JP2022019769A - Image processing apparatus, image forming apparatus, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To add, to an output image, security information that is not easily visually recognized under normal natural light and can be visually recognized when irradiated with light with a specific wavelength, and prevent the addition of the security information from being easily noticed compared with a case where the security information is added irrespective of the details of an image to be output.

SOLUTION: In an image forming apparatus 10, a K toner is replaced with an IR toner. A UI device 43 receives, as a designated color, the color of an image intended to be seen when irradiated with infrared light. A control part 42, when converting image data of an image to be printed into print data, converts a color value of the designated color received by the UI device 43 into a color value including a value for outputting the IR toner that is a special color material having absorption characteristics to infrared light.

SELECTED DRAWING: Figure 5

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to an image processing device, an image forming device and a program.

Patent Document 1 includes a printing means for performing a first printing process for printing an image visually recognizable under visible light and a second printing process for printing an image visually recognizable under ultraviolet light, and is irradiated with natural light. A printing device capable of realizing different images and unexpected image representations under and under ultraviolet light irradiation is disclosed.

Patent Document 2 discloses an image forming apparatus capable of realizing an originality guarantee print using an invisible light absorbing toner and an invisible light non-absorbing toner of similar colors by using an image forming apparatus for embedding an invisible image. Has been done.

Patent Document 3 discloses an image processing apparatus capable of embedding a digital watermark in a binary image by using a block error diffusion process.

In Patent Document 4, it is possible to suppress a decrease in color reproducibility of an original image even when an invisible image is formed by using a toner having an absorption characteristic of invisible light such as ultraviolet light and infrared light. The image forming apparatus is disclosed.

In Patent Document 5, a code pattern image in which a colored toner is arranged between transparent toners is printed to form a dot-like image having excellent light resistance and a stable shape regardless of the recording medium. The image forming apparatus is disclosed.

Patent Document 6 discloses an image forming apparatus that adjusts the densities of K single color gray and CMY mixed gray so as to be the same color under visible light to create a latent image that is difficult to see under visible light. There is.

Japanese Unexamined Patent Publication No. 2004-268555 JP-A-2007-127999 Japanese Unexamined Patent Publication No. 2009-071800 Japanese Unexamined Patent Publication No. 2009-231923 Japanese Unexamined Patent Publication No. 2010-139835 Japanese Unexamined Patent Publication No. 2013-223144

An invisible image formed by a special toner having absorption characteristics in the infrared region is added to the output image to provide a security function. However, even a special toner has some absorption characteristics in the visible region, so it is difficult to completely obscure the formed invisible image.

An object of the present invention is to compare with a case where security information that is difficult to see under normal natural light and becomes visible when irradiated with light of a specific wavelength is added to an output image regardless of the content of the output image. The present invention provides an image processing device, an image forming device, and a program capable of making it difficult to notice that security information has been added.

[Image processing device]
The image processing device of the first aspect of the present invention is a receiving means that accepts as a designated color the color used for the image to which security information is to be added from the images included in the image data received from the terminal device.
When converting the image data into print data, an image included in the image data received from the terminal device and using the designated color received by the receiving means is specified, and the specified image is specified. A conversion means for converting a color value expressing the shape of the image into a color value including a value for outputting a special color material having absorption characteristics for light of a specific wavelength, and then converting the image so as to form the specified image. , Is equipped.

The information processing apparatus according to the second aspect of the present invention is the information processing apparatus according to the first aspect, wherein the conversion means has the above-mentioned color value for expressing an image in which the designated color received by the reception means is not used. Converts to a color value that does not include the value that outputs the special color material.

The information processing apparatus according to the third aspect of the present invention is the image processing apparatus according to the second aspect, wherein the conversion means is cyan, magenta, or yellow for an image in which the designated color accepted by the reception means is used. For images that are converted to color values expressed using the color material and the special color material and the designated color received by the reception means is not used, the color expressed using the cyan, magenta, and yellow color materials. Convert to a value.

In the information processing apparatus according to the fourth aspect of the present invention, in the image processing apparatus according to any one of the first to third aspects, the designated color received by the receiving means is the designated color in the other device. It also has adjustment means to adjust so that they do not overlap.

[Image forming device]
The image forming apparatus according to the five aspects of the present invention comprises a receiving means for accepting as a designated color the color used for the image to which security information is to be added from the images included in the image data received from the terminal device.
When converting the image data into print data, an image included in the image data received from the terminal device and using the designated color received by the receiving means is specified, and the specified image is specified. A conversion means for converting a color value expressing the shape of the image into a color value including a value for outputting a special color material having absorption characteristics for light of a specific wavelength, and then converting the image so as to form the specified image. ,
It includes an output means for outputting an image based on the print data converted by the conversion means.

[program]
The program of the six aspects of the present invention includes a reception step of accepting as a designated color the color used for the image to which security information is to be added from the images included in the image data received from the terminal device.
When converting the image data into print data, an image included in the image data received from the terminal device and using the designated color received in the reception step is specified, and the specified image is specified. A conversion step of converting a color value expressing the shape of the image into a color value including a value for outputting a special color material having absorption characteristics for light of a specific wavelength, and then converting the image so as to form the specified image. Let the computer execute.

According to the first aspect of the present invention, when adding security information to an output image, which is difficult to see under normal natural light and becomes visible when irradiated with light of a specific wavelength, regardless of the image content to be output. It is possible to provide an image processing device capable of making it difficult to notice that security information has been added, as compared with the case of adding security information.

According to the second aspect of the present invention, it is possible to provide an image processing apparatus capable of setting a color value of an image to which security information is not added to a color value that does not include a special color material.

According to the third aspect of the present invention, the color value of the image to which the security information is added is a color value expressed by using the cyan, magenta, and yellow color materials and the special color material, and the color does not include the special color material. It is possible to provide an image processing apparatus capable of making a value a color value expressed by using a cyan, magenta, yellow color material and a special color material.

According to the fourth aspect of the present invention, when designating the color of an image to be visible when irradiated with light of a specific wavelength, it is possible to prevent the color from overlapping with the designated color designated by another device. A possible image processing apparatus can be provided.

According to the fifth aspect of the present invention, when adding security information to an output image, which is difficult to see under normal natural light and becomes visible when irradiated with light of a specific wavelength, regardless of the image content to be output. It is possible to provide an image forming apparatus capable of making it difficult to notice that security information has been added, as compared with the case of adding security information.

According to the sixth aspect of the present invention, when adding security information to an output image, which is difficult to see under normal natural light and becomes visible when irradiated with light of a specific wavelength, regardless of the image content to be output. It is possible to provide a program that can make it difficult to notice that security information has been added, as compared with the case of adding security information.

It is a system diagram which shows the structure of the image formation system of one Embodiment of this invention. It is sectional drawing which shows the structure of the image forming apparatus 10 in one Embodiment of this invention. It is a figure for demonstrating the state of setting the infrared absorption toner (IR toner) in place of K toner to the image forming apparatus 10. It is a block diagram which shows the hardware composition of the image forming apparatus 10 in one Embodiment of this invention. It is a block diagram which shows the functional structure of the image forming apparatus 10 in one Embodiment of this invention. It is a flowchart which shows the operation of the image forming apparatus 10 in one Embodiment of this invention. It is a figure which shows the image example which tries to add security information. It is a figure which shows the confirmation screen example of a designated color. It is a figure for demonstrating concretely how the image data of an RGB color space is converted into the print data of CMYIR. It is a figure which shows the appearance when the image which was output with the security information added is seen under natural light, and when it is imaged by an infrared camera or the like by irradiating with infrared rays. It is a figure for demonstrating how the company A, the company B, and the company C set different designated colors for the image as shown in FIG. 7. It is a figure for demonstrating how the discriminant image 60 composed of a plurality of patch images composed of various colors is provided in the margin portion in an image in advance. By setting the colors of two patch images as designated colors for each department from the discrimination image 60, a state of determining in which department the document on which the image is printed is printed will be described. It is a figure for. It is a figure for demonstrating various patterns when an image to which security information is added and a background image are printed superimposed. It is a flowchart which shows the operation of the image forming apparatus 10 when the image of the IR toner and the background image are printed on top of each other.

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

FIG. 1 is a diagram showing a system configuration of an image forming system according to an embodiment of the present invention.

As shown in FIG. 1, the image forming system of one embodiment of the present invention is composed of image forming devices 10a to 10c and terminal devices 20a and 20b interconnected by a network 40. The terminal devices 20a and 20b generate print data, and transmit the print data generated via the network 40 to the image forming devices 10a to 10c. The image forming devices 10a to 10c receive the print data transmitted from the terminal devices 20a and 20b, and output the image corresponding to the print data on the paper. The image forming devices 10a to 10c are so-called multifunction devices having a plurality of functions such as a printing (printing) function, a scanning function, a copying (copying) function, and a facsimile function.

Since the image forming apparatus 10a to 10c have the same configuration, they are referred to as the image forming apparatus 10 in the following description. Further, the terminal devices 20a and 20b are also expressed as the terminal device 20 in the same manner.

Next, the structure of the image forming apparatus 10 of the present embodiment will be described with reference to the cross-sectional view shown in FIG.

The image forming apparatus 10 has a printing apparatus 21 and an image reading apparatus 34, and the printing apparatus 21 has, for example, a three-stage recording medium supply cassette 22, and each of these recording medium supply cassettes 22 has a supply head 23. It is provided.

When one of the recording medium supply cassettes 22 is selected, the supply head 23 operates to supply the selected recording medium supply cassette 22 to the image forming unit 25 via the recording medium supply path 24.

The image forming unit 25 is provided with four image forming units, and each image forming unit includes cyan (C), magenta (M), yellow (Y), and black (K) photoconductors 26. At the same time, an intermediate transfer belt 27 is provided.

A charging device, an exposure device, a developing device, a primary transfer device, a cleaning device, etc. (not shown) are arranged around each photoconductor 26, and a toner image formed on each photoconductor 26 is transferred to an intermediate transfer belt 27. Transcribed. When black and white is set, only black is enabled.

The toner image of the intermediate transfer belt 27 is transferred to the transmitted recording medium by the secondary transfer roll 28 and fixed by the fixing device 29, and the recording medium on which the toner image is fixed passes through the recording medium discharge path 30. Is discharged to the discharge tray 31.

However, when double-sided printing is set, the recording medium whose surface is fixed by the fixing device 29 is sent from the recording medium discharge path 30 to the reversing device 32, inverted by the reversing device 32, and the recording medium reversing path 33. Is sent back to the recording medium supply path 24, and is sent to the image forming unit 25 to print the back surface.

The image reading device 34 has an automatic document feeding device 35 capable of reading double-sided documents, and the document is fed to the platen 36 by the automatic document feeding device 35, and the document is fed on the platen 36 by a reading unit including a CCD or the like. The image of is read. Further, the automatic document feeder 34 also serves as a platen cover, and the document can be placed on the platen 36 by opening the platen cover. The opening and closing of the platen cover can be detected by the platen cover opening / closing detector.

Further, the image forming apparatus 10 is provided with a modem for facsimile connected to a public line and a network communication device connected to a network such as a LAN. By using the network communication device provided in the image forming device 10, the image read by the image reading device 34 can be transmitted to a terminal connected to the network. By executing such processing, the image forming apparatus 10 also has a function as a facsimile transmission apparatus.

In the image forming apparatus 10 of the present embodiment, it is possible to execute a normal printing process for outputting an image on printing paper by the above-described configuration. Here, in the present embodiment, an image that cannot be visually recognized under natural light by the image forming apparatus 10 but is desired to be visible by irradiating light having a specific wavelength called infrared rays (wavelength of about 780 nm to 1 nm) is secured. Used for embedding in output paper as information.

Therefore, as shown in FIG. 3, for the image forming apparatus 10 in the image forming system of the present embodiment, the infrared absorbing toner (infrared absorbing toner) is used instead of the K toner for the K color image forming unit among the four image forming units. Hereinafter, it is abbreviated as IR (Infrared) toner.) Is set. Specifically, the K toner bottle is replaced with the IR toner bottle for use. The K toner bottle may be replaced with the IR toner bottle at the time of shipment from the factory of the image forming apparatus 10 or after the image forming apparatus 10 is installed in a place used by the user. Needless to say, at the time of shipment from the factory, IR toner may be placed in the position of the K toner bottle from the beginning without replacing the toner bottle.

Here, the IR toner is a toner made of a special color material having absorption characteristics for light having a specific wavelength in the infrared region.

When an image is formed on the printing paper using only this IR toner, the formed image becomes an invisible image that is not visible (difficult to be seen) under visible light (wavelength 380 nm to 780 nm).

Invisible means that it is difficult to visually recognize, and does not mean that it is completely difficult to visually recognize. Even IR toner, which is an invisible toner, has some absorption characteristics in the visible light region. Therefore, when an image is actually formed with IR toner on white paper, it may be visible even though it is an extremely light color. It is possible.

Since the K (black) toner is generally composed of a black color material mainly composed of carbon black, it has a wide absorption characteristic over an ultraviolet region, a visible light region, and an infrared region.

However, although the C (cyan), M (magenta), and Y (yellow) toners each have an absorption characteristic in the visible light region, they do not have an absorption characteristic in the infrared region. Therefore, the so-called process black, which is made by superimposing CMY toner, does not have absorption characteristics in the infrared region.

In this way, when the black image is formed by using the K toner, confusion occurs with the image of the IR toner when irradiating infrared rays to determine the presence or absence of security information. Therefore, in the present embodiment, as described above, IR toner is set in the image forming apparatus 10 instead of K toner, and the black image is configured by process black using CMY toner. Specifically, the image data prepared to be drawn with CMYK toner is color-converted by, for example, LUT (Look Up Table) so as to be expressed by CMY toner, or it is converted into print data in the CMY color space. On the other hand, the UCR process is not performed and the drawing is not performed with the K toner, while the image information to be displayed with the IR toner is separately set and drawn.

Next, FIG. 4 shows the hardware configuration of the image forming apparatus 10 in the image forming system of the present embodiment.

As shown in FIG. 4, the image forming apparatus 10 transmits and receives data to and from an external device and the like via a CPU 11, a memory 12, a storage device 13 such as a hard disk drive (HDD), and a network 30. It has a communication interface (IF) 14, a user interface (UI) device 15 including a touch panel or liquid crystal display and a keyboard, a scanner 16, and a print engine 17. These components are connected to each other via a control bus 18.

The print engine 17 prints an image on a recording medium such as printing paper through steps such as charging, exposure, development, transfer, and fixing.

The CPU 11 executes a predetermined process based on the control program stored in the memory 12 or the storage device 13 to control the operation of the image forming apparatus 10. In the present embodiment, the CPU 11 has been described as reading and executing a control program stored in the memory 12 or the storage device 13, but the program is stored in a storage medium such as a CD-ROM and stored in the CPU 11. It is also possible to provide.

FIG. 5 is a block diagram showing a functional configuration of the image forming apparatus 10 realized by executing the above control program.

As shown in FIG. 5, the image forming apparatus 10 of the present embodiment includes a print job receiving unit 41, a control unit 42, a UI device 43, a data storage unit 44, and an output unit 45.

The print job receiving unit 41 receives a print job (print instruction) transmitted from the terminal device 20 by communicating with the terminal device 20.

The control unit 42 converts the print job received by the print job receiving unit 41 into raster format print data by performing various drawing processes. Then, the control unit 42 temporarily stores the print data in the raster format after the drawing process in the data storage unit 44. Then, the control unit 42 executes the print process by transferring the print data stored in the data storage unit 44 to the output unit 45.

The UI device 43 performs display processing for the user based on the control by the control unit 42, and receives instructions, settings, and the like from the user. Then, the UI device 43 accepts the color of the image to be visible when irradiated with light (infrared ray) having a specific wavelength as a designated color.

The output unit 36 outputs an image on a recording medium such as printing paper based on the print data transferred from the control unit 32.

Here, when printing using a normal CMYK 4-color toner to which security information is not added, the control unit 42 converts the image data represented by the RGB color space into the print data represented by the CMYK color space. ..

However, in the image forming apparatus 10 of the present embodiment, the K toner is replaced with the IR toner as described above. Therefore, when the control unit 42 converts the image data of the image to be printed into print data, the control unit 42 has a special feature of absorbing the color value of the designated color received by the UI device 43 with respect to light of a specific wavelength. The IR toner, which is a color material, is converted into a color value including a value to be output. Accepting the color value of the specified color from the UI device 43 is an example, and the image forming apparatus 10 receives and accepts the image data specifying the color value and the area to be drawn by the IR toner through a network or the like, and the image data is used as the image data. It may be a value for outputting IR toner.

Specifically, first, the control unit 32 performs color conversion so as to draw the image data represented in the RGB color space in the CMYK space. Color conversion is performed by, for example, LUT (Look Up Table) so that the image data color-converted in the CMYK space (image data color-converted so as to be expressed by CMYK toner) is further expressed by CMY toner. On the other hand, the image information to be displayed by the IR toner received by the UI device 43 or the like is separately set and drawn by the IR toner.

That is, by performing such processing, the control unit 42 outputs the image data of the image to be printed so that the invisible image composed of the IR toner is superimposed on the image of the designated color. Convert to print data including values to output toner.

Further, when it is intended to add different security information to one image, for example, for different departments, individuals, and devices, the control unit 42 specifies that the designated color received by the own device is designated by the other device. Adjust so that it does not match or approximate the color. Specifically, when the designated color received in the own device is already designated in another device, the control unit 42 performs processing such as urging the user to change the received designated color.

In the present embodiment, the image forming apparatus 10 functions as an image processing apparatus that generates raster format print data based on a print job from the terminal apparatus 20, but the function as the image processing apparatus is the terminal apparatus 20. It may be realized in. For example, the printer driver installed in the terminal device 20 converts the image data to be printed into the print data in the raster format, and the image forming apparatus 10 prints based on the print data converted into the raster format. The process may be executed. In such a configuration, the terminal device 20 functions as an image processing device.

Next, the operation of the image forming apparatus 10 in the present embodiment will be described with reference to the flowchart of FIG.

In the following description, as an example, a case where security information is added to an image as shown in FIG. 7 will be described.

First, the UI device 43 accepts the designation of the color to which the security information is added (step S101). Here, a case where the round-shaped image 51 in the image example shown in FIG. 7 is selected as an image to which security information is added will be described. In this case, when the user designates the round image 51 by some operation method, for example, a screen as shown in FIG. 8 is displayed and the user is requested to confirm the designated color. Then, when the user operates the OK button in this screen example, the color (255, 0, 0) as the RGB value is registered as the designated color.

The color to which the security information is added may be specified not only by the RGB value but also by the CMYK value. Further, the image to which the security information is added may be directly specified, or when a certain area is specified, the image included in the area may be specified as the image to which the security information is added.

Then, when the designated color is registered, the control unit 42 confirms that the designated color does not overlap with the other device, and confirms that the designated color does not overlap with the designated color of the other device. Then, when the designated color of this time overlaps with the designated color of the other device, the control unit 42 prompts the user to select the designated color of the own device again, and the designated color for the other device. Is adjusted so that the designated color of the own device does not overlap with the designated color of the other device (step S102).

Then, when the designated color is determined, the control unit 42 converts the image data in the RGB color space into print data of the CMY special toner (CMYIR) using, for example, a DLUT (Direct Look Up Table). The specific process of the print data from the image data in the RGB color space to the CMYIR toner output is as described above.

When printing with normal CMYK toner, after converting the image data in the RGB color space into the print data in the CMY color space, UCR (Under Color Removal) processing is performed to determine the output value of the K toner. .. However, in the present embodiment, in order to add security information, after converting the image data in the RGB color space into the print data in the CMY color space, the UCR process is not performed or the UCR value is set to 0 and the K toner is used. There is no output (step S103).

Then, the control unit 42 draws the converted CMY value with the CMY toner for colors other than the designated color, but sets the K value for the designated color to the value for outputting the IR toner, and finally. It is set to a CMYIR value (step S104). This is an example of a case where K toner is replaced with IR toner in an image forming apparatus using CMYK toner, and if the image forming apparatus is designed to form an image with CMYIR toner from the beginning, the value of K is K. It is also possible to set a value for outputting IR toner without using. That is, in addition to setting a value for outputting IR toner to the K value of the CMYK value to obtain the final CMYIR value, image data in the RGB color space is created in CMY in the CMY color space without using K. The IR value may be set as a value different from the image data in the RGB color space and may be the final CMYIR value.

Specifically, as shown in FIG. 9, for the designated color RGB = (255, 0, 0), after converting to CMYK = (10, 100, 100, 0), the value 0 of K is IR. Replaced with the output value of the toner, CMYIR = (10, 100, 100, 20). Then, the control unit 42 uses the CMYK value as it is as the CMYIR value for colors other than the designated color.

That is, as can be seen with reference to FIG. 9, for the specified color, the value instructing the output of the IR toner when specifying the output amount of each color toner is, for example, 20%, whereas the value other than the specified color is used. As for the color of, all the values indicating the output of IR toner are 0%.

Then, the output unit 45 executes the image output process by printing the image based on such print data on the printing paper (step S105).

FIG. 10 shows how the image output in this way looks when viewed under natural light and when it is irradiated with infrared rays and captured by an infrared camera or the like.

FIG. 10A is a diagram showing how the output image looks when viewed under natural light. Since the round image 51 is an image of a designated color, it is formed of IR toner together with CMY toner. However, since the IR toner has almost no absorption characteristic for visible light, it hardly changes the color of the round image 51. Strictly speaking, since the IR toner itself has some tint under visible light, the color of the round image 51 may be slightly changed.

However, the user can hardly determine whether the security information is added and which of the security information is added only by looking at the image as shown in FIG. 10 (A).

Then, an image when such an image is irradiated with infrared rays and captured by an infrared camera or the like is shown in FIG. 10 (B). With reference to the image shown in FIG. 10B, it can be seen that the round image 51 is visible because it is formed of IR toner that absorbs infrared rays.

In this way, by adding an image formed by IR toner to a specific image of a specific place as security information, it is used for, for example, for authenticity determination of securities such as stock certificates, banknotes, tickets, tickets, etc. It becomes possible.

Also, by changing which color in the image is set as the specified color by department, individual, company, printer, etc., when a certain document leaks, it is possible to track where the leaked document leaked. Is possible.

For example, as shown in FIG. 11, when printing an image as shown in FIG. 7 is performed by company A, company B, and company C, different designated colors are set in the image forming apparatus 10 of each company. If the document on which the image is printed is leaked and found, it is possible to determine which company the document was printed by.

For example, if the leaked document is irradiated with infrared rays and the image emerged is a square image 52 as shown in FIG. 11 (A), the document can be identified as printed by company A. .. Similarly, if the leaked document is irradiated with infrared rays and the image emerged is the image 53 of the company name as shown in FIG. 11 (B), the document should be identified as printed by company B. Yes, in the case of a rectangular image 54 as shown in FIG. 11C, the document can be identified as printed by Company C.

As described above, if the specified color is selected only from the colors of the image in the image, the number of specified colors that can be set when there are few types of colors in the image is limited. ..

Therefore, as shown in FIG. 12, the image content is affected by providing the discrimination image 60 composed of a plurality of patch images composed of various colors in advance in the margin portion or the like in the image. The number of specified colors can be increased without any need.

For example, as shown in FIG. 13, by setting the colors of two patch images as designated colors for each department from the discrimination image 60, the document in which the image is printed is printed in which department. It is possible to determine whether the image is a product.

In other words, by irradiating the document to be judged with infrared rays and checking which department the two patch images that emerged are set for, it is possible to identify the department in which the document was printed. It becomes.

Further, if the combination of patch images is changed and printed for each image forming apparatus 10, it is possible to specify from which image forming apparatus 10 the document was printed.

When a printing process such as overprinting a form image (an image composed of at least one of a photographic object, a character object, a graphics object, etc.) is performed, FIG. 14A is used. As shown in, the image of the specified color and the background image may be printed on top of each other. Even in such a case, since the image of the designated color is formed by both the IR toner and the CMY toner, the printing process in which the security information is not known is realized.

In the above, the CMY toner value of the specified color is left as it is, and the K toner value is replaced with the IR toner value. On the other hand, when the control unit 42 converts the image data of the image to be printed into print data, the control unit 42 may convert the color value of the specified color to only the value for outputting the IR toner. good. That is, an image containing only IR toner may be formed without forming an image with CMY toner.

FIG. 14B shows the case where such an image of only IR toner is printed on the background image, and the state of the case where the image of only IR toner is printed directly on the printing paper without the background image. It is shown in FIG. 14 (C).

As shown in FIG. 14B, when an image containing only IR toner is printed on the background image, it is affected by the color of the background image, but if the color density of the background image is too low, the IR toner becomes The image may be visible.

Therefore, when the density value of the background image of the image formed by the IR toner is equal to or less than a preset value, the control unit 42 may be changed to increase the density of the background image.

The operation of the image forming apparatus 10 in the case of performing such processing will be described with reference to the flowchart of FIG.

Since the processing of steps S201 to S203 in the flowchart of FIG. 15 is the same as the processing of steps S101 to S103 described in the flowchart of FIG. 6, the description thereof will be omitted.

Then, when the image data in the RGB color space is converted into the print data expressed in the CMY color space, the control unit 42 uses the converted CMYK value as it is as the CMYIR value for the colors other than the designated color. For the designated color, the CMYK value is replaced with a value for outputting the IR toner to obtain the final CMYIR value (step S204).

That is, the control unit 42 converts the value (10, 100, 100, 0) shown in FIG. 9 into the value (0, 0, 0, 20) indicating the output of only the IR toner.

Then, when there is a background image that overlaps with the image (yes in step S205), the control unit 42 calculates the density value of the accounting image (step S206).

Then, when the calculated density value is smaller than the preset threshold value (no in step S207), the control unit 42 increases the density value of the background image (step S208).

If the amount of change in the concentration value is too large (yes in step S209), the control unit 42 indicates to the user that the change in the concentration value is large and asks for confirmation of the change (step S210).
Then, when the change confirmation is performed, the control unit 42 executes the output process of the output unit 45 based on the converted print data (step S211).

When there is no background image that overlaps with the image formed by the IR toner (no in step S205), and when the calculated density value is not smaller than the preset threshold value (yes in step S207), the density value is Even when the amount of change is not so large (no in step S209), the control unit 42 executes the output process of the output unit 45 based on the converted print data (step S211).

[Modification example]
In the above embodiment, the case where the K toner is replaced with the IR toner and used in the image forming apparatus having four image forming units has been described, but the present invention is not limited thereto. For example, when the present invention is applied to an image forming apparatus having five image forming units, IR toner is used in addition to the four-color regular toner of CMYK, and the security as described above is used. When printing with information added, IR toner may be switched and used instead of K toner. Similarly, for an image forming apparatus provided with six or more image forming units, the present invention can be realized by setting IR toner for any of the image forming units. ..

Further, in the above embodiment, the case where the IR toner is used as the special toner having the absorption property of invisible light has been described, but the present invention is the same even if the special toner having the absorption property of invisible light other than infrared rays such as ultraviolet rays is used. It is possible to realize it.

10, 10a-10c Image forming device 11 CPU
12 Memory 13 Storage device 14 Communication interface (IF)
15 User interface (UI) device 16 Scanner 17 Print engine 18 Control bus 20, 20a, 20b Terminal device 21 Printing device 22 Recording medium supply cassette 23 Supply head 24 Recording medium supply path 25 Image forming unit 26 Photoreceptor 27 Intermediate transfer belt 28 Secondary transfer roll 29 Fixing device 30 Recording medium discharge path 31 Discharge tray 32 Inversion device 33 Recording medium inversion path 34 Image reader 35 Automatic document feeder 36 Platen 40 Network 41 Print job receiver 42 Control unit 43 UI device 44 Data storage Part 45 Output section 51 Round-shaped image 52 Square-shaped image 53 Company name image 54 Rectangular image 60 Discrimination image

Claims (6)

A reception means that accepts as a designated color the color used for the image to which security information is to be added from the images included in the image data received from the terminal device.
When converting the image data into print data, an image included in the image data received from the terminal device and using the designated color received by the receiving means is specified, and the specified image is specified. A conversion means for converting a color value expressing the shape of the image into a color value including a value for outputting a special color material having absorption characteristics for light of a specific wavelength, and then converting the image so as to form the specified image. ,
Image processing device equipped with. The image according to claim 1, wherein the conversion means converts a color value representing an image in which the designated color received by the reception means is not used into a color value that does not include a value for outputting the special color material. Processing equipment. The conversion means converts an image using the designated color received by the reception means into a color value expressed by using a cyan, magenta, yellow color material and the special color material, and the reception means. The image processing apparatus according to claim 2, wherein an image in which the designated color accepted by is not used is converted into a color value expressed by using cyan, magenta, and yellow color materials. The image processing apparatus according to any one of claims 1 to 3, further comprising an adjusting means for adjusting the designated color received by the receiving means so as not to overlap with the designated color in another device. A reception means that accepts as a designated color the color used for the image to which security information is to be added from the images included in the image data received from the terminal device.
When converting the image data into print data, an image included in the image data received from the terminal device and using the designated color received by the receiving means is specified, and the specified image is specified. A conversion means for converting a color value expressing the shape of the image into a color value including a value for outputting a special color material having absorption characteristics for light of a specific wavelength, and then converting the image so as to form the specified image. ,
An output means that outputs an image based on the print data converted by the conversion means, and
An image forming apparatus equipped with. A reception step that accepts as a designated color the color used for the image to which security information is to be added from the images included in the image data received from the terminal device.
When converting the image data into print data, an image included in the image data received from the terminal device and using the designated color received in the reception step is specified, and the specified image is specified. A conversion step of converting a color value expressing the shape of the image into a color value including a value for outputting a special color material having absorption characteristics for light of a specific wavelength, and then converting the image so as to form the specified image. ,
A program that lets your computer run.

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