JP2008219331A - Image processor, image processing method and image processing program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processor capable of giving priority to either of the improvement of tracking performance and reduction in toner consumption, or adjusting the balance of the both. <P>SOLUTION: The image processor capable of embedding a dot pattern constituted of a plurality of dots as digital watermark data comprises: a pattern size calculation means for calculating the size of the dot pattern; a margin area calculation means for calculating the size of a margin area which is not a print object in a printable area where an original can be printed; a pattern size reception means for receiving the setting of the size of the dot pattern; a pattern size change means for changing the size of the dot pattern on the basis of the setting of the size received by the pattern size reception means; and an embedding means for embedding the dot pattern whose size is changed in the margin area. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image processing apparatus, an image processing method, and an image processing program, and more particularly to an image processing apparatus that can embed digital watermark data.

In a printing apparatus, digital watermarks are used to prevent unauthorized copying of paper on which image data has been printed or the image data itself, or to identify the source of the paper or image data. The digital watermark is composed of, for example, a dot pattern made up of a plurality of dots, and information on the output person can be read from the dot pattern. In this way, for example, the outflow route can be traced by embedding a digital watermark in the image data. The digital watermark is also used to verify the presence / absence and authenticity of tampering. For the digital watermark used in this way, for example, in Patent Document 1, a blank portion having no character data is detected and the blank is detected. A technique for embedding digital watermark data in a portion is described.
JP 2005-38243 A

  By the way, a technique for adjusting the density of digital watermark data by changing the size of the dot itself is known. That is, if the dot size is increased, the electronic watermark can be read reliably, but the density increases and the toner consumption increases. On the other hand, if the dot size is reduced, the density decreases and the toner consumption can be reduced.

  However, if the dot size is reduced, there is a possibility that the dots cannot be detected, which causes a problem in so-called tracking performance. As described above, there is a limit from the viewpoint of tracking performance to reduce the dot size for the purpose of reducing the toner consumption.

  The present invention has been made in view of the above-described problems in the prior art, and selects whether to give priority to improving tracking performance or reducing toner consumption or adjusting the balance between the two. An object of the present invention is to provide an image processing apparatus or the like that can be used.

  In order to achieve the above object, the image processing apparatus provided by the present invention calculates the size of a dot pattern on the assumption that a dot pattern composed of a plurality of dots can be embedded as digital watermark data. Pattern size calculating means, and margin area calculating means for calculating the size of a blank area that is not to be printed in a printable area where a document can be printed. The pattern size calculation means calculates the size of the dot pattern by expanding the digital watermark data set by the user into image data that can be visually recognized. The margin area calculation means calculates the size of the margin area by expanding the print image data set by the user into image data.

  The user who has obtained information about the size of the dot pattern and the size of the margin area determines how many dot patterns are embedded in the margin area. For example, by repeatedly embedding a plurality of dot patterns having the same information, even if there is a dot pattern that cannot be read in part, it can be read from other dot patterns, leading to improved tracking performance. On the other hand, by reducing the number of patterns to be embedded, toner consumption can be reduced.

  In this way, the user determines the number of embedding patterns and the size of the dot pattern based on the number of patterns in consideration of improvement in tracking performance and reduction in toner consumption.

  The image processing apparatus according to the present invention further includes pattern size changing means for changing the size of the dot pattern, and embedding means for embedding the dot pattern whose size has been changed as digital watermark data in the margin area.

  The pattern size changing means changes the size of the dot pattern based on the number of embedded patterns and the size of the dot pattern determined by the user as described above. For example, pattern size receiving means for receiving the setting of the size of the dot pattern may be provided, and the size may be changed based on the size setting received by the pattern size receiving means.

  As described above, according to the image processing apparatus of the present invention, the dot pattern size can be increased when priority is given to the reduction in toner consumption. As a result, the number of patterns that can be embedded is reduced and toner consumption can be suppressed. Note that even if the size of the dot pattern is increased, the size of the dot itself does not change.

  On the other hand, when priority is given to improving the tracking performance, the dot pattern size is reduced. As a result, it is possible to embed a large number of patterns having the same information, and even if there is a dot pattern that cannot be read in part, the possibility of reading from another dot pattern increases. In this way, priority can be given to either reducing toner consumption or improving tracking performance.

  Further, there is a case where it is desired not to give priority to either one but to suppress the toner consumption while maintaining a constant tracking performance. In such a case, by appropriately increasing the size of the dot pattern, it is possible to achieve a balance between tracking performance and toner consumption reduction.

  According to another aspect, the present invention can provide an image processing program for causing a computer to function as the above-described image processing apparatus, and a computer-readable recording medium on which the program is recorded.

  According to the present invention, priority can be given to either improvement of tracking performance or reduction of toner consumption, or the balance of both can be adjusted.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a simplified diagram of the overall configuration of an image processing system according to the present embodiment.

  The present invention is embodied as a computer 100 connected to a printing apparatus 101 such as a printer 102 or a multifunction machine 103 via a network 104 and an image processing program operating on the computer 100. As the computer 100, a general general-purpose computer such as a personal computer or a server can be used. The computer 100 generates a digital watermark and embeds the digital watermark in print image data. Then, the computer 100 outputs the print image data in which the digital watermark is embedded to the printing apparatus. The printing apparatus 101 prints a print image in which a digital watermark is embedded on paper based on the acquired print image data with a digital watermark.

  In the present embodiment, data embedded as a digital watermark is copy-forgery-inhibited pattern image data printed as a dot pattern together with print image data. Even if the paper on which the printed image is printed flows out, the source of the outflow can be identified by the tracking information embedded in the dot pattern consisting of multiple dots (also referred to as the tint block pattern or tint block tile). Outflow is deterred.

  FIG. 2 is a diagram illustrating an example of a hardware configuration of a computer used for image processing. The computer 100 has a CPU 201 and a bus 202. The CPU 201 is connected to the ROM 203 and the RAM 204 through the bus 202. When the computer 102 is started in accordance with a program instruction stored in the ROM 203, the CPU 201 operates a part or all of the OS 205 on the RAM 204. The RAM 204 stores files of print image data 210 and copy-forgery-inhibited pattern image data 211 based on user input.

  An input device 206, a display device 207, and a communication interface 208 are also connected to the bus 202. As the input device 206, a cursor device such as a mouse or a trackball, or a keyboard can be used. As the display device 207, a liquid crystal display or a CRT display can be used. A communication interface 208 connects the computer 100 to the network 104.

  Further, an HDD 209 is also connected to the bus 202 as one of storage devices. The HDD 209 stores a file of an image processing program 212 that executes processing of the print image data 210 for causing the computer 100 to function as an image processing apparatus. The CPU 201 reads the image processing program 212 from the HDD 209 via the bus 202 and executes processing of the print image data 210 in accordance with an instruction of the program 212. This process includes a process of embedding the copy-forgery-inhibited pattern image data 211 in the print image data 210.

  Further, the HDD 209 stores a file of the printer driver 213 in addition to the file of the image processing program 212. The file of the printer driver 213 is stored in advance in the HDD 209 according to the printing apparatus 101 used by the user of the computer 100, and is called when a print instruction is received from the user. The printer driver 213 converts the data into a format that can be processed by the corresponding printing apparatus 101, and outputs the print data to the printing apparatus 101. For example, when the printer 105 receives the print data via the network 104, the printer engine 216 prints the data on a sheet under the control of the printer controller 215.

  As described above, the computer 100 performs input / output to / from files on the ROM 203 and the HDD 209 in accordance with instructions from the image processing program 212 and the printer driver 213, and processes the print image data stored in the ROM 203. Function as.

  FIG. 3 is a diagram illustrating an example of the data structure of the tint block data. The copy-forgery-inhibited pattern data is output person information for specifying the outflow source, and is input from the input device by the user. The copy-forgery-inhibited pattern data 301 includes a computer-specific address (for example, a MAC (Media Access Control) address, IP address) necessary for transmitting and receiving data via the network, a host name given to the computer on the network, a printing date and time, Document names, user definitions (eg, user code or name), etc. can be used. The user does not necessarily need to input all items of the tint block data 301, and may input only desired data items. A tint block image (that is, a dot pattern composed of a plurality of dots) is generated based on the tint block data.

  FIG. 4 is a diagram illustrating an image in a state where print image data is output to the printable area. The print image data is input from the input device by the user. The printable area 401 of the present embodiment extends over the entire printing surface of the document, and the print area 402 (that is, the area that is scheduled to be printed) that is a print target and the blank area 403 that is not the print target (that is, no printing is performed). Scheduled area). A background pattern (that is, a dot pattern composed of a plurality of dots) is embedded in the blank area 403.

  Next, specific means for processing the print image data will be described. Each means shown below operates when the CPU 201 executes a program.

  FIG. 5 is a diagram illustrating an example of a functional configuration of the image processing apparatus. The computer 100 includes a tint block data reception unit 501, a tint block image data generation unit 502, a tint block image data storage unit 503, and a pattern size calculation unit 504.

  The background pattern data receiving unit 501 receives the background pattern data set by the user from the input device.

  A tint block image data generation unit 502 generates tint block image data representing a dot pattern composed of a plurality of dots (hereinafter referred to as tint block image data) based on tint block data input by the user. As described above, when the data amount of the copy-forgery-inhibited pattern data 501 is large, the high-priority copy-forgery-inhibited pattern data 501 may be extracted, and the copy-forgery-inhibited pattern data 501 may be generated based on the extracted copy-forgery-inhibited pattern data 501. The generated tint block image data is stored in the tint block image data storage unit 503.

  The pattern size calculation unit 504 calculates the size of the dot pattern generated by the copy-forgery-inhibited pattern image data generation unit 502. Specifically, the copy-forgery-inhibited pattern image data is read from the copy-forgery-inhibited pattern image data storage unit 503, and the image to be printed is developed into image data that can be visually recognized. In this embodiment, bitmap data expressing a dot pattern of a tint block pattern as a set of points (dots) aligned with a predetermined shape is used. Subsequently, referring to the image of the bitmap data, the size of one dot pattern is calculated. The shape of the dot pattern is preset by the user. The dot pattern of this embodiment is set to a square, and is obtained from the length in the vertical direction and the length in the horizontal direction (for example, 500 pix (vertical) × 500 pix (horizontal)).

  In addition, the computer 100 includes a print image data receiving unit 505, a print image data storage unit 506, a blank area calculation unit 507, a size ratio calculation unit 508, a pattern information display unit 509, a pattern size reception unit 510, and a pattern size change unit 511. Prepare.

  The print image data receiving unit 505 receives print image data input from the input device by the user, and stores the received print image data in the print image data storage unit 506.

  The margin area calculation unit 507 calculates the size of the margin area that is not the print target in the printable area where the document can be printed. Specifically, first, the print image data is read from the print image data storage unit 506 and developed into bitmap data. Subsequently, the size of the largest blank area is calculated with reference to the image of the bitmap data. As shown in FIG. 4, the blank area 403 of this embodiment is set to a square, for example, and is obtained as a vertical length and a horizontal length (for example, 2000 pix (vertical) × 2000 pix (horizontal)).

  A size ratio calculation unit 508 calculates a ratio between the size of the margin area and the size of the dot pattern calculated by the pattern calculation unit. For example, when the margin area is 2000 pix (vertical) × 2000 pix (horizontal) and the dot pattern is 500 pix (vertical) × 500 pix (horizontal), the size ratio is calculated as 4: 1. The size ratio calculation unit 508 also calculates a ratio between the size of the margin area and the size when the dot pattern calculated by the pattern calculation unit is enlarged.

  The pattern number calculation unit 509 calculates the number of dot patterns that can be embedded in the blank area. In the present embodiment, since both the dot pattern and the margin area are square, the number of patterns is calculated as the square of the size ratio. For example, if the size ratio between the blank area and the dot pattern is 4: 1, the number of patterns that can be embedded is calculated as 16 (4 × 4).

  The pattern information display unit 510 displays information related to the dot pattern on a display device such as a display.

  FIG. 6 is a diagram illustrating an example of information regarding a dot pattern. As the dot pattern information, the size of the margin area, the size of the dot pattern, the size ratio, the number of embedded dot patterns, and the like are displayed. In the margin area size column, the size calculated by the margin area calculation unit is displayed. The size (500 pix × 500 pix) calculated by the pattern size calculation unit and the size when the size is enlarged (for example, 1000 pix × 1000 pix, 2000 pix × 2000) are displayed in the column of the dot pattern size. In the size ratio column, the size ratio of the blank area and the dot pattern is displayed for each dot pattern size. In the column for the number of dot patterns to be embedded, the number of patterns that can be embedded in the blank area is displayed for each dot pattern size.

  The user who has obtained information regarding the dot pattern determines whether or not to change the size of the dot pattern, and if so, the size to be changed. Specifically, the dot pattern size is determined from the relationship between toner consumption and tracking performance. For example, when the size of the dot pattern is increased, the number of patterns that can be embedded in the blank area decreases. As a result, the amount of toner consumed for embedding the tint block can be reduced. In contrast, when the dot pattern size is not increased, a larger number of patterns can be embedded in the blank area. Thereby, for example, even if some dot patterns become unreadable, they may be read by other dot patterns.

  In this way, the user can determine whether to give priority to reducing toner consumption or improving tracking performance. Also, by appropriately increasing the size of the dot pattern, it is possible to maintain a constant tracking performance while reducing the toner consumption. When the user determines the size of the dot pattern, the user inputs the size using an input device such as a keyboard.

  The pattern size receiving unit 511 receives a dot pattern size setting based on a size input by the user.

  The pattern size changing unit 512 changes the size of the dot pattern based on the size setting received by the pattern size receiving unit 511.

  Hereinafter, a case where the size of the dot pattern is enlarged by the pattern size changing unit 512 will be described.

  FIG. 7 is a diagram showing a dot pattern with an enlarged size. FIG. 7A shows a dot pattern before enlargement, that is, a dot pattern of a size (500 pix × 500 pix) calculated by the pattern size calculation unit. FIG. 7B shows a dot pattern of a size (1000 pix × 1000 pix) enlarged twice. FIG. 7C shows a dot pattern that has been enlarged four times, that is, enlarged to the same size as the blank area (2000 pix × 2000 pix).

  Since the dot pattern before enlargement (FIG. 7A) and the dot pattern after enlargement (FIGS. 7B and C) are similar, the relative positions of the dots, that is, for example, the angle when three dots are connected (for example, In FIG. 7, the angle A) does not change even if it is enlarged. On the other hand, the distance between the dots after enlargement becomes longer by the size ratio than before the enlargement. For example, the distance L in FIG. 7A is four times the distance 4L after the enlargement in FIG. 7C. The size of each dot itself is kept constant before and after enlargement.

  FIG. 8 is an image diagram of an image in which a dot pattern is embedded in a margin area. FIG. 8A is an image diagram of an image in which a dot pattern (corresponding to FIG. 7A) before enlargement is embedded in a blank area. In this case, 16 pattern numbers can be embedded in the blank area. Therefore, even if it becomes impossible to read from some tracking patterns, the possibility of reading from other tracking patterns increases, which is excellent from the viewpoint of tracking performance.

  FIG. 8C is an image diagram of an image in which a dot pattern (corresponding to FIG. 7C) enlarged four times is embedded in a blank area. In this case, since the size is the same as the margin area, only one dot pattern can be embedded, and as a result, toner consumption can be reduced.

  FIG. 8B is an image diagram of an image in which a doubled dot pattern (corresponding to FIG. 7B) is embedded in a blank area. In this case, four dot patterns can be embedded in the blank area. Compared with FIG. 7A, the tracking performance is excellent, and compared with FIG. 7B, toner consumption can be reduced. In other words, by maintaining the tracking performance and reducing the toner consumption, it is possible to achieve the harmony between maintaining the tracking performance and reducing the toner consumption.

  As described above, the pattern size changing unit 513 changes the size of the dot pattern.

  The computer 100 further includes a tint block image data embedding unit 513 and a composite image data output unit 514.

  A copy-forgery-inhibited pattern image data embedding unit 513 generates a composite image data in which a dot pattern whose size has been changed is embedded as a copy-forgery-inhibited pattern image data in the margin area and the copy-forgery-inhibited pattern image is embedded in the print image.

  The composite image data output unit 514 outputs the composite image data to the printer 102, for example. Specifically, when the user executes printing from the application software, the printer driver that has received the processing request from the OS converts the composite image data into a format that can be processed by the corresponding printer, and the converted composite image data is converted into the format. Output to that printer.

  A processing procedure for embedding a background pattern of the computer will be described below. FIG. 9 is a flowchart showing a processing procedure for embedding a background pattern by the computer of this embodiment.

  When print image data is received by user input (S1), the print image data is stored in the print image data storage unit (S2). Then, the print image data is expanded into bitmap data, and the size of the margin area in the printable area is calculated (S3).

  Next, when copy-forgery-inhibited pattern data is received by user input (S4), copy-forgery-inhibited pattern image data is generated from the copy-forgery-inhibited pattern data (S5) and temporarily stored in the copy-forgery-inhibited pattern image data storage unit (S6). Then, the pattern size calculation unit calculates the size of one dot pattern constituting the tint block (S7). Here, the copy-forgery-inhibited pattern data is received after receiving the print image data, but the order is not particularly limited. For example, print tint block data and tint block data may be received in the order of user input.

  Subsequently, the size ratio calculation unit calculates the size ratio between the size of the blank area obtained in S3 and the size of the dot pattern obtained in S7 and the number of patterns that can be embedded in the blank area (S8). Information on the dot pattern such as the size ratio and the number of patterns is displayed on the display (S9).

  A user who sees the information displayed on the display can determine the size of the dot pattern based on the information and can input it from the keyboard. When the input of the size by the user is accepted (S10), the size is changed to the accepted size (S11).

  Subsequently, a dot pattern (background pattern image data) whose size has been changed is embedded, and composite image data including a background pattern is generated by combining the print image data and the background pattern image data (S13).

  As described above, in the image processing apparatus according to the present embodiment, the dot pattern size is increased when it is desired to reduce the toner consumption, and the dot pattern size is not increased when the tracking performance is improved. Can be. As a result, it is possible to select whether to give priority to the reduction of toner consumption or the improvement of tracking performance. Further, by appropriately increasing the size of the dot pattern, it is possible to reduce the toner consumption while maintaining a constant tracking performance.

  The image processing program used in the above-described embodiment can be provided to related parties or third parties by using an electric communication line such as the Internet or by storing it in a computer-readable recording medium. For example, a program command is expressed by an electric signal, an optical signal, a magnetic signal, etc., and the signal is placed on a carrier wave and transmitted, so that the program is provided on a transmission medium such as a coaxial cable, copper wire, or optical fiber Can do. Computer-readable recording media include optical media such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-R, and DVD-RW, and magnetic media such as a flexible disk. A semiconductor memory such as a flash memory or a RAM can be used.

  The embodiments described above do not limit the technical scope of the present invention, and various modifications and applications can be made within the scope of the present invention other than those already described.

  According to the image processing apparatus and the like according to the present invention, it is possible to select which one of reduction of toner consumption, improvement of tracking performance, and maintenance is prioritized, which is useful for a computer, a computer program, and the like.

1 is a simplified diagram of the overall configuration of an image processing system in the present embodiment. The mechanical block diagram of the computer in this Embodiment. The data block diagram of a tint block data file. The figure which shows the image image of the state in which print image data is output. FIG. 11 is a functional block diagram of a computer in this embodiment. The figure which shows the information regarding a dot pattern. The figure which shows an example of the dot pattern which expanded the size. The figure which shows the image image of the state which embedded the dot pattern in the blank area | region. 6 is a flowchart illustrating an image processing procedure of a computer according to the present embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Computer 101 Printing apparatus 102 Printer 103 Multifunction machine 210 Print image data 211 Copy-forgery-inhibited pattern image data 212 Image processing program 213 Printer driver 501 Copy-forgery-inhibited pattern data reception unit 502 Copy-forgery-inhibited pattern data generation unit 503 Copy-forgery-inhibited pattern image data storage unit 504 Pattern size calculation unit 505 Print image Data reception unit 506 Print image data storage unit 507 Margin area calculation unit 508 Size ratio calculation unit 509 Pattern number calculation unit 510 Pattern information display unit 511 Pattern size reception unit 512 Pattern size change unit 513 Background pattern embedding unit 514 Composite image data output unit

Claims (5)

An image processing apparatus capable of embedding a dot pattern composed of a plurality of dots as digital watermark data,
Pattern size calculating means for calculating the size of the dot pattern;
Margin area calculation means for calculating a size of a margin area that is not a print target in a printable area where a document can be printed;
Pattern size changing means for changing the size of the dot pattern;
Embedding means for embedding a dot pattern whose size has been changed in the margin area;
An image processing apparatus comprising: Pattern size accepting means for accepting the setting of the size of the dot pattern,
The image processing apparatus according to claim 1, wherein the pattern size calculation unit changes the size of the dot pattern based on the size setting received by the pattern size reception unit.   An image processing program for causing a computer to function as the image processing apparatus according to claim 1.   A computer-readable recording medium on which an image processing program for causing a computer to function as the image processing apparatus according to claim 1 is recorded. An image processing method for embedding a dot pattern composed of a plurality of dots as digital watermark data,
Calculating a size of the dot pattern;
Calculating a size of a blank area that is not a printable area in a printable area where a document can be printed;
Calculating a size of a blank area that is not a printable area in a printable area where a document can be printed;
A step of changing the size of the dot pattern, a step of embedding the changed dot pattern in the margin area as digital watermark data,
An image processing method comprising:

Images