JP4182998B2 - Image generating apparatus, image reading apparatus, unauthorized duplication prevention system, program, and output medium manufacturing method - Google Patents

Description

  The present invention relates to an image generation apparatus, an image reading apparatus, an unauthorized duplication prevention system, a program, and an output medium manufacturing method.

  In recent years, copying of documents has become extremely simple due to the widespread use of image forming apparatuses having a copying function, such as personal computers, printers, and copying machines. In such a situation, a manuscript to which copyright has been granted or a manuscript that prohibits unauthorized duplication such as “copy prohibited”, “restrict copying”, “confidential”, etc. (hereinafter collectively referred to as “confidential manuscript”). There is a drawback that copying is easily performed. In other words, an unauthorized reproduction of a so-called “confidential manuscript” printed output that is a manuscript image that includes character strings, figures, tables, graphs, etc. and that needs to prevent leakage of important information. The leakage of important information (confidential content) due to has become a problem. Therefore, it is necessary for an image forming apparatus having a copying function to have a function to prevent misuse and duplication of confidential documents.

  For this reason, various techniques for prohibiting or restricting arbitrary and arbitrary copying of confidential documents to a certain range have been proposed. This technology can be broadly divided into those that only give a malicious copy even when copied, those that print documents on copy-forgery-proof paper, and pattern images or “copy” that are hard to see in the copy-prohibited area. When copy prohibition marks such as “Prohibit” are printed, they are registered in advance, the marks are detected when the document is read, and these are compared with the registered marks. There are things that control the replication operation.

  For example, as a conventional technique for controlling unauthorized copying of a confidential document, Patent Document 1 proposes a technique for generating a pattern image by which an effect similar to that of a copy forgery prevention sheet is selected by image processing. Here, the copy forgery prevention paper is a paper on which a special pattern image is printed in advance, which is hard to be seen by human eyes, but which has a warning character or the like that is hidden when copied by a copying machine. When a document printed on this copy protection paper is copied with a copying machine, warning characters such as “Duplicate Prohibition” will stand out prominently on the copied material. In addition to deterrence, it is possible to distinguish between the original and the copy.

  The method described in Patent Document 1 has the same effect as when using a copy forgery prevention sheet by superimposing images on which a warning character portion and a background portion are subjected to dither processing with different specific densities. The obtained pattern image is synthesized with the input image data, and an effect similar to that obtained when a copy forgery prevention sheet is used using a normal sheet is obtained.

  However, with this method, when copying with a copying machine, a warning character appears in the background of the copied material, so that illegal copying can be suppressed psychologically, but copying itself cannot be stopped, and illegal copying Cannot be prevented.

  As an example of how to solve this problem, copy prohibition information is embedded in a confidential document, the copy prohibition information is detected from the image read by the copier, and the copy operation of the copier is controlled according to the detection result. The technique to do is proposed by patent documents 2-4 etc., for example.

  Patent Document 2 describes a method for recognizing a specific symbol added to a document whose copying is prohibited on the copier side. That is, the copying machine side is provided with a function of recognizing a specific symbol to prohibit unauthorized copying of the copy prohibited document.

  Patent Document 3 discloses a method of embedding duplication prohibition information or information permitting copying under specific conditions in a document to be printed out by barcode or digital watermark technology, and detecting the information to control the copy operation. Are listed.

  Patent Document 4 describes a method of embedding a two-dimensional code in the background of copy forgery prevention paper. In this method, duplication prohibition information can be included in the background two-dimensional code. Due to unauthorized copying of confidential documents, the copying machine is provided with a function for detecting the two-dimensional code, and if the two-dimensional code contains copy prohibition information, the copying operation is controlled to stop. Information leakage can be prevented.

Japanese Patent Laid-Open No. 7-231384 JP 2000-76458 A JP 2001-189855 A JP 2001-346032 A

  However, the above prior art has the following problems. First, in the method of recognizing a specific symbol and determining whether to stop or permit a copy operation as described in Patent Document 2, a specific user is permitted to copy for each document, It is not possible to perform advanced copy control operations such as permitting copying after the date and time.

  Further, in the method of embedding copy prohibition information with a digital watermark as described in Patent Document 3, the digital watermark is likely to be unrecognizable by generational copy (a copy repeated a plurality of times), that is, deleted by hard copy. Because it is easy, the information embedded by the digital watermark is lost, and it is not possible to know whether the document is a confidential document.

  Further, although the methods described in the above publications can control unauthorized copying of confidential documents, they cannot reliably prevent unauthorized copying. In other words, in order to reliably prevent unauthorized copying, it is necessary to recognize that the material to be copied in the copying machine is a confidential manuscript for which copying is prohibited and to provide a function for controlling the copying operation in the copying machine. . Here, since the detection function such as the prohibited copy mark and the bar code can be performed by a relatively simple technique, it is not difficult to provide all the copying machines with this function.

  However, the digital watermark detection function includes skew correction processing, code data alignment processing, processing to detect a dot pattern embedded in an image as a latent image (digital watermark detection processing), and error correction processing to increase determination accuracy. For example, many devices do not have a digital watermark detection function because they require a relatively large-scale processing and advanced technology and are expensive. This tendency is also observed in the case of a two-dimensional code. Under such circumstances, even if the data is copied by a copying machine that does not have a two-dimensional code or digital watermark detection function, the information embedded by the two-dimensional code or digital watermark is lost. , You will not even know if the document was a confidential document.

  Further, in the method described in Patent Document 2, or Patent Document 3 or Patent Document 4, since copy prohibition information is embedded by a specific symbol, a bar code, or a two-dimensional code, the copy prohibition information is displayed on the white background portion by human eyes. Since it is arranged so that it can be seen, it is obvious where the copy prohibition information exists in the document. For this reason, if a part with embedded duplication prohibition information such as a barcode is easily removed (hidden, painted, or cut) by a malicious user, the copy operation is not prohibited and is printed out. Therefore, it is not possible to effectively prevent the outflow to the outside. That is, in this case, a special symbol or bar code indicating a confidential manuscript has no meaning for the copying machine, and confidentiality depends only on the morals of the person using the copying machine.

  Also, in the methods described in Patent Document 3 and Patent Document 4, whether the copy operation is stopped or permitted only by detecting the digital watermark or barcode or two-dimensional code embedded in the document and decoding the information. However, in order to detect a digital watermark, a two-dimensional code, etc., it requires advanced detection / determination processing such as skew correction processing as described above. Productivity is reduced.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and without the need for advanced detection determination processing when generating a document image that is required to be prohibited from unauthorized duplication, unauthorized duplication of the output printed matter. It is an object of the present invention to provide a mechanism that makes it possible to prevent the problem more reliably.

That is, the image generation apparatus according to the present invention includes an image acquisition unit that acquires an original image, a control information acquisition unit that acquires control information for controlling copying of the original image, and control information acquired by the control information acquisition unit. The pattern image area generation unit that generates the pattern image area by changing the pattern image arrangement method according to the type of image, and the original image acquired by the image acquisition unit and the pattern image area generated by the pattern image area generation unit are combined And a composite image generating unit. Here, when the type of control information is a replication condition, the pattern image region generation unit arranges a plurality of different types of machine-readable pattern images according to a data array indicating the replication condition, thereby reproducing the replication condition. It is assumed that the condition image area is synthesized with the original image.

  An image reading device according to the present invention detects an image reading unit that reads an image generated by the image generation device according to the present invention, and a pattern image included in the read image read by the image reading unit. A pattern image detection unit and a control unit that controls the duplication operation based on the detection result detected by the pattern image detection unit are provided.

  The invention described in the dependent claims defines further advantageous specific examples of the image generating apparatus and the image reading apparatus according to the present invention.

  An unauthorized duplication prevention system according to the present invention includes the image generation device according to the present invention and the image generation device according to the present invention. Note that the image reading apparatus may further include a configuration including an image forming unit that visualizes the read image again, that is, an image forming apparatus.

  In addition, the image generation apparatus and the image reading apparatus or the image forming apparatus may be integrated or separate. In the case of separate bodies, the two devices may be arranged close to each other or may be connected to a network and located in a remote place.

  Furthermore, the program according to the present invention is suitable for realizing the image generation apparatus according to the present invention by software using an electronic computer (computer). The program may be provided by being stored in a computer-readable storage medium, or may be distributed via wired or wireless communication means.

  In the above configuration, code data (information for controlling the duplication operation) that can be detected at the time of duplication operation using the reader is associated with the pattern image, and the duplication operation is prohibited or canceled. Pattern images are two-dimensionally arranged at predetermined intervals so that control information can be represented. For example, a plurality of types of pattern images are two-dimensionally arranged to generate a plurality of types of pattern image regions of a predetermined size. The plurality of types of pattern image areas are repeatedly arranged according to a predetermined rule to generate a background image. Furthermore, a background image including this pattern image is superimposed on the original image to generate a composite image. For example, a code for prohibiting copying or a code for canceling the prohibition of copying is allocated to the plurality of types of pattern images.

According to the present invention, since a background image in which pattern images are arranged in a two-dimensional pattern having a predetermined area size and an original image are synthesized, it is based on an original image (for example, a confidential document) whose duplication operation needs to be controlled Thus, when generating an image, it is possible to obtain the same effect as using a copy forgery prevention sheet having a psychological deterrent effect against illegal duplication operation. By combining the copy condition image area representing the copy condition with the original image, the reading side extracts the copy condition from the copy condition image area included in the read image, and performs copying based on the copy condition. The operation can be controlled.

  In addition, the pattern image and the original image that constitute the background image overlap, and even if the presence of the pattern image is obvious, it cannot be easily removed, so by associating the copy code with the pattern image, Unauthorized duplication operations can be reliably prevented.

  In addition, since multiple types of pattern images representing prohibited copy codes are represented by relatively simple feature amounts such as hatched patterns, the processing is simple during the detection processing and determination processing on the reading device side, and the reading processing In parallel with this, forbidden duplication code detection processing and determination processing can be performed in real time, and it is not necessary for the user to perform advanced copy control operations in order to completely prohibit duplication operations.

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

  FIG. 1 is a diagram showing an overall configuration of an embodiment of an image forming system to which an unauthorized duplication prevention system according to the present invention is applied. The image forming system 1 includes a client terminal 2 that outputs a foreground image, which is an example of an original image, and a so-called multi-function device 3 having a print function and a copy function. They are connected by a network 9 such as a network or a dedicated line. The number of client terminals 2 is not limited to one, and many client terminals 2 may be connected.

  The client terminal 2 only needs to have a function of generating image information such as a personal computer or a word processor. The multifunction machine 3 includes a scanner unit 5 that reads an image and a raster scan (ROS) -based printer unit 7 that prints and outputs the image on a predetermined sheet.

  The image forming system 1 takes the form of a so-called network printer in which, for example, image data is transmitted from a client terminal 2 installed on the user side to the multifunction device 3 and an image is printed out by the multifunction device 3. Yes. For example, the user issues a document print instruction from the client terminal 2 to the multifunction device 3. At that time, the user adds the information to be embedded in the document to be printed through the input device 2a such as a keyboard or a mouse while checking the menu screen displayed on the display device 2b of the terminal by the printer driver installed in the client terminal 2. Set and input information.

  The additional information can include, for example, duplication prohibition information, condition information, latent image information, and the like as an example of control information for controlling duplication. Here, the copy prohibition information is information indicating that a document instructed to be printed out is not copied (prohibited from being copied) by a copying machine (including the multifunction machine 3). The condition information is information indicating a condition for enabling copying of a document instructed to be printed. For example, a personal identification number, a user ID number that permits copying (for example, an employee number), a date and time when copying prohibition is canceled, and copying Including the machine number of the copier, etc. The latent image information is information indicating a latent image character embedded in a background image described later.

  After setting these pieces of information, the user issues a print instruction. In response, the printer driver converts the document data (application data) into predetermined print data described in the print description language, adds additional information to the header portion of the print data, and then passes through the network 9. To the multifunction device 3. As the print data, for example, a page description language (PDL) format in which enlargement, rotation, deformation, etc. of figures and characters can be freely controlled is preferably used. Hereinafter, a description will be given in the form of using PDL data as print data.

  The header portion of the PDL data includes an IP (Internet Protocol) address of the client terminal 2 that has transmitted the print job, a user name that has transmitted the print job, a document file name to be printed, a time stamp of the document to be printed, and a document file. Encoded information such as a set secret level, a password set in the document file, or latent image information representing a latent image character string embedded as a latent image is added as additional information. Such additional information is added only to confidential documents and the like that need to be prohibited from being copied.

  The multifunction device 3 first checks the received PDL data. If any one of copy prohibition information, condition information, and latent image information is included, a background image in which a predetermined pattern image is two-dimensionally arranged according to a predetermined rule is generated, and the PDL data is used. It is combined with the generated document image (original image) and printed out (printed out). For example, if the received PDL data contains neither copy prohibition information nor condition information, only the document image generated from the PDL data is printed out.

  FIG. 2 is a block diagram illustrating a configuration of an embodiment of the multifunction machine 3. The multifunction machine 3 records images on a predetermined recording medium using xerography, and includes a scanner unit 5 that reads images and a printer unit 7 that prints and outputs images.

  The scanner unit 5 includes an image reading unit 10 that reads a document image, and an operation control unit 20 that receives a command from a user and has a control function such as reading and print output. The printer unit 7 includes an operation control unit 20 shared with the scanner unit 5, an image processing unit 40 that performs desired image processing on the image read by the image reading unit 10, and a composite image generation unit that generates a composite image. 50, a selector 80 that switches and outputs an image from the image processing unit 40 and an image from the composite image generation unit 50, and a raster scan-based image forming unit 90 that outputs the image on a sheet.

  The operation control unit 20 includes a duplication prohibition information detection unit 22 that detects duplication prohibition information from the image read by the image reading unit 10, a condition information detection unit 24 that detects condition information from the image read by the image reading unit 10, And a page buffer 26 that is an example of a storage unit that stores an image read by the image reading unit 10.

  The operation control unit 20 also receives PDL data from the client terminal 2 via the network 9, and has a network I / F (interface) unit 30 having a communication function with other network connection devices, the entire multifunction device. And a control panel 34 having a function of accepting information display and key input to the user. The control panel 34 includes a mode instruction unit 34a that accepts an operation mode of the multifunction machine 3 or other various settings using an input device such as a numeric keypad or a touch panel (not shown), and a display device 34b such as an LCD (liquid crystal) panel. .

  The multi-function device 3 can set two types of copy operation modes, “normal copy mode” and “conditional copy mode”, and is configured to perform different operations depending on the set copy operation mode. In this mode switching, the user instruction received by the mode instruction unit 34a of the control panel 34 is transmitted to the control unit 32, and the control unit 32 controls the copy prohibition information detection unit 22, the condition information detection unit 24, or the composite image generation unit 50. It is realized by doing. For example, the duplication prohibition information detection unit 22 operates only when “normal copy mode” is set, and is set so as not to operate in “conditional copy mode”. The condition information detection unit 24 is set to operate only when the “conditional copy mode” is set, and not to operate in the “normal copy mode”.

  The image reading unit 10 reads a document placed on a platen glass (not shown) with a reading optical system (not shown), and performs image pickup signal processing such as gain control, color separation, or white balance processing on the read document image. The image data R, G, and B representing the processed image are input to the duplication prohibition information detection unit 22 and the condition information detection unit 24 and stored in the page buffer 26.

  When receiving the request, the page buffer 26 sends the stored image to the condition information detection unit 24, the control unit 32, and the image processing unit 40. The image processing unit 40 reads out the original image stored in the page buffer 26 and performs image processing such as background removal processing and enhancement processing using a spatial filter, and the processed image is converted into a composite image generation unit 50, Alternatively, the image is input to the image forming unit 90 via the selection unit 80.

  The composite image generation unit 50 generates a document image by decomposing the PDL data received from the control unit 32. Further, the composite image generation unit 50 generates a background image including a pattern image corresponding to the copy prohibition information or a copy condition pattern image corresponding to the condition information under the control of the control unit 32. Then, the background image is combined with the document image that has been decomposed previously and the read image received from the image processing unit 40.

  The image forming unit 90 generates, for example, a binarized signal for each print color based on the image selected and output by the selection unit 80 or the image output from the control unit 32. For example, image data of the RGB color system is converted into image data of the YCrCb color system, and further, at least three (preferably four) from the YCrCb color system, for example, CMY color system or CMYK color system are converted. Raster data (binarized signal) subjected to mapping and color separation for print output is generated. In such raster data conversion processing, under color removal (UCR) for reducing the CMY components of the color image or gray component replacement (GCR) for partially replacing the reduced CMY components with the K component is performed.

  Further, the image forming unit 90 performs color separation linearization or similar processing in order to adjust the toner image of the output image created in response to the output data (CMYK or the like). The image forming unit 90 modulates and drives a light source (not shown) based on the generated binarized signal, scans the photoconductor drum (not shown), and forms an electrostatic latent image on the photoconductor drum. A printed output is obtained by transferring it onto a recording sheet.

  FIG. 3 is a block diagram illustrating a configuration of an embodiment of the composite image generation unit 50 provided in the multifunction machine 3. The composite image generation unit 50 includes a read image acquisition unit 502 that acquires a read image (scanned image) via the image processing unit 40, a print data acquisition unit 504 that acquires PDL data via the control unit 32, and a print data acquisition unit. A document image generation unit 506 that analyzes (decomposes) the PDL data acquired by 504 to generate a document image, and a document image buffer that is an example of a storage unit that stores the document image generated by the document image generation unit 506 508.

  The composite image generation unit 50 extracts the additional information such as copy prohibition information, condition information, or latent image information from the PDL data acquired by the print data acquisition unit 504, and the additional information extraction unit 510 extracts the additional information. A latent image generation unit 512 that generates a latent image based on the latent image information, an additional information encoding unit 514 that encodes the copy prohibition information and the condition information extracted by the additional information extraction unit 510 to generate code data, A pattern image storage unit 516 stores a pattern image represented by a plurality of types of dot patterns corresponding to code data obtained by encoding duplication prohibition information and condition information. Details of the pattern image will be described later.

  The latent image generation unit 512 reads a latent image character string represented by latent image information, rasterizes the read latent image character string using a predetermined font, and converts the latent image character image into a binary image. Generate. The additional information encoding unit 514 performs error correction encoding on the encoded data of the condition information input from the additional information extracting unit 4, and further copies the data by referring to the latent image character image data input from the latent image generating unit 512. The coded data of the prohibition information and the coded data of the error correction encoded condition information are converted into predetermined code data, and for example, a two-dimensional array of code data corresponding to one image is generated.

The font used when generating the latent image character image is preferably set with a relatively large number of points (for example, 48 points) in order to exhibit the same effect as the copy forgery prevention paper. The latent image character image is preferably converted into a binary image so as to satisfy the relationship of the following expressions 1) and 2).
1) Resolution of latent image character image = printer resolution ÷ number of horizontal pixels of pattern,
2) Number of vertical and horizontal pixels of latent image character image = number of vertical and horizontal pixels of document image ÷ number of horizontal pixels of pattern. When the horizontal (main scanning direction) number of pixels is 4960 × 7015 pixels, the resolution of the latent image character image is 50 dpi, and the vertical × horizontal number of pixels is 413 × 584 pixels. That is, it is set so that one pixel (one black pixel) of the latent image character image substantially corresponds to the size of one pattern image. As a result, the black pixels of the latent image character can be arranged in units of the size of the pattern image corresponding to the copy prohibition information and the condition information. Therefore, when the latent image character is embedded in the background image, the black pixel of the latent image character Are embedded in the size unit and array unit of the pattern image.

  The additional information encoding unit 514 can generate code data by encoding not only the additional information extracting unit 510 but also the copy prohibition information, the condition information, and the latent image information input via the control unit 32. It is like that. This is because the read image read by the image reading unit 10 can be combined with the background image. Further, when generating the code data, the additional information encoding unit 514 refers to the latent image image generated by the latent image generation unit 512 or stored in the latent image image buffer 515, so that the latent image portion Then, code data is converted according to a predetermined rule.

  Further, the composite image generation unit 50 generates a background image based on the code data (additional information) encoded by the additional information encoding unit 514 and the pattern image stored in the pattern image storage unit 516. The document image is read out from the background image buffer 520 and the document image buffer 508 which are an example of a storage unit for storing the background image generated by the generation unit 518 and the background image generation unit 518, and the background image is read out from the background image buffer 520. It has an image composition unit 522 that generates a composite image by superimposing both.

  The background image generation unit 518 refers to the code arrangement generated by the additional information encoding unit 514 and the pattern image corresponding to each code data stored in the pattern image storage unit 516, and the prohibited copy pattern image region and the condition A background image in which the pattern image area is repeatedly arranged in a two-dimensional manner according to a predetermined rule is generated.

  FIG. 4 is a flowchart illustrating an example of processing procedures of the composite image generation unit 50, particularly background image generation processing and image synthesis processing. Here, a description will be given of a form in which a composite image is printed out based on PDL data transmitted from the client terminal 2 (background image generation processing during printing).

  The control unit 32 temporarily stores the PDL data received via the network I / F unit 30 in an internal memory (not shown) (S100). Further, the control unit 32 notifies the composite image generation unit 50 that the PDL data has been received (S102).

  The print data acquisition unit 504 of the composite image generation unit 50 receives the PDL data from the internal memory of the control unit 32, and inputs the received PDL data to the document image generation unit 506 and the additional information extraction unit 510 (S104). The document image generation unit 506 interprets the PDL data, generates a document image, outputs the document image buffer 508, and stores it (S106). Here, the resolution of the generated document image matches the printer resolution.

  The additional information extraction unit 510 checks whether additional information is added to the header portion of the PDL data (S108). If added, the additional information is extracted (S108-YES), and the additional information is decomposed into duplication prohibition information, condition information, or latent image information (S110). Then, the additional information extraction unit 510 outputs the duplication prohibition information and the condition information to the additional information encoding unit 514 (S112), and outputs them to the latent image generation unit 512 (S113). The latent image information is information indicating what kind of latent image character is embedded in the pattern image. Specifically, the latent image character string, font type, font size, latent image character string It consists of information such as direction (angle).

  The latent image generation unit 512 generates a latent image based on the latent image information input from the additional information extraction unit 510 (S114). That is, a binary latent image is generated by drawing a latent image character string in a specified direction with a specified font type and font size. The latent image generation unit 512 inputs the generated latent image to the additional information encoding unit 514. Here, the resolution of the latent image is equal to the resolution obtained by dividing the resolution of the printer by the size of the pattern image to be described later. For example, when the printer resolution is 600 dpi (dots / inch) and the pattern image size is 12 pixels × 12 pixels, the resolution of the latent image is 50 dpi.

  The additional information encoding unit 514 determines whether copy prohibition information or condition information has been input (S116). If input, copy prohibition information and condition information are encoded (S116-YES, S118). On the other hand, if copy prohibition information has not been entered, or if it does not indicate that the document for which print output has been instructed is not to be copied by a copier, the process proceeds to the next process without generating a prohibited copy code array. (S116-NO).

  For example, when copy prohibition information is input, the additional information encoding unit 514 encodes the copy prohibition information to generate a copy prohibition code array having a predetermined area size (S120). Further, when the condition information is input, the additional information encoding unit 514 performs error correction encoding on the condition information to generate a condition code array having a predetermined area size (S120). Here, each element of the code array is code data “0” or code data “1”.

  For example, using a plurality of types of code data, a data string is generated so that the condition information can be expressed. Further, this data string (condition code; coded condition information) is subjected to error correction coding. The error-corrected data string is rearranged into a two-dimensional array (unit two-dimensional array) having a predetermined size. At this time, a data array such as the outermost circumference of the unit two-dimensional array is defined so as to facilitate positioning of the condition code array and no decoding error in the detection process and determination process (code decoding) in the reader. It should be noted (details will be described later).

  Next, the additional information encoding unit 514 repeatedly arranges the generated forbidden copy code array and condition code array in accordance with a predetermined rule, preferably in a two-dimensional manner, and has the same size as the entire latent image. A pattern number array having a size, that is, a pattern number array corresponding to the background image is generated (S122). If no forbidden code sequence (one of the two types) has been generated in step S118, the condition code sequence is placed in the portion of the forbidden code sequence that has not been generated. If no condition code sequence is generated, a forbidden copy code sequence is placed in the condition code sequence.

  In this case, only one of the two types of forbidden copy code sequences may be used, or the two types may be arranged in an appropriate combination. For example, one type of code data is arranged on the entire image. Alternatively, a plurality of types of code data are two-dimensionally arranged in a predetermined area size to generate a unit two-dimensional array. Further, the unit two-dimensional array is repeatedly arranged in either one of the vertical direction and the horizontal direction (one-dimensional shape), preferably both in the vertical direction and the horizontal direction (two-dimensional shape), so that one image can be obtained. Generate the code sequence for. At this time, if a condition code array of a unit two-dimensional array has been generated, this condition code array is also combined. When this condition code is used for canceling the prohibition of duplication within a certain range, it is preferable that a large number of the condition codes are repeatedly arranged not only on one place but also on the entire screen so as to be surely detected.

  Next, the additional information encoding unit 514 refers to the latent image, converts the code data of the pattern number array element corresponding to the coordinates of the black pixels in the latent image according to a predetermined rule, and converts this in the latent image. (S124, S126). At this time, the black pixels of the latent image character are embedded in the size unit of the pattern image. As a result, the pattern number array is in a state in which the latent image characters are drawn with the pattern number (for example, “2”) according to the predetermined rule on the background where the prohibited duplication code and the condition code are arranged side by side. The additional information encoding unit 514 inputs this pattern number array to the background image generation unit 518 (S126).

  The background image generation unit 518 refers to each element of the pattern number array input from the additional information encoding unit 514, and reads the pattern image corresponding to the pattern number from the pattern image storage unit 516, whereby the pattern image array A background image consisting of the set is generated (S130). Then, the background image generation unit 518 stores the generated background image in the background image buffer 520 (S132).

  Finally, the image composition unit 522 reads the background image from the background image buffer 520, reads the document image from the document image buffer 508 in parallel therewith, and synthesizes each pixel data to generate the entire composite image. (S134). Then, the image composition unit 522 inputs the generated composite image to the image forming unit 90 via the selection unit 80 (S136). The image forming unit 90 prints out the input composite image on paper (S138). Since the background image has already been synthesized by the image synthesis unit 522, the image forming unit 90 can print out the synthesized image in which the original document image and the background image are synthesized.

  FIG. 5 is a diagram illustrating an example of code data that can be detected during a duplication operation using a predetermined apparatus, and an example of a pattern image associated with the code data. Copy code prohibition information, condition information, or latent image information, which is an example of additional information, is assigned to the code data.

  For example, when the copy prohibition information indicates that a document for which a print output instruction has been received is to be prevented from being copied by a copying machine, one of the two types of prohibited copy code arrays shown in FIGS. 5 (A) and 5 (B). At least one is generated (see step S120 above). Here, in the forbidden copy code sequence of FIG. 5A, all the code data (pattern number) in the sequence is “0”, and the forbidden copy code sequence of FIG. The feature is that all code data is “1”. When the copy prohibition information is not input, or when it does not indicate that the document for which print output is instructed is not to be copied by the copying machine, the additional information encoding unit 514 performs the processing shown in FIGS. 5A and 5B. 2 types of forbidden copy code sequences shown in FIG.

  In the illustrated example, the size (region size) of the unit two-dimensional array is 20 (vertical scanning direction) × 20 horizontal (main scanning direction). Note that the area size is not limited to this example, and may be, for example, about ¼ or less of the entire image vertically and horizontally. However, since it does not have to be too small, for example, it is preferable that the size is such that about 100 “0” s or “1” s are included in one region size. In any case, it is preferable that the size is such that the unit two-dimensional array can be repeatedly arranged in the entire image.

  When the condition information is input, the additional information encoding unit 514 performs error correction encoding processing on the condition information to generate a condition code array as shown in FIG. If the condition code sequence is not generated, a forbidden copy code sequence is generated instead of the condition code sequence. The code array in FIG. 5C represents condition information encoded by a two-dimensional array (two-dimensional code) of code data “0” and “1”. The size (area size) of the unit two-dimensional array of the condition code array is also set to 20 (vertical scanning direction) × 20 horizontal (main scanning direction), similar to the prohibited copy code array.

  In addition, a synchronization code is assigned to the outer periphery of the condition code array by using a special data array to facilitate the positioning of the array (see FIG. 16 described later). In the illustrated example, the outer periphery of a rectangular area having a predetermined vertical and horizontal size is defined as a code consisting of all “1”. When the condition information is encoded, a two-dimensional code is generated by arranging the two-dimensional code in accordance with a predetermined rule while correcting a bit string corresponding to the condition information within the synchronization code. .

  At this time, the number of consecutive “0” s and “1” s is set to be smaller than the number of data strings on the side of the region excluding the synchronization code so as to be distinguished from the synchronization code. For example, in the case of an area size of 20 × 20, the number that continues vertically or horizontally is at least “17” or less. When decoding, the synchronization code represented by a special data array is referred to, and the code data arrayed therein is expanded into a data string (bit string) according to a predetermined rule, so that the condition information Is detected.

  In step S122, a plurality of prohibited copy code arrays and condition codes are repeatedly arranged according to a predetermined rule, and a pattern number array having the same size as the entire latent image is generated. As a result, for the entire image, the value of each element of the pattern number array is “0” or “1”.

  FIGS. 5D, 5E, and 5F show examples of pattern images stored in the pattern image storage unit 516. FIG. In both the main scanning direction and the sub-scanning direction in the figure, the size of the pattern image is 12 pixels × 12 pixels. For example, FIG. 5D is a pattern image corresponding to the code data (pattern number) “0”, and the starting point side of each scan is raised, that is, the black pixel exhibits a left-up diagonal line pattern. FIG. 5E shows a pattern image corresponding to the code data (pattern number) “1”, and the starting point side of each scan is lowered, that is, a black pixel has a slanting line pattern with a lower left. These two types of oblique line pattern images are examples of the first and second image patterns according to the present invention.

  Here, the two types of pattern images representing the forbidden duplication codes are such that the feature of the pattern represented by the black pixel dots is represented by one linear function. It should be noted that the detection process or the determination process on the reading apparatus side may be simple, and may be performed by a quadratic function or an arbitrary combination of a linear function and a quadratic function as in other embodiments described later. The feature of the pattern may be represented.

  FIG. 5F is a pattern image corresponding to code data (pattern number) “2”, which is an example of a pattern image after the coordinates of the black pixels in the latent image are changed in step S124. . In this example, the pixel pattern is a dot pattern image in which black pixels are dispersedly arranged at (3, 3), (1, 6), etc. (refer to the drawing for details of pixel coordinates).

  Accordingly, when viewed as the entire background image represented by the pattern image, the hatched pattern (in accordance with the data values of the prohibited copy code array (FIGS. 5A and 5B)) and the condition code array (FIG. 5C) ( 5D and 5B are converted into a two-dimensionally repeated state in a predetermined cycle according to a predetermined rule, and the latent image character portion is converted to an isolated dot pattern (FIG. 5F). It becomes the converted image.

  Here, the pattern number array corresponds to the resolution of an image obtained by dividing the printer resolution by the pattern size, and a pattern image generated based on the resolution is generated by replacing one element of the pattern number array with one pattern. Therefore, the generated pattern image matches the resolution of the printer.

  The pattern images “0”, “1”, and “2” have different black pixel arrangements, but the number of black pixels constituting each pattern image is substantially the same (7 pixels and 8 pixels). Regardless of the arrangement form of the pixels, the recognized density is substantially the same on the printed recording medium. Further, the pattern image “2” arranged at the corresponding position of the black pixel of the latent image character is a pattern image in which isolated dots are scattered and arranged as shown in FIG. It is difficult to reproduce isolated dots. Depending on the printing characteristics, even if the number of black pixels is approximately the same, the density may vary slightly depending on the arrangement of black pixels. Therefore, the black images that make up each pattern image have the same density after printing. It is preferable to set the number of pixels and the arrangement form.

  FIG. 6 is a diagram showing an example of a background image that is generated and printed out by combining and arranging pattern images as described above. Here, FIG. 6A shows the entire background image represented by the pattern image. This image data is a binary image of 1 bit / pixel. The character “COPY” in the figure is a latent image character, and since it actually has a density substantially the same as the background density, it is not clearly visible as shown in the figure, but is drawn so that it can be seen for explanation.

  FIG. 6C is an enlarged view of a part of this latent image character (a region surrounded by a rectangle). The inside of the latent image character is composed of a dot pattern image in which relatively fine dots are randomly arranged densely. Further, the background image outside the latent image character is composed of two types of oblique line patterns shown in FIGS. 5D and 5B (error of E). By associating data “0” and data “1” with these two types of hatched patterns, a two-dimensional code can be constructed. Although the pattern images formed inside and outside the latent image character are different, as described above, the average density (black pixel area per unit area) inside and outside the latent image character when printed on paper is substantially the same. It looks like a uniform gray background throughout the human eye.

  When the original on which the image shown in FIG. 6A is printed out is copied by a copying machine, relatively large dots outside the latent image character are faithfully copied and reproduced, but relatively fine dots inside the latent image character are Since the copying machine cannot faithfully reproduce the copy, as a result, only the outside (background portion) of the latent image character is reproduced on the copy output, and the latent image character portion is whitened out. As a result, as shown in FIG. A duplicate image is output. What is actually printed out on paper is an image in which the document image is synthesized with the background image shown in FIG. 6A, which includes a large number of pattern images according to a predetermined rule. The document image shows an example in which the document image is a pure white document image containing no characters or graphics.

  Since the black pixels of the latent image character are embedded in the size unit of the pattern image, the boundary between the pattern image corresponding to the copy prohibition information and the condition information and the pattern image corresponding to the latent image character is connected in a grid pattern. It becomes a form. Also, the process of generating the background image with reference to the code data of the pattern image may be performed in units of pattern image size, and the background image can be generated at high speed.

  FIG. 7 is a diagram showing another example of the background image generated in step S130. Also in this example, the latent image character “COPY” shown in FIG. 6 can be represented. Here, the hatched rectangle in the figure is the forbidden copy code array (code data “0”) in FIG. 5A, and the vertical hatched rectangle is the forbidden code array in FIG. 5B (code data “0”). 1 "), the dot-hatched rectangle is the condition code array (code data" 0 "or" 1 ") in FIG. 5C.

  As described above (see step S122), if no forbidden code is generated, a condition code is placed in the forbidden code in the figure. If a condition code is not generated, a prohibited copy code is placed in the condition code portion in the figure. Therefore, at this time, the value of each element of the pattern number array is “0” or “1”. FIG. 7A shows this state with corresponding hatching rectangles, and corresponds to the unit two-dimensional array shown in FIG.

  Here, the image areas of the unit two-dimensional array corresponding to the two types of prohibited copy code arrays are examples of the first and second pattern image areas according to the present invention. An image area of the unit two-dimensional array corresponding to the condition code array is an example of a replication condition image area according to the present invention. Further, the image area of the latent image character portion is the third pattern image area according to the present invention.

  FIG. 7B shows the result of changing the pattern number of the element of the pattern number array corresponding to the coordinates of the black pixel of the latent image character “COPY” to “2” by the additional information encoding unit 514. This pattern number arrangement is such that the pattern number “2” corresponding to the latent image character is drawn on the pattern arrangement of the background image in which the prohibited duplication code and the condition code are arranged in a repeating cycle according to a predetermined rule. It has become.

  As apparent from the above, the code data “0”, “1”, “2” correspond to the pattern images shown in FIGS. 5D to 5F, and are prohibited by the two-dimensional arrangement thereof. A duplicate code sequence and a condition code sequence are configured. Then, by arranging the code data in a two-dimensional manner in a predetermined repetition cycle, the corresponding background image is 1 so that control information for controlling the duplication operation (that is, the code data) can be detected. Types or a plurality of types of pattern images are arranged.

  In the previous example, the background image is generated so that the pattern image covers the entire surface of the original image, and this is combined with the original image. However, the pattern image may not necessarily be disposed on the entire surface. However, in order to prevent duplication prohibition information from being easily deleted, an important part in which information that must be transmitted to the user is described, for example, an original image including a text object, overlaps at least a part of the text part. Thus, it is preferable to generate a background image by arranging pattern images. In addition to the text object, a pattern image may be arranged so as to overlap an important part of the graphic object. That is, when the original image includes an essential object that must be transmitted to the user, the background image may be generated so that the pattern image overlaps at least a part of the essential object. It should be noted that such a superposition mode can be understood without needing to be shown in the figure, and thus illustration thereof is omitted.

  In addition, the array size of the forbidden copy code array and the condition code array is set to a predetermined size, such as a unit two-dimensional array (hereinafter, this size is also referred to as the area size of the control code array), and these are set in predetermined size units. By arranging in a predetermined repetition cycle (preferably two-dimensionally), a plurality of types of pattern images can be detected as control information (that is, the code arrangement and combinations thereof) as the corresponding background image. Will be placed.

  As described above, according to the composite image generation process by the composite image generation unit 50 of the first embodiment, the printed document image is an image such as a character embedded as a latent image when copied by a copying machine. As a result, it becomes a psychological deterrent against the act of duplicating illegally, and the original image and the compounded material can be distinguished by the image that emerges. In addition, the original image such as the original document overlaps with the background image, and even if the existence of the pattern image is obvious, it cannot be easily removed (hidden, painted, or cut), so it is prohibited to copy the pattern image. By associating the codes, it is possible to reliably prevent unauthorized duplication operations.

  In addition, since the characteristics of multiple types of pattern images representing prohibited copy codes are expressed by quadratic functions or less (in the previous example, two types of diagonal lines, which are examples of primary functions), detection processing on the reader side or The process is simple during the determination process. In other words, the copy prohibition code detection process and determination process can be performed in real time in parallel with the reading process. Therefore, at least for the control that completely prohibits the duplication operation, it is not necessary to allow the user to perform an advanced copy control operation.

  In addition, if a condition code is configured using such a plurality of types of pattern images, the condition code for canceling the prohibition of copying can be embedded in a confidential document, and the condition code can be set relatively on the reading device side. It can also be detected easily or reliably. Therefore, it is possible to automate advanced copy control operations such as allowing a specific user to copy for each document, or permitting copying after a predetermined date and time, and does not bother the user. . In addition, if a large number of condition codes are repeatedly arranged on the entire screen, even if some condition codes disappear due to embedding of latent image characters or synthesis with the original image, the embedded release conditions are accurately decoded. be able to.

  Next, a method for controlling the use mode of the composite image generated in this way, in particular, the duplication operation in the duplication device will be described. Here, “controlling the duplication operation” means prohibiting the duplication operation or allowing the duplication operation within a certain limited range.

  FIG. 8 is a flowchart showing an example of a processing procedure when a document document printed out according to the procedure shown in FIG. 4 is copied in the “normal copy mode” or the “conditional copy mode”. First, a processing procedure in the “normal copy mode” will be described.

  As a standard, the MFP 3 is set to “normal copy mode”. Therefore, it is usually not necessary to change the setting of the operation mode. If the “conditional copy mode” is set, the user may set the “normal copy mode” by operating the control panel 34 of the multifunction machine 3. In response to this, the control unit 32 sets the copy prohibition information detection unit 22 to operate and the condition information detection unit 24 not to operate.

  First, the image reading unit 10 reads a document document placed on the platen, stores the read document image in the page buffer 26, and inputs it to the duplication prohibition information detection unit 22 and the condition information detection unit 24. (S204).

  The copy prohibition information detection unit 22 is operable only in the “normal copy mode”, and whether or not a pattern image corresponding to the copy prohibition code is included in the document image read by the image reading unit 10, that is, the copy prohibition information detection unit 22 is prohibited. A copy code detection process is performed to determine whether or not the processing target image is a copy prohibited document (details will be described later), and the determination result is input to the control unit 32 (S206). Here, the processing in the duplication prohibition information detection unit 22 is performed in real time in synchronization with the image signal input from the image reading unit 10.

  The control unit 32 controls the output operation based on the determination result input from the duplication prohibition information detection unit 22 (S208). For example, when the determination result input from the copy prohibition information detection unit 22 indicates that the document is a copy prohibition document (a copy prohibition code is detected), the copy operation is stopped (S208—YES, S210). On the other hand, when the determination result indicates that the document is not a copy prohibition document (no copy prohibition code is detected), the control unit 32 selects the image from the image processing unit 40 to input to the image forming unit 90. In order to permit duplication, the copying operation is continued as follows (S208-NO, S212).

  The image processing unit 40 reads the document image stored in the page buffer 26 and performs image processing such as background removal processing, spatial filter enhancement processing, color conversion processing, or tone correction processing, and the selection unit 80 is operated. Then, the processed image is input to the image forming unit 90 (S214). The image forming unit 90 prints and outputs the image input from the image processing unit 40 side on paper as usual (S216).

  As described above, in the “normal copy mode”, when a document image read by the image reading unit 10 includes a pattern image indicating a copy prohibition code, the copy prohibition information detection unit 22 detects it. The copy operation can be prohibited. On the other hand, when the pattern image indicating the prohibited duplication code is not included, the read image can be printed out on the paper, so that a normal duplication operation is possible.

  Next, a processing procedure in the “conditional copy mode” will be described. First, the user operates the control panel 34 of the multifunction machine 3 to set “condition copy mode” (S200). Receiving this, the control part 32 displays the registration screen which inputs a user ID and a PIN on the control panel 34 (S202). The user inputs a user ID and a password on this screen. As a result, the “condition copy mode” is set, and the input user ID and password are notified to the control unit 32. The control unit 32 sets the copy prohibition information detection unit 22 so that it does not operate and the condition information detection unit 24 operates (S203).

  Next, the image reading unit 10 reads a document document placed on the platen, stores the read document image in the page buffer 26, and inputs it to the duplication prohibition information detection unit 22 and the condition information detection unit 24. (S224). The condition information detection unit 24 is operable only in the “condition copy mode”, and whether the pattern image corresponding to the condition code is included in the document image read by the image reading unit 10, that is, the condition code The detection process is performed, and the processing result is input to the control unit 32 (S226). Here, the processing in the condition information detection unit 24 is performed in real time in synchronization with the image signal from binarization processing, noise deletion processing, pattern detection processing, and storage of the pattern detection result in the buffer memory (details will be described later). To do).

  The control unit 32 determines the detection result input from the condition information detection unit 24 (S228). When the processing result does not indicate that the condition code has been detected, the control unit 32 stops the copy operation (S228-NO, S210).

  On the other hand, when the processing result indicates that the condition code is detected (S228-YES), the control unit 32 analyzes the content of the condition code and specifies the corresponding condition information (S230). The condition code is a code corresponding to condition information for permitting a copy operation of a document instructed to be printed within a certain range. For example, a code number, a user ID number (such as an employee number) permitting copying, and a copy The date and time when the prohibition is released, the machine number of the copying machine that permits copying, and the like can be expressed.

  The control unit 32 collates (compares) the machine number represented by the condition code with the machine number stored in the internal ROM (not shown; the same applies hereinafter) of the control unit 32, that is, the registered machine number (S232). When the detected machine number matches any of the registered machine numbers (S232-YES), the user ID and password entered from the control panel 34, and the user ID and password stored in the internal ROM, that is, The registered user ID and registered password are collated (compared) (S234).

  If the input user ID matches one of the registered user IDs, and the registered password corresponding to the registered user ID matches the input password (S234-YES), the control unit 32 reads the current date and time from an internal timer (not shown) and collates (compares) with the date and time when the copy prohibition indicated by the condition code is released (S236). When the current date and time has passed the date and time when the copy prohibition is canceled (S236-YES), the control unit 32 controls the selection unit 80 to input the image from the image processing unit 40 to the image forming unit 90, and copies the image. The operation is continued (S236-YES, S212-S216).

  On the other hand, in the collation of machine number (S232), the collation of user ID and password (S234), or the collation of release date and time (S236), when the collation conditions are not met (they do not coincide / the time has not elapsed) The replication operation is stopped (S232-NO, S234-NO, S236-NO, S210).

  As described above, in the “conditional copy mode”, when the pattern image indicating the condition code is included in the document image read by the image reading unit 10, the condition information detection unit 24 detects the pattern image. Only when a predetermined condition registered in advance is satisfied, the copying operation can be permitted. On the other hand, when the pattern image indicating the condition code is not included, the read image can be printed out on the paper, so that a normal copying operation is possible.

  FIG. 9 is a block diagram illustrating a configuration example of the duplication prohibition information detection unit 22. As shown in the figure, the duplication prohibition information detection unit 22 converts the input image data into binary data “0” or “1” (binarization processing), a binarization processing unit 220, and a binary A pattern image based on the noise removal processing unit 222 that reduces the noise component of the binary image data binarized by the binarization processing unit 220 and the binary image data in which the noise component is reduced by the noise removal processing unit 222. And a pattern detection processing unit 224 for detection.

  In addition, the duplication prohibition information detection unit 22 converts the code data arrangement pattern, which is the detection result output from the pattern detection processing unit 224, into a code arrangement corresponding to control information for controlling duplication (in the previous example, the duplication duplication code). A block processing unit 226 that divides the data into small blocks of a predetermined size according to the region size of the array, and the number of array data “0” and “1” that exist in the block that is divided by the block processing unit 226 And a number calculation unit 230 for calculating.

  Further, the duplication prohibition information detection unit 22 calculates a ratio of the number of array data “0” calculated by the number calculation unit 230, a calculation result by the number calculation unit 230, and a calculation result by the ratio calculation unit 230. And a determination processing unit 234 that performs a block attribute determination process. Here, the block attribute means whether the determination target block is a block representing a prohibited copy code array, a block representing a condition code array, or another block.

  FIG. 10 is a flowchart showing an example of a processing procedure (corresponding to step S206 in FIG. 8) in the duplication prohibition information detection unit 22. The binarization processing unit 220 converts the image data output from the image reading unit 10 into binary data “0” or “1”, and inputs the converted binarization data to the noise removal processing unit 222. (S300). The noise removal processing unit 222 removes noise components included in the binarized data, and inputs the binarized data from which noise has been removed to the pattern detection processing unit 224 (S302). For example, the noise removal processing unit 222 obtains a pixel block to which black pixels are connected, and sets each pixel of the pixel block whose size (number of connected pixels) is not within a predetermined range as a white pixel. Change. As the predetermined range, an appropriate range is set so that the hatched pattern is not deleted, and other patterns (isolated dot patterns, characters and graphics in the document, etc.) are deleted.

  The pattern detection processing unit 224 performs pattern detection processing for detecting the two types of oblique line pattern images shown in FIGS. 5D and 5E, and outputs 1-pixel 2-bit image data, which is the detection processing result. The data is input to the blocking processing unit 226 (S304). For example, the pattern detection processing unit 224 sequentially applies the pattern images (reference patterns) shown in FIGS. 5D and 5E at the position of each pixel in the image represented by the binarized data, and performs template matching. To detect the pattern image. The pattern detection processing unit 224 outputs data “0” when the pattern image shown in FIG. 5D is detected, and data “1” when the pattern image shown in FIG. 5E is detected. ", And if no pattern image can be detected, data" 2 "is output. That is, the pixel data is output as a code array in correspondence with the code data. Note that a pattern detection technique using template matching is a known technique, and thus a more detailed description is omitted.

  The block processing unit 226 divides the code array represented by “0”, “1”, “2”, which is the detection result of the pattern detection processing unit 224, into blocks of a predetermined size, and the result is the number calculation unit 230. (S306). For example, the block size is set to a size smaller than half of the region size of the forbidden copy code sequence and the condition code sequence (that is, the region size of the control code sequence), and at least one block is completely included in each code sequence. Set to a size like this.

  The number calculation unit 230 calculates the number of array data “0” and “1” existing in the block set by the blocking processing unit 226, and inputs the result to the ratio calculation unit 232 (S308). Further, the ratio calculation unit 232 inputs the total number of array data “0” and “1” to the determination processing unit 234 (S310). The determination processing unit 234 determines a block attribute based on the total number input from the number calculation unit 230 and the ratio input from the ratio calculation unit 232 (S312).

  Here, when the block to be processed is located inside a prohibited copy code array corresponding to a predetermined size (area size of the control code array) in which all the array data is “0”, a predetermined number or more is included in the block. Since the diagonal line pattern (FIG. 5D) corresponding to the array data “0” of FIG. 5 is detected and the diagonal line pattern corresponding to “1” (FIG. 5E) is hardly detected, the array data “0” is detected. The ratio of the corresponding diagonal pattern is high and should be close to 1.0.

  Further, when the processing target block is located inside the condition code array corresponding to a predetermined size (area size of the control code array) in which all the array data is “1”, a predetermined number or more of “ Since the oblique line pattern corresponding to “1” (FIG. 5E) is detected and the oblique line pattern corresponding to “0” is hardly detected, the ratio of the oblique line pattern corresponding to the array data “0” is low and almost 0. Should be close to zero.

  Further, when the processing target block includes at least a part of the condition code, a hatched pattern corresponding to a plurality of array data “0” (FIG. 5D) and a plurality of array data “1” is included in the block. Since the oblique line pattern (FIG. 5E) is detected, the ratio of the corresponding oblique line pattern corresponding to the array data “0” should be considerably lower than 1.0 and considerably higher than 0.0.

  If the input image data is an image in which a pattern image (any one of FIG. 5D, FIG. 5E, and FIG. 5F) indicating duplication prohibition information is embedded, the inside of the processing target block In this case, a plurality of forbidden copy codes of sequence data “0” and a plurality of forbidden codes of sequence data “1” should be embedded.

The determination processing unit 234 makes a pre-determination (first-stage determination process) for the block attribute as follows using the above characteristics. That is,
1) When the total number> threshold Th1 and the ratio> threshold Th2, the processing target block belongs to the area of the prohibited copy code “0”.
2) When the total number> threshold Th1 and (1-ratio)> threshold Th2, the processing target block belongs to the area of the prohibited duplication code “1”.
3) When neither of 1) and 2) is satisfied, the block to be processed does not belong to the region of the forbidden copy code sequence.
It is determined.

  Here, the threshold value Th1 is set by adding a margin to the theoretical number of patterns included in the block from the block size and the area size of the control code array. The threshold value Th2 is set to a value close to 1.0 (as an example, the threshold value Th2 = 0.95).

  The determination processing unit 234 separately counts the number of blocks determined to be prohibited copy code “0” and the number of blocks determined to be prohibited copy code “1” (S314). Then, the counted value is compared with the threshold Th3 (second stage determination process) (S316). Here, the threshold Th3 may be appropriately adjusted according to the number of types of prohibited copy codes.

  When the number of blocks determined to be the prohibited copy code “0” is equal to or greater than the threshold Th3 and the number of blocks determined to be the prohibited copy code “1” is equal to or greater than the threshold Th3, the determination processing unit 234 copies the image. The document is determined to be a prohibited document (S316-YES, S318), and other documents are determined not to be a copy-prohibited document (S316-NO, S320), and each determination result is input to the control unit 32 (S322).

  Next, as described in the description of FIG. 8, the control unit 32 stops the copy operation when the document is a copy prohibited document (S208-YES, S210), and permits the copy when the document is not a copy prohibited document. The copy operation is continued (S208-NO, S212).

  According to the above-described duplication prohibition information detection process, it is not necessary to accurately obtain the code data array corresponding to the pattern image and perform the decoding process, and the number of pattern images in the block regardless of the skew or misalignment of the image. It is possible to determine whether or not the document is a copy-prohibited document, and the amount of information is small (representing only the presence or absence of a prohibited copy code). Can be determined in real time in synchronization with the image signal input from the image reading unit 10.

  In the above embodiment, since a copy prohibited image is determined only when a predetermined number or more of two types of copy prohibited codes are detected, it is similar to a copy prohibited code in a normal image that is not a copy prohibited image. Even when a pattern image is included, determination accuracy can be improved without erroneous determination. Of course, a pattern image corresponding to one type of prohibited copy code may be embedded in the background image to determine whether the image is a copy prohibited image. Even if a pattern image corresponding to two types of forbidden copy codes is embedded in the background image, the determination may be made based on only one of the forbidden copy codes. However, in any case, it is inevitable that the determination accuracy is lowered as compared with the above embodiment.

  FIG. 11 is a block diagram illustrating a configuration example of the condition information detection unit 24. As shown in the figure, the condition information detection unit 24 is binarized by the binarization processing unit 240 that binarizes the input image data and the binarization processing unit 240, similarly to the duplication prohibition information detection unit 22. A noise removal processing unit 242 that reduces the noise component of the binarized binary image data, a pattern detection unit 244 that detects a pattern image based on the binary image data in which the noise component is reduced by the noise removal processing unit 242, and Have

  In addition, the condition information detection unit 24 includes a buffer memory 250 that is an example of a storage unit that stores the detection result of the pattern detection unit 244, and a condition code array portion with respect to an image arrangement reference based on data read from the buffer memory 250. A skew angle detection processing unit 252 for obtaining a skew angle that is an inclination. The condition information detection unit 24 detects a two-dimensional code based on the data read from the buffer memory 250 and the skew angle obtained by the skew angle detection processing unit 252, and expands the detected two-dimensional code into a bit string according to a predetermined rule. A code detection processing unit 254, and an error correction decoding unit 256 that performs predetermined error correction decoding processing on the bit string of the two-dimensional code detected and expanded by the code detection processing unit 254 and decodes it as condition information .

  FIG. 12 is a flowchart illustrating an example of a processing procedure (corresponding to step S226 in FIG. 8) in the condition information detection unit 24. The processing of the binarization processing unit 240, the noise removal processing unit 242, and the pattern detection unit 244 is the same as the processing of the corresponding function part of the copy prohibition information detection unit 22 (S400 to S404) (detailed description is omitted). .

  The pattern detection unit 244 stores the code arrangement represented by “0”, “1”, and “2”, which are detection results, in the buffer memory 250 (S406). The code arrangement stored in the buffer memory 250 is “0” for the data at the position where the pattern image shown in FIG. 5D corresponding to the code data “0” is detected, and FIG. 5 corresponding to the code data “1”. The data at the position where the pattern image shown in (E) is detected is a 1-pixel 2-bit code arrangement of “1” and “2” otherwise.

  Based on the code arrangement (image data) stored in the buffer memory 250, the skew angle detection processing unit 252 obtains the skew angle of the input image data, particularly the condition code arrangement part, and the obtained skew angle is the code detection processing unit 254. (S408). For example, the skew angle detection processing unit 252 obtains a skew angle by performing a Hough transform on a pixel having only code data (pixel value) “0” or “1” and obtaining a peak of a projection distribution on the angle axis. . Since a technique for obtaining a skew angle using Hough transform is a known technique, a more detailed description is omitted.

  The code detection processing unit 254 reads the code arrangement (image data) stored in the buffer memory 250 and detects a two-dimensional code from the condition code arrangement portion with reference to the skew angle detected by the skew angle detection processing unit 252 (S410). For example, the code detection processing unit 254 scans the image along the skew angle obtained by the skew angle detection processing unit 252 and corresponds to “0” or “1” data (corresponding to “0” or “1” of the code data). Take out). The synchronization code is found from the retrieved data string. The synchronization code is defined as, for example, a code in which the outer periphery of a rectangular area having a predetermined vertical and horizontal size is entirely composed of “1”. A bit array surrounded by the synchronization code is a two-dimensional code (condition code).

  The code detection processing unit 254 rearranges this bit array into a one-dimensional data string (bit string) and outputs it to the error correction decoding unit 256 (S412). The error correction decoding unit 256 performs predetermined error correction decoding processing on the bit string input from the code detection processing unit 254 (S414), decodes it as condition information, and outputs the decoded condition information to the control unit 32 (S416).

  Next, as described in the description of FIG. 8, the control unit 32 controls whether to permit or cancel the copy operation based on the condition information input from the error correction decoding unit 256. That is, when the copy restriction document includes the condition information, the control unit 32 analyzes the condition information, compares the contents with the information registered in the internal memory in advance, and if they match. While the copy operation is permitted (NO in S232, S234, S236, S212), the copy operation is stopped if they do not match (NO in S232, S234, S236, S210).

  According to the above condition information detection processing, since plural types (two types in the previous example) of prohibited copy codes are used and the condition codes are represented by combinations of the arrays, at least binarization processing, noise removal The processing, pattern detection processing, and storage of the pattern detection result in the buffer memory 250 can be processed in real time in synchronization with the image signal input from the image reading unit 10.

  In the above embodiment, the example in which the composite image generation unit 50 and the image forming unit 90 are incorporated in the same housing of the multifunction machine 3 has been described. However, the composite image generation unit 50 is separated from the image forming unit 90. It may be a housing. In this case, the composite image generation unit 50 generates a background image using the pattern image, combines the background image and the document image, and transfers the image to, for example, the image forming unit 90 connected via the network 9 or directly. It is better to have a configuration that prints out. The former form via the network 9 is an example applied to a so-called network printer.

  In the above embodiment, an example in which the background image is generated as an image having the same size as the document image and combined with the entire document image has been described. However, the present invention is not limited thereto, and the background image is generated as a size smaller than the document image. However, the background image may be combined with a part of the document image. In this case, the background image may be synthesized with the important part of the document image. By synthesizing at least the important part of the document image, it is possible to make it difficult to delete forbidden copy codes and condition codes contained in the background image. Can prevent unauthorized copying. Further, the image may be synthesized at a predetermined position such as the upper or lower part of the document image.

  As described above, according to the configuration and processing of the first embodiment, control information for controlling replication is assigned to a pattern image, and the pattern image is arranged in a two-dimensional manner according to a predetermined rule. Thus, illegal copying can be efficiently prevented during the copying operation.

  For example, a first code that can be embedded in a small amount of information but can be detected in real time (in the previous example, a prohibited copy code) and a second code that is difficult to detect in real time but has a large amount of information that can be embedded (in the previous example, a condition code) Are repeatedly embedded in the background of the document image using pattern images corresponding to the respective codes, copy prohibition information is assigned to the first code, and copy prohibition release conditions are assigned to the second code Can be controlled flexibly.

  For example, in the “normal copy mode” of a copying machine, if a copy prohibition code is detected in a scanned image, the copying operation is stopped, and unauthorized copying of confidential documents is made without reducing the copying productivity of the copying machine. Can be prevented. On the other hand, when a condition code is detected from the read image and the condition is met, a “conditional copy mode” that permits a copy operation is provided to meet conditions such as when a specific user or a predetermined date and time has passed. In this case, complicated copy control such as permitting a duplication operation can be automatically performed without bothering the user.

  In addition, by repeatedly arranging the first and second codes as corresponding pattern images over the entire background of the document image, it is difficult to delete control information for controlling duplication, and unauthorized copying is reliably prevented. Can do.

  When a latent image is included, the two codes are configured as part of the background image that exhibits the same effect as the copy forgery prevention paper, and should be copied by a copier that does not have a detection function. Even in such a case, since a warning character appears in the copied document, it can be recognized that the copied document is a confidential document. Further, it is possible to reliably leave copy prevention control information associated with the code in the copied document.

  FIG. 13 is a flowchart illustrating another example of the processing procedure of the background image generation process and the image composition process in the composite image generation unit 50. Hereinafter, this form is referred to as a second embodiment.

  In the first embodiment described above, the background image is combined with the PDL data transmitted from the client terminal 2 and printed out. However, in the second embodiment, the document image (read by the copying machine) A background image is synthesized with a (copy original). That is, the multifunction machine 3 synthesizes the background image with the image read by the image reading unit 10 when performing the copying operation. As a copying machine, the copying function portion of the multifunction machine 3 shown in the first embodiment can be used as it is. However, the operation is slightly different, and the MFP 3 is configured to be able to set a “composite copy mode” for combining the background image with the read image.

  First, the user operates the control panel 34 of the multifunction machine 3 to set the “composite copy mode” (S500). In response, the control unit 32 causes the control panel 34 to display a registration screen for inputting duplication prohibition information, condition information, and latent image information (S502). The user inputs duplication prohibition information, condition information, and latent image information on this screen (S504). As a result, the control unit 32 is notified that the “composite copy mode” has been set, and the copy prohibition information, the condition information, and the latent image information. The control unit 32 inputs the input duplication prohibition information, condition information, and latent image information to the composite image generation unit 50.

  As described in the first embodiment, the composite image generation unit 50 refers to the copy prohibition information, the condition information, and the latent image information input from the control unit 32 and is stored in the pattern image storage unit 516. The pattern image is read out, and the pattern image is two-dimensionally arranged according to a predetermined rule to generate a background image, and the generated background image is stored in the background image buffer 520 (S506).

  Next, the image reading unit 10 reads a document document placed on the platen, and stores the read document image in the page buffer 26 (S508). The image processing unit 40 reads the document image stored in the page buffer 26 and performs image processing such as background removal processing, enhancement processing by a spatial filter, color conversion processing, or tone correction processing, and the composite image generation unit 50. The processed image is input to the read image acquisition unit 502 (S510). The read image acquisition unit 502 transfers the input read image to the image composition unit 522 (S512).

  The image composition unit 522 captures the background image from the background image buffer 520 in synchronization with the read image input from the read image reading unit 10 (S514). Then, the image composition unit 522 synthesizes each pixel data, and inputs the synthesized image to the image forming unit 90 (S516). The image forming unit 90 prints the input composite image on paper (S518). Since the read image and the background image are combined by the image combining unit 522, the image forming unit 90 prints out a combined image in which the document image read by the image reading unit 10 and the background image are combined. Can do.

  FIG. 14 is a diagram illustrating another example of the pattern image. In the first embodiment, the pixel size of one pattern image is a rectangular size of vertical 12 × horizontal 12 pixels. However, the pixel size is not limited to this and may be a rectangular size or a rectangular size. In the case of the rectangular size, for example, as shown in FIG. 14A, the pattern image for the two forbidden codes described above can be used to be 12 × 24 pixels.

  Also in this case, as shown in the figure, the features of the patterns are different and the numbers of black pixels are made substantially the same so that a plurality of types of forbidden codes can be represented. In addition to the oblique line pattern, the feature quantity of the pattern represented by the arrangement direction of the black pixels can be represented by a combination of a linear function or a quadratic function, for example, a triangle shown in FIG. 14B, or FIG. A material that exhibits a straight line, a square, a circle, an ellipse, or the like such as a square close to a circle shown in C) may be used. Of course, the number of types of pattern images representing prohibited copy codes is not limited to two, and may be three or more.

  FIG. 15 is a diagram showing another example in the case where a unit two-dimensional array of prohibited copy code arrays and condition code arrays is repeatedly arranged over the entire original image. For comparison, FIG. 15A shows an example of the arrangement shown in FIG. 7 and FIG. 15B shows a simplified display thereof. In the first embodiment, a unit two-dimensional array of two types of forbidden copy code arrays indicated by “0” and “1” and a unit two-dimensional array of a condition code array indicated by “0/1” Although repeatedly arranged over the entire image, for example, as shown in FIG. 15C, one of the unit two-dimensional arrays “0” and “1” and the condition code array indicated by “0/1” These unit two-dimensional arrays may be repeatedly arranged over the entire image.

  Further, as shown in FIG. 15D, only one unit two-dimensional array of “0” and “1” may be repeatedly arranged in the entire image. In this case, the unit two-dimensional array is not correctly arranged over the entire image, but the pattern image representing the prohibited copy code is arranged two-dimensionally at a predetermined interval. When pattern images corresponding to a plurality of types of prohibited copy codes are used, the combination of the arrays can be used for the determination process, thereby reducing the possibility of erroneous determination. On the other hand, when a pattern image corresponding to one type of copy-prohibited code is used, the copy processing is improved because the determination process is simplified.

  Further, as shown in FIGS. 15E and 15F, only one of “0” and “1” is used for one scan line, and “0” is orthogonal to the scan line. "" And "1" may be alternately arranged.

  In FIG. 15D to FIG. 15F, the unit two-dimensional array of condition code arrays is not arranged, but may be appropriately scattered. In this case, it may be about 1 to 3, but a certain number of users can accurately decode the embedded release condition even if some condition codes disappear due to embedding of latent image characters or synthesis with the original image. Can do.

  FIG. 16 is a diagram for explaining the relationship between the synchronization code embedded in the outer periphery of the condition code array and the decoding process. Here, FIG. 16A shows an example of the condition code arrangement of the first embodiment, and FIGS. 16B and 16C show examples of other condition code arrangements.

  In the first embodiment, a pattern image corresponding to “0” or “1” as a two-dimensional code by enclosing the outermost periphery of the condition code array of the unit two-dimensional array with “1” and encoding the condition information therein. Had been placed. In this case, depending on the form of the pattern image, the synchronization code cannot be detected depending on the state of the original placed on the original placement table, that is, the scanning direction at the time of reading, and the position and inclination (skew angle) of the condition code array cannot be detected. Although it cannot be specified or the synchronization code can be detected, it is impossible to specify the upper, lower, left, and right, and a decoding error may occur during the decoding process of the condition code.

  For example, as shown in FIG. 16A, in the case of the condition code array of the first embodiment using the hatched pattern, the synchronization code can be detected when rotated 180 degrees, but the upper and lower sides cannot be specified, and the condition code In the decryption process, the internal data array is changed and decrypted, resulting in a decryption error. Further, when rotated 90 degrees or 270 degrees, the outermost periphery is detected instead of “1” instead of “1”. In this case, even if it can be determined that the left and right are rotated 90 degrees, the left and right cannot be specified, and as a result, a synchronization code cannot be detected or a condition code array can be found. Can not. This is not limited to the case where the outermost periphery is set to “1” using the oblique line pattern, but also occurs when the outermost periphery is set to “0” using the oblique line pattern. This also occurs when a pattern image is used in which the code data is reversed when rotated 90 degrees.

  Therefore, when using such a pattern image, it is preferable that the code data on one side of the upper, lower, left, and right sides be different from the code data on the other three sides. For example, as shown in FIG. 16B, “1” is assigned to the upper side and “0” is assigned to the lower side and the left and right sides. In this case, when it is rotated 180 degrees, “1” is arranged on the lower side and detected, so that it is possible to determine the upside down. Also, there is no change in the internal code data itself. Further, when rotated 90 degrees, one of the left and right sides is detected as “0”, and the other side is detected as “1”, so that the left and right 90 degrees rotation can be specified. . The internal code data is detected by being inverted. Therefore, it is possible to reliably detect the upper, lower, left and right, and by adjusting the rearrangement of the data in the condition code decoding process according to the document placement state (including the inversion of “0” and “1”), Decoding mistakes can be prevented.

  Note that, as shown in FIG. 16C, not only the outermost periphery but also the other inner two may be provided with a synchronization code. In this case, the outermost periphery and the respective synchronization codes inside thereof are different. For either one, the same code data is placed on the top, bottom, left and right, and different code data is placed on the top (bottom) and right (left). Although explanation of the rotation of the original and the detection result of the code data is omitted, in this case as well, the upper, lower, left, and right can be detected reliably, and the data when the condition code is decoded according to the original placement state. By adjusting the rearrangement (including the inversion of “0” and “1”), decoding errors can be prevented.

  FIG. 17 illustrates an image generation apparatus and an image forming apparatus (both are collectively referred to as an image processing apparatus) in software using a CPU and a memory, that is, an image processing apparatus is configured using an electronic computer (computer). It is the figure which showed an example of the hardware constitutions in the case of doing.

  The image processing apparatus 900 having this configuration includes a CPU 902, a ROM (Read Only Memory) 904, a RAM 906, and a communication I / F (interface) 908. Further, for example, a recording / reading device for reading and recording data from a storage medium such as a hard disk device 914, a flexible disk (FD) drive 916, or a CD-ROM (Compact Disk ROM) drive 918 may be provided.

  The hard disk device 914, the FD drive 916, or the CD-ROM drive 918 is used for registering program data for causing the CPU 902 to perform software processing, for example. The communication I / F 908 mediates transfer of communication data with a communication network such as the Internet.

  In addition, the image processing apparatus 900 includes a scanner I / F unit 932 that functions as a scanner and a printer I / F unit 934 that functions as a printer. These I / F units may be a cable connection or a wireless connection that can be connected at a short distance, and, like the communication I / F 908, are connected to a scanner or a printer via a communication network such as the Internet. There may be.

  The image processing apparatus 900 having such a configuration can be the same as the basic configuration and operation of the multifunction machine 3 shown in the above embodiment. A program that causes a computer to execute the above-described processing procedure is distributed through a recording medium such as a CD-ROM 922. Alternatively, the program may be stored in the FD 920 instead of the CD-ROM 922. Further, an MO drive may be provided to store the program in the MO, or the program may be stored in another recording medium such as a nonvolatile semiconductor memory card 924 such as a flash memory.

  Furthermore, the program may be downloaded and acquired from another server or the like via a communication network such as the Internet, or may be updated. In addition to the FD 920 and the CD-ROM 922, the recording medium includes an optical recording medium such as a DVD, a magnetic recording medium such as an MD, a magneto-optical recording medium such as a PD, a tape medium, a magnetic recording medium, an IC card, A semiconductor memory such as a miniature card can be used.

  An FD 920, a CD-ROM 922, or the like as an example of a recording medium can store a part or all of the functions of the flowchart showing the processing procedure in the multifunction machine 3 described in the above embodiments. Therefore, the following program and a storage medium storing the program can be provided. For example, the program for the image processing apparatus 900, that is, the software installed in the RAM 906 or the like includes the copy prohibition information detection unit 22, the condition information detection unit 24, the control unit 32, the image processing unit 40, and the like described in the above embodiments. Alternatively, each function unit such as the composite image generation unit 50 is provided as software.

  This software is stored in a portable storage medium such as a CD-ROM or FD as a scanner driver for a reading device, a printer driver for a printing device, or a scanner driver or a printer driver for a multifunction device, or a network. It may be distributed via. The software is not limited to the reading device, the printing device, or the multifunction device side, and may be provided to, for example, a user terminal or device. In this case, the original image and the background image can be synthesized also on the user side.

  For example, when the image generating apparatus or the image forming apparatus is configured by a computer, the CD-ROM drive 918 reads data or a program from the CD-ROM 922 and passes it to the CPU 902. The software is installed from the CD-ROM 922 to the hard disk device 914. The hard disk device 914 stores data or a program read by the FD drive 916 or the CD-ROM drive 918 and data created by the CPU 902 executing the program, and reads the stored data or program to read the CPU 902. To pass.

  The software stored in the hard disk device 914 is read by the RAM 906 and then executed by the CPU 902. For example, the CPU 902 executes the above-described processing procedure based on programs stored in the ROM 904 and the RAM 906, which are examples of recording media, so that the copy prohibition information detection processing, the condition information detection processing, the background image in the processing procedure are performed. A function for generating the image, or a process for synthesizing the original image and the background image can be realized by software.

  FIG. 18 is a diagram illustrating a preferred example of a configuration in which an image processing apparatus is configured using a computer. Hereinafter, this form is referred to as a third embodiment. Here, FIG. 18A is an example of the overall configuration of the image forming system, and FIG. 18B is a part related to background image generation processing and composite image generation processing on the client terminal 2 side, specifically a printer. It is a functional block diagram around a central control unit in which a driver is incorporated.

  The image forming system 1 according to the third embodiment includes a client terminal 2 such as a personal computer that generates document data, and a printer 8 that performs print processing based on the document data transferred from the client terminal 2.

  The client terminal 2 functions as an interface between the printer 8 and a data generation unit 950 that generates document data including text and graphics, a central control unit 960 that controls the operation of each unit of the client terminal 2, and the printer 8. An interface unit 970 and a storage medium 980 such as a hard disk that temporarily stores document data generated by the data generation unit 950 and intermediate data generated during data processing by the central control unit 960 are included.

  In the data generation unit 950, for example, an application program for generating document data including text and graphics is incorporated. Instead of generating the document data by the data generation unit 950, the document data that has been generated by an external device via a network (communication network) or a recording medium may be used.

  The central control unit 960 incorporates an OS (operating system) that is software for controlling the entire client terminal 2 and a printer driver that is software for controlling the printer 8. A printer driver is incorporated in the client terminal 2 so that the functional part of the composite image generation unit 50 housed in the multifunction machine 3 shown in the above embodiment operates using software called a printer driver. It is configured. . That is, a background image is generated by a printer driver, combined with PDL data of a document, and transferred to a printer 8 (including the MFP 3 in the previous example) via a network 9. Each function of background image generation processing and image composition processing is implemented as a computer program called a printer driver.

  Accordingly, the client terminal 2 functions as software based on the program. That is, a program is read from a CD-ROM or the like storing a program for configuring each functional unit and installed in a recording medium 980 such as a hard disk device, and the CPU (not shown) reads the program from the recording medium 980 and By executing the processing procedure shown, each function can be realized in software.

  As shown in FIG. 18B, the central control unit 960 (particularly the printer driver function part; the same applies hereinafter) provided in the client terminal 2 synthesizes a background image with document data input from an application program or the like. The image generation unit 50 is provided as software. The composite image generation unit 50 includes an additional information encoding unit 514, a background image generation unit 518, and an image synthesis unit 522 among the components shown in FIG. A storage medium 980 is used for the document image buffer 508, the pattern image storage unit 516, and the background image buffer 520. The basic operation is the same as in the above embodiment.

  FIG. 19 is a flowchart showing an example of processing procedures of the composite image generation unit 50 in the above-described configuration using a computer, in particular, background image generation processing and image synthesis processing. Here, a description will be given of a form (background image generation processing at the time of printing) in which the printer 8 prints out based on the PDL data transmitted from the client terminal 2.

  First, the user prepares document data by operating the data generation unit 950 or importing it from the outside at the client terminal 2 (S600). Then, a print instruction for the document is issued (S601). Upon receiving this command, the client terminal 2 displays a printer driver screen (S602). On this screen, the user sets additional information to be embedded in the document to be printed (S603). The additional information includes, as described above, duplication prohibition information that prevents a document instructed to be printed out from being copied by a copying machine, information condition information that indicates a condition for enabling copying of a document image instructed to be printed out, Alternatively, there is information indicating a latent image character embedded in the background image.

  When these settings are completed, the printer driver first generates a latent image (S604). Next, the copy prohibition information is encoded into a copy prohibition code, and a copy prohibition code array having a predetermined area size is generated (S606). Next, the condition information is encoded into a condition code, and a condition code array having a predetermined area size is generated (S608). Next, the forbidden copy code array and the condition code array having a predetermined area size are repeatedly arranged in a two-dimensional manner according to a predetermined rule to generate a pattern number array corresponding to the background image (S610).

  Next, referring to the latent image generated in step S604, the pattern number array of the pixels of the latent image character portion is converted according to a predetermined rule (S612, S614). Next, the pattern image corresponding to the code data of each element of the pattern number array is replaced, and this is repeated according to all the pattern number arrays to generate a background image (S616).

  After the above processing is completed, the client terminal 2 converts the document data instructed to be printed into PDL data (S618). Then, the background image drawing command generated in step S616 is inserted into the generated PDL data (S620). Thus, on the PDL data, a drawing command for synthesizing the background image is added to a drawing command for a document image which is an example of the original image. Finally, the PDL data to which the drawing command for synthesizing the background image is added is transmitted to the printer 8 via the network 9 (S622).

  The printer 8 interprets the PDL data received from the client terminal 2 as usual and generates an image for printing. That is, first, a document image is generated in accordance with a document image drawing command, and the background image is overlaid on the previously generated document image in accordance with a drawing command for synthesizing the background image. A binary image for printing combined with the image is generated. Therefore, the printer 8 can print out a composite image obtained by combining the original document image and the background image.

  In the third embodiment, an example has been described in which document data is converted into PDL data, a drawing command for synthesizing a background image is added and transmitted to the printer, and actual image synthesis processing is performed inside the printer. However, the present invention is not limited to this. For example, the document data is converted into image data inside the printer driver, the background image is further combined, and the PDL data of the combined image is transmitted to the printer. The generated document image generation unit may interpret the PDL data to generate a composite image, and then print it out. Alternatively, the image data synthesized by the client terminal may be transmitted to a printer or a multifunction device, and immediately printed out by an image composition unit provided on the printer or multifunction device printer side (in this case, PDL data Need not be interpreted).

  In the third embodiment, the example in which the PDL data of the document data to which the background image drawing command is added is transmitted to the printer or the multifunction device via the network and printed out has been described. When a client terminal and a reading device (scanner) are connected and a read image (scanned image) read by the scanner is printed out, a driver (in this case, a scanner driver may be used) as in the third embodiment. ) To generate a background image, combine it with the read image, send it to a printer, and print it out. This form is a form of scan and print using a network.

  In addition, for example, it may be configured to output to a printer connected in proximity to the client terminal and connected by cable connection or short-range wireless communication (for example, Bluetooth) and print out.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. Various modifications or improvements can be added to the above-described embodiment, and the forms added with such modifications or improvements are also included in the technical scope of the present invention. Moreover, said embodiment does not limit the invention concerning a claim, and all the combinations of the characteristics demonstrated in embodiment are not necessarily essential for the solution means of invention.

  For example, in the above-described embodiment, a pattern image is arranged in a two-dimensional manner according to a predetermined rule, so that a background image is once generated, and a composite image is generated by superimposing the background image and the original image. However, the present invention is not limited to this, and the composite image may be generated while the pattern image is gradually overlaid on the original image according to a predetermined rule.

1 is a diagram showing an overall configuration of an embodiment of an image forming system to which an unauthorized duplication prevention system according to the present invention is applied. 1 is a block diagram illustrating a configuration of an embodiment of a multifunction machine. FIG. 2 is a block diagram illustrating a configuration of an embodiment of a composite image generation unit provided in the multifunction machine. It is a flowchart which shows an example of the process sequence of a background image generation process and an image composition process in a composite image generation part. It is a figure which shows an example of the code data which can be detected at the time of a duplication operation | movement, and an example of the pattern image matched with this code data. It is a figure which shows an example of the background image produced | generated and printed out by combining and arrange | positioning a pattern image. It is a figure which shows the other example of the background image produced | generated by the synthesized image production | generation part. 5 is a flowchart showing an example of a processing procedure when copying a printed document document. It is a block diagram which shows the example of 1 structure of a duplication prohibition information detection part. It is the flowchart which showed an example of the process sequence in a duplication prohibition information detection part. It is a block diagram which shows the example of 1 structure of a condition information detection part. It is the flowchart which showed an example of the process sequence in a condition information detection part. It is a flowchart which shows another example of the process sequence of a background image generation process and an image composition process in a composite image generation part. It is a figure which shows the other example of a pattern image. It is a figure which shows the other example in the case of repeatedly arrange | positioning the unit two-dimensional arrangement | sequence of a prohibition duplication code arrangement | sequence and a condition code arrangement | sequence to the whole original image. It is a figure explaining the relationship between the synchronous code embedded in the outer periphery of a condition code arrangement | sequence, and a decoding process. It is the figure which showed an example of the hardware constitutions in the case of comprising using an electronic computer. It is a figure which shows a suitable example of the form which comprises an image processing apparatus using a computer. It is a flowchart which shows an example of each process sequence of a background image generation process and an image composition process in the composite image generation part in the structure using a computer.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Image forming system, 2 ... Client terminal, 3 ... Multifunction machine, 5 ... Scanner part, 7 ... Printer part, 8 ... Printer, 9 ... Network, 10 ... Image reading part, 20 ... Operation control part, 22 ... Duplication Prohibition information detection unit, 24 ... Condition information detection unit, 26 ... Page buffer, 30 ... Network I / F unit, 32 ... Control unit, 34 ... Control panel, 34a ... Mode indication unit, 34b ... Display device, 40 ... Image processing , 50... Synthetic image generation unit, 80... Selection unit, 90... Image forming unit, 220... Binarization processing unit, 222. ... number calculation section, 232 ... ratio calculation section, 234 ... determination processing section, 240 ... binarization processing section, 242 ... noise removal processing section, 244 ... pattern detection section, 250 ... buffer memo 252 ... Skew angle detection processing unit, 254 ... Code detection processing unit, 256 ... Error correction decoding unit, 502 ... Read image acquisition unit, 504 ... Print data acquisition unit, 506 ... Document image generation unit, 508 ... Document image buffer, 510 ... Additional information extraction unit, 512 ... Latent image generation unit, 514 ... Additional information encoding unit, 515 ... Latent image buffer, 516 ... Pattern image storage unit, 518 ... Background image generation unit, 520 ... Background image buffer, 522 ... Image composition unit

Claims (25)

An image acquisition unit for acquiring an original image;
A control information acquisition unit for acquiring control information for controlling reproduction of the original image;
A pattern image region generation unit that generates a pattern image region by changing a pattern image arrangement method according to the type of the control information acquired by the control information acquisition unit;
A composite image generation unit that combines the original image acquired by the image acquisition unit and the pattern image region generated by the pattern image region generation unit ;
When the type of the control information is a duplication condition, the pattern image region generation unit represents the duplication condition by arranging a plurality of different types of machine-readable pattern images according to a data array indicating the duplication condition. Composite the copy condition image area to the original image
An image generation apparatus characterized by that. The pattern image region generation unit generates the pattern image region representing copy prohibition in which a single machine-readable pattern image is arranged when the type of the control information is copy prohibition. The image generating apparatus according to 1. When the type of the control information is copy prohibition, the pattern image region generation unit performs copy prohibition arranged so that the ratio of the number of the same pattern images included in the pattern image region is larger than a predetermined value. The image generation apparatus according to claim 1, wherein the pattern image region to be expressed is generated. The pattern image region generation unit generates another pattern image region representing the copy prohibition using a single pattern image different from the pattern image used in the pattern image region representing the copy prohibition. ,
The composite image generation unit combines the pattern image region representing each copy prohibition generated by the pattern image region generation unit and the original image acquired by the image acquisition unit. The image generating apparatus described. The image generation apparatus according to claim 4, wherein the composite image generation unit arranges pattern image regions representing the copy prohibitions generated by the pattern image region generation unit in a predetermined repetition cycle. When the type of the control information is a duplication condition, the pattern image area generation unit arranges each pattern image used in the pattern image area representing each duplication prohibition according to a data array indicating the duplication condition. the image generating apparatus according to claim 1, characterized in that to produce a copy condition image area representing the copy condition. The composite image generation unit, the copy condition image area of a predetermined size, the image generating apparatus according to any one of claims 1, characterized in that arranged at a predetermined repetition cycle 6. The image according to any one of claims 1 to 7 , wherein the pattern image region generation includes information for specifying a position of the duplication condition image region in the duplication condition image region. Generator. The pattern image area generation unit decodes the duplication condition in which the same digital code is continuously arranged on the outer periphery of the duplication condition image area as information for specifying the position of the duplication condition image area The synchronization code part is arranged so that the number of consecutive identical digital codes is smaller than the number of data strings of the same digital code on the side of the area excluding the synchronization code part. Item 9. The image generation device according to Item 8 . The pattern image area generation section, the information for specifying the rotational orientation of the copy condition image area to any one of claims 1 to 9, characterized in that included in the copy condition image area The image generating apparatus described. A first control information acquisition unit that acquires first control information indicating the presence or absence of a duplication condition that is an example of the control information;
A second control information acquisition unit for acquiring information related to the replication condition when there is the replication condition;
An encoding unit that generates code data indicating the replication condition by performing error correction encoding on the information regarding the replication condition acquired by the second control information acquisition unit, and
The pattern image area generation section, any of the claims 1 to 10, characterized by arranging the pattern image according to the data sequence of the code data indicating the error correction coded the copy condition by the encoding unit The image generating apparatus according to claim 1. The original image includes a text object,
The composite image generation unit so as to overlap at least a portion of the text object in which the pattern image is included in the original image, any one of the claims 1 to 11, characterized in that is combined with the original image The image generating apparatus according to item 1. The original image includes a graphic object,
The composite image generating unit, any one of the claims 1 to 12, wherein the pattern image is synthesized with the original image so as to overlap at least a portion of the graphic objects contained in the original image The image generation apparatus according to item. When the type of the control information is a latent image, the pattern image area generation unit arranges the pattern images different from the pattern image used for the pattern image area indicating the copy prohibition and the copy condition image area. Generating the pattern image area representing a latent image;
The composite image generating unit, the pattern image regions representing the pattern the latent image of the image region generating unit has generated, among of claims 1 to 13, characterized by combining the original image by the image acquisition unit has acquired The image generation apparatus according to any one of the above. The image generation apparatus according to claim 14 , wherein the composite image generation unit uses a pattern image that cannot be resolved by an apparatus used for duplication as the pattern image for latent image information. The composite image generation unit is configured so that the number of output pixels per unit area of the pattern image for latent image information is equal to the number of output pixels per unit area of the pattern image representing the copy prohibition. 16. The image generation apparatus according to claim 14 , wherein the image generation apparatus is characterized in that: An image reading unit that reads an image generated by the image generation device according to any one of claims 1 to 16 ,
A pattern image detection unit for detecting the pattern image included in the read image read by the image reading unit; a control unit for controlling the duplication operation based on a detection result detected by the pattern image detection unit; An image reading apparatus comprising: The control unit, when the pattern image detection unit detects a pattern image area representing the duplication prohibition from the image read by the image reading unit, controls to prohibit the duplication operation. The image reading device according to 17 . When the pattern image detection unit detects a pattern image area representing the duplication condition from the image read by the image reading unit, the control unit cancels the duplication prohibition within a limited range that matches the condition, and performs duplication. The image reading apparatus according to claim 17 , wherein the image reading apparatus is controlled so as to allow the operation. The control unit determines whether the image is a copy-prohibited target image based on whether the pattern image detection unit detects a pattern image region representing the copy prohibition information, and the pattern image detection unit When the pattern image area representing the prohibition information is detected, the duplication operation is stopped, and when the pattern image detection unit detects the pattern image area representing the duplication condition from the image read by the image reading unit, 18. The image reading apparatus according to claim 17 , wherein control is performed so as to cancel the stop of the duplication operation in accordance with a condition indicated by an arrangement of pattern images in a pattern image area representing a duplication condition. The pattern image detection unit determines whether or not the determination target image block corresponds to the pattern image region indicating the duplication prohibition based on the number and ratio of the pattern images present in the determination target image block. The image reading apparatus according to claim 17 , wherein the determination is performed. The image generation device according to any one of claims 1 to 16 ,
An unauthorized duplication prevention system comprising: the image reading device according to any one of claims 17 to 21 . A program for an image generation device that synthesizes control information for controlling reproduction of an original image with the original image,
Computer
An image acquisition unit for acquiring an original image;
A control information acquisition unit for acquiring control information for controlling reproduction of the original image;
A pattern image region generation unit that generates a pattern image region by changing a pattern image arrangement method according to the type of the control information acquired by the control information acquisition unit;
While functioning as a composite image generation unit that combines the original image acquired by the image acquisition unit and the pattern image region generated by the pattern image region generation unit ,
When the type of the control information is a duplication condition, the pattern image region generation unit represents the duplication condition by arranging a plurality of different types of machine-readable pattern images according to a data array indicating the duplication condition. Make the copy condition image area function to be combined with the original image
A program characterized by that. Image reading for controlling the duplication operation by extracting the control information from the read image obtained by reading the image generated by the image generation device according to any one of claims 1 to 16. A program for a device,
Computer
A pattern image detection unit for detecting the pattern image included in the read image;
A program that functions as a control unit that controls the duplication operation based on a detection result detected by the pattern image detection unit. An output medium manufacturing method in which control information for controlling duplication is embedded in an original image,
The arrangement method of the pattern image by changing depending on the type of the control information, hit the synthesized pattern image region formed by arranging the pattern image in a predetermined order before Kihara image,
When the type of the control information is a duplication condition, a plurality of different types of machine-readable pattern images are arranged in accordance with a data array indicating the duplication condition, so that a duplication condition image area representing the duplication condition is displayed in the original image method for producing an output medium, characterized by synthesized.

Images