JP2021175183A - Image processing apparatus, image processing method, and program - Google Patents

Abstract

To provide an image processing apparatus, an image processing method, and program that can facilitate generation of image data when a fluorescent color different from a process color is used.SOLUTION: An image processing apparatus comprises: a first acquisition unit that acquires first image data to be subjected to color conversion; and a color conversion unit that, based on the dot area ratio of any one color of process colors indicated by the first image data, converts the first image data acquired by the first acquisition unit into second image data in which the dot area ratio is divided into the dot area ratio of a fluorescent color different from the process color and the dot area ratio of the process color.SELECTED DRAWING: Figure 3

Description

The present invention relates to an image processing apparatus, an image processing method and a program.

In general, an image recorded in process color by subtractive color mixing in a copier, a printer or the like has a narrower color reproduction range than an output image by additive color mixing in a display or the like. Since the color reproduction by the process color is due to subtractive color mixing, there is a feature that the lightness decreases and the color becomes sunken as the coloring materials are layered in order to produce a vivid color. Therefore, in order to widen the color reproduction range and improve the hue, studies such as searching for a coloring material and using a fluorescent substance have been made. Here, the process color indicates four versions of C (cyan), M (magenta), Y (yellow), and K (black). When reduced color mixing is performed using a fluorescent color material (fluorescent ink, fluorescent toner, etc.) to which a fluorescent substance has been added, a tint with higher brightness and saturation than when no fluorescent substance is added (CMYK process color) is reproduced. It is expected that the color reproduction range can be expanded.

For example, a typical fluorescent ink is fluorescent magenta. The spectral distribution characteristics of fluorescent magenta (hereinafter sometimes referred to as “NM” (Neon Magenta)) and process color magenta (hereinafter sometimes referred to as “M”) are shown in FIG. The first feature is that the two inks have peaks in the absorption spectrum in substantially the same band. The second feature is that the NM ink has a peak of the fluorescence spectrum on the long wavelength side of the peak of the absorption spectrum.

In the market, fluorescent inks are being used in offset printing machines, and fluorescent toners are being used in electrographers. In the case of an offset printing machine, there is an example in which fluorescent magenta is added to magenta in advance to make toned ink, and the ink is used instead of magenta ink. In this case, the image data can be created with the same process color as the conventional one. On the other hand, since the electro-camera handles toner one color at a time, the image data requires a fifth version for fluorescent magenta in addition to the process color. In electronic submission, the submission source condition is that the data is data that can be advanced to the printing process without processing, correction, adjustment, etc. at the printing company that is the submission destination, so the designer of the submission source creates the 5th edition. I have to do it. However, it is a heavy burden to create the fifth edition by oneself using a limited application. Therefore, there is a demand for a function that can easily decompose the image data submitted in the 4th edition into the 5th edition at the time of printing and easily specify the printable color to which the fluorescent toner is added.

As a technique for using a color material other than the process color, C (cyan) is used to reduce density unevenness when the process color CMYK is decomposed into CMYK, LC (light cyan), and LM (light magenta). ) A technique is disclosed in which LC (light cyan) ink is added so as to be maximum in the intermediate gradation range (around 75 to 95 [%]) where the ink increases, and the ink is reduced in the high saturation range (95 [%] or more). (For example, Patent Document 1).

However, as in the conventional technology, using a fluorescent color material of the same color instead of the process color has the advantage that the color does not sink, but since there is no color measurement standard and the color value cannot be defined, a color conversion algorithm is used. There is a problem that it cannot be built. Therefore, when creating image data, it is a general method to manually create a fluorescent plate, and skill is required when creating an image.

The present invention has been made in view of the above, and provides an image processing apparatus, an image processing method, and a program capable of facilitating the creation of image data when a fluorescent color different from the process color is used. The purpose is.

In order to solve the above-mentioned problems and achieve the object, the present invention has a first acquisition unit that acquires the first image data to be color-converted, and the first image acquired by the first acquisition unit. Based on the halftone dot area ratio of any one of the process colors shown in the first image data, the halftone dot area ratio of the fluorescent color different from the process color and the halftone dot area ratio of the process color are obtained. It is characterized in that it is provided with a color conversion unit for converting to the second image data distributed to and.

According to the present invention, it is possible to facilitate the creation of image data when a fluorescent color different from the process color is used.

FIG. 1 is a diagram showing an example of a configuration of a system including an image forming apparatus according to the first embodiment. FIG. 2 is a diagram showing an example of the hardware configuration of the image forming apparatus according to the first embodiment. FIG. 3 is a diagram showing an example of the configuration of the functional block of the controller of the image forming apparatus according to the first embodiment. FIG. 4 is a diagram showing an example of the configuration of the functional block of the color conversion unit of the controller of the image forming apparatus according to the first embodiment. FIG. 5 is a diagram showing an example of a BtoA table having a four-color profile. FIG. 6 is a diagram showing an example of a BtoA table having a five-color profile. FIG. 7 is a diagram showing an example of an AtoB table having a four-color profile. FIG. 8 is a diagram showing an example of an AtoB table having a five-color profile. FIG. 9 is a flowchart showing an example of a flow of a five-color profile generation process of the image forming apparatus according to the first embodiment. FIG. 10 is a flowchart showing an example of the flow of the printing process of the image forming apparatus according to the first embodiment. FIG. 11 is a flowchart showing an example of the flow of the color conversion process in the print process of the image forming apparatus according to the first embodiment. FIG. 12 is a graph showing the relationship between saturation and distribution rate. FIG. 13 is a diagram showing an example of the configuration of the functional block of the controller of the image forming apparatus according to the third embodiment. FIG. 14 is a diagram showing an example of a spot color dictionary. FIG. 15 is a flowchart showing an example of the flow of the spot color dictionary creation process of the image forming apparatus according to the third embodiment. FIG. 16 is a flowchart showing an example of the flow of the printing process of the image forming apparatus according to the third embodiment. FIG. 17 is a diagram showing the spectral distribution characteristics of fluorescent magenta and process color magenta. FIG. 18 is a diagram showing an example of the configuration of the functional block of the color conversion unit of the controller of the image forming apparatus according to the fourth embodiment. FIG. 19 is a diagram showing an example of a BtoA table having a five-color profile before change. FIG. 20 is a diagram showing an example of a BtoA table having a modified 5-color profile. FIG. 21 is a diagram showing an example of an AtoB table having a five-color profile before change. FIG. 22 is a diagram showing an example of an AtoB table having a modified 5-color profile. FIG. 23 is a graph showing an example of the relationship between saturation and distribution rate. FIG. 24 is a graph showing another example of the relationship between saturation and distribution rate. FIG. 25 is a flowchart showing an example of the flow of the five-color profile generation process after the change of the image forming apparatus according to the fourth embodiment. FIG. 26 is a flowchart showing an example of the flow of the color conversion process in the print process of the image forming apparatus according to the fourth embodiment. FIG. 27 is a diagram showing an example of the configuration of the functional block of the color conversion unit of the controller of the image forming apparatus according to the fifth embodiment. FIG. 28 is a diagram illustrating an operation of deriving saturation from cyan, magenta, yellow, and fluorescent magenta. FIG. 29 is a flowchart showing an example of the flow of the color conversion process in the print process of the image forming apparatus according to the fifth embodiment.

Hereinafter, embodiments of an image processing apparatus, an image processing method, and a program according to the present invention will be described in detail with reference to the drawings. Further, the present invention is not limited by the following embodiments, and the components in the following embodiments include those easily conceived by those skilled in the art, substantially the same, and so-called equivalent ranges. Is included. Furthermore, various omissions, substitutions, changes and combinations of components can be made without departing from the gist of the following embodiments.

[First Embodiment]
By using it in the same way as an offset printing machine in which a small amount of fluorescent color is mixed with the process color, the color does not sink even in a high-saturation color, and a vivid impression can be obtained. In this case, since the impression of appearance is more important than the numerical accuracy of color, for example, the device value of magenta may be distributed to magenta and fluorescent magenta. The actual color conversion is performed based on the ICC profile defined by the ICC (International Color Consortium). A large number of various color matching techniques such as a profile creation method and a color adjustment method as a color management means for printed matter are disclosed. These color matching techniques are not limited to electrophotographic printing presses, but can be applied across digital printers including inkjet, thermal printing presses, and peripheral devices thereof. In this embodiment, an example of color conversion using a profile will be described in detail.

As an outline of the present embodiment, in order to create a five-color profile, the magenta device values are distributed and the magenta and fluorescent magenta device values are calculated. Here, the five-color profile consists of a source profile and a printer profile, and the source profile defines the correspondence between the Lab values corresponding to the grid points of C, M, Y, K, and NM as inputs. The printer profile defines the correspondence between the values of C, M, Y, K, and NM corresponding to the grid points of L, a, and b as inputs. Here, the Lab value is a color value in the Lab color space. The controller of the image forming apparatus according to the present embodiment color-converts a CMYK image into a CMYK + NM image using a four-color profile and a five-color profile.

The distribution also includes, for example, calculating the device values of magenta and fluorescent magenta based on the device values of magenta. Specifically, when the device value of magenta before conversion is 1, (device value of magenta after conversion): (device value of fluorescent magenta after conversion) = 1-α: α (0 <α <1). ) (An example of a predetermined ratio), and (device value of magenta after conversion): (device value of fluorescent magenta after conversion) = 1-α: α + β (0 <α <1) , Β: Arbitrary value) (an example of a predetermined ratio), including calculating and converting a magenta device value and a fluorescent magenta device value.

Hereinafter, the embodiment will be described by taking (device value of magenta after conversion): (device value of fluorescent magenta after conversion) = 1-α: α (0 <α <1) as an example.

(System including image forming device)
FIG. 1 is a diagram showing an example of a configuration of a system including an image forming apparatus according to the first embodiment. The configuration of the system including the image forming apparatus 10 according to the present embodiment will be described with reference to FIG.

The system shown in FIG. 1 includes an image forming apparatus 10 and a PC (Personal Computer) 20. The image forming apparatus 10 and the PC 20 can communicate with each other via the network N.

The image forming apparatus 10 is an apparatus that performs image forming (printing) based on image data received from the outside or image data stored in its own storage device. The image forming apparatus 10 is assumed to be, for example, an MFP (Multifunction Peripheral), and is an example of an image processing apparatus.

The PC 20 is an information processing device that transmits image data to the image forming apparatus 10 together with a print command for the image data created or selected according to a user's operation. The PC 20 is not limited to a PC, and may be, for example, an information processing device such as a smartphone, a tablet terminal, or a scanner device.

The system configuration shown in FIG. 1 is an example, and may include, for example, a print server that manages a print job including image data output from the PC 20.

(Hardware configuration of image forming apparatus)
FIG. 2 is a diagram showing an example of the hardware configuration of the image forming apparatus according to the first embodiment. The hardware configuration of the image forming apparatus 10 according to the present embodiment will be described with reference to FIG.

As shown in FIG. 2, the image forming apparatus 10 according to the present embodiment includes a controller 200, an operation display unit 210, an FCU (Facsimile Control Unit) 220, a plotter 231 (printing apparatus), and a scanner 232. The color device 233 is connected to the PCI (Peripheral Component Interface) bus.

The controller 200 is a device that controls control, drawing, communication, and input from the operation display unit 210 of the entire image forming apparatus 10.

The operation display unit 210 is, for example, a touch panel or the like, which is a device that receives input to the controller 200 (input function) and displays the state of the image forming apparatus 1 (display function), and is an ASIC (Application Specific Integrated) described later. It is directly connected to the Circuit) 206.

The FCU 220 is a device that realizes a fax function, and is connected to the ASIC 206 by, for example, a PCI bus.

The plotter 231 is a device that realizes a printing function, and is connected to the ASIC 206 by, for example, a PCI bus. The scanner 232 is a function that realizes a scanner function, and is connected to the ASIC 206 by, for example, a PCI bus. The colorimeter 233 is a device that measures a color of an image printed on a recording medium and acquires a color value of a device-independent color space (for example, a Lab color space) as a color measurement value. For example, PCI. It is connected to ASIC206 by a bus.

The controller 200 includes a CPU (Central Processing Unit) 201, a system memory (MEM-P) 202, a north bridge (NB) 203, a south bridge (SB) 204a, a network I / F204b, and a USB (Universal Serial Bus). ) It has an I / F204c, a centronics I / F204d, an ASIC206, a local memory (MEM-C) 207, and an auxiliary storage device 208.

The CPU 201 controls the entire image forming apparatus 10, is connected to a chipset including a system memory 202, a north bridge 203, and a south bridge 204a, and is connected to other devices via this chipset.

The system memory 202 is a memory used as a memory for storing programs and data, a memory for expanding programs and data, a memory for drawing a printer, and the like, and has a ROM (Read Only Memory) and a RAM (Random Access Memory). doing. Of these, the ROM is a read-only memory used as a memory for storing programs and data, and the RAM is a memory for expanding programs and data, and a writable and readable memory used as a drawing memory for a printer and the like. ..

The north bridge 203 is a bridge for connecting the CPU 201, the system memory 202, the south bridge 204a, and the AGP (Accelerated Graphics Port) bus 205, and is a memory controller that controls reading and writing to the system memory 202, a PCI master, and a PCI master. It has an AGP target.

The south bridge 204a is a bridge for connecting the north bridge 203 to the PCI device and peripheral devices. The south bridge 204a is connected to the north bridge 203 via a PCI bus, and networks I / F204b, USB I / F204c, Centronics I / F204d, and the like are connected to the PCI bus.

The AGP bus 205 is a bus interface for a graphics accelerator card proposed to speed up graphic processing. The AGP bus 205 is a bus that speeds up the graphics accelerator card by directly accessing the system memory 202 with high throughput.

The ASIC 206 is an IC (Integrated Circuit) for image processing applications having hardware elements for image processing, and has a role of a bridge connecting the AGP bus 205, the PCI bus, the auxiliary storage device 208, and the local memory 207, respectively. The ASIC 206 includes a PCI target and an AGP master, an arbiter (ARB) that forms the core of the ASIC 206, a memory controller that controls the local memory 207, and a plurality of DMACs (Direct Memory Access) that rotate image data by hardware logic or the like. It is composed of a controller) and a PCI unit that transfers data between the plotter 231 and the scanner 232 via the PCI bus. For example, the FCU 220, the plotter 231 and the scanner 232, and the colorimeter 233 are connected to the ASIC 206 via the PCI bus. The ASIC 206 is also connected to a host PC (Personal Computer), a network, and the like (not shown).

The local memory 207 is a memory used as a copy image buffer and a code buffer.

The auxiliary storage device 208 is a storage device such as an HDD (Hard Disk Drive), SSD (Solid State Drive), SD (Secure Digital) card or flash memory, and stores image data, programs, font data, etc. And storage for accumulating forms.

The above-mentioned program of the image forming apparatus 10 may be recorded and distributed on a computer-readable recording medium (auxiliary storage device 208 or the like) in an installable format or an executable format file. good.

Further, the colorimeter 233 is supposed to perform data communication with the controller 200 via the PCI bus, but the present invention is not limited to this, and data communication with the controller 200 is performed via the network via the network I / F204b. It may be possible.

Further, the hardware configuration of the image forming apparatus 10 shown in FIG. 2 is an example, and it is not necessary to include all the constituent devices, or it may be provided with other constituent devices.

(Configuration and operation of functional blocks of the controller of the image forming apparatus)
FIG. 3 is a diagram showing an example of the configuration of the functional block of the controller of the image forming apparatus according to the first embodiment. FIG. 4 is a diagram showing an example of the configuration of the functional block of the color conversion unit of the controller of the image forming apparatus according to the first embodiment. FIG. 5 is a diagram showing an example of a BtoA table having a four-color profile. FIG. 6 is a diagram showing an example of a BtoA table having a five-color profile. FIG. 7 is a diagram showing an example of an AtoB table having a four-color profile. FIG. 8 is a diagram showing an example of an AtoB table having a five-color profile. The configuration and operation of the functional block of the controller 200 of the image forming apparatus 10 according to the present embodiment will be described with reference to FIGS. 3 to 8.

As shown in FIG. 3, the controller 200 of the image forming apparatus 10 includes a storage unit 301, a data input / output unit 302, a color conversion profile generation unit 303 (first generation unit), and an image data acquisition unit 304 (first). It has an acquisition unit), a color conversion unit 305, and an image output unit 306.

The storage unit 301 is a functional unit that stores a four-color ICC profile (four-color profile), a five-color ICC profile (five-color profile) generated by the color conversion profile generation unit 303, and the like. The storage unit 301 is realized by the auxiliary storage device 208 shown in FIG.

The data input / output unit 302 is a functional unit that reads data from the storage unit 301 and writes data to the storage unit 301. The data input / output unit 302 is realized by, for example, a program executed by the CPU 201 shown in FIG.

The color conversion profile generation unit 303 receives the four-color profile from the storage unit 301 via the data input / output unit 302, distributes the device values of magenta (M) (an example of the same color process color of the spot color), and distributes the magenta. (M) and fluorescent magenta (NM) (an example of a spot color, an example of a fluorescent color) are functional units that calculate device values and generate a five-color profile. Here, the device value indicates the halftone dot area ratio, which is the ratio of the halftone dot area to the unit area.

The same-color process color is a process color having a peak in the absorption spectrum close to the peak in the absorption spectrum of the fluorescent color among the process colors.

FIG. 5 shows a BtoA table with a 4-color profile. Here, "BtoA" means conversion from a Lab value to a CMYK value (or CMYK + NM value), and "AtoB" described later means conversion to a CMYK value (or CMYK + NM value). In the present embodiment, the color conversion profile generation unit 303 distributes the device values of the magenta (M) of the four-color profile acquired from the storage unit 301 via the data input / output unit 302 in order to generate the five-color profile. Therefore, when calculating the device values of magenta (M) and fluorescent magenta (NM), a fixed distribution rate is assigned. That is, in the color conversion profile generation unit 303, the CMYK values corresponding to the Lab values (Lab grid points) described in the BtoA table of the four-color profile as the printer profile are C = c (0 ≦ c ≦ 100) and Y, respectively. When = y (0 ≦ y ≦ 100) and K = k (0 ≦ k, ≦ 100), distribution is performed only for magenta (M), and using a fixed distribution rate α, C = c, M = The device value of the fluorescent magenta (NM) is calculated with α × m (0 ≦ m ≦ 100), Y = y, K = k, and NM = (1-α) × m. Here, the distribution rate α is 0 <α <1, and ideally α≈0.4 is appropriate. Then, the color conversion profile generation unit 303 distributes the above-mentioned magenta (M) to all the Lab values (Lab grid points) of the BtoA table of the four-color profile, and divides the magenta (M) and the fluorescent magenta (NM). Calculate the device value. Then, the color conversion profile generation unit 303 generates the BtoA table of the five-color profile shown in FIG. 6 by setting the CMYK + NM value corresponding to each Lab value (Lab grid point).

Similarly, the color conversion profile generation unit 303 adds NM values to each CMYK value (CMYK grid point) described in the AtoB table of the four-color profile as the source profile shown in FIG. 7 to make five colors. Expand to calculate magenta (M) and fluorescent magenta (NM) device values in the same manner as in the BtoA table described above. Then, the color conversion profile generation unit 303 generates the AtoB table of the five-color profile shown in FIG. 8 by setting each CMYK + NM value in the new AtoB table.

Here, the color conversion profile generation unit 303 rewrites only the device value in both the BtoA table and the AtoB table, and does not rewrite the Lab value constituting the PCS (Profile Connection Space). Then, the color conversion profile generation unit 303 rewrites the necessary tags when expanding from the 4-color profile to the 5-color profile.

The color conversion profile generation unit 303 stores the generated five-color profile in the storage unit 301 via the data input / output unit 302. The color conversion profile generation unit 303 is realized by, for example, a program executed by the CPU 201 shown in FIG.

The image data acquisition unit 304 is a functional unit that acquires CMYK image data (an example of the first image data) from, for example, a PC 20 or the like via a network N. The image data acquisition unit 304 sends the acquired CMYK image data to the color conversion unit 305. The image data acquisition unit 304 is realized by, for example, a program executed by the CPU 201 shown in FIG.

The color conversion unit 305 acquires CMYK image data from the image data acquisition unit 304, acquires a 4-color profile and a 5-color profile from the storage unit 301 via the data input / output unit 302, and acquires the acquired 4-color profile and 5 colors. It is a functional unit that color-converts the 4th edition CMYK image data into the 5th edition CMYK + NM image data (an example of the second image data) depending on the printer (platter 231) by using the profile. As the CMYK + NM image data, for example, color data created by changing the device value of each of C, M, Y, K, and NM in the range of 0 to 100 may be used.

As shown in FIG. 4, the color conversion unit 305 includes a source profile conversion unit 3051 and a printer profile conversion unit 3052.

The source profile conversion unit 3051 acquires a four-color profile from the storage unit 301 via the data input / output unit 302, and uses the four-color profile to configure four versions of CMYK image data acquired from the image data acquisition unit 304. It is a functional unit that converts the CMYK value of each pixel to be a Lab value. The source profile conversion unit 3051 sends the converted Lab value to the printer profile conversion unit 3052.

The printer profile conversion unit 3052 acquires a five-color profile from the storage unit 301 via the data input / output unit 302, and uses the five-color profile to convert the Lab value received from the source profile conversion unit 3051 into a CMYK + NM value. This is a functional unit that converts the image data of the 5th edition. The printer profile conversion unit 3052 sends the converted 5th version of CMYK + NM image data to the image output unit 306.

The color conversion unit 305 is realized by, for example, a program executed by the CPU 201 shown in FIG.

The image output unit 306 is a functional unit that outputs CMYK + NM image data color-converted by the color conversion unit 305 to a printer (plotter 231) and causes the printer to perform printing. The image output unit 306 is realized by, for example, a program executed by the CPU 201 shown in FIG.

Of the functional parts of the controller 200 shown in FIG. 3, at least a part of the functional parts realized by software (program) is realized by a hardware circuit such as FPGA (Field-Programmable Gate Array) or ASIC. You may.

Further, each functional unit of the controller 200 shown in FIG. 3 conceptually shows a function, and is not limited to such a configuration. For example, a plurality of functional units illustrated as independent functional units in the controller 200 shown in FIG. 3 may be configured as one functional unit. On the other hand, in the controller 200 shown in FIG. 3, the function of one functional unit may be divided into a plurality of functions and configured as a plurality of functional units.

(5 color profile generation process)
FIG. 9 is a flowchart showing an example of a flow of a five-color profile generation process of the image forming apparatus according to the first embodiment. The flow of the five-color profile generation process of the image forming apparatus 10 according to the present embodiment will be described with reference to FIG.

<Step S11>
First, the color conversion profile generation unit 303 acquires a four-color profile (first profile) from the storage unit 301 via the data input / output unit 302. Then, the process proceeds to step S12.

<Step S12>
The color conversion profile generation unit 303 acquires a BtoA table (see, for example, FIG. 5) from the acquired four-color profile. Then, the process proceeds to step S13.

<Step S13>
The color conversion profile generation unit 303 extracts CMYK values as grid point information from the acquired BtoA table of the four-color profile. Then, the process proceeds to step S14.

<Step S14>
The color conversion profile generation unit 303 distributes the magenta (M) device values among the extracted CMYK values to calculate the magenta (M) and fluorescent magenta (NM) device values. Then, the process proceeds to step S15.

<Step S15>
The color conversion profile generation unit 303 rewrites, for example, the CMYK values in the BtoA table of the acquired four-color profile with CMYK + NM values including the calculated magenta (M) and fluorescent magenta (NM) device values. Then, the process proceeds to step S16.

<Step S16>
When the processing of steps S13 to S15 is completed for all the CMYK values (grid point information) in the BtoA table of the four-color profile acquired by the color conversion profile generation unit 303 (step S16: Yes), the process proceeds to step S17. If it is not completed (step S16: No), the process returns to step S13. When the processing of steps S13 to S15 is completed for all the CMYK values (grid point information) in the BtoA table of the 4-color profile acquired by the color conversion profile generation unit 303, the BtoA table of the 5-color profile is generated. become.

<Step S17>
If the processes of steps S13 to S16 have already been performed for the AtoB table having the four-color profile (step S17: Yes), the process proceeds to step S19, and if not yet performed (step S17: No), the process proceeds to step S18. do.

<Step S18>
The color conversion profile generation unit 303 acquires an AtoB table (see, for example, FIG. 7) from the acquired four-color profile. Then, the process returns to step S13.

<Step S19>
Regarding the above processing, when the BtoA table and the AtoB table of the 5-color profile (second profile) are generated by the color conversion profile generation unit 303 for the BtoA table and the AtoB table of the 4-color profile, the color conversion profile generation unit 303 5. Rewrite the tags required for expansion to the 5-color profile. Then, the five-color profile generation process is completed.

(Printing process of image forming apparatus)
FIG. 10 is a flowchart showing an example of the flow of the printing process of the image forming apparatus according to the first embodiment. FIG. 11 is a flowchart showing an example of the flow of the color conversion process in the print process of the image forming apparatus according to the first embodiment. The flow of the printing process of the image forming apparatus 10 according to the present embodiment will be described with reference to FIGS. 10 and 11. It is assumed that the five-color profile shown in FIG. 9 described above is generated in advance and stored in the storage unit 301.

<Step S21>
First, when an operation of printing image data is performed by the user via the operation display unit 210, the image data acquisition unit 304 acquires the 4th version of CMYK image data via the network N. Then, the process proceeds to step S22.

<Step S22>
The image forming apparatus 10 executes the color conversion process shown in FIG. The color conversion process is executed in the flow of the following steps S221 to S227.

<< Step S221 >>
The source profile conversion unit 3051 of the color conversion unit 305 acquires the 4th version of CMYK image data acquired by the image data acquisition unit 304. Then, the process proceeds to step S222.

<< Step S222 >>
The source profile conversion unit 3051 acquires a four-color profile from the storage unit 301 via the data input / output unit 302. The printer profile conversion unit 3052 of the color conversion unit 305 acquires a five-color profile from the storage unit 301 via the data input / output unit 302. Then, the process proceeds to step S223.

<< Step S223 >>
The source profile conversion unit 3051 acquires the 4th version of CMYK image data from the image data acquisition unit 304. Next, the source profile conversion unit 3051 uses the acquired four-color profile (AtoB table) to convert the CMYK values of the pixels constituting the acquired four-version CMYK image data into Lab values. Then, the source profile conversion unit 3051 sends the converted Lab value to the printer profile conversion unit 3052. Then, the process proceeds to step S224.

<< Step S224 >>
The printer profile conversion unit 3052 converts the Lab value received from the source profile conversion unit 3051 into a CMYK + NM value using the acquired five-color profile (BtoA table), and in the fourth version of the CMYK image data, the target CMYK Replace the value with the CMYK + NM value. Then, the process proceeds to step S225.

<< Step S225 >>
When all the pixels of the 4th version CMYK image data are converted and replaced with CMYK + NM values (step S225: Yes), the process proceeds to step S226, and the processing is not completed for all the pixels (step S225). : No), the process returns to step S223.

<< Step S226 >>
The printer profile conversion unit 3052 generates image data in which all the CMYK values of the pixels constituting the 4th version CMYK image data are replaced with CMYK + NM values as the 5th version CMYK + NM image data. The CMYK + NM value constituting the 5th version of CMYK + NM image data is a device value depending on the printer (plotter 231). Then, the process proceeds to step S227.

<< Step S227 >>
The printer profile conversion unit 3052 sends the generated 5th version of CMYK + NM image data to the image output unit 306. Then, the color conversion process is completed, and the process proceeds to step S23 in FIG.

<Step S23>
The image output unit 306 outputs the 5th plate CMYK + NM image data color-converted by the color conversion unit 305 to a printer (plotter 231), and causes the printer to perform printing. Specifically, when the image data received from the color conversion unit 305 is the 5th plate, the image output unit 306 confirms that the toner at the 5th station of the plotter 231 is fluorescent magenta, and loads different toners. If so, for example, the operation display unit 210 is displayed with a notification urging the toner bottle to be replaced. Further, when the fluorescent magenta toner is loaded, the image output unit 306 outputs the 5th plate CMYK + NM image data to the printer (plotter 231) to execute printing.

As described above, in the image forming apparatus 10 according to the present embodiment, the color conversion profile generation unit 303 generates a five-color profile from the four-color profile, and the color conversion unit 305 uses the four-color profile from the four-version CMYK image data. It is assumed that the Lab value is converted into a Lab value, and the Lab value is converted into a CMYK + NM value by the 5-color profile, so that the color is converted into 5 versions of CMYK + NM image data. As a result, an algorithm for color conversion is constructed, and it is possible to facilitate the creation of image data when a fluorescent color material is used.

In the above-described embodiment, the device values of the magenta (M) of the four-color profile are distributed, the device values of the fluorescent magenta as the fluorescent color material are calculated, and the five-color profile is generated. Not limited to. For example, the device values of cyan (C) or yellow (Y) of the four-color profile may be distributed to calculate the device value of the fluorescent color material to generate the five-color profile.

[Second Embodiment]
The image forming apparatus according to the second embodiment will be described focusing on the differences from the image forming apparatus 10 according to the first embodiment. In the first embodiment, an operation using a fixed distribution ratio has been described in order to generate a 5-color profile from a 4-color profile. In this embodiment, the operation of changing the distribution rate according to the Lab value when generating the five-color profile will be described. The hardware configuration and the functional block configuration of the image forming apparatus according to the present embodiment are the same as the configurations described in the first embodiment.

FIG. 12 is a graph showing the relationship between saturation and distribution rate. The relationship between saturation and distribution rate will be described with reference to FIG.

As shown in FIG. 12, the distribution rate α is determined according to the saturation S, and when the device value of magenta (M) is distributed to the device value of fluorescent magenta (NM), the grid point (Lab value) is used. The distribution rate α determined from the saturation S is used. That is, the color conversion profile generation unit 303 calculates the saturation S from the Lab values (Lab grid points) described in the BtoA table of the four-color profile as the printer profile, and determines the distribution rate α according to the saturation S. decide. For example, as shown in FIG. 12, the color conversion profile generation unit 303 predetermines a function that defines the relationship between the saturation S and the distribution rate α, and determines the distribution rate α from the saturation S. Just do it. The determination of the distribution rate α by the color conversion profile generation unit 303 may be executed in step S14 of FIG. 9 described above. The other processes of the five-color profile generation process and the print process of the image forming apparatus 10 are the same as those described above in the first embodiment.

The same effect as that of the first embodiment described above can be obtained by the above operation.

[Third Embodiment]
The image forming apparatus according to the third embodiment will be described focusing on the differences from the image forming apparatus 10 according to the first embodiment. In the first embodiment, the operation of distributing the device value of the process color to the device value of the fluorescent color as it is has been described. In this case, the color value defined in the Lab color space may not match the color value of the target color. In the present embodiment, the operation of calculating the device values of other process colors based on at least the device values of the fluorescent color and the color values of the target color to obtain the color values close to the target color will be described. The hardware configuration of the image forming apparatus according to the present embodiment is the same as the configuration described in the first embodiment.

Among the designers, specify the color by referring to the patch color (target color) of the color sample book. Here, examples of the target color include a color sample book specified by a DIC color guide (registered trademark) or PANTONE (registered trademark), a color specified by a color chip, and the like. For example, a DIC color guide. In the case, it is specified by a color name such as "DIC001". In these color sample books, a color sample sample composed of a plurality of patches and a corresponding Lab value are provided, and the described Lab value becomes the color value of the target color. Hereinafter, the data consisting of a pair of a color name and a color value in the color sample book will be referred to as color sample data. In addition, in order to match the color measurement conditions when creating the color reproduction characteristics in the color reproduction characteristic creation unit 313 described later, the result of color measurement by the colorimeter 233 may be used as the target color.

In addition, although there is currently no official regulation for numerically controlling fluorescent colors, for example, assuming that a user views a printed matter under a fluorescent lamp that does not contain ultraviolet rays, the Commission Internationale de l'Eclairage (CIE) It can be represented by an approximate color using the Lab color space, which is standardized by the International de I'Eclairage) and is also adopted by the Japanese JIS (Japanese Industrial Standards). By using these, it is possible to create a profile in which a fluorescent color is mixed with a process color, or to create a spot color dictionary. In this embodiment, the operation of creating a spot color dictionary for reproducing the target color in the color sample book will be described.

(Configuration and operation of functional blocks of the controller of the image forming apparatus)
FIG. 13 is a diagram showing an example of the configuration of the functional block of the controller of the image forming apparatus according to the third embodiment. FIG. 14 is a diagram showing an example of a spot color dictionary. The configuration and operation of the functional block of the controller 200a of the image forming apparatus according to the present embodiment will be described with reference to FIGS. 13 and 14.

As shown in FIG. 13, the controller 200a includes a storage unit 301, a data input / output unit 302, a spot color dictionary generation unit 303a (second generation unit), an image data acquisition unit 304 (first acquisition unit), and the like. It has a color conversion unit 305a, an image output unit 306, a chart image generation unit 311, a color measurement value acquisition unit 312 (second acquisition unit), and a color reproduction characteristic creation unit 313 (creation unit).

The storage unit 301 is a functional unit that stores a four-color profile and color sample data (color sample information), and stores a spot color dictionary and the like generated by the spot color dictionary generation unit 303a described later. The storage unit 301 is realized by the auxiliary storage device 208 shown in FIG.

The data input / output unit 302 is a functional unit that reads data from the storage unit 301 and writes data to the storage unit 301. The data input / output unit 302 is realized by, for example, a program executed by the CPU 201 shown in FIG.

The spot color dictionary generation unit 303a receives the four-color profile and the color sample data from the storage unit 301 via the data input / output unit 302, and magenta (M) (spot color) in the target color described in the color sample data. It is a functional unit that distributes the device values of the same color process color) and calculates the device values of magenta (M) and fluorescent magenta (NM) (an example of a spot color and an example of a fluorescent color). Then, the spot color dictionary generation unit 303a calculates the color reproduction characteristics in which the device value of the printer (platter 231) received from the color reproduction characteristic creation unit 313 and the color value (the color measurement value of the colorimeter 233) are associated with each other. A device value that reproduces the Lab value of the target color is calculated using the device value of the fluorescent magenta (NM), and a spot color dictionary (dictionary) is generated.

Here, an example of a spot color dictionary (an example of four colors) is shown in FIG. As shown in FIG. 14, in the spot color dictionary, a color name (Colorname) as a spot color (spot color) is associated with a device value.

The spot color dictionary generation unit 303a stores the generated spot color dictionary in the storage unit 301 via the data input / output unit 302. The spot color dictionary generation unit 303a is realized by, for example, a program executed by the CPU 201 shown in FIG.

The image data acquisition unit 304 is, for example, a functional unit that acquires PDF (Portable Document Form) image data (an example of first image data) in which spot color information is written from a PC 20 or the like via a network N. The image data acquisition unit 304 is realized by, for example, a program executed by the CPU 201 shown in FIG.

The color conversion unit 305a acquires PDF image data in which spot color information is written from the image data acquisition unit 304, receives the spot color dictionary from the storage unit 301 via the data input / output unit 302, and uses the spot color dictionary. By converting all the spot colors used in the PDF image data into CMYK + NM values, the color is converted into 5th version CMYK + NM image data (an example of the second image data) depending on the printer (platter 231). It is a functional part. The color conversion unit 305a is realized by, for example, a program executed by the CPU 201 shown in FIG.

The image output unit 306 is a functional unit that outputs the 5th plate CMYK + NM image data color-converted by the color conversion unit 305a to a printer (plotter 231) and causes the printer to perform printing. The image output unit 306 is realized by, for example, a program executed by the CPU 201 shown in FIG.

The chart image generation unit 311 holds chart data for obtaining the color reproduction characteristics of the printer (plotter 231), and has a function of generating the chart data as image data in PDF format (hereinafter referred to as chart image data). It is a department. Here, the chart data is data in which each of C, M, Y, K, and NM is combined for each predetermined gradation value. For example, when the gradation value is set to every 20 [%] per color, 6 ⁵ = Data including 7776 patches. The chart image generation unit 311 sends the generated chart image data to the color reproduction characteristic creation unit 313 and the image output unit 306. The chart image generation unit 311 is realized by, for example, a program executed by the CPU 201 shown in FIG.

The color measurement value acquisition unit 312 is a functional unit that acquires the color measurement value (Lab value) measured by the colorimeter 233. The color measurement value acquisition unit 312 includes C, A color measurement value (Lab value) of a non-device-dependent color space (Lab color space) is obtained for a patch in which M, Y, K, and NM are combined for each gradation value. The colorimeter 233 may measure the color according to the operation of sliding the colorimeter 233 on the recording medium of the chart image data, or the chart image data in the printer (platter 231). The color may be measured according to the detection of the output of. The color measurement value acquisition unit 312 is realized by, for example, a program executed by the CPU 201 shown in FIG.

The color reproduction characteristic creation unit 313 refers to the CMYK + NM value of the CMYK + NM chart image data received from the chart image generation unit 311 and the recording medium of the chart image data printed out from the plotter 231 acquired by the color measurement value acquisition unit 312. It is a functional unit that creates a color reproduction characteristic that associates with a color measurement value (Lab value). The color reproduction characteristic creation unit 313 sends the created color reproduction characteristic to the spot color dictionary generation unit 303a. The color reproduction characteristic creation unit 313 is realized by, for example, a program executed by the CPU 201 shown in FIG.

Of the functional parts of the controller 200a shown in FIG. 13, at least a part of the functional parts realized by software (program) may be realized by a hardware circuit such as FPGA or ASIC.

Further, each functional unit of the controller 200a shown in FIG. 13 conceptually shows a function, and is not limited to such a configuration. For example, a plurality of functional units illustrated as independent functional units in the controller 200a shown in FIG. 13 may be configured as one functional unit. On the other hand, in the controller 200a shown in FIG. 13, the functions of one functional unit may be divided into a plurality of functions and configured as a plurality of functional units.

(Spot color dictionary creation process)
FIG. 15 is a flowchart showing an example of the flow of the spot color dictionary creation process of the image forming apparatus according to the third embodiment. The flow of the spot color dictionary creation process of the image forming apparatus according to the present embodiment will be described with reference to FIG.

<Step S31>
First, the spot color dictionary generation unit 303a acquires a four-color profile and color sample data from the storage unit 301 via the data input / output unit 302. Then, the process proceeds to step S32.

<Step S32>
The spot color dictionary generation unit 303a acquires a BtoA table (for example, see FIG. 5) from the acquired four-color profile. Then, the process proceeds to step S33.

<Step S33>
The spot color dictionary generation unit 303a acquires the Lab value of the target color of 1 from the acquired color sample data. Then, the process proceeds to step S34.

<Step S34>
The spot color dictionary generation unit 303a acquires the magenta (M) device value corresponding to the Lab value of the target color acquired from the color sample data in the acquired four-color profile. Then, the spot color dictionary generation unit 303a distributes the acquired device values of magenta (M) in the same manner as the color conversion profile generation unit 303 of the first embodiment or the second embodiment, and magenta ( Calculate device values for M) and fluorescent magenta (NM). Then, the process proceeds to step S35.

<Step S35>
The spot color dictionary generation unit 303a receives the color reproduction characteristics from the color reproduction characteristic creation unit 313, fixes the calculated device value of the fluorescence magenta (NM), and reproduces the Lab value of the target color using the color reproduction characteristics. Calculate the device values of C, M, Y, and K. Then, the process proceeds to step S36.

<Step S36>
The spot color dictionary generation unit 303a writes information relating the target color and the calculated CMYK + NM value to the spot color dictionary. Then, the process proceeds to step S37.

<Step S37>
If the processing of steps S33 to S36 is completed for all the target colors of the color sample data (step S37: Yes), the process proceeds to step S38, and if not completed (step S37: No), the process returns to step S33. ..

<Step S38>
The spot color dictionary generation unit 303a generates a spot color dictionary composed of information in which all target colors are associated with the calculated CMYK + NM value, and stores (saves) the spot color dictionary in the storage unit 301 via the data input / output unit 302. ). Then, the spot color dictionary creation process is completed.

(Printing process of image forming apparatus)
FIG. 16 is a flowchart showing an example of the flow of the printing process of the image forming apparatus according to the third embodiment. The flow of the printing process of the image forming apparatus according to the present embodiment will be described with reference to FIG.

<Step S41>
First, when an operation of printing the image data is performed by the user via the operation display unit 210, the image data acquisition unit 304 acquires the PDF image data in which the spot color information is written via the network N. do. Then, the process proceeds to step S42.

<Step S42>
The color conversion unit 305a acquires the PDF image data acquired by the image data acquisition unit 304, and acquires the spot color dictionary from the storage unit 301 via the data input / output unit 302. Then, the process proceeds to step S43.

<Step S43>
The color conversion unit 305a uses the acquired spot color dictionary to convert the spot color used (described) in the PDF image data into a CMYK + NM device value (CMYK + NM value). Then, the process proceeds to step S44.

<Step S44>
When the conversion process by the color conversion unit 305a for all the spot colors in the PDF image data is completed (step S44: Yes), the process proceeds to step S45, and when it is not completed (step S44: No), the process returns to step S43.

<Step S45>
In steps S43 and S44, the color conversion unit 305a converts all the spot colors used in the PDF image data into CMYK + NM values, thereby converting the colors into 5 versions of CMYK + NM image data depending on the printer (plotter 231). Convert and generate. Then, the process proceeds to step S46.

<Step S46>
The color conversion unit 305a sends the generated 5th version of CMYK + NM image data to the image output unit 306. Then, the image output unit 306 outputs the 5th version of CMYK + NM image data to a printer (plotter 231), and causes the printer to perform printing.

As described above, in the image forming apparatus according to the present embodiment, the spot color dictionary generation unit 303a acquires the device value of the fluorescent magenta (NM) corresponding to the target color from the four-color profile and the color sample data, and the color of the printer. Device values of C, M, Y, and K are calculated using the reproduction characteristics, and a spot color dictionary is generated. Then, the spot color of the PDF image data is converted into the CMYK + NM value of the 5th version by the color conversion unit 305a by using the spot color dictionary, so that the color is converted into the CMYK + NM image data of the 5th version. As a result, an algorithm for color conversion is constructed, and it is possible to facilitate the creation of image data when a fluorescent color material is used. Further, by generating the spot color dictionary, the target color in the color sample book can be reproduced.

In the present embodiment, the operation of calculating the CMYK device value from the device value of the fluorescent magenta (NM) and the target color by using the color reproduction characteristic has been described, but the present invention is not limited to this. If the method of inserting black (K) is set in advance in consideration of graininess, the CMY device value can be calculated from the device values of fluorescent magenta (NM) and black (K) and the target color. Is also possible.

[Fourth Embodiment]
The image forming apparatus according to the fourth embodiment will be described focusing on the differences from the image forming apparatus 10 according to the first embodiment. In the first embodiment, an operation of easily generating a 5-color profile from a 4-color profile using a fixed distribution ratio and converting the image data of the 4th plate into the image data of the 5th plate in which fluorescent magenta is distributed is performed. explained. In the present embodiment, an operation of converting the ratio of the device values of magenta and fluorescent magenta using a profile will be described in order to maintain the gray expression from the image data of the 5th edition. The hardware configuration of the image forming apparatus according to the present embodiment is the same as the configuration described in the first embodiment.

As described above, replacing the process color with a fluorescent color material of the same color has the advantage that the color does not sink, but the replaced fluorescent color material is mixed with gray to express gray. It is known that the ratio of color changes and the color shifts from the gray color that you want to express, and that the appearance is significantly affected, especially in low-saturation areas. Since the gray expression is expressed by a mixture of process colors, numerically accurate reproduction is required. Therefore, do not change the mixing ratio of C (cyan), M (magenta), and Y (yellow) as much as possible (if the ratio has already been adjusted including the fluorescent color material, the ratio including the fluorescent color material). Is preferable. Here, the expressions of gray and gray are not gray, which means gray, but the colors in the desaturated, grayish color region and the expressions of the colors. For example, when a new fluorescent magenta color material is used in the image data of the 4th edition, the distribution ratio of magenta and fluorescent magenta is set, and when the output is gray, the fluorescent color material is not used and the output is other than gray. Can maintain the gray ratio in the process color by increasing the color mixing ratio of the fluorescent color material.

As an outline of the present embodiment, in order to prevent the gray expression of the five-color profile from being out of balance, the ratio between the magenta device value and the fluorescent magenta device value is changed based on the saturation, and the magenta and fluorescence are changed. Calculate the magenta device value. In the controller of the image forming apparatus according to the present embodiment, an operation of color-converting the 5th version of CMYK + NM image data into the 5th version of CM'YK + NM'image data having different device values of M and NM will be described as an example. It should be noted that the present embodiment is not limited to color conversion from the image data of the 5th edition to the image data of the 5th edition, and the present embodiment is also applied to the case of color conversion from the image data of the 4th edition to the image data of the 5th edition. It is possible to apply.

Details will be described later, but in the present embodiment, changing the ratio of the magenta device value and the fluorescent magenta device value based on the saturation is performed as follows, for example.

The device value before the change is as follows.
Magenta device value before change: m
Fluorescent magenta device value before change: n
(0 ≦ m ≦ 100, 0 ≦ m ≦ 100)

Calculate the changed device value as follows.
Magenta device value after change: mm x γ
After change Fluorescent magenta device value: n + m × γ
(0 ≤ γ ≤ 1)

Here, γ is a value based on saturation, and is a value that becomes 0 when the saturation is low and increases when the saturation is high.

The changed device value may be calculated as follows.
Magenta device value after change: mm x γ
After change Fluorescent magenta device value: n + m × γ + β
(0 ≤ γ ≤ 1, β: arbitrary value)

Hereinafter, a case where the device value of the changed magenta is calculated as mm × γ and the device value of the changed fluorescent magenta is calculated as n + m × γ will be described as an example.

(Configuration and operation of functional blocks of the controller of the image forming apparatus)
FIG. 18 is a diagram showing an example of the configuration of the functional block of the color conversion unit of the controller of the image forming apparatus according to the fourth embodiment. FIG. 19 is a diagram showing an example of a BtoA table having a five-color profile before change. FIG. 20 is a diagram showing an example of a BtoA table having a modified 5-color profile. FIG. 21 is a diagram showing an example of an AtoB table having a five-color profile before change. FIG. 22 is a diagram showing an example of an AtoB table having a modified 5-color profile. FIG. 23 is a graph showing an example of the relationship between saturation and distribution rate. FIG. 24 is a graph showing another example of the relationship between saturation and distribution rate. The configuration and operation of the controller of the image forming apparatus according to the present embodiment will be described with reference to FIGS. 18 to 24.

In the configuration shown in FIG. 3 above, the controller 200 of the image forming apparatus 10 according to the present embodiment is used instead of the data input / output unit 302, the image data acquisition unit 304, and the color conversion unit 305, respectively. It has a unit 302b, an image data acquisition unit 304b, and a color conversion unit 305b.

The storage unit 301 includes a five-color ICC profile (hereinafter referred to as a five-color profile before change) before changing the ratio of the device values of magenta and fluorescent magenta, and a magenta and magenta generated by the color conversion profile generation unit 303. It is a functional unit that stores an ICC profile of five colors (hereinafter, referred to as a five-color profile after the change) after changing the ratio of the device values of the fluorescent magenta. The storage unit 301 is realized by the auxiliary storage device 208 shown in FIG.

The data input / output unit 302b is a functional unit that reads data from the storage unit 301 and writes data to the storage unit 301. The data input / output unit 302b is realized by, for example, a program executed by the CPU 201 shown in FIG.

The color conversion profile generation unit 303 (third generation unit) receives the five-color profile before change from the storage unit 301 via the data input / output unit 302b, and magenta (M) (an example of the same color process color of the fluorescent color). And a function to calculate the device values of magenta (M) and fluorescent magenta (NM) by changing the ratio of the device values of fluorescent magenta (NM) (an example of fluorescent color) and generate a 5-color profile after the change. It is a department.

FIG. 19 shows a BtoA table of the five-color profile before the change. In the present embodiment, the color conversion profile generation unit 303 performs magenta (M) and fluorescence of the unchanged five-color profile acquired from the storage unit 301 via the data input / output unit 302b in order to generate the changed five-color profile. The ratio of the magenta (NM) device values is changed to assign a distribution ratio when calculating the magenta (M) and fluorescent magenta (NM) device values. That is, in the color conversion profile generation unit 303, the CMYK + NM values corresponding to the Lab values (Lab grid points) described in the BtoA table of the five-color profile before change as the printer profile are C = c (0 ≦ c ≦ 100), respectively. , Y = y (0 ≦ y ≦ 100), K = k (0 ≦ k ≦ 100), the ratio is changed only for the device values of magenta (M) and fluorescent magenta (NM), and the saturation is changed. Magenta (M) and fluorescence as C = c, M = mm × γ (mn × γ> 0), Y = y, K = k, NM = n + m × γ using the based partition factor γ. Calculate the magenta (NM) device value. Here, the distribution rate γ has a value of 0 ≦ γ ≦ 1 and is determined based on the saturation X directly obtained from the Lab value (specifically, a and b of the Lab values). Percentage. For example, the distribution rate γ may be determined so that the value becomes smaller as the saturation becomes smaller (the value becomes larger as the saturation becomes larger), at least in a predetermined range of saturation. For example, when the saturation X obtained from a and b of the Lab values is 17 or less (that is, when the saturation is low), γ = 0 (that is, not distributed), and when the saturation X is 34 or more (that is, when the saturation is low). That is, when the saturation is high), γ ≈ 1, and when the saturation X is 17 <X <34, the distribution rate γ may take a value as shown in FIG. 23 as an example. The value of the distribution rate γ in FIG. 23 is an example, and the value as shown in FIG. 24 may be taken. That is, if it is less than the predetermined saturation X (for example, 17), the distribution rate γ may be set to 0, and if it is larger than the predetermined saturation X, the distribution rate γ may be set to 1. Then, the color conversion profile generation unit 303 changes the ratio of all the Lab values (Lab lattice points) of the BtoA table of the five-color profile before the change with respect to the above-mentioned magenta (M) and fluorescent magenta (NM) device values. Then, the device values of magenta (M) and fluorescent magenta (NM) are calculated. Then, the color conversion profile generation unit 303 generates the BtoA table of the changed five-color profile shown in FIG. 20 by setting the CMYK + NM value corresponding to each Lab value (Lab grid point). _{The m max} and n _{max in} FIGS. 19 and 20 are, for example, "100".

Similarly, the color conversion profile generation unit 303 describes each CMYK + NM value (CMYK + NM grid points) described in the AtoB table of the five-color profile before change as the source profile shown in FIG. 21 in the same manner as in the above-mentioned BtoA table. , Magenta (M) and Fluorescent Magenta (NM) device values are calculated. Then, the color conversion profile generation unit 303 generates an AtoB table of the changed five-color profile shown in FIG. 22.

Here, the color conversion profile generation unit 303 rewrites only the device value in both the BtoA table and the AtoB table, and does not rewrite the Lab value constituting the PCS. Then, the color conversion profile generation unit 303 rewrites the necessary tags.

The color conversion profile generation unit 303 stores the generated five-color profile in the storage unit 301 via the data input / output unit 302b. The color conversion profile generation unit 303 is realized by, for example, a program executed by the CPU 201 shown in FIG.

The image data acquisition unit 304b is a functional unit that acquires CMYK + NM image data (an example of the first image data) from, for example, a PC 20 or the like via a network N. The image data acquisition unit 304b sends the acquired CMYK + NM image data to the color conversion unit 305b. The image data acquisition unit 304b is realized by, for example, a program executed by the CPU 201 shown in FIG.

The color conversion unit 305b acquires CMYK + NM image data from the image data acquisition unit 304b, acquires a five-color profile from the storage unit 301 via the data input / output unit 302b, and uses the acquired five-color profile to acquire 5 This is a functional unit that color-converts the CMYK + NM image data of the plate into the CM'YK + NM'image data of the 5th plate (an example of the second image data) depending on the printer (platter 231). As the CMYK + NM image data and the CM'YK + NM'image data, for example, color data created by changing the device value of each of C, M, Y, K, and NM in the range of 0 to 100 may be used. ..

As shown in FIG. 18, the color conversion unit 305b includes a source profile conversion unit 3051b and a printer profile conversion unit 3052b.

The source profile conversion unit 3051b acquires a five-color profile before change (AtoB table) from the storage unit 301 via the data input / output unit 302b, and acquires the five-color profile before change from the image data acquisition unit 304b using the five-color profile before change. This is a functional unit that converts the CMYK + NM value of each pixel constituting the 5th version of CMYK + NM image data into a Lab value. The source profile conversion unit 3051b sends the converted Lab value to the printer profile conversion unit 3052b.

The printer profile conversion unit 3052b acquires the changed 5-color profile (BtoA table) from the storage unit 301 via the data input / output unit 302b, and receives the changed 5-color profile from the source profile conversion unit 3051b using the changed 5-color profile. This is a functional unit that converts a Lab value into 5 versions of CM'YK + NM'image data composed of CM'YK + NM' values. The printer profile conversion unit 3052b sends the converted 5th version of CM'YK + NM'image data to the image output unit 306.

The color conversion unit 305b is realized by, for example, a program executed by the CPU 201 shown in FIG.

The image output unit 306 is a functional unit that outputs the CM'YK + NM'image data color-converted by the color conversion unit 305b to a printer (plotter 231) and causes the printer to perform printing. The image output unit 306 is realized by, for example, a program executed by the CPU 201 shown in FIG.

Of the functional parts of the controller 200 according to the present embodiment, at least a part of the functional parts realized by software (program) may be realized by a hardware circuit such as FPGA or ASIC.

Further, each functional unit of the controller 200 according to the present embodiment conceptually shows a function, and is not limited to such a configuration. For example, a plurality of functional units shown as independent functional units in the controller 200 may be configured as one functional unit. On the other hand, the function of one functional unit may be divided into a plurality of functions in the controller 200 and configured as a plurality of functional units.

(5 color profile generation process)
FIG. 25 is a flowchart showing an example of the flow of the five-color profile generation process after the change of the image forming apparatus according to the fourth embodiment. The flow of the modified five-color profile generation process of the image forming apparatus 10 according to the present embodiment will be described with reference to FIG. 25.

<Step S11a>
First, the color conversion profile generation unit 303 acquires the unchanged five-color profile (first profile) from the storage unit 301 via the data input / output unit 302b. Then, the process proceeds to step S12a.

<Step S12a>
The color conversion profile generation unit 303 acquires a BtoA table (see, for example, FIG. 19) from the acquired five color profiles before change. Then, the process proceeds to step S13a.

<Step S13a>
The color conversion profile generation unit 303 extracts the CMYK + NM value as grid point information from the acquired BtoA table of the five color profiles before change. Then, the process proceeds to step S14a.

<Step S14a>
The color conversion profile generation unit 303 changes the ratio of the device values of magenta (M) and fluorescent magenta (NM) to the extracted CMYK + NM values by the method described above, and changes the ratio of the device values of magenta (M) and fluorescent magenta (NM). Calculate the device value. Then, the process proceeds to step S15a.

<Step S15a>
For example, the color conversion profile generation unit 303 rewrites the acquired CMYK + NM value of the BtoA table of the five color profiles before change with the CM'YK + NM'value including the calculated magenta (M) and fluorescent magenta (NM) device values. Then, the process proceeds to step S16a.

<Step S16a>
When the processing of steps S13a to S15a is completed for all the CMYK + NM values (lattice point information) in the BtoA table of the five color profiles before change acquired by the color conversion profile generation unit 303 (step S16a: Yes), the process proceeds to step S17a. If the transition has not been completed (step S16a: No), the process returns to step S13a. When the processing of steps S13a to S15a is completed for all the CMYK + NM values (lattice point information) in the BtoA table of the 5 color profile before change acquired by the color conversion profile generation unit 303, the BtoA table of the 5 color profile after change is displayed. It will be generated.

<Step S17a>
If the processing of steps S13a to S16a has already been performed on the AtoB table of the five-color profile before the change (step S17a: Yes), the process proceeds to step S19a, and if it has not been performed yet (step S17a: No), step S18a Move to.

<Step S18a>
The color conversion profile generation unit 303 acquires an AtoB table (see, for example, FIG. 21) from the acquired five color profiles before change. Then, the process returns to step S13a.

<Step S19a>
The color conversion profile generation unit 303 changes the tag information such as the date of the five-color profile after the change as necessary. When the BtoA table and AtoB table of the 5 color profile before change are generated by the color conversion profile generation unit 303, the BtoA table and AtoB table of the 5 color profile after change (second profile), the generation process of the 5 color profile after change To finish.

(Color conversion processing in the printing processing of the image forming apparatus)
FIG. 26 is a flowchart showing an example of the flow of the color conversion process in the print process of the image forming apparatus according to the fourth embodiment. The color conversion process shown in FIG. 26 corresponds to the process of step S22 (color conversion process shown in FIG. 11) shown in FIG. 10 of the first embodiment described above. The flow of the color conversion process in the print process of the image forming apparatus 10 according to the present embodiment will be described with reference to FIG. 26. It is assumed that the five-color profile (BtoA table) shown in FIG. 25 described above is generated in advance and stored in the storage unit 301.

<Step S221a>
The source profile conversion unit 3051b of the color conversion unit 305b acquires the 5th version of CMYK + NM image data acquired by the image data acquisition unit 304b. Then, the process proceeds to step S222a.

<Step S222a>
The source profile conversion unit 3051b acquires the unchanged five-color profile from the storage unit 301 via the data input / output unit 302b. The printer profile conversion unit 3052b of the color conversion unit 305b acquires the changed five-color profile from the storage unit 301 via the data input / output unit 302b. Then, the process proceeds to step S223a.

<Step S223a>
Next, the source profile conversion unit 3051b uses the acquired five-color profile before change (AtoB table) to convert the CMYK + NM values of the pixels constituting the acquired fifth version of CMYK + NM image data into Lab values. Then, the source profile conversion unit 3051b sends the converted Lab value to the printer profile conversion unit 3052b. Then, the process proceeds to step S224a.

<Step S224a>
The printer profile conversion unit 3052b converts the Lab value received from the source profile conversion unit 3051b into a CM'YK + NM'value using the acquired changed 5-color profile (BtoA table), and in the 5th version of CMYK + MN image data. , The target CMYK + NM value is replaced with the CM'YK + NM'value. Then, the process proceeds to step S225a.

<Step S225a>
When all the pixels of the 5th edition CMYK + NM image data before conversion are converted and replaced with the CM'YK + NM'value (step S225a: Yes), the process proceeds to step S226a and the processing is completed for all the pixels. If not (step S225a: No), the process returns to step S223a.

<Step S226a>
The printer profile conversion unit 3052b is a CM'YK + NM'value in which the ratio of the device values of magenta (M) and fluorescent magenta (NM) is changed for all the CMYK + NM values of the pixels constituting the 5th version of CMYK + NM image data before conversion. The image data replaced with is generated as the converted 5th edition CM'YK + NM'image data. The CM'YK + NM'values constituting the converted 5th version CM'YK + NM'image data are device values depending on the printer (plotter 231). Then, the process proceeds to step S227a.

<Step S227a>
The printer profile conversion unit 3052b sends the generated converted 5th version CM'YK + NM'image data to the image output unit 306. Then, the color conversion process is finished.

As described above, in the image forming apparatus 10 according to the present embodiment, the color conversion profile generation unit 303 generates a five-color profile after the ratio change from the five-color profile before the change, and the color conversion unit 305b generates the fifth version of CMYK + NM image data. The ratio of the device values of magenta (M) and fluorescent magenta (NM) by converting from to the Lab value by the 5 color profile before the change and converting the Lab value to the CM'YK + NM'value by the 5 color profile after the change. Is supposed to be color-converted to the modified 5th edition CM'YK + NM'image data. As a result, an algorithm for color conversion is constructed, the gray balance when using a fluorescent color material is suppressed, and image data having vividness, which is an advantage of the fluorescent color material, can be created. Can be done.

In the above-described embodiment, the ratio of the device values of the magenta (M) and the fluorescent magenta (NM) of the five-color profile before the change is changed to calculate the device value of the fluorescent magenta as the fluorescent color material, and after the change. It is assumed that a five-color profile is generated, but the present invention is not limited to this. For example, the ratio of the device values of cyan (C) and fluorescent cyan (NC), or yellow and fluorescent yellow (NY) of the five-color profile before the change is changed, each device value is calculated, and the five-color profile after the change is obtained. It may be generated.

Also, as described above, even when inputting the image data of the 4th edition, the gray balance is lost by using the 4-color profile (AtoB table) instead of the 5-color profile (AtoB table) before the change. It is possible to convert the image data of the 4th edition to the image data of the 5th edition.

[Fifth Embodiment]
The image forming apparatus according to the fifth embodiment will be described focusing on the differences from the image forming apparatus 10 according to the fourth embodiment. In the fourth embodiment, the operation of converting the ratio of the device values of magenta and fluorescent magenta using a profile has been described in order to maintain the gray representation from the image data of the 5th edition. In the present embodiment, an operation of converting the ratio of the device values of magenta and fluorescent magenta without using a profile will be described in order to maintain the gray expression from the image data of the 5th edition. The hardware configuration of the image forming apparatus according to the present embodiment is the same as the configuration described in the first embodiment.

As an outline of the present embodiment, in order to suppress the imbalance of the gray expression of the five-color profile, the ratio of the magenta device value and the fluorescent magenta device value is based on the saturation without using the profile. Change and calculate magenta and fluorescent magenta device values. In the controller of the image forming apparatus according to the present embodiment, an operation of color-converting the 5th version of CMYK + NM image data into the 5th version of CM'YK + NM'image data having different device values of M and NM will be described as an example. It should be noted that the present embodiment is not limited to color conversion from the image data of the 5th edition to the image data of the 5th edition, and the present embodiment is also applied to the case of color conversion from the image data of the 4th edition to the image data of the 5th edition. It is possible to apply.

(Configuration and operation of functional blocks of the controller of the image forming apparatus)
FIG. 27 is a diagram showing an example of the configuration of the functional block of the color conversion unit of the controller of the image forming apparatus according to the fifth embodiment. The configuration and operation of the controller of the image forming apparatus according to the present embodiment will be described with reference to FIG. 27.

The controller 200 of the image forming apparatus 10 according to the present embodiment does not have the data input / output unit 302 and the color conversion profile generation unit 303 in the configuration shown in FIG. 3 described above, and does not include the image data acquisition unit 304 and the color conversion unit 304. Instead of the unit 305, it has an image data acquisition unit 304c and a color conversion unit 305c, respectively.

The storage unit 301 is a functional unit that stores information on the function of the saturation X and the distribution rate γ as shown in FIG. 23 or FIG. 24, for example. The storage unit 301 is realized by the auxiliary storage device 208 shown in FIG.

The image data acquisition unit 304c is a functional unit that acquires CMYK + NM image data (an example of the first image data) from, for example, a PC 20 or the like via a network N. The image data acquisition unit 304c sends the acquired CMYK + NM image data to the color conversion unit 305c. The image data acquisition unit 304c is realized by, for example, a program executed by the CPU 201 shown in FIG.

The color conversion unit 305c acquires CMYK + NM image data from the image data acquisition unit 304c, and uses the acquired 5th version CMYK + NM image data as the 5th version CM'YK + NM'image data (second image) depending on the printer (platter 231). It is a functional part that converts colors to (an example of data). For the CMYK + NM image data and the CM'YK + NM'image data, color data created by changing the device value of each of C, M, Y, K, and NM in the range of 0 to 100 is used.

As shown in FIG. 27, the color conversion unit 305c includes a saturation derivation unit 3051c and a distribution calculation unit 3052c.

The saturation derivation unit 3051c is a functional unit that derives the saturation X from the CMYK + NM value of each pixel constituting the 5th version of CMYK + NM image data acquired from the image data acquisition unit 304c. FIG. 28 shows a state in which points having a device value of 0% (white paper) and points C, M, Y, and NM having a device value of 100% (solid) are plotted on a hue plane. C, M, and Y have an angle difference of about 120 degrees as a hue angle, and NM has a hue angle substantially equal to M. Therefore, since the saturation X may be obtained by obtaining the distance from the achromatic color axis, for example, the device value c of C, the device value m of M, the device value y of Y, and the device value n of NM are used. , C + (m + n) · cos2π / 3 + y · cos4π / 3 can be obtained from the absolute value. That is, the saturation X is calculated from the following equation (1).

X = | c + (m + n) ・ cos2π / 3 + y ・ cos4π / 3 | ・ ・ ・ (1)

The saturation X is obtained by the above equation (1) because it can be approximately gray when c = m = y, and similarly, if c = (m + n) = y and gray. This is because it is necessary to change the ratio based on the saturation and maintain the ratio of fluorescent magenta (NM). Therefore, the saturation derivation unit 3051c derives the saturation X from the CMYK + NM value of each pixel constituting the 5th version of CMYK + NM image data acquired from the image data acquisition unit 304c, for example, by calculating the above equation (1). do. Then, the saturation derivation unit 3051c sends the derived saturation X and the 5th version of CMYK + NM image data to the distribution calculation unit 3052c.

The distribution calculation unit 3052c is a functional unit that calculates the distribution rate γ from the saturation X derived by the saturation derivation unit 3051c. Specifically, the distribution calculation unit 3052c reads out the information of the function of the saturation X and the distribution rate γ stored in the storage unit 301, for example, as shown in FIG. 23 or FIG. 24, and reads from the saturation derivation unit 3051c. From the acquired saturation X, the distribution rate γ is calculated based on the function. Then, the distribution calculation unit 3052c changes the ratio only for the device values of magenta (M) and fluorescent magenta (NM) among the acquired 5th edition CMYK + NM image data, and uses the calculated distribution ratio γ to C. CM'YK + NM'value by calculating the device values of magenta (M) and fluorescent magenta (NM) with = c, M = mm × γ, Y = y, K = k, NM = n + m × γ. It is converted into 5 versions of CM'YK + NM'image data consisting of. The distribution calculation unit 3052c sends the converted 5th version of CM'YK + NM'image data to the image output unit 306.

The color conversion unit 305c is realized by, for example, a program executed by the CPU 201 shown in FIG.

The image output unit 306 is a functional unit that outputs the CM'YK + NM'image data color-converted by the color conversion unit 305c to a printer (plotter 231) and causes the printer to perform printing. The image output unit 306 is realized by, for example, a program executed by the CPU 201 shown in FIG.

Of the functional parts of the controller 200 according to the present embodiment, at least a part of the functional parts realized by software (program) may be realized by a hardware circuit such as FPGA or ASIC.

Further, each functional unit of the controller 200 according to the present embodiment conceptually shows a function, and is not limited to such a configuration. For example, a plurality of functional units shown as independent functional units in the controller 200 may be configured as one functional unit. On the other hand, the function of one functional unit may be divided into a plurality of functions in the controller 200 and configured as a plurality of functional units. For example, the saturation derivation unit 3051c and the distribution calculation unit 3052c may be combined into one unified image processing unit.

(Color conversion processing in the printing processing of the image forming apparatus)
FIG. 29 is a flowchart showing an example of the flow of the color conversion process in the print process of the image forming apparatus according to the fifth embodiment. The color conversion process shown in FIG. 29 corresponds to the process of step S22 (color conversion process shown in FIG. 11) shown in FIG. 10 of the first embodiment described above. The flow of the color conversion process in the print process of the image forming apparatus 10 according to the present embodiment will be described with reference to FIG. 29.

<Step S221b>
The saturation derivation unit 3051c of the color conversion unit 305c acquires the 5th edition CMYK + NM image data acquired by the image data acquisition unit 304c. Then, the process proceeds to step S222b.

<Step S222b>
The saturation derivation unit 3051c extracts the device value (CMYK + NM value) of the target pixel from the acquired 5th version of CMYK + NM image data. Then, the process proceeds to step S223b.

<Step S223b>
The saturation derivation unit 3051c derives the saturation X from the extracted CMYK + NM value, for example, by calculating the above equation (1). Then, the saturation derivation unit 3051c sends the derived saturation X and the 5th version of CMYK + NM image data to the distribution calculation unit 3052c. The saturation derivation unit 3051c may send the 5th version of CMYK + NM image data to the distribution calculation unit 3052c only once. Then, the process proceeds to step S224b.

<Step S224b>
The distribution calculation unit 3052c calculates the distribution rate γ from the saturation X derived by the saturation derivation unit 3051c. Specifically, the distribution calculation unit 3052c reads out the information of the function of the saturation X and the distribution rate γ stored in the storage unit 301, for example, as shown in FIG. 23 or FIG. 24, and reads from the saturation derivation unit 3051c. From the acquired saturation X, the distribution rate γ is calculated based on the function. Then, the process proceeds to step S225b.

<Step S225b>
The distribution calculation unit 3052c uses the calculated distribution rate γ to set C = c, M = mm × γ, Y = y, K = k, NM = n + m × γ, and magenta (M) and fluorescent magenta ( Calculate the device value of NM), change the ratio only for the device values of magenta (M) and fluorescent magenta (NM), convert to CM'YK + NM'value, and become the target in the 5th edition of CMYK + MN image data. Replace the CMYK + NM value with the CM'YK + NM'value. Then, the process proceeds to step S226b.

<Step S226b>
When all the pixels of the 5th edition CMYK + NM image data before conversion are converted and replaced with the CM'YK + NM'value (step S226b: Yes), the process proceeds to step S227b and the processing is completed for all the pixels. If not (step S226b: No), the process returns to step S222b.

<Step S227b>
The distribution calculation unit 3052c sets the ratio of the device values of magenta (M) and fluorescent magenta (NM) to the CM'YK + NM'value for all the CMYK + NM values of the pixels constituting the 5th version of CMYK + NM image data before conversion. The replaced image data is generated as the converted 5th edition CM'YK + NM'image data. The CM'YK + NM'values constituting the converted 5th version CM'YK + NM'image data are device values depending on the printer (plotter 231). Then, the process proceeds to step S228b.

<Step S228b>
The distribution calculation unit 3052c sends the generated converted 5th version CM'YK + NM'image data to the image output unit 306. Then, the color conversion process is finished.

As described above, in the image forming apparatus 10 according to the present embodiment, the saturation X is derived from the 5th version of CMYK + NM image data before conversion using the device value, and the distribution rate γ is obtained from the saturation X. Using the distribution ratio γ, the ratios of the device values of magenta (M) and fluorescent magenta (NM) are changed, and the color is converted into 5th edition CM'YK + NM'image data. As a result, the same effect as that of the fourth embodiment described above can be obtained, and the profile generation process for converting to the Lab value in advance and converting from the Lab value can be omitted.

In the above-described embodiment, the ratio of the device values of the magenta (M) and the fluorescent magenta (NM) before the change is changed to calculate the device value of the fluorescent magenta as the fluorescent color material, and the CM'after the change is made. The YK + NM'value is calculated, but the value is not limited to this. For example, the ratio of the device values of cyan (C) and fluorescent cyan (NC) before the change, or yellow and fluorescent yellow (NY) is changed, each device value is calculated, and the changed CM'YK + NM'value is obtained. It may be what you want.

Further, the image data acquired by the image data acquisition unit 304c may be the image data of the 4th version. In this case, for example, the saturation is calculated assuming that the device value of the NM is 0, and the distribution rate is calculated. It should be done.

Further, the distribution rate may be changed not only based on the saturation but also by calculating the brightness from the value of K and the saturation of CMY + NM.

Further, in each of the above-described embodiments, when at least one of the functional units of the controllers 200 and 200a of the image forming apparatus is realized by executing a program, the program is provided by being incorporated in a ROM or the like in advance. Further, in each of the above-described embodiments, the program executed by the controllers 200 and 200a of the image forming apparatus is a CD-ROM (Compact Disc Read Only Memory) or a flexible disk (Compact Disc Read Only Memory) in an installable format or an executable format file. It may be configured to be recorded and provided on a computer-readable recording medium such as an FD), a CD-R (Compact Disk-Recordable), or a DVD (Digital Versaille Disc). Further, in each of the above-described embodiments, the program executed by the controllers 200 and 200a of the image forming apparatus is stored on a computer connected to a network such as the Internet and provided by downloading via the network. You may. Further, in each of the above-described embodiments, the program executed by the controllers 200 and 200a of the image forming apparatus may be configured to be provided or distributed via a network such as the Internet. Further, in each of the above-described embodiments, the program executed by the controllers 200 and 200a of the image forming apparatus has a module configuration including at least one of the above-mentioned functional units, and the actual hardware is the CPU 201. Is generated by reading a program from the above-mentioned storage device (for example, system memory 202 or auxiliary storage device 208, etc.) and executing the program, so that each of the above-mentioned functional units is loaded on the main storage device. ..

10 Image forming device 20 PC
200, 200a controller 201 CPU
202 system memory (MEM-P)
203 Northbridge (NB)
204a Southbridge (SB)
204b Network I / F
204c USB I / F
204d Centronics I / F
205 AGP
206 ASIC
207 Local memory (MEM-C)
208 Auxiliary storage 210 Operation display 220 FCU
231 Plotter 232 Scanner 233 Colorimeter 301 Storage unit 302, 302b Data input / output unit 303 Color conversion profile generation unit 303a Spot color dictionary generation unit 304, 304b, 304c Image data acquisition unit 305, 305a to 305c Color conversion unit 306 Image output Part 311 Chart image generation part 312 Color measurement value acquisition part 313 Color reproduction characteristic creation part 3051, 3051b Source profile conversion part 3051c Saturation derivation part 3052, 3052b Printer profile conversion part 3052c Distribution calculation part N network

Japanese Patent No. 6357744

The device value before the change is as follows.
Magenta device value before change: m
Fluorescent magenta device value before change: n
(0 ≦ m ≦ 100, 0 ≦ n ≦ 100)

Claims (18)

The first acquisition unit that acquires the first image data to be color-converted, and
The first image data acquired by the first acquisition unit is obtained from the halftone dot area ratio of any one of the process colors indicated by the first image data, and the halftone dot area of a fluorescent color different from that of the process color. A color conversion unit that converts to the second image data distributed to the rate and the halftone dot area ratio of the process color, and
Image processing device equipped with. The second image data is one of the halftone dot area ratio of the fluorescent color included in the second image data and the halftone dot area ratio of the process color corresponding to the halftone dot area ratio of the fluorescent color. (1-α): α (0 <distribution rate α <1), where 1 is the halftone dot area ratio of the process color corresponding to the color value indicated by the first image data. The image processing apparatus according to claim 1. The process color in which the halftone dot area ratio is distributed from the halftone dot area ratio of the fluorescent color is a same-color process color having an absorption spectrum peak close to the peak of the absorption spectrum of the fluorescent color among the process colors. The image processing apparatus according to claim 1 or 2. From the net spot area ratio of the same color system process color of the fluorescent color included in the first profile that associates the color value of the predetermined color space with the net spot area ratio of the process color, the fluorescent color is determined by the distribution ratio α. First generation to generate a second profile in which the combination of the net point area ratio of the process color and the net point area ratio of the fluorescent color and the color value of the color space are associated with each other. With more parts,
The first image data includes the halftone dot area ratio of the process color.
The color conversion unit uses the first profile to convert the halftone dot area ratio of the process color of the first image data into a color value in the color space, and uses the second profile to convert the color value. The image processing apparatus according to claim 2, wherein the halftone dot area ratio of the process color and the halftone dot area ratio of the fluorescent color are converted into the second image data. From the first profile that associates the color value of a predetermined color space with the net spot area ratio of the process color, the net spot area ratio of the process color corresponding to the color value of the color space corresponding to the target color of the color sample information can be obtained. Obtained and distributed from the net point area ratio of the same color process color of the fluorescent color to the net point area ratio of the fluorescent color by the distribution ratio α among the net point area ratios of the process color, and color reproduction of the printing apparatus. Using the characteristics, the net spot area ratio of the process color is calculated from the net spot area ratio of the fluorescent color, and the combination of the calculated net spot area ratio of the process color and the net spot area ratio of the fluorescent color and the above A second generation unit that generates a dictionary associated with the target color is further provided.
The first image data includes spot color information, and the color conversion unit uses the dictionary to obtain the halftone dot area ratio of the process color and the halftone dot area ratio of the fluorescent color from the spot color information of the first image data. The image processing apparatus according to claim 2, wherein the image processing apparatus is converted into the second image data by converting the image into the second image data. A second acquisition unit that acquires color values measured by a colorimeter for a chart image including a plurality of types of charts printed and output from the printing apparatus.
A creation unit that creates the color reproduction characteristics in which the halftone dot area ratio of the process color of the chart image and the halftone dot area ratio of the fluorescent color are associated with the color value acquired by the second acquisition unit.
The image processing apparatus according to claim 5, further comprising. The image processing apparatus according to any one of claims 2, 4 to 6, wherein the distribution rate α is a fixed value. The image processing apparatus according to claim 7, wherein the distribution rate α is 0.4. The image processing apparatus according to claim 4, wherein the first generation unit calculates saturation from color values in the color space included in the first profile, and determines the distribution rate α according to the saturation. The image processing according to claim 5 or 6, wherein the second generation unit calculates the saturation from the color value of the color space included in the first profile, and determines the distribution ratio α according to the saturation. Device. The color conversion unit uses a distribution rate having a positive correlation with the saturation obtained from the saturation obtained based on the halftone dot area ratio of the process color of the first image data, and uses the halftone dot area ratio of the one color. The image processing apparatus according to claim 1, wherein the point area ratio and the halftone dot area ratio of the fluorescent color are calculated. When the saturation obtained based on the halftone dot area ratio of the process color of the first image data is equal to or less than a predetermined threshold value, the color conversion unit uses the halftone dot area ratio of the one color to obtain the halftone dot area ratio of the fluorescent color. The image processing apparatus according to claim 1, wherein the point area ratio is not distributed. When the distribution ratio is γ, the color conversion unit sets m: n, which is the ratio m: n of the halftone dot area ratio m of the one color and n, which is the halftone dot area ratio of the fluorescent color. × γ: The image processing apparatus according to claim 11, which changes to n + m × γ. From the halftone dot area ratio of the one color included in the first profile that associates the color value of the predetermined color space with the halftone dot area ratio of the process color, the halftone dot area ratio of the fluorescent color is changed by the distribution ratio. A third generation unit that distributes and generates a second profile that associates the combination of the halftone dot area ratio of the process color and the halftone dot area ratio of the fluorescent color with the color value of the color space is further provided.
The first image data includes the halftone dot area ratio of the process color.
The color conversion unit uses the first profile to convert the halftone dot area ratio of the process color of the first image data into a color value in the color space, and uses the second profile to convert the color value. The image processing apparatus according to claim 11 or 13, which converts the halftone dot area ratio of the process color and the halftone dot area ratio of the fluorescent color into the second image data. The image processing apparatus according to any one of claims 11 to 13, wherein the color conversion unit derives the saturation by using the halftone dot area ratio of the process color of the first image data. The image processing apparatus according to any one of claims 1 to 15, wherein the fluorescent color is fluorescent magenta. The acquisition step of acquiring the first image data to be the target of color conversion,
The acquired first image data is obtained from the halftone dot area ratio of any one of the process colors indicated by the first image data, the halftone dot area ratio of a fluorescent color different from the process color, and the halftone dot area ratio of the process color. A color conversion step for converting to the second image data distributed to the halftone dot area ratio, and
Image processing method having. On the computer
The acquisition step of acquiring the first image data to be the target of color conversion,
The acquired first image data is obtained from the halftone dot area ratio of any one of the process colors indicated by the first image data, the halftone dot area ratio of a fluorescent color different from the process color, and the halftone dot area ratio of the process color. A color conversion step for converting to the second image data distributed to the halftone dot area ratio, and
A program to execute.

Images