WO2006043487A1 - Color processing apparatus, color processing method, program, and storage medium - Google Patents
Color processing apparatus, color processing method, program, and storage medium Download PDFInfo
- Publication number
- WO2006043487A1 WO2006043487A1 PCT/JP2005/018988 JP2005018988W WO2006043487A1 WO 2006043487 A1 WO2006043487 A1 WO 2006043487A1 JP 2005018988 W JP2005018988 W JP 2005018988W WO 2006043487 A1 WO2006043487 A1 WO 2006043487A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- spectral reflectance
- color
- synthetic
- synthetic color
- spot
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/46—Colour picture communication systems
- H04N1/56—Processing of colour picture signals
- H04N1/60—Colour correction or control
- H04N1/62—Retouching, i.e. modification of isolated colours only or in isolated picture areas only
- H04N1/622—Retouching, i.e. modification of isolated colours only or in isolated picture areas only with simulation on a subsidiary picture reproducer
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Facsimile Image Signal Circuits (AREA)
- Color Image Communication Systems (AREA)
- Color, Gradation (AREA)
- Image Processing (AREA)
Abstract
This invention has as its object to correctly reproduce a synthetic color obtained by synthesizing a plurality of colors. To achieve this object, a color processing apparatus of this invention includes a spot color database (113) for holding spectral reflectance of first and second colorants in correspondence with a plurality of densities, a synthetic color spectral reflectance calculation unit (122) for calculating a spectral reflectance of a synthetic color obtained when the first and second colorants are synthesized at a predetermined density, on the basis of the spectral reflectance held by the spot color database (113), a synthetic color calculation unit (123) for calculating values on a predetermined color space, which specify the synthetic color, by converting the spectral reflectance of the synthetic color onto the predetermined color space, and a printing device (107) for reproducing the synthetic color on the basis of the values calculated by the synthetic color calculation unit (123).
Description
DESCRIPTION
COLOR PROCESSING APPARATUS, COLOR PROCESSING METHOD, PROGRAM, AND STORAGE MEDIUM
TECHNICAL FIELD
The present invention relates to a processing technique for reproducing a synthetic color expressed by subtractive color mixture of a plurality of color formers on a simulation device.
BACKGROUND ART
It is a common practice to execute color proof using a simulation device such as a calibration printing press, electrophotographic/ink-jet PC printer, PC monitor, or the like before main print processing by a printing press when print operations are executed using the printing press upon providing a print service, publishing service, or the like.
Since color proof is made with reference to the output result (printer output, monitor output, or the like) output by the simulation device, a color reproduced on that output result desirably matches that expressed by the printing press in the main print processing. For this reason, a technique for accurately simulating (reproducing) various colors expressed by the printing press used in the main print processing on such simulation device is demanded.
In general, the printing press expresses various colors by subtractive color mixture of four color formers, i.e., cyan (C), magenta (M), yellow (Y), and black (K), and these four colors are called "process colors".
The simulation device used in the color proof reproduces colors expressed by subtractive color mixture of the process colors using a color management technique. That is, by absorbing the color reproduction characteristic difference between devices (printing press and simulation device) using a color profile as a database that describes the device characteristics, various colors expressed by subtractive color mixture of the process colors can be accurately reproduced on the simulation device.
However, in the printing press, colors are often expressed using color formers other than the process colors called spot color inks in addition to the process colors. This is for the following reasons. First, some colors are hard to reproduce by subtractive color mixture of the process colors. Second, print cost can be reduced using the spot color inks. Processing when the aforementioned color management technique is applied to reproduce the colors of such spot color inks on the simulation device will be examined. When the user inputs the name of a spot color ink in accordance with a user interface of that
technique, values (which are assumed to be pre-stored) on a color space, which specify the color of that spot color ink, are read out (e.g., the values on a device-independent color space such as L*a*b* or the like are read out) . After that, the readout values are converted into values such as C, M, Y, and K values or the like on a device-dependent color space. When the converted values are output to the simulation device, color reproduction of that specific color ink is realized on the simulation device.
Also, a technique for predicting a reproduced color using a spectral reflectance has been proposed.
However, the aforementioned color management technique can be applied to color reproduction of a color (unicolor) expressed using one spot color ink, but cannot be applied to color reproduction of a synthetic color obtained by synthesizing a plurality of spot color inks.
This is for the following reason. That is, in case of the color management technique, upon reproducing the synthetic color of spot color inks, two values (respective values on a predetermined color space, which specify the color of each specific color ink) indicating the colors of respective spot color inks, must be converted into one value by arbitrary calculations on the device-dependent color space.
However, the calculation result does not always correctly indicate the synthetic color.
A practical example will be described below. For example, when a cyan value (cyan density value) is 90% upon converting the values of a given spot color (the values on the device-independent color space which specify that spot color) into C, M, Y, and K values as those on the device-dependent color space, and a cyan value (cyan density value) is 80% upon converting the values of another spot color (the values on the device-independent color space which specify that spot color) into C, M, Y, and K values as those on the device-dependent color space, the cyan value of a synthetic color obtained by synthesizing these two spot colors is 170% when the cyan values are simply added to each other. However, since the allowable cyan density value is a maximum of 100%, the calculated cyan density value does not indicate an accurate result.
Such calculation error occurs since a synthetic color cannot be expressed in principle by arithmetic operations such as addition and multiplication of two density values (vector values) on the device-dependent color space.
The same applies to the device-independent color space. On the color spaces such as L*a*b*, XYZ, and the like used in color management, it is impossible to calculate the value of a synthetic color (the values on
the device-independent color space which specify the synthetic color) by the arithmetic operations of the density values of colors which form the synthetic color.
Against this background, there is a demand to establish a processing technique that can precisely reproduce the synthetic color of specific colors by correctly calculating the value of the synthetic color of the specific colors.
DISCLOSURE OF INVENTION
The present invention has been made in consideration of the above problems, and has as its object to provide a processing technique that can precisely reproduce a synthetic color obtained by synthesizing a plurality of colors.
In order to achieve the above object, a color processing apparatus according to the present invention comprises the following arrangement. That is, a color processing apparatus for simulating a synthetic color reproduced using first and second colorants, comprising: holding unit configured to hold spectral reflectance of a plurality of densities of each of the first and second colorants; input unit configured to input color signal data of the first and second colorants;
first spectral reflectance acquisition unit configured to acquire a first spectral reflectance corresponding to the color signal data of the first colorant from the spectral reflectance of the first colorant held by the holding unit; second spectral reflectance acquisition unit configured to acquire a second spectral reflectance corresponding to the color signal data of the second colorant from the spectral reflectance of the second colorant held by the holding unit; synthetic color spectral reflectance calculation unit configured to calculate a spectral reflectance of the synthetic color using the first and second spectral reflectance; and output color signal calculation unit configured to calculate an output color signal on the basis of the spectral reflectance of the synthetic color.
According to the present invention, a synthetic color obtained by synthesizing a plurality of colors can be correctly reproduced.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.
BRIEF DESCRIPTION OF DRAWINGS The features and advantages of the present invention will be sufficiently understood by reading the detailed description of the preferred embodiments together with the following accompanying drawings. Fig. 1 is a block diagram showing the system arrangement of a color processing apparatus according to the first embodiment of the present invention;
Fig. 2 is a functional block diagram of a synthetic color calculation function in the color processing apparatus;
Fig. 3 shows a process in which the spectral reflectance of a synthetic color obtained by synthesizing two spot colors are calculated from those of the two spot colors;
Fig. 4 is a chart showing the flow of processing when a printer output is made using the synthetic color calculation function;
Fig. 5 shows an example of a user interface when the synthetic color of spot colors are reproduced on a PC monitor;
Fig. 6 is a block diagram showing the system arrangement of a color processing apparatus according to the second embodiment of the present invention; Fig. 7 is a chart showing the flow of processing when a synthetic color is calculated on the basis of information about two spot colors input from the user
via a user interface, and the calculated synthetic color is displayed on a display device;
Fig. 8 is a chart showing the sequence for generating a spot color database, and the sequence for calculating the spectral reflectance on the basis of the generated spot color database and information about a spot color;
Fig. 9 shows a process in which a spectral reflectance RA(Y, λ) at a density value γ which meets β < γ < α is calculated from a spectral reflectance RA(<X, λ) of a spot color A at a density value α and a spectral reflectance Rλ(β, λ) of the identical spot color A at a density value β; and
Fig. 10 is a view respectively showing a state wherein two spot color inks are printed on different paper sheets by a printing press, and a state wherein these two spot color inks are printed on an identical print sheet.
BEST MODE FOR CARRYING OUT THE INVENTION
Preferred embodiments of the present invention will be described in detail hereinafter with reference to the accompanying drawings.
[First Embodiment] Fig. 1 is a block diagram showing the system arrangement of a color processing apparatus (100) according to an embodiment of the present invention.
Referring to Fig. 1, reference numeral 101 denotes a control memory (ROM); 102, a central processing unit; 103, a memory (RAM); 104, an external storage device (e.g., a hard disk); 105, an input device (e.g., a keyboard and mouse); 106, a display device (e.g., a monitor); 107, a printing device (e.g., a printer); and 108, a bus. The external storage device 104 stores a control program (RIP system 112) required to implement a synthetic color calculation function, a database (spot color database 113) that stores data used in that control program, and another application program (DTP application program 111). These control program, database, and application program are loaded onto the memory 103 via the bus 108 under the control of the central processing unit 102 and are executed by the central processing unit 102.
The DTP application 111 is a control program required to produce a print product, and expresses print data by a page description language. The RIP system 112 is a control program required to render print data, which is generated by the DTP application
111 and is described in the page description language, into bitmap data. In this embodiment, the RIP system
112 further comprises an I/F unit 121, synthetic color spectral reflectance calculation unit 122, and synthetic color calculation unit 123.
The I/F unit 121 receives, from the DTP application 111, "information about spot colors" included in print data generated by the DTP application 111, and outputs the values of a synthetic color calculated by the synthetic color calculation unit 123.
The synthetic color spectral reflectance calculation unit 122 calculates the spectral reflectance of a synthetic color on the basis of those of spot colors read out from the spot color database 113 on the basis of the information about spot colors received via the I/F unit 121. The synthetic color calculation unit 123 calculates the values of a synthetic color on a device-independent color space on the basis of the spectral reflectance of the synthetic color calculated by the synthetic color spectral reflectance calculation unit 122. A CMYK conversion unit 124 converts the values on the device-independent color space into C, M, Y, and K values for the printing device (those on a device-dependent color space) using a color profile of the printing device.
Fig. 2 is a functional block diagram of the synthetic color calculation function in the color processing apparatus 100. In order to calculate values of a synthetic color obtained by synthesizing two spot colors, the synthetic color spectral reflectance calculation unit 122 receives information about two spot colors (information of the spot color names.
density values, and the like) included in print data generated by the DTP application 111.
The synthetic color spectral reflectance calculation unit 122 obtains corresponding spectral reflectance data from the spot color database 113 on the basis of the input information about the two spot colors, and calculates the spectral reflectance of a synthetic color obtained by synthesizing the two spot colors. The synthetic color calculation unit 123 calculates synthetic color values by converting the spectral reflectance of the synthetic color calculated by the synthetic color spectral reflectance calculation unit 122 onto values on a device-independent color space such as CIE-Lab or the like using light source information. The light source information is that used upon observing an output image, and for example, D50 or the like is used.
Note that a method of calculating values that specify a color having a given spectral reflectance by converting the spectral reflectance into values on the device-independent color space is known to those who are skilled in the art, and a description thereof will be omitted. The CMYK conversion unit 124 converts the synthetic color values into C, M, Y, and K values for the printing device using the color profile of the
printing device. The color profile is the same as that used in the conventional color management technique, and is a color profile defined by, e.g., ICC.
Fig. 3 shows a process in which a spectral reflectance (303) of a synthetic color obtained by synthesizing two spot colors (spot colors A and B) at predetermined density values (α, β) is calculated from those (301, 302) of these two spot colors, i.e., conceptually shows the flow of processing in the synthetic color spectral reflectance calculation unit 122.
The spectral reflectance means a reflection factor of light of an object for each wavelength. Let RA(CI, λ) be the spectral reflectance of light of a wavelength λ of a given object (an object applied with the spot color ink A at a predetermined density value α) A. Then, energy of reflected light when light of the wavelength λ becomes incident on that object (the object applied with the spot color ink A at the predetermined density value α) is RA(CI, λ) times of energy of the incident light.
Synthesis of a color by subtractive color mixture in printing or the like can be considered that energy of light which becomes RA(C., λ) times by an object A and density value α further becomes Rβ(β, λ) times by an object B and density value β (where RA(OC, λ) is the spectral reflectance of the object A and density value
α, and Rβ(β, λ) is that of the object B and density value β). That is, a spectral reflectance RAB(OI, β, λ) of a synthetic color obtained by synthesizing two spot colors at predetermined density values can be obtained by calculating RA(CI, λ) x Rβ(β, λ) for each wavelength. Fig. 4 is a chart showing the flow of processing when a printer output is made to the printing device 107 using the synthetic color calculation function. When the DTP application 111 is executed and a page description language including information about two spot colors is output, the RIP system 112 calculates values of a synthetic color of the two spot colors on the basis of the information about the two spot colors input from the DTP application 111, converts them into data on a color space (a CMYK color space in general) corresponding to the printing device 107, and then transfers C, M, Y, and K data to the printing device 107. As a result, the printing device 107 can reproduce the synthetic color of the spot colors as the values on the color space (device CMYK) unique to the printing device.
As can be seen from the above description, according to this embodiment, upon calculating the values of a synthetic color obtained by synthesizing a plurality of spot colors other than the process colors, the spectral reflectance of the synthetic color of the two spot colors is calculated using those of the spot
colors. Hence, the synthetic color upon synthesizing the two spot color inks, which is hard to reproduce conventionally, can be reproduced accurately on the simulation device. Since a spectral reflectance is converted into device-independent values, and the converted values are then converted into device-dependent values, the device-dependent values can be calculated from the spectral reflectance without using any complicated method.
In this embodiment, the values of a synthetic color generated by synthesizing two spot colors are to be calculated. However, the present invention is not limited to this, and can be applied to synthesis of process colors, and that of a spot color and process color. [Second Embodiment]
In the description of the first embodiment, the synthetic color of spot colors included in print data generated by the DTP application is accurately reproduced by the printing device 107. However, the present invention is not limited to this. For example, the spot color names and density values may be input using a user interface, and a synthetic color upon synthesizing colors based on the input spot color names and density values may be accurately reproduced by the display device 106 (a control program that implements
such function will be referred to as a "spot color synthesis simulation system" hereinafter) .
Fig. 5 shows an example of the user interface when the synthetic color of spot colors is reproduced on the display device 106. As shown in Fig. 5, the user inputs a spot color name to a spot color 1 input field 501 or selects it from a pull-down list 503. Next, the user inputs a density value of the spot color input to the spot color 1 input field to a density value input field 505 on percentage.
Likewise, the user inputs a spot color name to a spot color 2 input field 502 or selects it from a pull-down list 504. Next, the user inputs a density value of the spot color input to the spot color 2 input field to a density value input field 506 on percentage.
Upon detection of preparation of all data required to make a synthetic color calculation of the spot colors, a spot color synthesis simulation 601 displays a synthetic color 507 obtained by synthesizing the two input spot colors on a dialog.
Fig. 6 is a block diagram showing the system arrangement of a color processing apparatus (600) according to the second embodiment of the present invention. As shown in Fig. 6, the external storage device 104 stores the spot color synthesis simulation 601, and spot color database 113. The spot color synthesis simulation system 601 comprises a user
interface (UI) unit 611 for displaying the UI shown in Fig. 5 on the display device 106, and a device RGB conversion unit 612 for displaying the values of the synthetic color calculated by the synthetic color calculation unit 123 on the display device 106, in addition to the synthetic color spectral reflectance calculation unit 122 and synthetic color calculation unit 123.
Fig. 7 is a chart showing the flow of processing when the values of a synthetic color are calculated on the basis of two spot colors input by the user via the user interface and the calculated values of the synthetic color are displayed on the display device 106 in the color processing apparatus 600 shown in Fig. 6. As shown in Fig. 7, the spot color synthesis simulation system 601 uses information (spot color names and density values) about spot colors input by a user 701 on a user interface 500 via the input device 105 in calculations of the values of the synthetic color. In the spot color synthesis simulation system 601, the synthetic color spectral reflectance calculation unit 122 and synthetic color calculation unit 123 are enabled to calculate the values of the synthetic color, as in the first embodiment. The values of the synthetic color calculated by the synthetic color calculation unit 123 are converted into R, G, and B values by the device RGB conversion unit 602, and the
converted R, G, and B values are output to the display device 106. The display device 106 receives and displays the R, G, and B values. As a result, the user can confirm the synthetic color of the two spot colors on the display device 106.
As can be seen from the above description, according to this embodiment, the user can confirm, on the display device, the synthetic color obtained when he or she arbitrarily designates spot colors and their density values via the user interface 500, and the designated spot colors are synthesized at the designated density values. [Third Embodiment]
As described in the first and second embodiments, the synthetic color value calculations are implemented using the spectral reflectance in the spot color database, which correspond to the spot color names and density values input to the synthetic color spectral reflectance calculation unit. For this purpose, in order to accurately reproduce the synthetic color, it is important to accurately acquire the spectral reflectance. Hence, in this embodiment, a method of generating the spot color database will be explained.
Fig. 8 shows the sequence for generating the spot color database 113 in Fig. 2, and the sequence for extracting a spectral reflectance on the basis of the
spot color name and density value using the generated spot color database.
In order to generate the spot color database 113, a patch image 801 is printed using a spot color ink to be registered in the spot color database 113. This patch image 801 includes an array of all patches ranging from a density value = 0% to a density value = 100%. That is, when density control is made in 8-bit precision, the number of patches is 256. The printed patch image 801 is measured by a colorimeter which can measure a spectral reflectance, and spectral reflectance 802 obtained for the respective patches are saved in the spot color database 113. In this case, the spot color name and density values are simultaneously saved as index values. In order to improve the accuracy of the spot color database 113, this operation is repeated a plurality of times, and data with higher reliability are registered in the spot color database 113 using their average values or the like.
In order to obtain a spectral reflectance from the spot color database 113, a spot color name and density value are input to the spot color database 113, which outputs the spectral reflectance corresponding to the input spot color name and density value.
On the patch image, patches of all the density values are arranged. However, the present invention is
not particularly limited to this, and patches may be arranged at given density intervals.
For example, patches with density values starting from 0% may be arranged at 10% density intervals. When the print result obtained in this manner is measured by the colorimeter, only spectral reflectance at 10% density intervals are obtained. However, spectral reflectance corresponding to those between the obtained neighboring density values can be obtained by executing interpolation (for example: linear interpolation) processing for each wavelength.
Fig. 9 shows a process in which a spectral reflectance RA(Y, λ) at a density value γ which meets β < γ < α is calculated from a spectral reflectance RA(OI, λ) of a spot color A at a density value α and a spectral reflectance RA(β, λ) of the identical spot color A at a density value β. Paying attention to the position of a given wavelength λl in Fig. 9, a spectral reflectance RA(Y# λl) at the density value γ and λl can be calculated from a spectral reflectance RA(CI, λl) at the density value α and λl and a spectral reflectance RA(β, λl) at the density value β and λl by an interpolation calculation such as linear interpolation given by: U)
The spot color database is generated by saving the spectral reflectance calculated in this manner in the spot color database 113 as that of the spot color A at the density value λ. [Fourth Embodiment]
In the first and second embodiments, the spectral reflectance of a synthetic color is calculated by multiplying those of spot colors A and B which form the synthetic color. However, the spectral reflectance of the spot colors A and B respectively include those of a paper sheet (printing medium) on which the spot colors A and B are printed. For this reason, the spectral reflectance of the synthetic color calculated by multiplying these factors redundantly includes that of the paper sheet. Hence, in this embodiment, color reproduction with higher accuracy is realized by avoiding the calculated spectral reflectance of the synthetic color from redundantly including that of the paper sheet. Fig. 10 shows a state wherein two spot color inks are respectively printed on predetermined paper sheets by a printing press (1001, 1011), and a state wherein these two spot color inks are printed on an identical paper sheet (1021). As shown in Fig. 10, let RA(α, λ) be the spectral reflectance when the first spot color (to be referred to as "spot color A" hereinafter) is printed on a paper sheet at a density value α, and RB(β,
λ) be the spectral reflectance when the second spot color(to be referred to as "spot color B" hereinafter) is printed on a paper sheet at a density value β.
A synthetic color spectral reflectance RAB(CI, β, λ) to be calculated upon printing the spot colors A and B are simultaneously printed on a paper sheet 1002 can be roughly calculated by RA(α, λ) x RB(β, λ) as in the first embodiment. However, since both RA(ex, λ) and Rβ(β, λ) include attenuation of light energy by the paper sheet 1002 itself, the spectral reflectance of the paper sheet 1002 itself is redundantly multiplied in this calculation.
For this reason, in order to make a strict calculation, attenuation due to the paper sheet 1002 must be taken into consideration. In order to make a calculation that considers the spectral reflectance of the paper sheet 1002, the spot color database 113 must have the spectral reflectance of the paper sheet 1002 itself. Let Rp(λ) be the obtained spectral reflectance of the paper sheet 1002. Then, the synthetic color spectral reflectance RAB(CC, β. λ) can be calculated to cancel the spectral reflectance of the paper sheet, which is redundantly multiplied, by:
RM(a,β,λ)-RA{a,λ)xRB(β,λ)+RP[λ) (2) RAB(CI. β. λ) obtained in this manner is converted into values on a device-independent color space (e.g., CIE-Lab) by calculation, and the converted values are
further converted into values on a device-dependent color space corresponding to the output device, thus allowing accurate color expression of the synthetic color of the spot colors in various devices. As can be seen from the above description, in the color processing apparatus according to this embodiment, since the synthetic color spectral reflectance can be calculated in consideration of the spectral reflectance of the paper sheet, the synthetic color of the spot colors can be reproduced more accurately. [Other Embodiments]
Note that the present invention may be applied to either a system constituted by a plurality of devices (e.g., a host computer, interface device, reader, printer, and the like), or an apparatus consisting of a single equipment (e.g., a copying machine, facsimile apparatus, or the like).
The objects of the present invention are also achieved by supplying a storage medium, which records a program code of a software program that can implement the functions of the above-mentioned embodiments to the system or apparatus, and reading out and executing the program code stored in the storage medium by a computer (or a CPU or MPU) of the system or apparatus. In this case, the program code itself read out from the storage medium implements the functions of the above-mentioned embodiments, and the storage medium
which stores the program code constitutes the present invention.
As the storage medium for supplying the program code, for example, a floppy® disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, nonvolatile memory card, ROM, and the like may be used.
The functions of the above-mentioned embodiments may be implemented not only by executing the readout program code by the computer but also by some or all of actual processing operations executed by an OS
(operating system) running on the computer on the basis of an instruction of the program code.
Furthermore, the functions of the above-mentioned embodiments may be implemented by some or all of actual processing operations executed by a CPU or the like arranged in a function extension board or a function extension unit, which is inserted in or connected to the computer, after the program code read out from the storage medium is written in a memory of the extension board or unit.
As many apparently widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims.
CLAIM OF PRIORITY
This application claims priority from Japanese Patent Application No. 2004-304346 filed on October 19, 2004, the entire contents of which are hereby incorporated by reference herein.
Claims
CLAIMS 1. A color processing apparatus for simulating a synthetic color reproduced using first and second colorants, comprising: holding unit configured to hold spectral reflectance of a plurality of densities of each of the first and second colorants; input unit configured to input color signal data of the first and second colorants; first spectral reflectance acquisition unit configured to acquire a first spectral reflectance corresponding to the color signal data of the first colorant from the spectral reflectance of the first colorant held by said holding unit; second spectral reflectance acquisition unit configured to acquire a second spectral reflectance corresponding to the color signal data of the second colorant from the spectral reflectance of the second colorant held by said holding unit; synthetic color spectral reflectance calculation unit configured to calculate a spectral reflectance of the synthetic color using the first and second spectral reflectance; and output color signal calculation unit configured to calculate an output color signal on the basis of the spectral reflectance of the synthetic color.
2. The apparatus according to claim 1, wherein the spectral reflectance held by said holding unit are spectral reflectance for respective patches obtained by measuring a patch image including patches of a plurality of densities obtained by changing the density of the first or second colorant.
3. The apparatus according to claim 1, wherein the spectral reflectance held by said holding unit are spectral reflectance calculated by applying interpolation processing to two spectral reflectance with different densities.
4. The apparatus according to claim 1, wherein said synthetic color spectral reflectance calculation unit calculates the spectral reflectance of the synthetic color by multiplying the spectral reflectance of the first and second colorants.
5. The apparatus according to claim 1, wherein said synthetic color spectral reflectance calculation unit calculates the spectral reflectance of the synthetic color by dividing a product of the spectral reflectance of the first and second colorants by a spectral reflectance of a printing medium on which the synthetic color is printed.
6. A color processing method for simulating a synthetic color reproduced using first and second colorants, comprising: a holding step of holding spectral reflectance of a plurality of densities of each of the first and second colorants; an input step of inputting color signal data of the first and second colorants; a first spectral reflectance acquisition step of acquiring a first spectral reflectance corresponding to the color signal data of the first colorant from the spectral reflectance of the first colorant held in the holding step; a second spectral reflectance acquisition step of acquiring a second spectral reflectance corresponding to the color signal data of the second colorant from the spectral reflectance of the second colorant held in the holding step; a synthetic color spectral reflectance calculation step of calculating a spectral reflectance of the synthetic color using the first and second spectral reflectance; and an output color signal calculation step of calculating an output color signal on the basis of the spectral reflectance of the synthetic color.
7. The method according to claim 6, wherein the spectral reflectance held in the holding step are spectral reflectance for respective patches obtained by measuring a patch image including patches of a plurality of densities obtained by changing the density of the first or second colorant.
8. The method according to claim 6, wherein the spectral reflectance held in the holding step are spectral reflectance calculated by applying interpolation processing to two spectral reflectance with different densities.
9. The method according to claim 6, wherein the synthetic color spectral reflectance calculation step includes a step of calculating the spectral reflectance of the synthetic color by multiplying the spectral reflectance of the first and second colorants.
10. The method according to claim 6, wherein the synthetic color spectral reflectance calculation step includes a step of calculating the spectral reflectance of the synthetic color by dividing a product of the spectral reflectance of the first and second colorants by a spectral reflectance of a printing medium on which the synthetic color is printed.
11. A storage medium storing a control program for making a computer implement a color processing method of claim 6.
12. A control program for making a computer implement a color processing method of claim 6.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004-304346 | 2004-10-19 | ||
| JP2004304346A JP2006121186A (en) | 2004-10-19 | 2004-10-19 | Information processor, information processing method and program, storage medium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2006043487A1 true WO2006043487A1 (en) | 2006-04-27 |
Family
ID=36202904
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/JP2005/018988 WO2006043487A1 (en) | 2004-10-19 | 2005-10-11 | Color processing apparatus, color processing method, program, and storage medium |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP2006121186A (en) |
| WO (1) | WO2006043487A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012155309A (en) * | 2011-01-05 | 2012-08-16 | Ricoh Co Ltd | Image forming device |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5411692B2 (en) * | 2009-12-28 | 2014-02-12 | キヤノン株式会社 | Image processing apparatus and image processing method |
| JP2011244126A (en) * | 2010-05-17 | 2011-12-01 | Seiko Epson Corp | Calibration device, calibration method, spectral reflectance prediction device, and spectral reflectance prediction method |
| WO2014050312A1 (en) * | 2012-09-25 | 2014-04-03 | Ｄｉｃグラフィックス株式会社 | System, method, and program for predicting color value of ink halftone |
| DE102014221207B3 (en) * | 2014-10-20 | 2015-09-24 | Heidelberger Druckmaschinen Ag | Method for calculating a spot color database |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04155226A (en) * | 1990-10-18 | 1992-05-28 | Sakata Corp | Adjustment of coloring agent |
| JP2000321141A (en) * | 1999-05-17 | 2000-11-24 | Toyo Ink Mfg Co Ltd | Method and system for recombining spectral reflectance |
| JP2002223368A (en) * | 2000-11-27 | 2002-08-09 | Ricoh Co Ltd | Device for evaluating picture quality, method for predicting evaluating picture quality, and recording medium |
| JP2003326749A (en) * | 2002-05-10 | 2003-11-19 | Canon Inc | Reproduction color estimating apparatus and method |
| JP2004271478A (en) * | 2003-03-12 | 2004-09-30 | Toppan Printing Co Ltd | Device and method for color correction |
-
2004
- 2004-10-19 JP JP2004304346A patent/JP2006121186A/en not_active Withdrawn
-
2005
- 2005-10-11 WO PCT/JP2005/018988 patent/WO2006043487A1/en active Application Filing
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04155226A (en) * | 1990-10-18 | 1992-05-28 | Sakata Corp | Adjustment of coloring agent |
| JP2000321141A (en) * | 1999-05-17 | 2000-11-24 | Toyo Ink Mfg Co Ltd | Method and system for recombining spectral reflectance |
| JP2002223368A (en) * | 2000-11-27 | 2002-08-09 | Ricoh Co Ltd | Device for evaluating picture quality, method for predicting evaluating picture quality, and recording medium |
| JP2003326749A (en) * | 2002-05-10 | 2003-11-19 | Canon Inc | Reproduction color estimating apparatus and method |
| JP2004271478A (en) * | 2003-03-12 | 2004-09-30 | Toppan Printing Co Ltd | Device and method for color correction |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012155309A (en) * | 2011-01-05 | 2012-08-16 | Ricoh Co Ltd | Image forming device |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2006121186A (en) | 2006-05-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7692831B2 (en) | Image processing apparatus and method thereof | |
| US8045186B2 (en) | Image processing apparatus, image processing method, computer readable medium and data signal | |
| EP2774042B1 (en) | Method and apparatus for controlling the color accuracy of digital printing devices | |
| US20050083346A1 (en) | Reproduction color prediction apparatus and method | |
| EP1365579B1 (en) | Image processing apparatus, method and program | |
| US7583405B2 (en) | Method for remote proofing of DFE color architecture | |
| US6833937B1 (en) | Methods and apparatus for color mapping | |
| US20070002342A1 (en) | Systems and methods for evaluating named colors against specified print engines | |
| US7729011B2 (en) | Color adjustment apparatus, color adjustment method, color-conversion-parameter generating apparatus, color conversion parameter generation method, color converting apparatus, color conversion method, computer readable medium and data signal | |
| US20110299101A1 (en) | Profile processing apparatus, profile processing method, and storage medium | |
| US7499202B2 (en) | Color image data correcting method, color image data correcting device, and color correction table producing program | |
| WO2006043487A1 (en) | Color processing apparatus, color processing method, program, and storage medium | |
| US7511854B2 (en) | Image processing device, image processing method and image processing system | |
| US7595910B2 (en) | Method for making a dot for dot proof | |
| EP2690857B1 (en) | Color adjustment apparatus, color adjustment method, and non-transitory computer-readable recording medium storing a color adjustment program | |
| JP2009071617A (en) | Image processor, image processing method and program | |
| JP4459128B2 (en) | Color processing method and apparatus | |
| WO2007137624A1 (en) | Ad-hoc color gamut representation | |
| JP2001045313A (en) | Method and device for converting color, color conversion program storage medium and method for correcting color | |
| US20170339284A1 (en) | Method for color matching printers | |
| JP2003326768A (en) | Apparatus and method for optimizing color material | |
| JP2004064543A (en) | Image processing apparatus and method | |
| WO2003095212A1 (en) | Reproduction color prediction apparatus and method | |
| JPH09261492A (en) | Color predictive expression preparing device | |
| JPH0767130B2 (en) | Halftone dot area ratio determination device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| AK | Designated states |
Kind code of ref document: A1 Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS KE KG KM KP KR KZ LC LK LR LS LT LU LV LY MA MD MG MK MN MW MX MZ NA NG NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SM SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW |
|
| AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): BW GH GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LT LU LV MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG |
|
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
| NENP | Non-entry into the national phase |
Ref country code: DE |
|
| 122 | Ep: pct application non-entry in european phase |
Ref document number: 05793263 Country of ref document: EP Kind code of ref document: A1 |