JP2007166332A - Apparatus and method for processing image - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processing apparatus capable of burying code information without reducing print speed. <P>SOLUTION: A composite machine 1 includes an image development means 2 for entering a document image, fixed information, and page unit information; a control means 9 for encoding the fixed information and the page unit one as a fixed information code and a page information one; a background pattern image generation means 10 for arranging each code encoded by the control means 9 in a prescribed region of the image to generate the background pattern image; an image composite means 11 for compositing the document image and the background pattern one; and a print means 12 for providing on output of the composite image composited by the image composite means 11. The background pattern image generation means rewrites only a region for arranging the page information code in the background pattern image for each page of the document image to be output. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image processing apparatus and an image processing method capable of preventing information leakage of confidential documents.

  In recent years, with the spread of personal computers, printers, and copying machines, there has been a problem of information leakage due to unauthorized copying of confidential documents printed out. As a conventional technology for preventing and suppressing unauthorized copying of confidential documents, when printing confidential documents, copy prohibition information is embedded in the image and then printed out, and when copying, the original is read and embedded in the image. Multifunction devices having an illegal copy prohibition function are being studied, such as detecting copy prohibition information being detected and stopping normal copy operations when copy prohibition information is included (see, for example, Patent Document 1). ).

  Further, the illegal copy prohibition function has been developed, and two types of copy prohibition information in an image and copy permission condition information (for example, a personal identification number) for permitting copying under a specific condition when a confidential document is printed. Information is embedded and printed out, and at the time of copying, two types of information, copy-prohibited information and copy-permitted condition information, embedded in the image are detected from the scanned image to determine whether the copy-permitted condition is met. A multifunction device having an advanced illegal copy prohibition function is also considered, in which the copy operation is stopped when the copy permission condition is not met, but the copy operation is performed when the copy permission condition is met. Here, as an embedding method of copy prohibition information / copy permission condition information, for example, the following method has been proposed (for example, see Patent Document 2).

  That is, a background copy-forgery-inhibited pattern image having a comparatively low density is synthesized with a minute pattern on the entire background of the document image. The background copy-forgery-inhibited pattern image is composed of two regions, a latent image character region and a background region, and each region is composed of different micropatterns. The latent image character area is composed of a relatively small dot pattern, and the background area is composed of an array of two kinds of minute oblique line patterns. The two types of diagonal lines represent bits 0 and 1, respectively, and two-dimensional code images in which the two types of diagonal patterns are two-dimensional arrays of a predetermined size are repeatedly arranged adjacent to each other in the background portion. It has become. The copy permission condition information is embedded in this two-dimensional code.

As copy prohibition information, the inside of the two-dimensional array is embedded with a special code composed of a diagonal line pattern corresponding to bit 0, or the inside of the two-dimensional array is embedded with a special code composed of a diagonal line pattern corresponding to bit 1. As another conventional example for preventing unauthorized copying of confidential documents, when printing confidential documents, information related to the user who performed the printing, date / time information, etc. are embedded and printed out. An image processing apparatus that analyzes a user, a client PC, a printer, and a date and time embedded in an image that has been read and read to identify an information leakage source has been studied. This function can be configured as an additional function of the conventional multifunction peripheral.
JP 2003-280469 A JP 2003-283790 A

  However, when embedding different information in units of pages such as page numbers as information to be embedded when a confidential document is printed out, it is necessary to generate a background copy-forgery-inhibited pattern image in which code information is embedded in units of pages and combine it with the document image. Therefore, there is a problem that the processing time for generating the background copy-forgery-inhibited pattern image becomes long and the printing speed is reduced.

  SUMMARY An advantage of some aspects of the invention is that it provides an image processing apparatus and an image processing method capable of embedding code information without reducing printing speed.

  In order to solve the above problems, an image processing apparatus of the present invention includes an image input unit for inputting a document image, an information input unit for inputting fixed information and page unit information, and the fixed information and the page unit information. Coding means for coding as a fixed information code and a page information code; and a background tint pattern image creating means for generating a background tint pattern image by arranging each code coded by the coding means in a predetermined area of the image; An image synthesizing unit that synthesizes the document image and the background tint block image; and an image output unit that outputs a synthesized image synthesized by the image synthesizing unit. Every time, the area where the page information code is arranged is rewritten in the background pattern image.

  According to the present invention, information to be embedded is divided into information that is switched in units of pages such as page numbers, and information that is always fixed such as user information and machine identification information, and individual digital codes are generated. . Then, the background pattern image is divided into a plurality of code blocks, and it is determined which information code is arranged in each code block. A code image including only the fixed information code is generated and stored in advance. At the start of printing, a page unit information code is generated and inserted into the background pattern image. For the second and subsequent pages, only a page unit information code is newly generated, and only that portion is inserted to form a background tint block image for each page. Since it is only necessary to generate a minimum number of images for each page, the processing time can be shortened and a decrease in printing speed can be suppressed.

  The image processing apparatus of the present invention further includes an image storage unit that stores the document image and the background background pattern image in association with a page number, and the background background pattern image generation unit includes, for each page of the document image to be output, Rewriting only the area where the page information code is arranged in the background background pattern image, generating a plurality of background background images corresponding to each page of the document image and storing them in the image storage means, the image composition means, The document image and the background pattern image of each page stored in the image storage unit are read and combined.

  In the image processing apparatus of the present invention, the information input unit further inputs job unit information, the encoding unit encodes the job unit information as a job information code, and the background tint block image generation unit includes the job unit information. Every time, only the area where the job code is arranged is rewritten in the background tint pattern image. According to the present invention, when there is job unit information to be switched to a print job unit, such as UUID, a job unit information code is generated based on the job unit information and is inserted into the background pattern image. Since it is only necessary to generate a minimum number of images for each job, the processing time can be shortened and a decrease in printing speed can be suppressed.

  The image processing method of the present invention includes an image input step for inputting a document image, an information input step for inputting fixed information and page unit information, and the fixed information and the page unit information as a fixed information code and a page information code, respectively. A coding step for coding; a background tint block image generating step for generating a background tint block image by arranging each code coded by the coding means in a predetermined region of the image; and the document image and the background tint block image An image synthesizing step, and an image output step for outputting the synthesized image synthesized by the image synthesizing unit, wherein the background tint block image generating step includes the background tint block image for each page of the document image to be output. The area where the page information code is arranged is rewritten. According to the present invention, it is only necessary to generate a minimum number of images for each page, so that the processing time can be shortened and a decrease in printing speed can be suppressed.

  According to the present invention, it is possible to provide an image processing apparatus and an image processing method capable of embedding code information without reducing the printing speed.

  Hereinafter, the best mode for carrying out the present invention will be described. FIG. 1 is a block diagram of a multifunction machine according to an embodiment of the present invention. The multifunction device 1 as an image processing apparatus has a plurality of functions such as a print function, a copy function, and a scan function. The multi-function device 1 is connected to a client PC (personal computer) connected to a network such as a LAN (Local Area Network). As shown in FIG. 1, the multi-function device 1 includes an image developing unit 2 as an image input unit and an information input unit, an image storage unit 3, a reading unit 4, a scanned image processing unit 5, a prohibited code detecting unit 6, a digital code decoding unit. Means 7, user interface means 8, control means 9 as code means, background tint block image generation means 10, image composition means 11, and printing means 12 as image output means.

  The image expansion means 2 generates document image data by performing drawing processing of print data (hereinafter referred to as “PDL data”) described in a print description language (PDL) input via the LAN, and draws the drawing. The document image data is stored in the image storage means 3. The image storage unit 3 stores the document image and the background copy-forgery-inhibited pattern image in association with the page number. The reading unit 4 reads a document placed on the platen and outputs the read image data to the scanned image processing unit 5. The scanned image processing unit 5 performs image processing such as image correction, color conversion, and enlargement / reduction on the read image, and stores the image in the image storage unit 3. The prohibition code detection means 6 detects the prohibition code from the image read by the reading means 4. The digital code decoding means 7 decodes the digital code from the image read by the reading means 4. The user interface means 8 has an input / output device such as a touch panel display, and is a part that receives various operations and input of embedded information from the user.

  The control means 9 controls the entire multifunction device 1. The control means 9 encodes the fixed information, job information, and page unit information as a fixed information code, job information code, and page information code, respectively. The fixed information includes a machine identification ID of the MFP, a network address (IP address, MAC address), and the like. The job information includes a job identification ID, a transmission source PC network address, a user ID, an output start date and time, a total number of pages, and the like. The page information includes a page number and the like. The part information is information on some of the copies.

  The background copy-forgery-inhibited pattern image generation means 10 generates a background copy-forgery-inhibited pattern image by arranging each code encoded by the control means 9 in a predetermined area of the image. At this time, the background copy-forgery-inhibited pattern image generation means 10 rewrites only the area in which the page information code is arranged in the background copy-forgery-inhibited pattern image for each page of the output document image. That is, for each page of the document image to be output, the background pattern image generation unit 10 rewrites only the area where the page information code is arranged in the background pattern image and generates a plurality of background pattern images corresponding to each page of the document image. And stored in the image storage means 3. The image composition unit 11 synthesizes the document image and the background pattern image generated by the background pattern image generation unit. At this time, the image synthesizing unit 11 reads and synthesizes the document image and the background tint block image of each page accumulated in the image accumulating unit 3. The printing unit 12 prints and records the combined image data synthesized by the image synthesizing unit 11 on a sheet and outputs it.

  Next, background tint block image generation processing will be described. FIG. 2 is a schematic diagram for explaining the code. FIG. 3 is a schematic diagram for explaining the pattern number arrangement. Additional information (copy prohibition information, condition information, latent image information) is input from the control unit 9 to the background tint block image generation unit 10. The background tint block image generation means 10 generates a latent image based on the input latent image information. 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, and latent image character string direction ( Angle) and other information. The background copy-forgery-inhibited pattern image generation means 10 generates a binary latent image image by drawing a latent image character string in the specified direction with the specified font type and font size.

  Here, the resolution of the latent image is a resolution obtained by dividing the resolution of the printer by the size of a pattern to be described later. For example, when the printer resolution is 600 dpi and the pattern size is 12 pixels × 12 pixels, the resolution of the latent image is 50 dpi. The background copy-forgery-inhibited pattern image generation means 10 encodes the input copy prohibition information and condition information.

  First, when the copy prohibition information indicates that the document that has been printed out is not to be copied by the copying machine, two types of copy prohibition codes shown in FIGS. 2A and 2B are generated. Here, the copy prohibition code in FIG. 2 (A) has a bit 0 in the entire code, and the copy prohibition code in FIG. is there. When copy prohibition information is not input or when it does not indicate that a document that has been printed out is not to be copied by a copying machine, the two types of codes shown in FIGS. 2A and 2B are generated. Not done.

  Next, when condition information is input, an error correction code is applied to the condition information to generate a digital code as shown in FIG. The digital code in FIG. 2C represents a bit string of the encoded condition information by the arrangement of bit 0 and bit 1. The outer periphery of the cord has a special bit pattern for facilitating the positioning of the cord. Next, a plurality of the generated codes are repeatedly arranged as shown in FIG. 3A to generate a pattern number array having the same size as the size of the latent image. Here, the hatched rectangle in FIG. 2 is the copy prohibition code in FIG. 2A, the vertical hatched rectangle is the copy prohibition code in FIG. 2B, and the dot hatched rectangle is in FIG. 2C. It has become a digital code.

  If a copy prohibition code is not generated, a digital code is placed in the copy prohibition code portion in the figure. If a digital code is not generated, a copy prohibition code is placed in the digital code portion in the figure. At this time, the value of each element of the pattern number array is 0 or 1. Next, referring to the latent image, the pattern number of the element of the pattern number array corresponding to the coordinates of the black pixels in the latent image is changed to 2. If this is performed for all the black pixels in the latent image, the pattern number arrangement is such that the latent image characters are drawn with the pattern number 2 on the background where the copy prohibition code and the digital code are arranged side by side. This state is shown in FIG. A black “COPY” portion in the figure indicates a portion in which the pattern array number is changed to “2”. This pattern number array is output to the background tint block image generation means 10.

  The background copy-forgery-inhibited pattern image generation unit 10 refers to each element of the input pattern number array, reads a pattern corresponding to the pattern number from the pattern storage unit, and converts it into a pattern image, thereby generating a background copy-forgery-inhibited pattern image. The generated background tint block image is stored in the image storage means 3.

  4A and 4B are schematic diagrams showing examples of patterns stored in the pattern storage unit. FIG. 4A is a pattern corresponding to pattern number 0, FIG. 4B is a pattern corresponding to pattern number 1, and FIG. 4C is a pattern number. 2 is a pattern corresponding to 2. Here, the pattern number array corresponds to the resolution of the image obtained by dividing the printer resolution by the pattern size, and the pattern image generated based on this 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. Also, the pattern image is an image in which the latent image character is converted into an isolated dot pattern by converting it into a hatched pattern corresponding to the bit value of the copy prohibition code and digital code.

  The pattern image generated in this way is stored in the image storage means 3 as a background tint block image, is synthesized with the document image data, and is printed out on paper. FIG. 5 is a schematic diagram illustrating an example of print output and copy output. An example of a printed image is shown in FIG. 5A (for convenience of explanation, the document image shows an example of a pure white image having no image elements). FIG. 5C is an enlarged view of the area surrounded by the rectangle in FIG. FIG. 5B shows a copy output image when FIG. 5A is copied by a copying machine.

  Next, an operation at the time of printing when generating a background copy-forgery-inhibited pattern image for each page will be described. FIG. 6 is a code layout diagram. The background pattern image generation means 10 finally generates a background pattern image as shown in FIG. As shown in FIG. 6, a copy prohibition code T1 with all bits 0 inside the code and a copy prohibition code T2 with all bits 1 inside the code are arranged every other code. , Job information code B and page information code C are sequentially arranged. Here, the fixed information code A is always the same code even when the job or page is changed, the job information code B is the same code in the same job, and the page information code C is different for each page. FIG. 7 is a diagram of the initial background pattern image stored in the image storage unit 3.

  FIG. 8 is an operation flowchart during printing. In step S11, print data is received via the network and notified to the control means 9. In step S <b> 12, the image development unit 2 generates a document image by decomposing the received print data, and stores the document image in the image storage unit 3. For multiple pages, decompose all pages. In step S 13, the initial background pattern image stored in the image storage unit 3 is read out and input to the background pattern image generation unit 10. Here, as shown in FIG. 7, the initial background tint block image is pre-arranged with bit 0 and bit 1 prohibition codes and fixed information codes, and the area BX and page where the job information code B is to be embedded. No code is stored in the area CX where the information code C is to be embedded.

  In step S14, job information is input from the control means 9 to the background pattern image generation means 10 to generate a background pattern image. In step S15, the background copy-forgery-inhibited pattern image generation unit 10 generates a job code image from the job information, and writes the job code image in the area BX in which the job code of the initial background copy-forgery-inhibited pattern image is arranged. In step S16, the page information of the first page is encoded, and the page code image is written in the area CX in which the page code of the initial background pattern image is arranged. In step S17, the control unit 9 starts image output for the first page. The image composition unit 11 reads the document image of the first page from the image storage unit 3, composes the background pattern image input from the background pattern image generation unit 10, and outputs it to the printing unit 12. In step S18, printing (image formation) is performed on the paper by the printing means 12. In step S19, steps S16 to S19 are repeated for all pages. When all pages are printed, the printing operation is terminated.

  Next, another operation example of the multifunction peripheral according to the embodiment of the present invention will be described. FIG. 9 is another flowchart of the operation of the multifunction machine 1 according to the embodiment of the present invention. Here, an example of generating and accumulating background copy-forgery-inhibited pattern images for all pages and outputting them at once is shown.

  In step S21, print data is received via the network and notified to the control means 9. In step S <b> 22, the image development unit 2 generates a document image by decomposing the received print data, and stores the document image in the image storage unit 3. For multiple pages, decompose all pages. In step S 23, the initial background pattern image stored in the image storage unit 3 is read out and input to the background pattern image generation unit 10. Here, similarly to the above, the prohibition code and the fixed information code are arranged in advance in the initial background pattern image. In step S24, job information is input from the control unit 9 to the background tint block image generation unit 10 to generate a background tint block image.

  In step S25, the background copy-forgery-inhibited pattern image generation means 10 generates a job code image from the job information, and writes the job code image in the area BX (FIG. 7) in which the job code of the initial background copy-forgery-inhibited pattern image is arranged. In step S26, the page information of the first page is encoded, and the page code image is written in the area CX (FIG. 7) in which the page code of the initial background pattern image is arranged to generate the background pattern image of the first page. The image is stored in the image storage unit 3 in association with the document image of the eye. Similarly, background copy-forgery-inhibited pattern images for all pages are generated and stored in the image storage means 3. In step S27, after the background tint block image generation process is completed, the control unit 9 starts image output. The image synthesizing unit 11 reads out the document image and the background copy-forgery-inhibited pattern image sequentially from the first page from the image storage unit 3, synthesizes them, and outputs them to the printing unit 12. In step S28, the printing unit 12 performs printing (image formation) on the paper. In step S29, steps S27 to S29 are repeated for all pages. When all pages are printed, the printing operation is terminated.

  According to the above embodiment, the information to be embedded is divided into information that switches in units of pages, such as page numbers, and fixed information such as user information, machine identification information, etc., and individual digital codes are generated. To do. Then, the background pattern image is divided into a plurality of code blocks, and it is determined which information code is arranged in each code block. A background copy-forgery-inhibited pattern image including only the fixed information code is generated and stored in advance. At the start of printing, a page unit information code is generated and inserted into the background pattern image. For the second and subsequent pages, only a page unit information code is newly generated, and only that portion is inserted to form a background tint block image for each page. Since it is only necessary to generate a minimum number of images for each page, the processing time can be shortened and a decrease in printing speed can be suppressed.

  Note that the image processing method of the present invention is realized by the multifunction device 1. The multi-function device 1 is realized using, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The image processing method of the present invention can be realized as a program executed by controlling a computer. This program can be provided by being stored and distributed in a magnetic disk, an optical disk, a semiconductor memory, or other recording media, or distributed via a network.

  Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications, within the scope of the gist of the present invention described in the claims, It can be changed.

1 is a block diagram of a multifunction machine according to an embodiment of the present invention. It is a schematic diagram explaining a code | cord | chord. It is a schematic diagram explaining a pattern number arrangement | sequence. It is a schematic diagram which shows the example of a pattern. It is a schematic diagram which shows the example of a print output and a copy output. FIG. It is a figure of the initial background tint block image accumulated in the image accumulation means. 6 is an operation flowchart at the time of printing of the multifunction peripheral according to the embodiment of the present invention. 6 is another operation flowchart of the multi-function peripheral according to the embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Multifunction machine 2 Image expansion means 3 Image storage means 4 Reading means 5 Scan image processing means 6 Prohibition code detection means 7 Digital code decoding means 8 User interface means 9 Control means 10 Background tint block image generation means 11 Image composition means 12 Printing means

Claims (4)

An image input means for inputting a document image;
Information input means for inputting fixed information and page unit information;
Encoding means for encoding the fixed information and the page unit information as a fixed information code and a page information code, respectively;
A background copy-forgery-inhibited pattern image generating means for generating a background copy-forgery-inhibited pattern image by arranging each code encoded by the encoding means in a predetermined region of the image;
Image synthesizing means for synthesizing the document image and the background copy-forgery-inhibited pattern image;
Image output means for outputting a synthesized image synthesized by the image synthesizing means,
The image processing apparatus according to claim 1, wherein the background tint block image generation unit rewrites an area where the page information code is arranged in the background tint block image for each page of the document image to be output. Image storage means for storing the document image and the background copy-forgery-inhibited pattern image in association with page numbers;
The background pattern image generation means rewrites only a region in which the page information code is arranged in the background pattern image for each page of the document image to be output, and generates a plurality of background pattern images corresponding to each page of the document image. Generated and stored in the image storage means,
2. The image processing apparatus according to claim 1, wherein the image synthesizing unit reads out and synthesizes the document image and the background tint block image of each page accumulated in the image accumulation unit. The information input means further inputs job unit information,
The encoding means encodes the job unit information as a job information code,
The image processing apparatus according to claim 1, wherein the background tint block image generation unit rewrites only an area where the job code is arranged in the code image for each job. An image input step for inputting a document image;
An information input step for inputting fixed information and page unit information;
A coding step of coding the fixed information and the page unit information as a fixed information code and a page information code, respectively;
A background copy-forgery-inhibited pattern image generating step for generating a background copy-forgery-inhibited pattern image by arranging each code encoded by the encoding means in a predetermined region of the image;
An image synthesis step of synthesizing the document image and the code image;
An image output step of outputting a synthesized image synthesized by the image synthesizing means,
The image processing method according to claim 1, wherein the background pattern image generation step rewrites only a region where the page information code is arranged in the background pattern image for each page of the document image to be output.

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