JP2020182050A - Printing method and image processing device - Google Patents

Abstract

To generate a profile that reproduces the color of an input image with high accuracy after a printed matter is laminated.SOLUTION: A printing method includes the steps of: printing a multi-patch color chart CT0 on a recording medium ME1; measuring the printed color chart CT1 to obtain a first spectral reflectance R1 before laminating; measuring a laminated color chart CT2 to obtain a second spectral reflectance R2 after the lamination; creating a spectral reflectance conversion formula that converts the first spectral reflectance R1 to the second spectral reflectance R2; calculating the spectral reflectance of the printed matter after laminating using the spectral reflectance conversion formula; creating a post-lamination profile that reproduces the color of an input image IM0 after laminating on the basis of the spectral reflectance after laminating and a light source distribution of an observation light source; and creating a device link profile 640 from the pre-lamination profile and the post-lamination profile.SELECTED DRAWING: Figure 5

Description

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

Printed matter printed by an inkjet method may be subjected to a laminating process in which the printed matter is coated with a protective film such as a laminating film in order to improve the weather resistance of the image. In order to improve the color reproducibility that reproduces the color of the input image of the printed matter after the laminating process, for example, Patent Document 1 obtains the spectral reflectance of the printed matter, estimates the optical property value of the protective film, and obtains it. A method for predicting the optical reflectance of a printed matter with a protective film is disclosed by using the spectral reflectance of the printed matter and the estimated optical property value of the protective film.

Japanese Unexamined Patent Publication No. 2011-75304

However, it has been difficult to generate a profile that accurately reproduces the color of the input image after the laminating process only by predicting the spectral reflectance of the printed matter after the laminating process as shown in Patent Document 1.

The printing method of the present application is a printing method in the case of printing an input image on a recording medium to be laminated, and is a color chart printing step of printing a color chart of a plurality of patches on the recording medium, and the printed color. A first spectral reflectance acquisition step of measuring the color of the chart to acquire the first spectral reflectance before laminating, and a second spectral reflectance after measuring the color of the laminated color chart and laminating. A second spectral reflectance acquisition step for acquiring the above, a spectral reflectance conversion formula creation step for creating a spectral reflectance conversion formula for converting the first spectral reflectance into the second spectral reflectance, and the spectral reflectance. The post-lamination spectral reflectance calculation step of calculating the spectral reflectance of the printed matter on which the input image is printed using the rate conversion formula, and the calculated spectral reflectance and observation light source after the laminating process. A profile creation step of creating a post-laminating profile that reproduces the color of the input image after laminating based on the light source distribution of the above, and a pre-laminating profile and the laminating process that reproduce the color of the input image before laminating. It is characterized by having a device link profile creation step of creating a device link profile from a post-profile.

In the above printing method, it is preferable that the spectral reflectance conversion formula creation step creates the spectral reflectance conversion formula for each wavelength at an arbitrary interval in visible light.

In the above printing method, in the step of creating the spectral reflectance conversion formula, a plurality of types of the results of creating the spectral reflectance conversion formula are stored in a database, and based on the database, machine learning is used to store the spectral reflectance. It is preferable to create a rate conversion formula.

In the above printing method, it is preferable that the step of calculating the spectral reflectance after the laminating process uses machine learning to calculate the spectral reflectance after the laminating process.

In the above printing method, the result of the spectral reflectance obtained by measuring the color of the printed matter printed with the input image converted by the post-lamination profile after the laminating process and the input image converted by the pre-lamination profile are obtained. The color difference ΔE between the result of the spectral reflectance measured by measuring the color of the printed matter is preferably 2 or less in the color in the gamut of the printed matter after the laminating process.

The image processing apparatus of the present application is an image processing apparatus that generates print data for printing on a recording medium for laminating an input image, and a color chart of a plurality of printed patches is measured before laminating. The first spectral reflectance is converted to the second spectral reflectance based on the first spectral reflectance and the second spectral reflectance measured after laminating the color chart. A spectral reflectance conversion formula is created, and the spectral reflectance of the printed matter on which the input image is printed is calculated using the spectral reflectance conversion formula, and the calculated spectral reflectance after the laminating process is used. A post-laminate profile that reproduces the color of the input image after laminating is created based on the light source distribution of the observation light source, and a pre-laminating profile and a post-laminating profile that reproduce the color of the input image before laminating. It is characterized by including a processing unit that creates a device link profile based on the above.

The figure which schematically illustrates the outline of the image processing which concerns on embodiment. The block diagram which shows the schematic structure of the image processing apparatus. The flowchart explaining the printing method at the time of printing the printed matter to be laminated. The figure which shows the process of acquiring the 1st and 2nd spectral reflectances. The figure which shows the detail of the 2nd color separation table in FIG. The figure which shows the spectral reflectance with respect to the wavelength. The figure which shows the relationship between the 1st spectral reflectance and the 2nd spectral reflectance. The figure explaining the device link table.

Hereinafter, embodiments embodying the present invention will be described with reference to the drawings.

Embodiment FIG. 1 is a diagram schematically illustrating an outline of image processing according to the embodiment. First, an outline of image processing will be described with reference to FIG.

In the image processing shown in FIG. 1, CMYK (C: cyan, M: magenta, Y: yellow, and CMYK) (C: cyan, M: magenta, Y: yellow, and CMYK) from the color value RGBin of the input image IM0 by the RIP (Raster Image Processor) 400 realized in the image processing device 100 described later , K: Black) is converted into a color value cmyk1 representing a print color. The output color value cmyk1 is obtained after laminating by the ink usage INK1 that reproduces the color of the input image IM0 in the printed image IM1 in the state of not being laminated by the first color separation table 750a, or by the second color separation table 750b. The printed image IM1'in this state is converted into an ink usage amount INK2 that reproduces the color of the input image IM0, and the printing device 200 forms an image.

The RIP 400 is composed of hardware or software. The color value of the input image IM0 input to the RIP 400 may be an RGB color space, a CMYK color space, or the like. Further, the color value output from the RIP 400 may be a CMYK color space, an RGB color space, or the like. In the present embodiment, it is assumed that the input color value is the RGB color space and the output color value is the CMYK color space.

The RIP 400 has a first profile 610 and a second profile 620. The first profile 610 is a device-dependent color space such as an RGB color space that depends on a specific device that handles the input image IM0, and a device-independent CIE (International Commission on Illumination) L ^* a ^* b ^* color space or the like. This is an ICC (International Color Consortium) profile that describes the correlation with the dependent color space. In the following description, the CIE L ^* a ^* b ^* color space will be referred to as the LAB color space. The second profile 620 is an ICC profile that describes the correlation between a device-dependent color space such as a CMYK color space and a device-independent color space such as a LAB color space that depends on the printing device 200.

The color value RGBin of the input image IM0 is converted into the color value Lab of the LAB color space according to the A2B table for converting the color value of the device-dependent color space to the color value of the device-independent color space in the first profile 610. It is converted to the color value cMYK1 of the CMYK color space according to the B2A table for converting the color value of the device-independent color space to the color value of the device-dependent color space depending on the printing device 200 in the profile 620.

The color value cmyk1 is converted into data representing the ink usage amounts INK1 and INK2 by the first color separation table 750a or the second color separation table 750b, transmitted to the printing apparatus 200, and used for printing. In addition to the printing colors of CMYK, the printing apparatus 200 has Lc (light cyan) having a lower density than C, Lm (light magenta) having a lower density than M, Dy (dark yellow) having a higher density than Y, and K. It has a low concentration of Lk (light black) and the like. When the image processing apparatus 100 divides the color value cmyk1 into dark and light colors according to the first color separation table 750a, the printed image IM1 can reproduce the color value cmyk1. When the printing apparatus 200 uses inks of a total of 6 colors of C, M, Y, K, Lc, and Lm, for example, the first color separation table 750a has the color values cmyk1 and C, M, Y in the CMYK color space. , K, Lc, and Lm are tables associated with gradation values representing ink usage INK1.

FIG. 2 is a block diagram showing a schematic configuration of an image processing device. Next, the schematic configuration of the image processing apparatus 100 will be described with reference to FIG.

The image processing device 100 includes a CPU (Central Processing Unit) 111 as a processing unit, a ROM (Read Only Memory) 112, a RAM (Random Access Memory) 113, a storage device 114, an input device 115, and a communication I / F (interface) 118. , I / F 119 for a color measuring device and a display device 130. The image processing device 100 controls color management using an ICC (International Color Consortium) profile, a printing job for causing the printing device 200 to print, and the like. Each part of the image processing apparatus 100 is connected via a bus so that information can be input and output from each other. The ROM 112, the RAM 113, and the storage device 114 are memories, and at least the ROM 112 and the RAM 113 are semiconductor memories. A liquid crystal display panel or the like can be used for the display device 130. The image processing device 100 can be configured by using a personal computer. A part or all of the image processing device 100 may be incorporated in the printing device 200.

The storage device 114 stores an OS (operating system) (not shown), an ICC profile, a first color separation table 750a, a second color separation table generation program, and the like. As the storage device 114, a non-volatile semiconductor memory such as a flash memory or a magnetic storage device such as a hard disk can be used. The RAM 113 is a storage medium for securing an area for storing a program in which the CPU 111 operates, a working area for operating the CPU 111, and the like.
The CPU 111 appropriately reads the information stored in the storage device 114 into the RAM 113, executes various processes by executing the read program, and generates print data that causes the printing device 200 to execute printing.

As the input device 115, a pointing device, hard keys including a keyboard, a touch panel attached to the surface of a display panel, and the like can be used. The communication I / F 118 is connected to the communication I / F 210 of the printing device 200, and inputs / outputs information such as print data to the printing device 200. The I / F 119 for the color measuring device is connected to the color measuring device 120, and obtains color measuring data including the color measuring value from the color measuring device 120. As the standard of I / F 118, 119, 210, USB (Universal Serial Bus), short-range wireless communication standard and the like can be used. The communication of the I / F 118, 119, 210 may be wired, wireless, or network communication such as LAN (Local Area Network) or the Internet.

The color measuring device 120 can measure each patch of the color charts CT1 and CT2 formed on the recording medium ME1 and output the spectral reflectances R1 and R2 and the color measurement value. Patches are also called color tags. The colorimetric value is, for example, a value representing the brightness L and the chromaticity coordinates a and b in the LAB color space. The image processing device 100 acquires color measurement data from the color measurement device 120 and performs various processes. The color measuring device 120 may have a configuration incorporated in the printing device 200.

The printing device 200 is an inkjet printer that ejects various inks from the recording head 220 to form printed images IM1 and IM2 based on the print data generated by the image processing device 100. For example, in the case of the recording head 220 that ejects C ink, M ink, Y ink, and K ink, the recording head 220 is supplied with CMYK ink from the ink cartridges Cc, Cm, Cy, and Ck, respectively, and the nozzle Nc, CMYK ink droplets 280 are ejected from Nm, Ny, and Nk, respectively. When the ink droplet 280 lands on the recording medium ME1, ink dots are formed on the recording medium ME1. As a result, a printed matter having the printed images IM1 and IM2 on the recording medium ME1 is obtained.

FIG. 3 is a flowchart illustrating a printing method when printing a printed matter to be laminated. FIG. 4 is a diagram showing a step of acquiring the first and second spectral reflectances. FIG. 5 is a diagram showing details of the second color separation table in FIG. FIG. 6 is a diagram showing the spectral reflectance with respect to the wavelength. FIG. 7 is a diagram showing the relationship between the first spectral reflectance and the second spectral reflectance. FIG. 8 is a diagram illustrating a device link table. Next, a printing method of the printed matter to be laminated will be described with reference to FIGS. 3 to 8.

Step S101 is a color chart printing step for printing a color chart of a plurality of patches. The operator prints a color chart having a plurality of patches. As the color chart, for example, an "ISO 12642-2 / ECI 2002" test chart including a 1485 patch can be adopted. The color value RGBin of the color chart image CT0 of the color chart is converted from the device-dependent RGB color space to the color value Lab of the device-independent LAB color space based on the A2B table included in the first profile 610, and further laminated. Based on the B2A table included in the second profile 620 as the previous profile, it is converted into the color value cmyk1 of the device-dependent CMYK color space depending on the printing device 200. The color value cmyk1 is converted into the ink usage amount INK1 based on the first color separation table 750a, and print data for causing the printing apparatus 200 to execute printing is generated. The printing apparatus 200 ejects various inks based on the print data to obtain a color chart CT1 which is a printed matter printed on the recording medium ME1.

Step S102 is a first spectral reflectance acquisition step of measuring the color of the printed color chart CT1 and acquiring the first spectral reflectance R1 before laminating. The operator measures the color of the color chart CT1 printed by using the color measuring device 120 connected to the image processing device 100. The spectral reflectance data obtained by measuring the color of each patch is stored in the storage device 114 as the first spectral reflectance R1 before laminating.

Step S103 is a second spectral reflectance acquisition step of measuring the color of the laminated color chart CT2 and acquiring the second spectral reflectance R2 after the laminating process. The operator laminates the recorded medium ME1 on which the color chart CT1 is printed using the laminating apparatus 300, and obtains the color chart CT2 which is the laminated printed matter. The operator measures the color of the laminated color chart CT2 using the color measuring device 120 connected to the image processing device 100. The spectral reflectance data obtained by measuring the color of each patch is stored in the storage device 114 as the second spectral reflectance R2 after the laminating process.

Step S104 is a step of creating a spectral reflectance conversion formula for creating a spectral reflectance conversion formula for converting the first spectral reflectance R1 to the second spectral reflectance R2. FIG. 6 illustrates, as an example, the spectral reflectance of a patch that does not eject any ink, that is, the paper-white recording medium ME1. The horizontal axis of FIG. 6 represents the wavelength, and the vertical axis represents the spectral reflectance. The solid line shows the first spectral reflectance R1 before laminating, and the broken line shows the second spectral reflectance R2 after laminating. As shown in FIG. 6, the color changes due to the difference in spectral reflectance before and after the laminating process.

FIG. 7 shows the spectral reflectance of the same wavelength in each patch. The horizontal axis of FIG. 7 represents the first spectral reflectance R1, and the vertical axis represents the second spectral reflectance R2. Each measurement point shown in FIG. 7 illustrates the relationship between the first spectral reflectance R1 and the second spectral reflectance R2 at a wavelength of 570 nm for each patch. The CPU 111 refers to the first spectral reflectance R1 and the second spectral reflectance R2 stored in the storage device 114, and converts the first spectral reflectance R1 to the second spectral reflectance R2. Create a rate conversion formula. The spectral reflectance conversion formula can be expressed in the form of R2 = aR1 + b as a linear function, for example.

In the process of creating the spectral reflectance conversion formula, the spectral reflectance conversion formula is created for each wavelength at an arbitrary interval in visible light. Since the change in the spectral reflectance before and after the laminating process depends on the wavelength, the CPU 111 generates, for example, a spectral reflectance conversion formula for each wavelength in the wavelength range of 380 nm to 730 nm of visible light at intervals of 10 nm. Steps S101 to S104 may be repeatedly executed by changing the type of the recording medium ME1 and the type of the laminated film. A plurality of types of spectral reflectance conversion formulas may be generated according to the type of the recording medium ME1 and the type of the laminated film, and stored in the storage device 114 in advance.

The CPU 111 stores a plurality of types of the results of creating the spectral reflectance conversion formula in a database in the storage device 114, and based on the stored database, uses machine learning to obtain the first spectral reflectance R1 and the second spectral reflectance R1. A spectral reflectance conversion formula may be created from the spectral reflectance R2. As machine learning, known methods such as decision trees, random forests, clustering, support vector machines, and neural networks can be adopted. Although the spectral reflectance conversion formula has been described as being represented by a linear function, it may be represented by a function of second order or higher.

Step S105 is a post-lamination spectral reflectance calculation step for calculating the spectral reflectance of the printed matter on which the input image is printed by using the spectral reflectance conversion formula. The CPU 111 calculates the spectral reflectance after laminating from a plurality of types of spectral reflectance conversion formulas according to the type of the recording medium ME1 used, the type of the laminated film, and the like. The CPU 111 may calculate the spectral reflectance after the laminating process by using machine learning based on the accumulated database.

Step S106 creates a third profile 630 as a post-lamination profile that reproduces the color of the input image IM0 of the printed matter after the laminating process based on the calculated spectral reflectance after the laminating process and the light source distribution of the observation light source. This is the profile creation process. The third profile 630 is an ICC profile that describes the correlation between the device-dependent color space such as the CMYK color space that depends on the printing device 200 and the device-independent color space.

The observation light source is an illumination light source at the place where the printed image IM1'is posted. Examples of the observation light source include D65, which is a standard illuminant, D50, D55, D75, which are daylight illuminants, and F2, F6 to F12, which are fluorescent lamps, and the light source distribution data is stored in the storage device 114. For example, the CPU 111 calculates the color value cMYK2 of the CMYK color space that reproduces the color of the input image IM0 after the laminating process from the spectral reflectance after the laminating process calculated in step S105 and the spectral distribution data of the D50. Then, the CPU 111 includes a third profile 630 including a B2A table that converts the color value Lab of the device-independent LAB color space into the color value cmyk2 of the device-dependent CMYK color space depending on the printing device 200, as shown in FIG. create.

The B2A table of the third profile 630 is data that defines the correspondence between the coordinate values Lj, aj, bj of the color value Lab and the coordinate values c2j, m2j, y2j, k2j of the color value cmyk2 of the printing apparatus 200. The grid points GD2 of the B2A table in this case are usually arranged in the Lab color space at substantially equal intervals on the L-axis, a-axis, and b-axis. The variable j is a variable that identifies the grid point GD2 set in the Lab color space. It should be noted that steps S101 to S106 may be performed in advance of printing or at the time of printing.

Step S107 is a device link profile creation step of creating a device link profile 640 from the second profile 620 and the third profile 630 as the pre-lamination profile that reproduces the color of the input image IM0 before the laminating process. In the following description, the device link profile 640 will be referred to as DLP640. The device-dependent CMYK color space color value cmyk1 output from the RIP 400 shown in FIG. 1 is converted into a device-independent LAB color space color value Lab according to the A2B table included in the second profile 620.

The A2B table of the second profile 620 is data that defines the correspondence between the coordinate values c1i, m1i, y1i, k1i of the color value cmyk1 and the coordinate values Li, ai, bi of the color value Lab. The grid points GD1 of the A2B table in this case are usually arranged in the CMYK color space at substantially equal intervals on the C-axis, M-axis, Y-axis, and K-axis. The variable i here is a variable that identifies the grid point GD1 set in the CMYK color space.

The A2A table shown in FIG. 8 is an example of DLP640 created by synthesizing the A2B table of the second profile 620 and the B2A table of the third profile 630 by the CPU 111. The DLP640 corresponds to the coordinate values c1i, m1i, y1i, k1i of the color value cmyk1 output from the RIP400 and the coordinate values c2i, m2i, y2i, k2i of the color value cmyk2 that reproduce the color of the input image IM0 after laminating. It is the data that defines. The grid point GD1 of the A2A table in this case is the grid point of the A2B table of the second profile 620. The variable i here is a variable that identifies the grid point GD1 set in the CMYK color space.

Step S108 is a step of creating a second color separation table. The CPU 111 synthesizes the DLP 640 created in step S107 and the existing first color separation table 750a to newly create a second color separation table 750b. The second color separation table 750b represents the color value cmyk1 of the CMYK color space and the ink usage INK2 of C, M, Y, K, Lc, Lm, etc. that reproduce the color of the input image IM0 after laminating. The table is associated with the gradation value. The steps S104 to S108 are processed by the CPU 111 executing the second color separation table generation program stored in the storage device 114.

Step S109 is a color separation table conversion step of converting from the first color separation table 750a to the second color separation table 750b. When printing the printed matter to be laminated, the CPU 111 converts the first color separation table 750a to the second color separation table 750b. As a result, the print image IM2 is formed on the recording medium ME1 by the printing apparatus 200, and the recording medium ME1 on which the print image IM2 is formed is laminated by the laminating apparatus 300 to reproduce the color of the input image IM0. The printed image IM1'can be obtained. For convenience of explanation, FIG. 1 shows two printing routes, one is not laminated and the other is laminated. However, in reality, the first color separation table 750a is shown depending on the presence or absence of lamination. And the second color separation table 750b are converted.

When the printed matter is not laminated, the color value RGBin of the input image IM0 is converted into the color value cmyk1 of the CMYK color space by the second profile 620, and the printed image IM1 that reproduces the color of the input image IM0 is formed by the printing device 200. To. When the printed matter is laminated, the color value cMYK1 in the CMYK color space is converted into the color value cMYK2 in the CMYK color space by the third profile 630 included in the second color separation table 750b, and the color of the input image IM0 after the laminating process. The printed image IM2 that reproduces the above is formed by the printing device 200. The printed image IM2 is laminated by the laminating apparatus 300 to obtain a printed image IM1'that reproduces the color of the input image IM0. The color difference ΔE between the result of the spectral reflectance obtained by measuring the color of the printed image IM1 with the color measuring device 120 and the result of the spectral reflectance obtained by measuring the color of the printed image IM1'with the color measuring device 120 is in the gamut of the printed image IM'. In the color in, it was 2 or less.

As described above, according to the printing method and the image processing apparatus 100 according to the present embodiment, the following effects can be obtained.
In the printing method when printing the input image IM0 on the recording medium ME1 to be laminated, the color chart CT1 printed on the recording medium ME1 and the color chart CT2 further laminated are measured. A spectral reflectance conversion formula is created from the acquired first spectral reflectance R1 before laminating and the second spectral reflectance R2 after laminating. The third profile 630 that reproduces the color of the input image IM0 after the laminating process is created based on the spectral reflectance conversion formula. Since the third profile 630 is based on an accurate measured value, a profile that reproduces the color of the input image IM0 with high accuracy is generated after laminating the printed matter.

In this printing method, a spectral reflectance conversion formula is generated for each wavelength of 10 nm intervals in the visible light wavelength range of 380 nm to 730 nm. As a result, the third profile 630 can be preferably created.

By using machine learning to create the spectral reflectance conversion formula, the color reproducibility of the input image IM0 by the third profile 630 is improved.
By using machine learning to predict the spectral reflectance after laminating, the color reproducibility of the input image IM0 by the third profile 630 is improved.

The color difference ΔE obtained from the spectral reflectance of the printed image IM1 printed when not laminated and the spectral reflectance of the printed image IM1'obtained by laminating the printed image IM2 printed when laminated is , The color in the gamut of the printed image IM'was 2 or less. Thereby, it is possible to provide a printing method in which the color difference ΔE is 2 or less in the color in the gamut of the printed image IM'.

The image processing apparatus 100 that generates print data for printing on the recording medium ME1 to which the input image IM0 is laminated has an actually measured first spectral reflectance R1 before the laminating process and a second spectral after the laminating process. Based on the spectral reflectance conversion formula created from the reflectance R2, a third profile 630 that reproduces the color of the input image IM0 after the laminating process is created. Since the third profile 630 is based on accurate measured values, it is possible to generate the third profile 630 that reproduces the color of the input image IM0 with high accuracy after laminating the printed matter.

The contents derived from the embodiment are described below.

The printing method is a printing method for printing an input image on a recording medium to be laminated, and is a color chart printing step of printing a color chart of a plurality of patches on the recording medium and the printed color chart. The first spectral reflectance acquisition step of measuring the color and acquiring the first spectral reflectance before the laminating process and the second spectral reflectance after the laminating process by measuring the color of the laminated color chart are acquired. A second spectral reflectance acquisition step, a spectral reflectance conversion formula creation step for creating a spectral reflectance conversion formula for converting the first spectral reflectance into the second spectral reflectance, and the spectral reflectance conversion. The post-lamination spectral reflectance calculation step of calculating the spectral reflectance of the printed matter on which the input image is printed using the formula, and the calculated spectral reflectance after the laminating process and the light source of the observation light source. A profile creation step of creating a post-laminating profile that reproduces the color of the input image after laminating based on the distribution, and a pre-laminating profile and a post-laminating profile that reproduce the color of the input image before laminating. It is characterized by having a device link profile creation step of creating a device link profile from and.

According to this method, when the input image is printed on the recording medium to be laminated, the printing method is based on the colorimetric first spectral reflectance before the laminating process and the second spectral reflectance after the laminating process. A post-laminate profile is created based on the created spectral reflectance conversion formula. Since the post-laminating profile is based on accurate measured values, it is possible to generate a profile that reproduces the color of the input image with high accuracy after laminating the printed matter.

In the above printing method, it is preferable that the spectral reflectance conversion formula creation step creates the spectral reflectance conversion formula for each wavelength at an arbitrary interval in visible light.

According to this method, it is possible to preferably create a post-lamination profile by creating a spectral reflectance conversion formula for each wavelength at an arbitrary interval.

In the above printing method, in the step of creating the spectral reflectance conversion formula, a plurality of types of the results of creating the spectral reflectance conversion formula are stored in a database, and based on the database, machine learning is used to store the spectral reflectance. It is preferable to create a rate conversion formula.

According to this method, the color reproducibility of the input image by the post-lamination profile is improved by using machine learning to create the spectral reflectance conversion formula.

In the above printing method, it is preferable that the step of calculating the spectral reflectance after the laminating process uses machine learning to calculate the spectral reflectance after the laminating process.

According to this method, the color reproducibility of the input image by the post-lamination profile is improved by using machine learning to predict the spectral reflectance after the laminating process.

In the above printing method, the result of the spectral reflectance obtained by measuring the color of the printed matter printed with the input image converted by the post-lamination profile after the laminating process and the input image converted by the pre-lamination profile are obtained. The color difference ΔE between the result of the spectral reflectance measured by measuring the color of the printed matter is preferably 2 or less in the color in the gamut of the printed matter after the laminating process.

According to this method, the color difference ΔE between the printed matter printed and laminated based on the post-laminated profile and the printed matter printed based on the pre-laminated profile is the color in the gamut of the printed matter after laminating. A printing method of 2 or less can be provided.

The image processing device is an image processing device that generates print data for printing on a recording medium on which an input image is laminated, and a color chart of a plurality of printed patches is measured before laminating. Spectral reflectance that converts the first spectral reflectance into the second spectral reflectance based on the spectral reflectance of 1 and the second spectral reflectance measured after laminating the color chart. A rate conversion formula is created, the spectral reflectance after laminating of the printed matter on which the input image is printed is calculated using the spectral reflectance conversion formula, and the calculated spectral reflectance after laminating and the observation light source. A post-laminating profile that reproduces the color of the input image after laminating is created based on the light source distribution of, and the pre-laminating profile and the post-laminating profile that reproduce the color of the input image before laminating are used. It is characterized by including a processing unit that creates a device link profile based on the device link profile.

According to this configuration, the image processing apparatus creates a post-lamination profile based on the colorimetric first spectral reflectance and the second spectral reflectance. Since the post-laminating profile is based on an accurate measured value, it is possible to generate a profile that reproduces the color of the input image with high accuracy after laminating the printed matter.

100 ... image processing device, 111 ... CPU as a processing unit, 112 ... ROM, 113 ... RAM, 114 ... storage device, 115 ... input device, 120 ... color measuring device, 130 ... display device, 200 ... printing device, 300 ... Laminating device, 610 ... 1st profile, 620 ... 2nd profile as pre-laminating profile, 630 ... 3rd profile as post-laminating profile, 640 ... device link profile, 750a ... 1st color separation table, 750b ... Second color separation table, CT0 ... color chart image, CT1, CT2 ... color chart, IM0 ... input image, IM1, IM1', IM2 ... printed image as printed matter, ME1 ... recorded medium, R1 ... first spectrum Reflectance, R2 ... Second spectral reflectance.

Claims (6)

This is a printing method for printing an input image on a recording medium to be laminated.
A color chart printing process for printing a color chart of a plurality of patches on the recording medium, and
A first spectral reflectance acquisition step of measuring the color of the printed color chart to acquire the first spectral reflectance before laminating, and
A second spectral reflectance acquisition step of measuring the color of the laminated color chart to acquire a second spectral reflectance after the laminating process, and
A step of creating a spectral reflectance conversion formula for creating a spectral reflectance conversion formula for converting the first spectral reflectance into the second spectral reflectance,
A post-lamination spectral reflectance calculation step for calculating the post-lamination spectral reflectance of a printed matter on which the input image is printed using the spectral reflectance conversion formula.
A profile creation step of creating a post-lamination profile that reproduces the color of the input image after laminating based on the calculated spectral reflectance after laminating and the light source distribution of the observation light source.
A device link profile creation step of creating a device link profile from a pre-lamination profile that reproduces the color of the input image before laminating and a post-lamination profile.
A printing method characterized by having. The step of creating the spectral reflectance conversion formula is
The printing method according to claim 1, wherein the spectral reflectance conversion formula is created for each wavelength at an arbitrary interval in visible light. The step of creating the spectral reflectance conversion formula is
Claim 1 or claim, wherein a plurality of types of the results of creating the spectral reflectance conversion formula are stored in a database, and the spectral reflectance conversion formula is created by using machine learning based on the database. Item 2. The printing method according to item 2. The step of calculating the spectral reflectance after laminating is
The printing method according to any one of claims 1 to 3, wherein the spectral reflectance after the laminating process is calculated by using machine learning. The result of the spectral reflectance obtained by measuring the color of the printed matter printed with the input image converted by the post-lamination profile after the laminating process,
The result of the spectral reflectance obtained by measuring the color of the printed matter printed with the input image converted by the pre-lamination profile, and
The printing method according to any one of claims 1 to 4, wherein the color difference ΔE of the above is 2 or less in the color in the gamut of the printed matter after the laminating process. An image processing device that generates print data for printing on a recording medium on which an input image is laminated.
The above is based on the first spectral reflectance measured by pre-laminating the printed color chart of a plurality of patches and the second spectral reflectance measured after laminating the color chart. A spectral reflectance conversion formula for converting the first spectral reflectance into the second spectral reflectance was created.
Using the spectral reflectance conversion formula, the spectral reflectance after laminating of the printed matter on which the input image is printed is calculated.
Based on the calculated spectral reflectance after the laminating process and the light source distribution of the observation light source, a post-lamination profile that reproduces the color of the input image after the laminating process is created.
A device link profile is created based on the pre-lamination profile and the post-lamination profile that reproduce the color of the input image before laminating.
An image processing device including a processing unit.

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