying prevention means 31 Control unit 32 Communication means 33 Release means 34 Second storage means

Claims (5)

Feature extraction means for extracting a predetermined image pattern or a predetermined color distribution as a feature from an image signal for each of a plurality of originals ;
A correlation value for determining the degree of coincidence between a predetermined comparison image pattern or predetermined comparison color distribution data registered in advance and the predetermined image pattern or predetermined color distribution and specifying a copy-prohibited original for each original. Correlation means to calculate
Storage means for storing the correlation value for each original ;
A copy stop unit that calculates a cumulative value obtained by accumulating the correlation values stored for each document and stops a normal copy function when the cumulative value is equal to or greater than a predetermined value; Processing equipment. The image processing apparatus according to claim 1 , wherein the correlation value for each document stored in the storage unit is initialized after the stop of the copy stopping unit is released. Feature extraction means for extracting a predetermined image pattern or a predetermined color distribution as a feature from an image signal for each original of a plurality of originals, a predetermined comparison image pattern or predetermined comparison color distribution data registered in advance, and the predetermined Correlation means for calculating a correlation value for determining a copy-prohibited document from each image document or a predetermined color distribution for each document ,
Storage means for storing at least comprises a history information and said correlation value for each storage image data and the document for each of the document generated from the image signal for each of the document,
A copy stop unit that calculates a cumulative value obtained by accumulating the correlation values of the history information stored for each document and stops a normal copy function when the cumulative value is equal to or greater than a predetermined value. A featured image processing apparatus. 4. The image processing apparatus according to claim 3 , wherein a correlation value of the history information for each document stored in the storage unit is initialized after the stop of the copy stopping unit is released. A feature extracting step of extracting a predetermined image pattern or a predetermined color distribution as a feature from an image signal for each original of a plurality of originals ;
A correlation value for determining the degree of coincidence between a predetermined comparison image pattern or predetermined comparison color distribution data registered in advance and the predetermined image pattern or predetermined color distribution and specifying a copy-prohibited original for each original. A correlation step to calculate
A storage step of storing the correlation value for each original ;
A duplication stop step of calculating a cumulative value obtained by accumulating the correlation values stored for each original, and stopping a normal duplication function when the cumulative value is equal to or greater than a predetermined value. How to stop copying prohibited manuscripts.

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