JP2007150659A - Image processor, image processing method, image processing program, and record medium recorded therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processor, an image processing method, and an image processing program capable of suppressing highlighting of a latent image in woven pattern printing, and to provide a record medium recorded with the image processing program. <P>SOLUTION: A printer driver 22 comprises a printing setting portion 23 for performing various settings in woven pattern printing, an angle corrector 24 for correcting a relative angle between a watermark character and a background pattern in woven pattern printing, a woven pattern generator 25 for embedding the watermark character into the background pattern to generate a woven pattern, and a print data generator 26 for generating a print data to be printed from the woven pattern. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to an image processing apparatus, an image processing method, an image processing program, and a recording medium on which an image processing program is recorded, which generates a tint block pattern for printing a latent image reproduced at the time of copying and a background that disappears at the time of copying.

Conventionally, to prevent unauthorized copying of confidential documents, copying with a copier is "prohibited"
There is a case where special printing (hereinafter referred to as “background pattern printing”) in which warning characters appear is performed (for example, see Patent Document 1). In copy-forgery-inhibited pattern printing, a portion that is reproduced and emerges by copying is called a “latent image”, and a portion that is erased by copying is called a “background”.

The technique described in Patent Document 1 performs copy-forgery-inhibited pattern printing by making the numbers of halftone lines of the latent image and the background different. Specifically, in the dot processing, the dot concentration type dither method is applied to the latent image portion, and the dot dispersion type dither method is applied to the background portion, so that the latent image portion having a low halftone line number and a high halftone dot portion are applied. Background pattern printing is performed by creating a background portion with the number of dotted lines and embedding the latent image portion in the background portion. The printed matter with the tint block printed is difficult to distinguish between the latent image and the background because the latent image is buried in the background, and it is difficult for the user to recognize that the tint block printed matter is the tint block printed matter. However, when copying a printed matter with copy-forgery-inhibited pattern printed, a latent image with a low number of halftone lines can be read, while a background with a high number of halftone lines cannot be read. Only the latent image remains. As described above, when the copy-forgery-inhibited pattern printed matter is copied, the background that does not correspond to the resolution of the copying machine disappears and the latent image appears on the copied matter, so that the copy of the printed matter can be suppressed.

JP 2001-197297 A

However, in the technique described in Patent Document 1, the boundary between the latent image and the background is emphasized in the tint block printed matter, so that the latent image may be discriminated before copying. FIG. 11 is a diagram for explaining how the boundary is emphasized. As shown in FIG. 11A, an example of a copy-forgery-inhibited pattern print when a character “copy prohibited” is used as a latent image is shown. FIG. 11B shows a state in which the region near the boundary between the latent image and the background is enlarged, with the upper half showing the dots formed on the background and the lower half forming the latent image. As described above, in the tint block printing, the number of halftone lines of the latent image and the background is different, and the number of halftone lines of the latent image is lower than the number of halftone lines of the background.

At this time, at the boundary between the latent image and the background, the dots of the latent image and the dots of the background are connected, and one line (line a in FIG. 11B) appears to emerge. However, FIG.
In this example, an example is shown in which dots on the boundary are connected. However, a line in which dots are periodically connected may emerge depending on the dot arrangement of the latent image and the background. in this way,
Conventional copy-forgery-inhibited pattern printing is inconvenient because dots are connected at the boundary between the latent image and the background to enhance the latent image and read the latent image.

SUMMARY An advantage of some aspects of the invention is that it provides an image processing apparatus, an image processing method, an image processing program, and a recording medium on which the image processing program is recorded.

In order to solve the above problems, the present invention is an image processing apparatus that embeds a latent image reproduced during copying in a background pattern representing a background that disappears during copying, and generates a tint block pattern corresponding to dots formed during printing. An angle correction unit that corrects the relative angle between the direction of the latent image and the direction of the background pattern, and a tint block pattern that generates a tint block pattern by superimposing dots formed on the latent image on dots formed on the background pattern. Generating means.

According to this configuration, by correcting the relative angle between the direction of the latent image and the direction of the background pattern, it is possible to suppress the connection of dots at the boundary portion where the latent image and the background are superimposed. That is, if the relative angle between the direction of the latent image and the direction of the background pattern changes, the relative positional relationship between the dots formed on the latent image and the dots formed on the background in the tint block pattern changes, so the relative angle is corrected. As a result, the dot connection can be reduced. Therefore, it is possible to generate a tint block pattern that suppresses enhancement of the latent image due to dots connected at the boundary between the latent image and the background.

In addition, when the dots of the latent image and the dots of the background pattern are periodically arranged at different periods (that is, the number of halftone lines is different), the dots are periodically connected at the boundary portion between the latent image and the background. The emphasis by can be suppressed.

Here, the latent image is a character, and the angle correction means preferably corrects the relative angle between the direction of the character and the direction of the background pattern.

In this way, by correcting the relative angle between the direction of the character and the direction of the background pattern, it is possible to generate a tint block pattern in which the emphasis of the character that is a latent image is suppressed.

Here, the direction of the character is a direction indicating the direction of the character, and the angle correction means preferably corrects the character by rotating the character as a latent image.

In this way, by rotating the character, the positional relationship of the dots at the boundary between the character and the background is corrected, so that emphasis of the character that is a latent image can be suppressed.

Here, the direction of the character is the direction in which the dots formed on the character are arranged, and the angle correction means preferably corrects by rotating the direction in which the dots formed on the character as a latent image are arranged.

In this way, by rotating the dot arrangement direction of the latent image, the positional relationship of the dots at the boundary between the character and the background is corrected, so that emphasis of the character that is the latent image can be suppressed.

Here, it is preferable that the angle correction means corrects when the relative angle between the direction of the character and the direction of the background pattern is a predetermined angle at which the character is emphasized.

  In this way, correction can be made as appropriate when characters are emphasized.

Here, the direction of the background pattern is preferably the direction in which dots formed in the background pattern are arranged.

In this way, by correcting the relative angle between the dots formed corresponding to the background pattern and the direction of the latent image, correction is performed to change the positional relationship of the dots at the character boundary, and the latent image is enhanced. Can be suppressed.

The present invention may also be a method invention. That is, the present invention is an image processing method for generating a tint block pattern corresponding to dots formed at the time of printing by embedding a latent image reproduced at the time of copying in a background pattern representing a background that disappears at the time of copying. And an angle correction step for correcting the relative angle between the direction of the background pattern and the background pattern, and a background pattern generation step for generating a background pattern by superimposing dots formed on the latent image on dots formed on the background pattern. It is characterized by that.

Furthermore, the present invention may be an aspect of a program and a recording medium on which the program is recorded. That is, the present invention is an image processing program for generating a tint block pattern corresponding to dots formed at the time of printing by embedding a latent image reproduced at the time of copying in a background pattern representing a background that disappears at the time of copying. For the latent image or background pattern read from the storage unit for storing the latent image and the background pattern, the relative angle between the direction of the latent image and the direction of the background pattern is corrected, and the corrected latent image or background pattern is stored in the storage unit. A storage unit angle correction unit, a copy-forgery-inhibited pattern generation unit that generates a copy-forgery-inhibited pattern pattern by superimposing dots formed on the latent image on dots formed on the background pattern based on the latent image or background pattern read from the storage unit; It is made to function as. Recording media on which image processing programs are recorded include flexible disks, CD-ROMs, DVD-ROMs, ICs
Various media readable by a computer, such as a card and a memory card, can be used.

(First embodiment)
A first embodiment according to the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram illustrating a configuration of a system according to the first embodiment. As shown in FIG.
The printing system 1 includes a host computer 2, a printer 3 connected to the host computer 2, and a display 4 such as an LCD. Note that the printing system 1 according to the first embodiment is a so-called host-based system that generates bitmap data corresponding to the presence or absence of dots formed by the printer 3 on the host computer 2 side.

The host computer 2 is a host device for the printer 3 and is, for example, a general-purpose personal computer. As shown in FIG. 1, the host computer 2 includes a CPU 10, a ROM
11, a RAM 12, a hard disk (hereinafter referred to as “HD”) 13, a CD-ROM drive 14, and an interface (hereinafter referred to as “I / F”) 15, which are connected to each other via a bus 16.

The CPU 10 is a part that controls each component of the host computer 2. The ROM 11 is a non-volatile memory in which a predetermined program for controlling the host computer 2 is recorded, and the RAM 12 is a general-purpose memory used as a working memory.

The HD 13 records an application program, an image processing program according to the present invention, and the like. The image processing program may be recorded in advance on the HD 13 or a CD.
A program supplied in a form recorded on a recording medium such as the ROM 5 and read by the CPU 10 by the CD-ROM drive 14 may be stored in the HD 13.

The I / F 15 is a part where the display 4 and the printer 3 are connected via a cable, and performs data transmission to the display 4 and data transmission / reception with the printer 3.

Then, the CPU 10 reads and executes the image processing program recorded in the HD 13 so that the host computer 2 functions as the image processing apparatus 20 having the printer driver 22. As shown in FIG. 1, the image processing apparatus 20 according to the present embodiment includes an application 21 in addition to the printer driver 22.

The application 21 is a print request source for the printer 3 and functions by the CPU 10 executing an application program recorded on the HD 13. As described later, when printing is set from the printer driver 22, the application 2
1 passes a print request and image data to be printed to the printer driver 22.

The printer driver 22 is a part that performs various settings in printing and generates print data for printing a background pattern for the image data received from the application 21, and includes a print setting unit 23, an angle correction unit 24, and a background pattern generation. Unit 25 and print data generation unit 26
And a print data output unit 27.

The print setting unit 23 transmits data to the display 4 via the I / F 15 to display a print setting screen, and displays various setting conditions input by a user using a keyboard, a mouse (not shown), or the like according to the print setting screen. Perform the acquisition process. Print setting information indicating the setting conditions acquired via the I / F 15 is stored in the RAM 12.

Here, the settings made by the print setting unit 23 include settings related to copy-forgery-inhibited pattern printing. That is, the print setting unit 23 displays a copy-forgery-inhibited pattern print setting screen for performing settings related to copy-forgery-inhibited pattern printing on the display 4 so that the user sets various setting conditions for copy-forgery-inhibited pattern printing. The contents set in the copy-forgery-inhibited pattern print setting screen include selection of whether to perform copy-forgery-inhibited pattern printing
There are watermark character setting, background pattern setting, and the like in tint block printing.

For the watermark character setting, in the copy-forgery-inhibited pattern print setting screen, “copy prohibited”, “COPY”
The character string that is a watermark character can be selected from a plurality of selection candidate character strings such as “”, and when an arbitrary character string is selected, character data that is outline data representing the selected character string is displayed. Generated. Furthermore, the character angle can be set for the watermark character. Here, as shown in FIG. 2, the angle of the character is an angle with respect to the direction of the character itself (baseline direction) with the horizontal direction of the printed page (that is, the scanning direction at the time of printing) as a reference (0 °). The watermark character angle is a (°) in the counterclockwise direction. The value of the watermark character angle a can be arbitrarily set by the user on the copy-forgery-inhibited pattern print setting screen. However, the angle reference is not limited to this, and may be the vertical direction of the printed page. The character data for each selection candidate is stored in advance in the HD 13.

Regarding the setting of the background pattern, one background pattern can be arbitrarily selected from a plurality of selection candidates on the tint block print setting screen. For the background pattern, the printer 3
The data corresponding to the presence / absence of dots formed by the image is stored in advance in the HD 13 for each of a plurality of background patterns, and the number of dot lines of the background pattern corresponding to the background that disappears at the time of copying is the dot image dot network described later. It shall be higher than the number of dotted lines.

Here, a direction also exists for the background pattern. The direction of the background pattern is a direction in which dots formed during printing corresponding to the background pattern are arranged. As shown in FIG. 3, the direction in which the dots of the background pattern are arranged is opposite to the reference (0 °). Background pattern angle b (
°). Note that the value of the background pattern angle b is predetermined for each of a plurality of selection candidate background patterns and is recorded in the HD 13.

The angle correction unit 24 performs angle correction processing for generating character data obtained by rotating a character in accordance with conditions set on the tint block print setting screen. Specifically, as shown in FIG. 4, the character data 50 is angle-corrected so as to rotate the character selected on the copy-forgery-inhibited pattern print setting screen (see FIG. 4A), and character data representing the angle-corrected character is displayed. 51 is generated (see FIG. 4B).
.

The copy-forgery-inhibited pattern generation unit 25 uses the angle-corrected character data 51 and the background pattern 70 to generate a copy-forgery-inhibited pattern 53 in which a watermark character is embedded on the background pattern 70. Specifically, after the character data 51 subjected to angle correction is developed into bitmap data, a watermark image 60 indicating the presence or absence of dots for each pixel or predetermined area (see FIG. 4C).
Is applied to generate the watermark character pattern 52 (see FIG. 4D).

A watermark image 60 that associates characters with the presence or absence of dots formed by the printer 3 is stored in the HD 13 in advance. The watermark image 60 is a table representing the presence or absence of dots to be associated with each pixel or predetermined area. By applying the watermark image 60 to characters developed into bitmap data, a watermark character corresponding to the presence or absence of dots is displayed. A watermark character pattern 52 can be generated. The watermark image 60 shown in FIG. 4C represents an example of a 4 × 4 matrix, but the size of the watermark image 60 and the position of the dots are not limited to this.

The copy-forgery-inhibited pattern generation unit 25 performs processing for generating a copy-forgery-inhibited pattern 53 by embedding the latent image in the background so that the dots represented by the watermark character pattern 52 are overwritten and overwritten on the dots of the background pattern 70. (Refer FIG.4 (f)).

The print data generation unit 26 generates bitmap data corresponding to the presence / absence of dots formed by the printer 3 from the image data to be printed delivered by the application 21. Then, print data is generated such that the dots of the image to be printed are overwritten and overwritten with the dots of the tint block pattern 53.

The print data output unit 27 transmits the generated print data to the printer 3 via the I / F 15 and performs processing for causing the printer 3 to perform printing.

The printer 3 is an electrophotographic laser printer, and performs printing by forming dots on printing paper in accordance with an image signal obtained by subjecting received print data to pulse width modulation.

As described above, the image processing apparatus 20 according to the first embodiment performs angle correction for inclining the watermark character in tint block printing, so that the relative angle between the watermark character angle a and the background pattern angle b is increased. The corrected print data is generated.

  Next, processing performed by the image processing apparatus 20 will be described in detail according to a flowchart.

When the user performs various print-related settings including the copy-forgery-inhibited pattern printing on the print setting screen displayed on the display 4 by the print setting unit 23, various setting information is stored in the RA.
The printing process shown in the flowchart of FIG. 5 is started in the state stored in M12.

When the process is started, first, in step S100, the CPU 10 refers to the setting information stored in the RAM 12, and determines whether the tint block printing is designated for the printing. If copy-forgery-inhibited pattern printing is designated (Yes), the process proceeds to step S200. If the copy-forgery-inhibited pattern printing is not designated (No), the process proceeds to step S400 to perform normal printing.

In step S200, the background pattern generation unit 25 performs a background pattern generation process for generating a background pattern. FIG. 6 is a flowchart showing the flow of the tint block pattern generation process.

When the copy-forgery-inhibited pattern generation process is started, step S20 is performed according to the flowchart of FIG.
1, the CPU 10 specifies the type of the background pattern selected from the setting information stored in the RAM 12, and acquires the background pattern 70 by reading the data representing the specified background pattern from the HD 13. As described above, the background pattern angle b is HD13.
In this case, the value of the background pattern angle b is read out from the HD 13 together with the background pattern 70 and obtained.

In step S202, the CPU 10 acquires the type of watermark character selected from the setting information stored in the RAM 12, and reads and acquires character data 50 representing the selected character from the HD 13.

Next, in step S203, the CPU 10 reads the setting information stored in the RAM 12 and acquires the value of the watermark character angle a set by the user.

In step S204, the angle difference between the watermark character angle a and the background pattern angle b (=
It is determined whether or not the relative angle that is the absolute value of ab) is a predetermined angle for emphasizing the watermark character. Specifically, it is determined whether or not the following formula is established.
| A−b | = α × (n−1) (where α = 45 °, n is an integer of 1 or more) (1)

Formula (1) is demonstrated. The value of “α × (n−1)” is set so as to have a high probability of being taken as the angle of the line constituting the character. For example, looking at the lines constituting the character string of “copy prohibited”, in addition to the line extending horizontally (0 °) and the line extending vertically (90 °) with respect to the character direction, the angle is about 45 °. There are many lines extending diagonally. Watermark character angle a
And the background pattern angle b match these values, these lines match the direction of the background pattern, and dots appear on the horizontal, vertical, and diagonal lines with respect to the character direction. Since it is connected, a part of the boundary of the character is emphasized. Therefore, by determining whether or not the condition of Expression (1) is satisfied, it is determined whether or not a part of the character is emphasized, and the angle correction is performed when the emphasis occurs. However, the value of α is not limited to “45 °”, and may be, for example, “30 °” or “15 °”, and the value of α is predetermined for each selected character string. It is good. Further, the determination performed in step S204 is not limited to the determination of whether the left side and the right side of Equation (1) match, and the absolute value of the difference between the left side and the right side is a predetermined angle (for example, “5 ° Etc.) or the like may be determined.

In this way, it is determined whether the character is emphasized by the expression (1). If the condition of the expression (1) is satisfied (Yes), the process proceeds to step S205, and the print setting unit 23 corrects the angle on the display 4. For example, the user can reset the watermark character angle a, or the angle correction unit 24 can change the setting of the value of the watermark character angle a slightly (for example,
Then, the process returns to step S203 again. If it is determined in step S204 that the condition of expression (1) is not satisfied (No), the process proceeds to step S206.

Next, in steps S206 to S208, a bitmap image in which the character is rotated according to the watermark character angle a is generated, and a process of generating a tint block pattern by embedding the character as a latent image in the background pattern 70 is performed.

Therefore, in step S206, the CPU 10 performs angle correction for rotating the character data 50 by the watermark character angle a (see FIG. 4B), and the angle-corrected character data 5 is displayed.
1 is stored in the RAM 12.

Next, in step S207, the CPU 10 expands the angle-corrected character data 51 into bitmap data, and then applies the watermark image 60 (see FIG. 4C) for each pixel or predetermined area of the expanded data. In this manner, a watermark character pattern 52 representing the watermark character by the presence or absence of dots formed by the printer 3 is generated (see FIG. 4D). The generated watermark character pattern 52 is stored in the RAM 12.

Next, in step S208, the CPU 10 determines the background pattern 7 read from the HD 13.
A copy-forgery-inhibited pattern 53 corresponding to the presence / absence of dots formed by the printer 3 is generated by superimposing the characters of the watermark character pattern 52 read from the RAM 12 on 0, and the RAM 1
2 memorize. Specifically, a background pattern 70 representing dots to be formed on the background (FIG. 4E)
(See) is stored in the RAM 12 from the HD 13, and the dot of the watermark character pattern 52 is overwritten on the dot of the background pattern 70 and overwritten. That is, the area where the dots overlap is overwritten so that the dots of the watermark character pattern 52 are left preferentially, and the tint block pattern 53 shown in FIG. 4F is obtained.

Next, in step S209, the CPU 10 determines the tint block pattern 5 stored in the RAM 12.
3 is displayed on the display 4 to allow the user to confirm the copy-forgery-inhibited pattern printing. The user confirms the generated copy-forgery-inhibited pattern 53 on the copy-forgery-inhibited pattern confirmation screen, and then permits printing as it is or resets the watermark character using the operation panel 40 (see FIG. 1) provided in the printer 3. Perform the operation.

In step S210, the CPU 10 determines whether printing is permitted according to an input from the user. If an input for resetting the watermark character is received, it is determined that printing is not permitted (No), and the process proceeds to step S211. In step S211, after stopping the display of the copy-forgery-inhibited pattern pattern confirmation screen, the copy-forgery-inhibited pattern print setting screen is displayed on the display 4 and the setting of the watermark character type, the watermark character angle a, the background pattern, etc. is changed by the user.
The process returns to step S201. When an input indicating that printing is permitted is accepted in step S210, it is determined that printing with the generated tint block pattern is permitted (Yes), and the tint block pattern generation process is terminated.

When the copy-forgery-inhibited pattern generation processing ends, the processing returns to the flowchart of FIG. 5, and in step S300, the print data generation unit 26 performs dot processing on the image data to be printed received from the application 21 to generate dot After the image is expanded into a bitmap image corresponding to the presence / absence of the dot, the dot is overwritten so as to be superimposed on the bitmap image of the tint block pattern 53 stored in the RAM 12 to generate print data.

Next, in step S400, the print data output unit 27 transmits the print data to the printer 3. When the printer 3 prints according to the received print data, copy-forgery-inhibited pattern printing is performed, and the printing process in FIG. 5 ends.

In addition, the process of step S203-S206 is the angle correction process as described in a claim, step S
The process 208 corresponds to a tint block pattern generation process.

According to the system of the present embodiment, since the relative angle between the direction of the watermark character and the direction of the background pattern is corrected, the condition of Expression (1) is satisfied with respect to the direction of the watermark character and the direction of the background pattern. No tint block printing can be performed. FIG. 7 shows an example of a tint block printed material by the present system. As shown in FIG. 7A, in the tint block printed matter 80, the watermark characters are arranged such that the watermark character direction (a °) is inclined with respect to the background pattern direction (b °). The relative angle between the direction of the background pattern (b °) and the direction of the watermark character (a °) is an angle that does not satisfy Expression (1). In addition, in addition to the background and watermark characters, an image 81 to be printed designated by the application 21 is printed on the tint block printed matter 80.

FIG. 7B shows an enlarged view of the vicinity of the boundary between the watermark character and the background in FIG. As shown in FIG. 7B, by performing angle correction for appropriately tilting the watermark character, compared to the state of FIG. 11, the boundary portion between the dot of the watermark character and the background dot as a latent image (FIG. 7). In line b) of (b), the dot connection is reduced. In this manner, the dot connection can be suppressed by performing the angle correction.

Also, since the background is printed with a higher number of dotted lines than the watermark characters (latent image), the background disappears when copying by a copying machine. The disappearance at the time of copying is not limited to disappearance at the time of copying by all copying machines, but means that it disappears at the time of copying by some copying machines having a reading resolution incapable of reading the background. . That is, when copying with a copier whose reading resolution is lower than the resolution printed by the printer, the background with the number of dotted lines higher than the on / off threshold value of the pixel read by the copier disappears and the latent image reproduced at the time of copying is lost. This means that the background disappears at the time of copying by a copying machine which is set to a threshold value such that the number of halftone lines constituting the image is reproduced.

  Hereinafter, effects in the first embodiment will be described.

(1) In copy-forgery-inhibited pattern printing, it is possible to suppress the emphasis of characters that are latent images by connecting dots at the boundary between the watermark character and the background.

(2) Even if the dots formed on the latent image and the dots formed on the background are different in period, it is possible to suppress character emphasis caused by the dots being periodically connected at the boundary between the latent image and the background.

(3) Since the angle correction is performed according to the condition of the expression (1), it is possible to appropriately correct when the dots are easily connected in consideration of the direction of the character and the direction of the background pattern.

(Second Embodiment)
Next, a second embodiment according to the present invention will be described. In the second embodiment, the angle correction unit 24 performs angle correction by tilting the dot arrangement of the watermark image without changing the angle of the character itself. In this case, the angle correction unit 24 generates the watermark image 61 in which the dot position is rotated by performing the angle correction, taking the watermark image 60 having the dot arrangement shown in FIG. b)). A watermark character pattern is generated by applying the angle-corrected watermark image 61 to each pixel or predetermined area in which character data is expanded, and a watermark pattern pattern is overlapped with dots of the watermark character pattern and background pattern dots. Is generated.

As a result, a tint block printed material shown as an example in FIG. 9A is obtained. Since the character data is not rotated, the watermark character itself is not inclined by the angle correction as shown in FIG. However, as shown in FIG. 9B in which the vicinity of the boundary between the latent image and the background in FIG. 9A is enlarged, the direction of the dots arranged in the latent image (watermark character) is inclined with respect to the background dots. Therefore, the connection of dots in the line c at the boundary between the latent image and the background can be suppressed.

According to the second embodiment, the following effects can be obtained in addition to the effects obtained by the first embodiment.

(4) Since the angle of the watermark character itself does not change due to the angle correction, the influence on the printed matter is reduced by the angle correction. In other words, the correction prevents the watermark character from being tilted against the user's intention.

(Third embodiment)
Next, a third embodiment according to the present invention will be described. FIG. 10 is a diagram illustrating a configuration according to the third embodiment. As shown in FIG. 10, the printing system 10 according to the third embodiment.
0 includes a host computer 110 and a printer 120, and the printer 120 includes an image processing apparatus 130 and a print engine 140. That is, the image processing apparatus 130
The print engine 140 includes a print setting unit 23, an angle correction unit 24, a tint block pattern generation unit 25, and a print data generation unit 26. The print engine 140 performs printing according to the print data generated on the printer side.

At this time, the print setting unit 23 displays a copy-forgery-inhibited pattern print setting screen on a display panel (not shown) provided in the printer 3 and sets various conditions. However, the processing performed by the print setting unit 23 may be performed on the host computer side.

In the third embodiment, for the background pattern 70 and the watermark image 60, data stored in advance in a memory (not shown) provided in the printer 3 is used.

  According to the third embodiment, the same effect as that of the first embodiment can be obtained.

Although the first to third embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and can be implemented in various forms without departing from the spirit of the present invention. You can also Hereinafter, a modification will be described.

(Modification 1) In the above-described embodiment, printing is performed with less emphasis on characters by rotating the characters that are latent images and changing the relative angles with respect to the background pattern 70 that is the background in tint block printing. It was. As a first modification, the background pattern 70 may be rotated to correct the relative angle. Alternatively, the angle may be corrected by rotating the character and the background pattern 70 in the opposite directions.

(Modification 2) In the above embodiment, the character portion is a latent image reproduced during copying. As a second modification, the character may be a background that disappears during copying, and the background pattern 70 may be a latent image that is reproduced during copying. In this way, the background pattern 70 is copied at the time of copying, while the character disappears and the background color of the printing paper appears for the character portion, so that the character buried in the background at the time of copying can be highlighted.

(Modification 3) In the above embodiment, the angle of the character string is changed by changing the angle of the character string when the relative angle between the direction of the selected character string and the direction of the background pattern is a predetermined angle according to the equation (1). Correction was performed. A relative angle to be emphasized for each character type may be set in advance, and for a character whose relative angle with the background pattern 70 matches the set relative angle, angle correction may be performed for each character.

(Modification 4) The portion to be a latent image in tint block printing is not limited to characters, but can be applied to figures, images, and the like. That is, the tint block pattern may be generated by tilting the figure or image by performing angle correction on the figure data and image data instead of the character data.

(Modification 5) In the embodiment described above, data corresponding to dots formed by the printer 3 is generated by using the background pattern 70 and the watermark image 60 prepared in advance. As a fifth modification, as described in Patent Document 1, the dot dispersion type dither method is applied to the background pattern, the dot concentration type dither method is applied to the character data subjected to angle correction for the character,
Copy-forgery-inhibited pattern printing may be realized by performing halftone dot processing so as to have different numbers of halftone lines.

(Modification 6) In the above embodiment, in addition to the latent image and background in the tint block printing, the image to be printed specified by the application 21 is further overlapped for printing. As a fifth modification, printing according to a tint block pattern 53 having a latent image and a background may be performed to create a copy prevention sheet. The user can obtain a copy-forgery-inhibited pattern printed matter by causing the printer 3 of the present invention or another ordinary printer to feed the copy-preventing paper and further printing a desired image.

(Modification 7) The image processing apparatus of the present invention is not limited to a printer, and can be applied to a copying machine, a fax machine, and the like. In addition to copying machines, devices that copy tint block printed matter
It can also correspond to a scanner.

The figure which showed the structure of the system which concerns on 1st Embodiment. Explanatory drawing for demonstrating a character angle. Explanatory drawing for demonstrating a pattern angle. The figure explaining angle correction and tint block pattern generation. (A) is character data, (b) is angle-corrected character data, (c) is a watermark image, (d) is a rotated watermark character pattern, (e) is a background pattern, and (f) is a background pattern. Figure. The flowchart figure which showed the flow of the process performed at the time of printing. The flowchart figure which showed the flow of the process of the tint block pattern generation process. The figure which showed an example of the tint block printed matter. (A) is the figure which showed the whole tint block printed matter, (b) is the figure which expanded the boundary vicinity of a latent image and a background. The figure explaining angle correction and tint block pattern generation. (A) is a watermark image, (b) is a diagram showing an angle-corrected watermark image. The figure which showed an example of the tint block printed matter by the system which concerns on 2nd Embodiment. (A) is the figure which showed the whole tint block printed matter, (b) is the figure which expanded the boundary vicinity of a latent image and a background. The figure which showed the structure of the system which concerns on 3rd Embodiment. Explanatory drawing for demonstrating the connection of a dot. (A) is the figure which showed the whole tint block printed matter, (b) is the figure which expanded the boundary vicinity of a latent image and a background.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Printing system, 2 ... Host computer as a computer, 3 ... Printer, 4
Display, 5 ... CD-ROM as recording medium, 10 ... CPU, 11 ... ROM, 1
2 ... RAM as a storage unit, 13 ... hard disk, 14 ... CD-ROM drive, 15
Interface, 16 ... Bus, 20 ... Image processing device, 21 ... Application, 22 ...
Printer driver, 23... Print setting unit, 24... Angle correction unit as angle correction means, 25.
Copy-forgery-inhibited pattern generation unit as copy-forgery-inhibited pattern generation unit, 26... Print data generation unit, 27... Print data output unit, 40 ... operation panel, 50 ... character data, 51 ... character data with angle correction, 52. ... ground pattern, 60 ... watermark image, 61 ... watermark image with angle correction, 70 ... background pattern, 80 ... printed background pattern, 81 ... image to be printed, a ... watermark character angle, b ... background pattern angle.

Claims (9)

An image processing apparatus that embeds a latent image reproduced at the time of copying in a background pattern representing a background that disappears at the time of copying, and generates a tint block pattern corresponding to dots formed at the time of printing,
Angle correction means for correcting a relative angle between the direction of the latent image and the direction of the background pattern;
An image processing apparatus comprising: a tint block pattern generation unit configured to superimpose dots formed on the latent image on dots formed on the background pattern to generate a tint block pattern. The image processing apparatus according to claim 1,
The latent image is a character;
The angle correction means corrects a relative angle between the direction of a character and the direction of the background pattern. The image processing apparatus according to claim 2,
The direction of the character is a direction indicating the direction of the character,
The image processing apparatus according to claim 1, wherein the angle correction means corrects the character as a latent image by rotating the character. The image processing apparatus according to claim 2,
The direction of the character is a direction in which dots formed on the character are arranged,
The image processing apparatus according to claim 1, wherein the angle correction unit corrects the rotation by rotating a direction in which dots formed in a character as a latent image are arranged. An image processing apparatus according to any one of claims 2 to 4,
The angle correction means includes
An image processing apparatus, wherein a correction is performed when a relative angle between the direction of the character and the direction of the background pattern is a predetermined angle at which the character is emphasized. An image processing apparatus according to any one of claims 1 to 5,
The image processing apparatus according to claim 1, wherein the direction of the background pattern is a direction in which dots formed in the background pattern are arranged. An image processing method for generating a copy-forgery-inhibited pattern corresponding to dots formed at the time of printing by embedding a latent image reproduced at the time of copying in a background pattern representing a background that disappears at the time of copying,
An angle correction step of correcting a relative angle between the direction of the latent image and the direction of the background pattern;
An image processing method comprising: a tint block pattern generation step of generating a tint block pattern by superimposing dots formed on the latent image on dots formed on the background pattern. An image processing program for embedding a latent image reproduced at the time of copying in a background pattern representing a background that disappears at the time of copying, and generating a tint block pattern corresponding to dots formed at the time of printing,
Computer
For the latent image or the background pattern read from the storage unit that stores the latent image and the background pattern, the relative angle between the direction of the latent image and the direction of the background pattern is corrected,
Storage unit angle correction means for storing the corrected latent image or background pattern in the storage unit;
Based on the latent image or the background pattern read from the storage unit, functions as a tint block pattern generation unit that generates a tint block pattern by superimposing dots formed on the latent image on dots formed on the background pattern An image processing program characterized in that A computer-readable recording medium on which the image processing program according to claim 8 is recorded.

Images