JP2006340215A - Apparatus, method, and program for guaranteeing print information and print information verifying apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable to properly guarantee and verify printed contents printed on a sheet of paper. <P>SOLUTION: Print image authenticating information for guaranteeing the printed contents PR is generated from a printed image PR printed on a sheet of paper OP, and a print image authenticating code BC1 obtained two-dimensionally coding the print image authenticating information is printed on the paper OP and stored. Then, when the print contents are verified, the print image authenticating information is generated from the print image PR printed on a sheet of paper XP with a code, the print image authenticating information is restored from the print image authenticating code BC1 printed on the pater XP, and these two pieces of print image authentication information are collated with each other. Thus, the true or false of the print contents of the paper XP can be verified. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a print information guarantee apparatus, a print information guarantee method, a print information guarantee program, and a print information verification apparatus, and is particularly suitable for application to guarantee print contents written on paper.

  Conventionally, paper has been used as an object to be printed with various contents, and the paper on which the printed contents have been printed is, for example, various exchange media such as commodity exchange media such as money, content certification media such as certificates, or information storage media such as personal works. It often has high value because it functions as a medium.

For this reason, various countermeasures for preventing unauthorized duplication of the print contents of paper have been considered. As the countermeasures, for example, pattern information based on patterns of commonly used paper (hereinafter referred to as plain paper). A method for verifying the validity by verifying the print information obtained from the paper and the printed pattern information is verified by the applicant of the present patent application. It has been proposed (see, for example, Patent Document 1).
PCT / JP2005 / 001176

  In recent years, in addition to preventing unauthorized copying of print contents, it has been demanded to prevent unauthorized alteration of print contents such as rewriting the amount of a bill or the name of a certificate.

  However, although the above-described verification method of validity can prevent unauthorized copying of print contents, there is a problem that tampering of print contents cannot be prevented.

  The present invention has been made in consideration of the above points, and is a print information guarantee device, a print information guarantee method, a print information guarantee program, and a print printed on paper, which can appropriately guarantee the print contents printed on paper. An object of the present invention is to propose a printing information verification apparatus capable of appropriately verifying the contents.

  In order to solve such a problem, in the present invention, a print image is obtained from print contents printed on paper, print authentication information is generated from the print image to guarantee the print contents, and the print authentication information is printed on paper. By printing and storing, the print content can be guaranteed by the printed print authentication information.

  In the present invention, a print image is acquired from the print content printed on the paper, print authentication information is generated from the acquired print image to verify the authenticity of the print content, and the print image is printed on the paper. Print contents printed on the paper by acquiring the print authentication information from the paper and verifying the authenticity of the print contents by comparing the authentication information generated from the print contents with the authentication information obtained from the paper Can be verified appropriately.

  According to the present invention, the print authentication information generated from the print content printed on the paper and the print authentication information generated from the print content by printing the print authentication information generated from the print content written on the paper on the paper. The print information assurance device, the print information guarantee method, the print information guarantee program, and the paper, which can verify the authenticity of the print contents by comparing with the information, and can appropriately guarantee the print contents written on the paper. It is possible to realize a print information verification apparatus capable of appropriately verifying the print content described in (1).

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

(1) Print Information Protection Method First, the print content protection method according to this embodiment will be described. In this print content protection method, print authentication information is generated from the print content itself to be protected printed on the photographic paper, and the validity of the print content is verified using the print authentication information.

  That is, as shown in FIG. 1A, the print information protection device acquires the print contents printed on the original print paper OP as the print image PR, and generates print authentication information from the print image PR. Further, the print information protection device generates a print authentication code BC1 by converting the print authentication information into a two-dimensional barcode, and prints it on a predetermined area on the original photographic paper OP.

  When the print information protection apparatus verifies the validity of the print contents of the print paper (hereinafter referred to as code-added print paper) XP on which the print authentication code BC1 is printed, as shown in FIG. In addition, the print image PR is acquired from the code-added photographic paper XP to generate print authentication information, and the print authentication information is also generated from the print authentication code BC1 of the code-added photographic paper XP, and both are collated. Then, the print information protection device determines that the print content is valid if they match, and determines that the print content is not valid if they do not match.

  That is, in this print content protection method, when the print content of the code-added print paper XP with the print authentication code BC1 is tampered with, for example, added or rewritten, the print content is generated from the tampered print content. Since the print authentication code BC1 does not match the print authentication code BC1 attached to the code-added photographic paper XP, it is possible to detect falsification of the print content.

  In this printing information protection method, the printing paper itself is identified based on the pattern (pattern) of the fibers constituting the paper.

  As shown in FIG. 1 (A), the print information protection apparatus uses a print pattern from a print pattern in a previously designated area (hereinafter referred to as a pattern acquisition area) AR of the print image on the original print paper OP. Paper authentication information for identifying the paper OP is generated. Further, the print information protection device generates a paper authentication code BC2 by converting the paper authentication information into a two-dimensional bar code, and prints it on a predetermined area of the original photographic paper OP.

  As shown in FIG. 1B, the printing information protection preventing apparatus verifies the authenticity of the code-added photographic paper XP itself from the pattern pattern in the pattern acquisition area AR on the code-added photographic paper XP. In addition to generating information, paper authentication information is also generated from the paper authentication code BC2 of the code-added photographic paper XP, and the two are collated. The print information protection apparatus determines that the code-added photographic paper XP is valid when the two match, and determines that it is an illegal copy when the two do not match.

  That is, in this print content protection method, when the print content of the code-added photographic paper XP is copied to another paper, the paper authentication code BC2 generated from the copied code-added photographic paper (hereinafter referred to as XPc), Since the paper authentication code BC2 attached to the code-added photographic paper XPc does not match, it is possible to detect an illegal copy of the print content.

  As described above, in this print content protection method, the print content is printed on the original print paper OP by preventing the copy of the print content by identifying the print paper based on the paper authentication information and preventing the falsification of the print content based on the print authentication information. The print contents are surely protected.

(2) Configuration of Print Information Protection Device According to the Present Embodiment In FIG. 2, reference numeral 1 denotes the overall configuration of the print information protection device according to the present embodiment. For the control unit 2 that controls the entire information protection device 1 The scanner unit 4 and the printer unit 5 are connected via the bus 3.

  The control unit 2 includes a central processing unit, a work memory, and an information storage memory. In the information storage memory, the position information of the print designation area of the print contents and the pattern acquisition area AR for each standard size of paper (these are stored). Various information such as character string information for two-dimensional barcode (referred to as code character string information) and various programs are stored. And the control part 2 is made to perform various processes using the various information memorize | stored in the information storage memory suitably according to the program loaded to the work memory.

  Actually, the control unit 2 sends an image reading command to the scanner unit 4 when a predetermined command for printing the print authentication code BC1 is given from the operation unit (not shown).

  Then, as a response result of this command, the control unit 2 is supplied with data of the print image PR (hereinafter referred to as original print image data D1) on the original print paper OP (FIG. 1A) from the scanner unit 4. If the print authentication code is detected, the print authentication code generation mode is entered.

  In this case, the control unit 2 generates print authentication information from the print image given by the original print image data D1 in accordance with print authentication code generation processing to be described later, and the character string data (hereinafter referred to as print authentication code data D2). To the printer unit 5. The print authentication code data D2 is printed on the printing paper OP as the print authentication code BC1 (FIG. 1A) by the printer unit 5.

  Further, when a predetermined print verification command is given from the operation unit, the control unit 2 sends a print content read command and a print authentication code read command to the scanner unit 4.

  Then, as a response result of these commands, the control unit 2 prints the data of the print image PR read from the code-added printing paper XP (FIG. 1B) (referred to as read print image data D3) and the print authentication code BC1. When data (referred to as read print authentication code data D4) is given from the scanner unit 4, the print authentication mode is entered.

  In this print authentication mode, the control unit 2 generates print authentication information from the print image given by the read print image data D3 and also generates print authentication information from the read print authentication code data D4 in accordance with print authentication processing described later. , Match these. The control unit 2 determines that the print content is valid only when a match rate higher than a predetermined match rate is obtained.

  The control unit 2 sends a pattern reading command to the scanner unit 4 when a predetermined command for printing the paper authentication code BC2 is given from the operation unit.

  When the control unit 2 receives the pattern image data in the pattern acquisition area AR on the photographic paper OP from the scanner unit 4 as a response result of this command (hereinafter referred to as original pattern image data D11), the control unit 2 Transition to authentication code generation mode.

  In this case, the control unit 2 generates paper authentication information from the pattern image given by the original pattern image data D11 in accordance with a paper authentication code generation process to be described later, and the character string data (hereinafter referred to as paper authentication code data D12). ) To the printer unit 5. The paper authentication code data D12 is printed on the photographic paper OP by the printer unit 5 as the paper authentication code BC2 (FIG. 1A).

  Further, when a predetermined paper verification command is given from the operation unit, the control unit 2 sends a pattern reading command and a paper authentication code reading command to the scanner unit 4.

  Then, as a response result of these commands, the control unit 2 prints pattern image data in the pattern acquisition area AR read from the code-added photographic paper XP (hereinafter referred to as read pattern image data D13) and data of the paper authentication code BC2. When this is given from the scanner unit 4 (referred to as reading paper authentication code data D14), the paper authentication mode is entered.

  In this paper authentication mode, the control unit 2 generates paper authentication information from the pattern image given by the read pattern image data D13, and also generates paper authentication information from the read paper authentication code data D14, and collates them. The control unit 2 determines that the code-added photographic paper XP is valid only when a match rate equal to or higher than a predetermined reference match rate is obtained.

On the other hand, the scanner unit 4 has a transmissive mode, a reflective mode, and a code reading mode. When a pattern image reading command is given from the control unit 2, the transmissive mode, and when the image reading command is given, the reflective mode is used. When the print authentication code reading command and the paper authentication code reading command are given, the code reading mode is executed.

  In practice, in the transmission mode, the scanner unit 4 is obtained by irradiating light to the original photographic paper OP or code-added photographic paper XP placed on the document table and transmitting the photographic paper OP or XP. The pattern projection light is imaged on a solid-state image sensor via an optical system. Then, the scanner unit 4 performs A / D (Analog / Digital) conversion processing or the like on the pattern image signal obtained from the solid-state image sensor, and obtains the original pattern image data D11 or the read pattern image data D13 obtained as a result. It is sent to the control unit 2.

  In the reflection mode, the scanner unit 4 serving as an image acquisition unit irradiates light to the original photographic paper OP or the code-added photographic paper XP placed on the document table and reflects the photographic paper OP. The printed content reflected light is imaged on a solid-state image sensor via an optical system. Then, the scanner unit 4 performs A / D conversion processing or the like on the print content image signal obtained from the solid-state image sensor, and sends the original print image data D1 or the read print image data D3 obtained as a result to the control unit 2. Send it out.

  Further, in the code reading mode, the scanner unit 4 as the authentication information acquisition unit activates the two-dimensional code reader 4a connected to the scanner unit 4 and supplies the read print supplied by being read by the two-dimensional code reader 4a. The authentication code data D4 and the paper print authentication code data D14 are sent to the control unit 2.

  In this manner, the scanner unit 4 can read the print content, the pattern image, and the authentication code by executing the mode according to the various commands given from the control unit 2.

  On the other hand, the printer unit 5 includes font information for two-dimensional codes (hereinafter referred to as code font information), and positional information (hereinafter referred to as print authentication codes BC1 and BC2 for various standard sizes of paper). (Referred to as code position information) is stored in the internal memory, and the printing process is executed using these information as appropriate.

  In this case, when the print authentication code data D2 and the paper authentication code data D12 are given from the control unit 2, the printer unit 5 performs a pulse width modulation process or the like on the code data, and outputs the print data obtained as a result. Send to print head. As a result, the print authentication code BC1 and the paper authentication code BC2 are printed at predetermined positions on the photographic paper OP set on the photographic paper base by driving the print head unit based on the print data, code font information, and code position information. It becomes.

(3) Processing of Control Unit Here, when the processing contents of the control unit 2 are functionally classified, as shown in FIG. 3, the print authentication information PRID is generated from the print contents and based on the print authentication information PRID. Print authentication unit 10 that performs print authentication, paper authentication unit 20 that generates paper authentication information PPID from a paper pattern and performs paper authentication based on the paper authentication information PPID, and print authentication information PRID and paper authentication information PPID 2 It can be broadly divided into a two-dimensional code conversion unit 30 that performs conversion into code data of a three-dimensional bar code and vice versa.

  Hereinafter, the print authentication code generation process and the print authentication process performed by the print authentication unit 10, and the paper authentication code generation process and the paper authentication process performed by the paper authentication unit 20 will be described in detail.

(3-1) Print Authentication Code Generation Processing First, print authentication code generation processing by the print authentication unit 10 will be described. In the print authentication code generation mode, the original print image data D1 obtained from the print paper OP is input from the scanner unit 4 to the area dividing unit 11 of the print authentication unit 10 as the authentication information generation unit.

  The area dividing unit 11 serving as a dividing unit divides the print image given by the print image data D1 into n divided images Gd (Gd1 to Gdn) as shown in FIG. 4, and performs a subsequent FFT (Fast Fourier transform). To the unit 12. In this example, the print image is divided into 4 vertical x 4 horizontal n = 16. However, the number of divisions is not limited to this, and each divided image Gd is in close contact with the surrounding divided image Gd. (There is no gap between the divided images Gd). However, a gap may be provided between the divided images Gd or the divided images Gd may be overlapped.

  The FFT unit 12 serving as a spectrum generation unit performs a fast Fourier transform process on each of the plurality of segmented images Gd to generate a power spectrum (FIG. 5) of each image, and supplies this to the subsequent component ratio calculation unit 13. To do.

  The component ratio calculation unit 13 serving as a ratio calculation unit firstly sets the power spectrum of each segmented image Gd to a power spectrum that is equal to or higher than a predetermined reference frequency (referred to as a power spectrum in a high frequency range) and a power that is less than the reference frequency. Divide into spectrum (this is called the power spectrum in the low frequency range). 6 and 7 show examples of the power spectrum in the high frequency region and the power spectrum in the low frequency region, respectively.

  Subsequently, for each of the segmented images Gd, the component ratio calculation unit 13 sets the power of the entire power spectrum in the high frequency range (referred to as high frequency range power PwHn) and the power of the entire power spectrum in the low frequency range (referred to as “low”). A ratio of frequency band power PwLn (referred to as a divided frequency component ratio Rf (Rf1 to Rfn)) is calculated and supplied to the print authentication information calculation unit 14 at the subsequent stage. This divided frequency component ratio Rf is given by Rf = PwH / PwL.

  Since the divided frequency component ratios Rf1 to Rfn vary depending on the print contents (pictures) of the respective divided images Gd1 to Gdn, this can be used as a feature amount of the divided image Gd for image identification.

  For example, 16 divided images Gd1 to Gd16 are generated for each of the nine types of images # 1 to # 9 shown in FIG. 8A, and the divided frequency component ratios Rf1 to Rf16 of the divided images Gd1 to Gdn are listed. The result is shown in FIG. Note that image # 1 is a random pattern, images # 2 to # 6 and # 8 are various live-action images, # 7 is a text document, and # 9 is a real image of # 8 subjected to image processing.

  FIG. 9 shows the correlation between the divided frequency component ratios Rf for the same region of nine types of images # 1 to # 9 (in this case, the divided image Gd1). FIG. 9 shows the correlation coefficient between the segment frequency component ratio Rf of the image # 8 and the segment frequency component ratio Rf of another image as a reference.

  The correlation coefficients of the images # 1 to # 7 unrelated to the image # 8 are all low values of 0.4 or less, whereas the correlation coefficient of the image # 9 obtained by processing the image # 8 is 0. .9, which is a high value, and it can be understood that image identification using the divided frequency component ratio Rf is possible.

  The print authentication information calculation unit 14 as the authentication information calculation unit supplies each value of the divided frequency component ratios Rf1 to Rfn to the two-dimensional code conversion unit 30 as the print authentication information PRID. The two-dimensional code conversion unit 30 performs two-dimensional bar code conversion processing based on the code character string information with respect to the print authentication information PRID to generate print authentication code data D2, and sends this to the printer unit 5.

  As a result, the print authentication code data D2 is printed on the printing paper OP by the printer unit 5 as the print authentication code BC1 (FIG. 1A).

(3-2) Print Authentication Processing Next, print authentication processing by the print authentication unit 10 will be described. In the print authentication mode, the scanned image data D3 obtained from the code-added photographic paper XP is input from the scanner unit 4 to the area dividing unit 11 of the print authentication unit 10.

  In this case, the print authentication unit 10 generates the segment image Gd by the region division unit 11 and the power spectrum of each segment image Gd by the FFT unit 12 for the read print image data D3, as in the print authentication code generation process described above. Generation, calculation of the divided frequency component ratio Rf by the component ratio calculation unit 13, and calculation of the print authentication information PRID by the print authentication information calculation unit 14 are sequentially performed, and the print authentication information PRID is supplied to the verification unit 15.

  In addition, in the print authentication mode, the scanner unit 4 gives the read print authentication code data D4 obtained by reading the print authentication code BC1 to the two-dimensional code conversion unit 30. The two-dimensional code conversion unit 30 converts the read print authentication code data D4 into print authentication information PRID based on the code character string information, and supplies this to the verification unit 15 of the print authentication unit 10.

  Then, the collation unit 15 as a verification unit collates the print authentication information PRID obtained from the print image of the code-added photographic paper XP with the print authentication information PRID obtained from the print authentication code BC1, and based on the correlation. It is determined whether the print contents are valid.

  Specifically, for the divided frequency component ratios Rf1 to Rfn given by the two print authentication information PRID, a correlation coefficient is calculated between the corresponding ones, and the average value of the calculated correlation coefficients is a predetermined threshold value ( For example, when the value is 0.5) or more, it is determined that the print content is legitimate without tampering, and when the average value of each correlation coefficient is less than the threshold, the print content is falsified. It is determined that it is an unfair thing that may have been applied.

(3-3) Paper Authentication Code Generation Processing Next, paper authentication code generation processing by the paper authentication unit 20 will be described. In the paper authentication code generation mode, the original pattern image data D11 obtained from the pattern image IM1 (FIG. 10A) of the photographic paper OP is input from the scanner unit 4 to the low frequency component extraction unit 21 of the paper authentication unit 20. Is done.

  The low frequency component extraction unit 21 extracts the low frequency component pattern image IM2 (FIG. 10B) from the original pattern image data D11.

  Specifically, the low frequency component extraction unit 21 acquires data of the pattern image IM1 from the original pattern image data D11 provided from the scanner unit 4 based on the region position information stored in the internal memory, and the acquired pattern. Frequency component data is generated by performing Fourier transform processing on the data of the image IM1.

  Then, the low-frequency component extraction unit 21 sets the data value of the high-frequency component equal to or higher than a predetermined threshold to “0” for the frequency component data, and then performs an inverse Fourier transform process on the low-frequency component pattern image IM2. Data (hereinafter referred to as low-band pattern image data) is generated and sent to the image separation unit 22.

  In this way, the low frequency component extraction unit 21 extracts various noise components generally included in the high frequency components of the image, such as noise of the solid-state imaging device in the scanner unit 4 by extracting the low frequency component pattern image IM2. It is possible to eliminate the deterioration of the pattern pattern (feature amount) extraction accuracy in the paper authentication information generation unit 24 and to improve the reliability of the collation result of the collation processing in the collation unit 25.

  The image separation unit 22 sequentially detects the luminance value of the low frequency component pattern image IM2 of the low frequency pattern image data supplied from the low frequency component extraction unit 21 for each pixel, and the detection result is a predetermined low luminance threshold value ( Hereinafter, the white component pattern image WIM (FIG. 7B) is configured such that pixels other than pixels having a luminance value equal to or lower than that (hereinafter referred to as white threshold) (hereinafter referred to as white pixels) are converted to the highest luminance level. )) Is extracted, the data of the white component pattern image WIM is sent to the area dividing unit 23 as white component pattern image data.

  The image separation unit 22 also detects pixels (hereinafter referred to as “pixels”) having luminance values that are equal to or higher than a predetermined high luminance threshold (hereinafter referred to as “black threshold”). The black component pattern image BIM (FIG. 11C) is extracted so that the pixels other than the black pixel are converted to the lowest luminance level, and the data of the black component pattern image BIM is converted into the black component pattern image data. To the area division unit 23.

  In this way, the image separation unit 22 separates the white component pattern image WIM (FIG. 11B) from the black component pattern image BIM (FIG. 11C), thereby reducing the degree of complexity of the pattern. Can be reduced.

  As shown in FIG. 11, the area dividing unit 23 has an area (hereinafter referred to as white damascene) in which the pattern included in the white component pattern image WIM (FIG. 11B) is a unit of a set of adjacent white pixels. The black component pattern image BIM (FIG. 11C) is divided into areas (hereinafter referred to as black damashes) each having a set of adjacent black pixels as a unit.

  Specifically, the area dividing unit 23 detects all white pixels from the white component pattern image WIM of the white component pattern image data supplied from the image separation unit 22, and then arbitrarily selects as shown in FIG. A total of 8 pixels (hereinafter referred to as 8 neighboring pixels) of 4 pixels in the vertical and horizontal directions and 4 pixels in the oblique direction adjacent to the target pixel AP are sequentially connected. Then, for example, as shown in FIG. 12B, the area dividing unit 23 associates the identification information with the group of white pixels that have been connected so far when the white pixel is no longer detected in the eight neighboring pixels, and the white dama WD1. , WD2... And WDn. The area dividing unit 23 also applies a plurality of black dama BDs to the black component pattern image BIM (FIG. 11C) of the black component pattern image data supplied from the image separation unit 22 in the same manner as the white component pattern image WIM. (BD1 to BDn) are formed.

  In this way, the area dividing unit 23 divides the pattern included in the white component pattern image WIM into a plurality of white damascene WDs (WD1 to WDn), and the pattern included in the black component pattern image BIM includes a plurality of black damascene BD ( By dividing the pattern into BD1 to BDn), it becomes possible to analyze the pattern in detail, thereby improving the pattern pattern (feature amount) extraction accuracy in the subsequent paper authentication information calculation unit 24, and consequently the matching unit Thus, the reliability of the collation result of the collation process at 25 can be improved.

  The paper authentication information calculation unit 24 extracts the pattern pattern so as to calculate the feature amount of the shape in each white dama WD (WD1 to WDn) and each black dama BD (BD1 to BDn). In this case, it is difficult for the paper authentication information calculation unit 24 to calculate the feature amounts of the white dama WD and the black dama BD as they are because the shapes thereof are complicated. Therefore, the white dama WD and the black dama BD are each determined. Approximate a rectangle. That is, the paper authentication information calculation unit 24, as shown in FIG. 13, the center coordinates (xc, yc), the long side l, the short side w, and the long side l for each dama (white dama WD or black dama BD). And the horizontal axis is calculated as a feature amount (hereinafter referred to as a rectangular information value).

  Specifically, the paper authentication information calculation unit 24 calculates individual feature amounts for each white dama WD (WD1 to WDn) of white dama data supplied from the area division unit 23, and the white dama WD. If the luminance value of the pixels that constitutes I is I (x, y),

The primary image moment M00, the secondary image moments M10 and M01, and the tertiary image moments M20, M02, and M11 are calculated according to the image moment Mpq defined by

  Then, the pattern pattern extraction unit 14 uses these primary, secondary, and tertiary image moments M00, M10, M01, M20, M02, and M11 to calculate the center coordinates (xc, yc) as follows:

And the long side l and the short side w

And calculate the angle θ

Calculate according to

  In this way, the paper authentication information calculation unit 24 calculates the feature amount (rectangular information value) for each white dama WD (WD1 to WDn).

  Further, the paper authentication information calculation unit 24 also applies the black dama data BD (BD1 to BDn) of the black dama data supplied from the area dividing unit 23 to the above-described formula (1), similarly to the white dama WD (WD1 to WDn). The feature amount (rectangular information value) for each black dama BD is calculated using equation (4).

  The feature amounts of the white dama WD (WD1 to WDn) and the black dama BD (BD1 to BDn) thus calculated (hereinafter referred to as pattern feature amounts) are stored in the area pattern image IM1 (FIG. 6A). Since it is a value representing the characteristic shape of the pattern that it has, it means the extraction result itself of the pattern pattern included in the area pattern image IM1.

  Then, the paper authentication information calculation unit 24 supplies the pattern feature amount to the two-dimensional code conversion unit 30 as the paper authentication information PPID. The two-dimensional code conversion unit 30 performs two-dimensional bar code conversion processing based on the code character string information on the paper authentication information PPID to generate paper authentication code data D12 and sends it to the printer unit 5.

  As a result, the paper print authentication code data D2 is printed on the printing paper OP as the paper authentication code BC2 (FIG. 1A) by the printer unit 5.

(3-4) Paper Authentication Processing Next, paper authentication processing by the paper authentication unit 20 will be described. In the paper authentication mode, the read pattern image data D13 obtained from the code-added photographic paper XP is input from the scanner unit 4 to the low frequency component extraction unit 21 of the paper authentication unit 10.

  In this case, the paper authentication unit 20 generates the low-frequency pattern image data by the low-frequency component extraction unit 21 and the white component pattern by the image separation unit 22 for the read pattern image data D13, as in the paper authentication code generation process described above. Generation of image data and black component pattern image data, division of white dama WD and black dama by area division unit 23, calculation of paper authentication information PPID by paper authentication information calculation unit 24, and collation of the paper authentication information PPID To the unit 25.

  In addition, in the paper authentication mode, the reading unit authentication code data D14 obtained by reading the paper authentication code BC2 is supplied from the scanner unit 4 to the two-dimensional code conversion unit 30. The two-dimensional code conversion unit 30 converts the reading paper authentication code data D14 into the paper authentication information PPID based on the code character string information, and supplies this to the verification unit 25 of the paper authentication unit 20.

  The collation unit 25 collates the pattern pattern indicated by the paper authentication information PPID obtained from the pattern image of the code-added photographic paper XP with the pattern pattern indicated by the paper authentication information PPID obtained from the paper authentication code BC2. When a matching rate equal to or higher than a predetermined reference matching rate is obtained as a result of this collation, it is determined that the code-added photographic paper XP is valid.

(4) Operation and Effect In the above configuration, the print information protection apparatus 1 prints print authentication information based on the feature amount from the print image PR to be protected printed on the original print paper OP (FIG. 2A). A print authentication code BC1 generated by generating a PRID and converting it into a two-dimensional bar code is stored in the print paper OP.

  The print information protection device 1 generates print authentication information PRID from the print image PR and verifies print authentication when verifying the validity of the print contents of the code-added print paper XP to which the print authentication code BC1 is attached. The print authentication information PRID is also restored from the code BC1, and the validity of the print contents is verified by comparing these two print authentication information PRID.

  Therefore, the print information protection apparatus 1 can determine the validity of the print image PR itself based on the print image PR to be protected and the print authentication code BC1.

  According to the above configuration, the print authentication information PRID generated from the protected print image PR printed on the original print paper is stored in the original print paper as the print authentication code BC1, and when the validity of the print contents is verified. Since the validity of the print image PR is determined based on the print authentication information PRID generated from the print image PR of the code-attached photographic paper and the print authentication information PRID restored from the print authentication code BC1, With this configuration, it is possible to verify the print information by detecting falsification of the print content.

(5) Other Embodiments In the above-described embodiment, the divided frequency component ratios Rf1 to Rfn for each of the divided images Gd1 to Gdn are calculated, and these values are directly used as the print authentication information PRID. The present invention is not limited to this, and the print authentication information PRID may be generated by processing the divided frequency component ratios Rf1 to Rfn.

  For example, the calculated divided frequency component ratios Rf1 to Rfn are ranked based on the magnitudes of the values, and the print authentication information PRID is generated based on this rank.

  As an example in this case, the number of sections of the section image is n = 9, and the values of each section frequency component ratio Rf are Rf1 = 11, Rf2 = 10, Rf3 = 13, Rf4 = 9, Rf5 = 14, Rf6 = 8, Assuming that Rf7 = 17, Rf8 = 4, and Rf9 = 5, the order is Rf7, Rf5, Rf3, Rf1, Rf2, Rf4, Rf6, Rf9, and Rf8 in descending order.

  When the print authentication unit 10 generates the print authentication code, each of the area numbers (in this case, 7, 5, 3, 1, 2, 4, 6, 9, 8) of the divided frequency component ratios Rf ranked in this way is displayed. An n-digit numerical value (75312698 in this case) is generated by sequentially assigning to the digit, and this numerical value is set as the print authentication information PRID, converted into the print authentication code BC1, and stored on the original photographic paper.

  At the time of print authentication, the print authentication unit 10 directly collates the print authentication information PRID composed of an n-digit value generated from the print image PR with the print authentication information PRID composed of an n-digit value restored from the print authentication code BC1. The correlation coefficient is calculated, and when the correlation coefficient is equal to or greater than a predetermined threshold (for example, 0.5), it is determined that the contents of the print are legitimate ones that have not been tampered with. When the number is less than the threshold value, it is determined that this print content is unfair that may have been tampered with. This method has an advantage that the correlation coefficient calculation process at the time of print authentication becomes light.

  Further, in the above-described embodiment, the print authentication information PRID is generated based on the divided frequency component ratios Rf1 to Rfn for the divided images Gd1 to Gdn obtained by dividing the print image PR. Not limited to this, the print authentication information PRID may be generated from the whole without dividing the print image PR. In this case, the print authentication unit 10 generates low-frequency print image data and white component prints for the print image data D1 obtained from the print image PR, as in the paper authentication information PPID generation process in the paper authentication unit 20 described above. The print authentication information PRID is generated by sequentially generating the image data and the black component print image data, and dividing the white dama and the black dama.

  Then, at the time of print authentication, the print authentication unit 10 collates the image pattern indicated by the print authentication information PRID generated from the print image PR with the image pattern indicated by the print authentication information PRID restored from the print authentication code BC1. If a matching rate equal to or higher than a predetermined reference matching rate is obtained as a collation result, it is determined that the print image PR is valid.

  Further, in the above-described embodiment, as a means for verifying the print contents based on the print authentication information stored by the storage means, the pattern pattern is authenticated by collating with the method described above with reference to FIGS. However, the present invention is not limited to this, and verification may be performed by other methods. In this case, the same effect as that of the above-described embodiment can be obtained.

  Furthermore, in the above-described embodiment, the case where the configuration shown in FIG. 2 is applied as the print information protection device has been described. However, the present invention is not limited to this, and various other configurations can be applied. it can.

  In this case, an application program that causes the control unit to execute the above-described various processes or a part of the processes is installed in, for example, an existing apparatus that handles paper such as a copying machine, a newly manufactured apparatus, or a computer. You may make it do.

  As the program storage medium for installing the application program in this manner, for example, only a package medium such as a flexible disk, a CD-ROM (Compact Disc-Read Only Memory), a DVD (Digital Versatile Disc), a semiconductor memory, and a removable hard disk can be used. Alternatively, a magnetic disk or the like in which application programs are temporarily or permanently stored may be used. Means for storing these application programs in the program storage medium include local area networks, the Internet, digital satellite broadcasting, and the like. A wired or wireless communication medium may be used, and the data may be stored via various communication interfaces such as a router and a modem.

FIG. 5 is a schematic diagram for explaining a print content protection method. It is a block diagram which shows the structure of the printing information protection apparatus by this Embodiment. It is a block diagram which shows the structure of a control part. FIG. 6 is a schematic diagram for explaining the division of a print image. It is a basic diagram which shows a power spectrum. It is a graph which shows the power spectrum of a high frequency range. It is a graph which shows the power spectrum of a low frequency range. It is a graph which shows the relationship between a printing content and its component ratio. It is a graph which shows the relationship between a component ratio and a correlation coefficient. It is a basic diagram with which it uses for description of extraction of a low frequency component. It is an approximate line figure used for explanation of separation of an image. It is an approximate line figure used for explanation of the division of white dama (black dama). It is an approximate line figure used for explanation of calculation of a feature-value.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Print information protection apparatus, 2 ... Control part, 4 ... Scanner part, 4a ... Two-dimensional code reader, 5 ... Printer part, 10 ... Print authentication part, 11 ... Area division part, 13 ... ... component ratio calculation unit, 14 ... print authentication information calculation unit, 15 ... collation unit, 20 ... paper authentication unit, 21 ... low frequency component extraction unit, 22 ... image separation unit, 23 ... region Splitting section, 24... Paper authentication information calculating section, 25... Collating section, 30.

Claims (5)

Image acquisition means for acquiring a print image from the print content printed on paper;
Authentication information generating means for generating print authentication information from the print image acquired by the acquisition means to guarantee the print content;
Authentication information storage means for printing and storing the print authentication information on the paper;
A printing information guarantee device characterized by comprising: The authentication information generating means includes
A dividing means for dividing the print image into a plurality of divided images;
Spectrum generating means for performing a fast Fourier transform on each of the plurality of segmented images and generating a power spectrum for each of the segmented images,
A ratio calculating means for dividing the power spectrum for each of the plurality of segmented images into a power spectrum in a high frequency region and a power spectrum in a low frequency region, and calculating a power ratio of both for each of the plurality of segmented images;
The print information assurance device according to claim 1, further comprising authentication information calculation means for calculating the print authentication information based on a power ratio for each of the plurality of segmented images. An image acquisition step of acquiring a print image from the print content printed on paper;
An authentication information generating step for generating print authentication information from the acquired print image in order to guarantee the print content;
An authentication information storage step for printing and storing the print authentication information on the paper;
A printing information guarantee method characterized by comprising: For a given computer
An image acquisition step of acquiring a print image from the print content printed on paper;
An authentication information generating step for generating print authentication information from the acquired print image in order to guarantee the print content;
An authentication information storage step for printing and storing the print authentication information on the paper;
A print information assurance program characterized in that Image acquisition means for acquiring a print image from the print content printed on paper;
Authentication information generating means for generating print authentication information from the print image acquired by the acquisition means for verifying the authenticity of the print content;
Authentication information acquisition means for acquiring the print authentication information printed on the paper from the paper;
Verification means for verifying authenticity of the print content by comparing the authentication information generated from the print content by the authentication information generation means with the authentication information acquired from the paper by the authentication information acquisition means; An apparatus for verifying print information according to claim 1, comprising: