JP2002262115A - Image processor, color conversion definition generating device, image processing method, color conversion definition generating method, and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processor and method that can process single color version image data and n-color version image data even when which of them are received and reproduce nearly the same color as a color of image data equivalent to the single color version image data and the n-color version image data. SOLUTION: An input image data recognition section 1 recognizes whether input image data are CMYK image data or monochromatic image data, when the input image data are the CMYK image data, the recognition section 1 gives the CMYK image data directly to a color conversion section 3, which converts the color of the data into C'M'Y'K' data. When the input image data are the monochromatic image data, the input image data recognition section 1 instructs an output of image data where C, M, Y are all 0 to a dummy data attachment section 2, attaches dummy image data to the monochromatic image data to obtain the CMYK image data and a color conversion section 3 conducts color conversion. Thus, the same reproduction is obtained even from the monochromatic image data or the CMYK image data equivalent to the monochromatic image data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus for processing n-color image data, a color conversion definition generating apparatus and a color conversion definition generating method for generating a conversion definition used in the image processing apparatus, and a method thereof. It relates to a storage medium storing a program for executing such processing or a color conversion definition.

[0002]

2. Description of the Related Art In the printing, advertising, and publishing industries, image signals are, for example, C (cyan) M (magenta) Y (yellow) K
In many cases, color signals are separated into four colors including black, such as (black), or monochrome (K single color) color signals. Regarding single color, it is less than monochrome,
It may be handled in each of Y, M, and C single colors.

[0003] In the printing industry and the like, there is a business custom called color proofing or color proofing. Before printing a large number of prints ordered by a client by rotary printing or the like (printing on this machine), so-called proof printing is performed, and the printing of the client is performed. Through the process of obtaining consent. If the CMYK is a digital color signal, the proof printing can be performed using a marking method other than printing, for example, a printer of a thermal sublimation type, an inkjet, a xerography, or the like. When proof printing is performed using a printer, the CMYK four-color image data is reproduced on the basis of the CMYK four-color image data separated into four colors of CMYK so as to be the same as the reproduced colors when the main printing is performed. Needs to be converted into CMYK 4-color image data for a printer that performs proof printing. Similarly, in the case of single-color printing, it is necessary to convert the single-color plate image data into single-color plate image data for a printer that performs proof printing so that the reproduced color of the single-color plate image is the same as the reproduced color when this machine is printed. There is. The conversion from the device-dependent CMYK four-color plate image data to the printer-dependent C'M'Y'K 'four-color plate image data for the same device is called CMYK → C'M'Y'K' image conversion. Further, the CMYK four-color image data may be referred to as a four-color electronic document. Similarly, the conversion from the device-dependent monochromatic image data to monochromatic image data for a printer also depends on the device is referred to as mono image conversion, and particularly when the monochrome is K, is referred to as monochrome image conversion. Further, the monochrome image data may be referred to as a monochrome electronic document, and particularly when the monochrome is K, may be referred to as a monochrome electronic document. Further, in the electronic manuscript according to the present invention, each CMYK plate and a single-color plate are assumed to be multi-valued images unless otherwise specified, but are not limited thereto.

As described above, the ability to perform color proofing with a given printer using an electronic document as an input means not only color proofing but also on-demand printing if the printer output is the final output. . That is, if an electronic original is transmitted via various networks and printed at a destination, a remote color proof can be obtained. Also, an electronic original can be transmitted via various networks and the print at the destination can be regarded as a final output. For example, remote on demand printing.

[0005] In order to perform high-speed CMYK->C'M'Y'K'image conversion, a color conversion mechanism is required. As a color conversion mechanism, a method using a neural network is disclosed in JP-A-2-241271, and a method using both a multidimensional table and interpolation is disclosed in Japanese Patent Publication No. 58-16180. Also, a method using a high-order polynomial is known. Actually, the neural network as described above, a method in which a multidimensional table and interpolation are used together (multidimensional table type conversion), a high-order polynomial, etc.
A mechanism for adjusting the gradation independently for each of C, M, Y, and K colors by using Log transformation, exponentiation (γ transformation) or any other function form (gradation conversion), or UCR (UnderColor Re)
The color conversion mechanism is realized in combination with the operation associated with the color conversion. Of these, gradation conversion is one for speeding up.
It is known that a one-dimensional table is used simply by using a LUT (Lookup Table).
I'm calling

CMYK → C'M 'using a color conversion mechanism
In order to perform Y'K 'image conversion, the coupling coefficient when a neural network is applied, the table value when a multi-dimensional table and interpolation are used together,
When a higher-order polynomial is used, it is necessary to appropriately determine the coefficient of the polynomial, when performing gradation conversion, a value such as an LUT, and when performing UCR, it is necessary to appropriately determine the coefficient associated with the UCR. These determination targets are collectively referred to as color conversion coefficients or conversion definitions, and generating the color conversion coefficients or conversion definitions is referred to as characterization. In particular,
Characterization for CMYK->C'M'Y'K'image conversion is called CMYK->C'M'Y'K' color conversion, and its color conversion coefficient is CMYK->C'M'Y'K'color conversion. We will call them coefficients. Similarly, regarding color conversion from a single color to a single color, various color conversion methods and color conversion coefficient generation methods are also known. The most common method is to convert from a single color to a single color with a one-dimensional LUT.

[0007] Characterization is often
The color conversion coefficients generated and realized by the computer program are recorded in a file or a memory together with the number of necessary data and other information when read. This recorded one is called a profile.

The image processing apparatus receives a profile by some means, processes an electronic document according to the received profile, and outputs the processed image by an image output device such as a printer to obtain a desired print. As described above, an apparatus such as a computer for performing characterization and an image processing apparatus are generally independent of each other, but the image processing apparatus itself may have a characterization function. Further, it is possible to improve the convenience of remote printing by transmitting / receiving an electronic document with a profile included in the electronic document. In this manner, remote color proofing, remote printing, and the like described above can be performed.

As a representative profile used for performing color conversion, International C
There is an ICC profile format defined by the color Consortium (ICC). This I
In the CC profile format, a bidirectional conversion definition between an L ^* a ^* b ^* color space, an XYZ color space, and a CMYK color space is recorded, and a conversion definition of a single color or a conversion of three or four colors is recorded. It is a definition. Also, Pos
Although tScript (registered trademark) is an image format, it has a built-in conversion definition for monochrome and n-color plates.

Usually, when these conversion definitions are used, a color space independent of a device such as an L ^* a ^* b ^* color space or an XYZ color space or a color space depending on an input device such as an RGB color space is used. Is used for conversion to a CMYK color space or the like depending on an output device such as a printer. Since the bidirectional conversion definition is recorded in the ICC profile format as described above, by combining the forward and reverse conversion definitions, the CM as described above is obtained.
YK → C′M′Y′K ′ color conversion coefficients can be obtained, and CMYK → C′M′Y′K ′ color conversion can be performed.
Similarly, K → K ′ color conversion is also possible.

However, conventional CMYK → C'M'Y '
An apparatus capable of K 'color conversion does not use a conversion definition for monochrome, and has not been configured to accept monochrome monochrome image data. For this reason, monochrome monochromatic image data has not been accepted, or four-color image data has to be created externally and then input.

On the other hand, the conversion definitions for the monochrome and n-color plates as described above are defined so that the best color conversion is performed, but the conversion results of both are not sufficiently satisfied. Did not. For example, it is assumed that monochrome image conversion from K of the first output device to K ′ of the second output device is performed on image data composed of K single colors. Since the image is monochrome, a monochrome profile described in the ICC profile format will be applied, and a processing result will be obtained. In the case of PostScript, monochrome processing is performed, and the processing result will be obtained. In addition, by the CMYK → C′M′Y′K ′ color conversion, C = M = equivalent to the above-described image data composed of K single colors.
Y = 0, that is, CMYK → C′M′Y ′ for 4-color image data in which no CMY color material is used
If the K 'color conversion is performed, the same output result as when the monochrome processing is performed is expected.

However, at least one of C ', M' and Y '
Generally, the color is an output image having a value other than 0. Therefore, for example, a colorimetric value in an L ^* a ^* b ^* color space or the like after forming the image based on the conversion result of the four-color image data, and a colorimetric value after forming the image subjected to the monochrome processing. Values rarely match. Also,
Since the comparison is made between the image reproduced in four colors and the image reproduced in monochrome, there is little coincidence even when comparing only the brightness, that is, only L ^* . That is, even if equivalent image data is input, there is a problem that colors are different between a case where the conversion definition for the single color plate is used and a case where the conversion definition for the four color plate is used.

In particular, such a situation occurs depending on conditions for generating the CMYK → C′M′Y′K ′ color conversion coefficients. For example, a K-plate generation condition (UC) to be considered when creating CMYK image data for the first output device
R: Under Color Removal)
In order to save (K save) when converting to C'M'Y'K 'for the output device of C, the CMYK → C'M'Y'K' In both cases, the colorimetric values of the output images should match, but in practice, they will be slightly different. Also, CMYK → C '
The intention of creating the M′Y′K ′ color conversion coefficients is that the white reference (for example, printing paper) of the first output device and the white reference (for example, printing paper) of the second output device are different in the colorimetric value.
The output result differs depending on whether the intention is to achieve relative tonal matching, which is regarded as the same, or whether it is intended to be absolute colorimetric matching, which is absolutely the same. In addition, the CM is
Even if some operation is added to the YK → C′M′Y′K ′ color conversion coefficient, the output result will be different.

In general, single-color image processing has an advantage that processing can be performed at higher speed. Therefore, there is no attempt to use a conversion definition for four-color planes for single-color image data. There was no solution to such a problem.

[0016]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and can process either single-color image data or n-color image data, and can process a single-color image. An object of the present invention is to provide an image processing apparatus and an image processing method capable of performing substantially the same color reproduction when equivalent image data is input as data and n-color plane image data. It is another object of the present invention to provide a color conversion definition generation device and a color conversion definition generation method for generating a conversion definition used in such an image processing device and image processing method. It is still another object of the present invention to provide a storage medium storing programs executed by these devices, programs for implementing these methods, or conversion definitions.

[0017]

According to the present invention, there is provided an n-color image processing means for performing a color conversion process on n-color image data. , N
The color conversion processing is performed by the color plate image processing means. Also, n
When single-color image data consisting of one of the colors is input, dummy color-plate image data is added to colors other than the single color to form n-color image data. Color conversion processing. This enables the input of single-color image data even if only the n-color image processing means is provided. Even when n-color image data equivalent to the single-color image data is input, the output results of the two are obtained. Can be matched.

Further, the present invention provides both n-color image processing means for performing color conversion processing on n-color image data and monochromatic image processing means for performing gradation conversion processing on single-color image data. It is characterized by having. Thereby, both the n-color image data and the mono-color image data can be handled, and the mono-color image data can be processed at high speed by the mono-color image processing means. In this configuration, a result obtained by adding dummy color plate image data for a color other than the single color to the single color plate image data and performing color conversion processing by the n color plate image processing unit as n color plate image data, It is preferable that the gradation conversion process is performed by the monochrome image processing means so that the result of performing the gradation processing on the monochrome image data by the monochrome image processing means is substantially equal. As a result, the output result after the processing can be made substantially equal between the monochrome image data and the equivalent n-color image data.

The color conversion process performed on the n-color image data can be applied to the multi-color to multi-color conversion for converting the n-color image data into the m-color image data. Also, in the configuration having the n-color image processing means and the mono-color image processing means, it is considered appropriate to match with a one-dimensional index such as density, brightness, reflectance, saturation, and color difference from the white reference. The present invention is applicable as long as it is a single color of n colors and a single color of m colors. Preferably, the n and m colors are of the same quality, such as CMYK of the first output device and C'M'Y'K 'of the second output device, and more preferably, n and m are If the number is the same, a similar match can be obtained for all n colors. Conversely, if they are not the same, they are not necessarily unsuitable. For example, in the case of a conversion definition for converting L ^* a ^* b ^* to CMYK, there is a case where L ^* single color data is converted to K single color, and there is no problem in terms of matching brightness.

Further, according to the present invention, there is provided an apparatus and a method for generating a conversion definition to be set in the monochrome image processing means as described above, wherein dummy image data is added to monochrome image data, or monochrome image data is added. , And converts the color signal of the input device into the color signal of the output device, converts the converted color signal of the output device into a color signal independent of the device, and converts the color signal independent of the device. A signal or a part of a device-independent color signal or an index derived from a device-independent color signal (for example, brightness, reflectance, saturation, color difference, color difference based on paper white, etc., optical density, etc.) and It is characterized by associating the monochromatic gradation characteristics of the output side device, and generating a conversion definition for converting monochromatic input image data into monochromatic output image data based on the result of the association. In this manner, a conversion definition for converting monochrome image data can be generated.

Further, as an apparatus and method for more accurately generating a conversion definition for monochrome image data, n-color image data in which dummy image data is added to monochrome image data, or dummy image data in which monochrome image data is added The n-color plate data to which the data is added is converted from the n-color signal of the input device to the n-color signal of the output device, and the n-color signal of the output device is further converted to a color signal independent of the device. Indices derived from the independent color signal or a part of the device-independent color signal or the device-independent color signal (eg, lightness, reflectance, saturation, color difference, color difference based on paper white, etc., optical density) Such)
And a monochromatic gradation characteristic of the output side device, and a conversion definition for converting monochromatic input image data to monochromatic output image data based on the result of the association.

The conversion definition for the monochrome image data generated in this way is created according to the conversion definition for the n-color image data, and the result of processing the monochrome image data by the monochrome image processing means is obtained. The result obtained by processing the n-color image data equivalent to the single-color image data by the n-color image processing means can be substantially matched.

The conversion definition for the monochrome image data created in this way is created based on the conversion definition for the n-color image data.
It is convenient to perform the actual image processing if it is stored and managed as one recording format. For example, a so-called profiler that generates a conversion definition for n-color image data creates a conversion definition for single-color image data at the same time, and holds both as one set, for example, in the form of a single file. Good to put.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing the configuration of the present invention, some theoretical explanation will be given. First, C (cyan), M (magenta), and Y as n colors including black to be used.
Assuming four colors (yellow) and K (black), the color space of the colorimetric value or colorimetric system is L ^* a ^* b ^* , and the device-dependent color space is CMYK.

(Forward color prediction model) First, CMY
K to L^*a^*b^*Or L^*a^*b^*
A method for obtaining CMYK will be described. In addition, this
Unless otherwise specified, CMYK is used in a general sense
No, it is not specified in the input CMYK. Also examples
As L^*a^*b^*Uses color space but other color spaces
It may be. L from CMYK^*a^*b^*Seeking
In order to obtain the color chart,
Created by an image output device^*a^*b^*Measure the color
You. This allows CMYK and L^*a^*b^*Numerous pairs with
Is obtained. This CMYK and L^*a ^*b^*Pair of elementary days
Let's call it. L from CMYK^*a^*b^*Predict
To build models based on raw data
Has been done. L from CMYK^*a^*b^*Predict
The model will be referred to as a forward color prediction model.

The most general method of the forward color prediction model is a high-order polynomial approximation by the method of least squares. Also, for example, as described in JP-A-2-241271, a model that predicts elementary data as teacher data by a neural network, or JP-A-10-262215
As described in Japanese Unexamined Patent Publication No. 7, a model predicting using weighted linear regression is known. These models are called black box models and are not affected by the characteristics of the image output device and the method of tone reproduction such as area modulation or density modulation. On the other hand, in order to obtain colorimetric matching accuracy,
Raw data of hundreds to thousands of colors is required.

(Inverse color prediction model) L^*a^*b^*To CM
A method for obtaining YK will be described. In general, L^*a
^*b^*The direction to find CMYK from is a one-to-many relationship (many
Solution), and the solution is uncertain because it is not a single-valued function.
No. Therefore, one of CMYK is restricted under some condition.
And fixed, given L^*a^*b^*And one fixed
, The remaining three values are obtained. For example
"High-precision color conversion using flexible UCR", Japan
n Hardcopy 94 Transactions, IEEJ, P
In 177, the given L^*a^*b^*The greatest to satisfy
K (maxK) is one, and K is an appropriate UCR rate β
fixed by multiplying maxK, L^*a^*b^*And K
A method for obtaining CMY from the above is described. like this
And L^*a^*b^*And one of CMYK is fixed,
A model for predicting the three colors is called an inverse color prediction model.

However, the range of L ^* a ^* b ^{* that} can be reproduced by all combinations of CMYK is determined by the image output device and output conditions, and is called a color gamut. If L ^* a ^* b ^* exceeding the color gamut is given, no solution is obtained for any combination of CMYK. Similarly, even if L ^* a ^* b ^* is within the color gamut, no solution can be obtained if the fixed color value is inappropriate. For example, even if K of the lightness lower than the L ^* value (lightness) of the given L ^* a ^* b ^* is fixed and CMY is obtained, the given L ^* a
It cannot be the same as ^* b ^* . This is because adding CMY to K lowers the brightness but does not increase it. Thus, even when the value is out of the color gamut or the fixed value is inappropriate, it is preferable that a solution exists as a model for the K correction process described later.

Normally, CMYK is in the range of 0 to 100%. However, in the inverse color prediction model, a negative value or a value exceeding 100 may be allowed without particularly limiting the range. However, since the value does not actually exist, that is, the value does not exist in the raw data, the inverse color prediction model is extrapolated based on the raw data. In other words, it is more preferable that the inverse color prediction model not only be within the color gamut but also have a high extrapolation ability. If CMY is obtained by inverse prediction, C, M, or Y is out of an appropriate range, that is, a negative value, 100
If the value exceeds, it can be determined that the solution is inappropriate, so that the correction process can be performed.

(Color Gamut Compression) Although the concept of the color gamut has been described above, when the output device assumed on the input side is different from the output device actually output as in the present invention, the color gamut naturally differs. In this case, the inverse color prediction model cannot be solved. Therefore, it is preferable to perform color gamut compression from the input color gamut to the output color gamut. Various schemes have been devised for color gamut compression, and a detailed description thereof will be omitted.

(Principle of the Invention) The above is the description of CMYK → C ′
This is an indispensable means for creating color conversion coefficients for M'Y'K 'color conversion. Next, in the present invention, absolute colorimetric matching,
The principle for performing partial colorimetric matching and relative colorimetric matching will be described. It is assumed that an appropriate number of raw data on the input side and raw data on the output side are prepared in advance. In addition, two types of the above-described forward color prediction model, an input forward color prediction model and an output forward color prediction model, are prepared. The reverse color prediction model is prepared, two types of an input reverse color prediction model and an output reverse color prediction model. It is assumed that As a suitable CMYK->C'M'Y'K'color conversion method that satisfies requirements such as making these matches highly accurate and aligning the reproduction start points,
A first one-dimensional lookup table (hereinafter, referred to as LUT1), a four-dimensional table type color conversion unit (hereinafter, referred to as 4DLUT), and a second one-dimensional lookup table (hereinafter, LUT1)
UT2). That is,
CMYK is converted to C1M1Y1K1 by LUT1,
Converted to C2M2Y2K2 by 4DLUT, LUT2
To convert to C'M'Y'K '. Also, assume that CMYK and C'M'Y'K 'are 8 bits for each color.

(Absolute Colorimetric Matching) The LUT 1 is created in such a manner that the gradation of each single color C1M1Y1K1 and the color difference ΔE from the white of the input paper become linear. Take K as an example.
C, M, and Y are all 0%, and when K is 0%, the color difference ΔE = 0 from white on paper. It is assumed that the color difference from white ΔE = q when K = 100%. If all gradations of K are 8 bits, there are 256 gradations from 0 to 255, so (C,
M, Y, K) = (0, 0, 0, Ki) (Ki = 0, 1,
.., 255) into the input forward color prediction model.
L ^* a ^* b ^* value (Li, ai, b) at (0, 0, Ki)
i) is obtained, and △ Ei is obtained from Expression 1. ΔEi = [(Li−L0) ² + (ai−a0) ² + (bi−b0) ² ] ^1/2 Equation 1 Here, (L0, a0, b0) is L ^* a ^* of paper white ^. b ^*
It is.

Furthermore, △ Ei is obtained by normalizing △ Ei as in equation (2). ΔEi ′ = ΔEi / q × 100 Equation 2 Ki and ΔEi ′ have a one-to-one correspondence. ΔEi ′ is plotted on the horizontal axis, Ki is plotted on the vertical axis, and approximation by regression or polygonal line approximation is performed. Then, the conversion definition of LUT1 from K to K1 is determined. The same applies to each single color of CMY.

Similarly to the LUT 1, the LUT 2 is created using the output order model such that the gradation of each single color of C2M2Y2K2 and the color difference ΔE from the white on the output side paper become linear. However, what is created here is C'M'Y'K '
→ Look-up table for performing gradation conversion in the direction of C2M2Y2K2. When actually used at the time of color conversion processing, the reverse conversion, that is, C2M2Y2K2 → C ′
A one-dimensional look-up table for converting in the direction of M'Y'K 'will be used. In the case of gradation conversion, since there is a one-to-one correspondence, inverse conversion can be easily obtained.

By designing LUT1 and LUT2 as described above, C1M1Y1K1 and C2M2Y2
The relationship between the single colors corresponding to K2 becomes substantially linear, and there is an effect of reducing the interpolation error of the 4DLUT created in the next step. In addition, since fine gradation control of all 256 gradations can be performed, a portion where the gradation width is large in the vicinity of white in the past is canceled and CMYK → C′M′Y′K ′ color conversion is performed. This has the effect that the reproduction start points of C′M′Y′K ′ can be easily aligned.

In the above description, the LUT1 and LUT2 are created such that the color difference ΔE from white is linear. However, a single color such as optical density, reflectance, brightness, or equivalent neutral density or equivalent neutral brightness is used. Any index may be used as long as it is an index used for gradation design and evaluation. However, in order to perform partial colorimetric matching and relative colorimetric matching, it is more preferable that the input / output relationship of the lookup table can be converted from a minimum value of 0 to 0 and a maximum value of 100 to 100. .

Next, from C1M1Y1K1 to C2M2Y2
A method of creating a 4DLUT for converting to K2 will be described. The 4DLUT can be created by the following five steps. C1M1Y1 is all 0, that is, (0,0,0, K
In 1), L ^* a ^* b ^* is predicted by an input forward color prediction model, and only the L ^* value at this time is set to L1. Similarly, (0,
(0, 0, K2) is also determined by the output forward color prediction model.
^* a ^* b ^* is predicted, and only the L ^* value at this time is defined as L2. Then, a correspondence between K1 and K2 is created such that L1 = L2. This is referred to as L butting. K2 is obtained from K1 by this L butting. From the C1M1Y1K1 input forward color prediction model, L ^* a
Predict ^* b ^* . If L ^* a ^* b ^* exceeds the color gamut on the output side, color gamut compression is performed, and L ^* a ^* b ^* is changed within the color gamut on the output side. From L ^* a ^* b ^* and K2 by K butting, C2M2
Y2 is obtained by an output inverse color prediction model. If C2M2Y2 is not an appropriate value, K2 is adjusted, C2M2Y2 is calculated again, and an appropriate value of C2M2Y2 is obtained.
Find K2. (K correction processing)

The process of (2) is a process for reducing K2 when K2 due to L butting in step (2) is excessive.
On the other hand, there are cases where K2 is not enough.
May be adjusted in the direction of increasing. Also, LU
When performing the processing of T1 and LUT2, it is also possible to omit the step.

From such a process, or
By repeating the steps from to for the grid points of the 4DLUT, the table value of the 4DLUT can be obtained.

(Partial Colorimetric Matching) Partial colorimetric matching is a reproduction method in which, for example, when the input is K single color, the output is also reproduced in K single color. This is realized by rewriting a part of the table of the 4DLUT created by absolute colorimetric matching. In the 4DLUT, the input C1M1Y1K1
Is an address for drawing a table, and its table value may be considered as C2M2Y2K2. For example, in order to make the input white white even when outputting, the white address (C1, M1,
(Y1, K1) = (0, 0, 0, 0) is forcibly set to the table value (C2, M2, Y2, K2) = (0, 0, 0, 0)
It is good. Similarly, K1 is a single color (0, 0, 0, K
In the case of 1), C2 = M2 = Y2 = 0 is forcibly set, and
(0, 0, 0, K2). To guarantee single-color reproduction of Y, it is sufficient to set C2 = M2 = K2 = 0 at (0, 0, Y1, 0), similarly to K. Similarly, to guarantee process black (when K1 is 0 and only C1M1Y1 has a value), the table value of (C1, M1, Y1, 0) is forcibly set to K2 = 0 and (C2, M2, Y
2,0). Also, (C1, M1, Y1, K
1) = (0,0,0,100), the table value is forcibly changed to (C2, M2, Y2, K2) = (0, 0,
0, 100), black solid can be reproduced as black solid.

(Relative colorimetric matching) Relative colorimetric matching is performed by changing the white of each of the input raw data and the output raw data to a unified white standard, and converting the changed raw data. Based on this, it is sufficient to perform perfect colorimetric matching or partial colorimetric matching. When the colorimetric value is L ^* a ^* b ^* , the changed colorimetric value is called a relative L ^* a ^* b ^* . Hereinafter, the relative L ^*
A method for changing to a ^* b ^* will be described.

The relationship between L ^* a ^* b ^* and the tristimulus values XYZ is shown in equations 3-1 to 3-1. L ^* = 116 · (Y / Yo) ^1/3 -16 Equation 3-1 a ^* = 500 [(X / Xo) ^1/3 − (Y / Yo) ^1/3 ] Equation 3-2 b ^* = 200 [(Y / Yo) ^1/3 − (Z / Zo) ^1/3 ] Expression 3-3 Here, (Xo, Yo, Zo) is a tristimulus value of the light source. (X / Xo) ^1/3 = P, (Y / Yo) ^1/3 = Q,
(Z / Zo) ^1/3 = R, the L ^* a ^* b ^* value of paper white is expressed as (L
w, aw, bw) and (P, Q, R) at that time are represented by (Pw,
Qw, Rw) and the white reference value of the relative L ^* a ^* b ^* is (L
o, ao, bo) Lw = 116 · Qw-16 Expression 4-1 aw = 500 (Pw-Qw) Expression 4-2 bw = 200 (Qw-Rw) Expression 4-3 Here, the adjustment coefficients α, β, and γ are introduced, and Lo = 116 · β · Qw−16 Expression 5-1 ao = 500 (α · Pw−β · Qw) Expression 5-2 bo = 200 (β Qw-γRw) α, β, and γ can be solved from Equation 5-3. Given L ^* a
P, Q, and R are ^calculated for ^* b ^* , and α · P, β · Q,
As gamma · R, be returned to the L ^* a ^* b ^*, relative L ^* a ^* b
^* This operation is performed by inputting the raw data L ^* a ^* b ^* ,
And if it is performed for the output raw data L ^* a ^* b ^* ,
The input and output white L ^* a ^* b ^* values match.

In the formulas 3-1 to 3-3, X / Xo =
E, Y / Yo = F, Z / Zo = G, (Lw, a
(E, F, G) at (w, bw) is (Ew, Fw, G
If written as w), it can be converted into a relative Lab by the formulas 6-1 to 6-1. Lr = 116 · (F / Fw) ^1/3 −16 Equation 6-1 ar = 500 [(E / Ew) ^1/3 − (F / Fw) ^1/3 ] Equation 6-2 br = 200 [ (F / Fw) ^1/3 − (G / Gw) ^1/3 ] Equation 6-3 (Lr, ar, br) in Equations 6-1 to 3 are relative L ^*
a ^* b ^* .

As described above, the LUT is obtained by the absolute colorimetric matching.
1 and the LUT 2 and the 4DLUT, and the 4DLUT can be realized by modifying its contents so as to be reproduced by partial colorimetric matching and relative colorimetric matching.

FIG. 1 is a block diagram showing a first embodiment of the image processing apparatus of the present invention. Further, it also shows a configuration example for realizing the first embodiment of the image processing method of the present invention. In the figure, 1 is an input image data recognition unit, 2 is a dummy data addition unit, and 3 is a color conversion unit. In the first embodiment, an example is shown in which dummy image data is added to single-color image data, and the conversion definition for the n-color image data is applied as n-color image data. The n-color plane image data is composed of four color planes of CMYK, and is referred to as CMYK image data.
Also, after the color conversion, it is assumed that the image is composed of four color plates in the same manner. Here, C'M'Y'K 'and C'M'
It is referred to as Y'K 'image data. The monochrome image data is assumed to be K image data, and is referred to as monochrome image data. In each of the following embodiments,
The same applies unless otherwise noted.

The input image data recognizing section 1 recognizes whether the input image data is CMYK image data or monochrome image data, and if the input image data is CMYK image data,
It is sent directly to the color converter 3. When the input image data is monochrome image data, the monochrome image data is sent to the color conversion unit 3 as K-version image data, and the C, M, and Y-version dummy data are sent to the dummy data addition unit 2. Is generated.

According to the instruction from the input image data recognizing unit 1, the dummy data adding unit 2 outputs image data of C, M, and Y, that is, 0, that is, a value that does not include a color material. Thus, when the input image data is monochrome image data, the C, M, and Y pixels are added to the pixels to be processed for monochrome image data, and are sent to the color conversion unit 3.

The color conversion unit 3 converts the CMYK image data into C′M′Y′K ′ image data using the conversion definition for the CMYK four-color image data, and outputs it. If the input image data is CMYK image data, C, M,
Since all four colors of Y and K are sent directly from the input image data recognizing unit 1, they are converted into C'M'Y'K 'image data. When the input image data is monochrome image data, the monochrome image data is set to K,
Since C, M, and Y are sent from the dummy data adding unit 2, color conversion processing may be performed in the same manner as CMYK image data.

With such a configuration, the color conversion unit 3 can similarly perform the color conversion processing whether the input image data is monochrome image data or CMYK image data. The same processing result can be obtained even when the input image data is monochrome image data or when CMYK image data equivalent to the monochrome image data is input.

In the configuration shown in FIG. 1, the unit of processing in the color conversion unit 3 is arbitrary, and for example, processing can be sequentially performed for each input pixel. Alternatively, for example, a color conversion process is performed after adding dummy data to the entire monochrome image, or a processing system that handles an image in block units as a processing mode is configured to add dummy data for each block. Is also good.

FIG. 2 is a block diagram showing a second embodiment of the image processing apparatus of the present invention. Further, it also shows a configuration example for realizing the second embodiment of the image processing method of the present invention. In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals. Reference numeral 4 denotes a monochrome color conversion unit. In the first embodiment described above, the CMYK
C'M'Y 'output as a conversion result of monochrome image data to apply the conversion definition to image data
It is conceivable that K 'image data does not always satisfy C' = M '= Y' = 0. In the second embodiment, a single color is assured even after processing the single color plane image data, and
An example in which high-speed conversion processing is performed is shown. In this example, four colors (n = 4) of C, M, Y, and K are used.

The input image data recognition section 1 recognizes whether the input image data is CMYK image data or monochrome image data. If the input image data is CMYK image data, the CMYK image data is sent to the color conversion unit 3. If the input image data is monochrome image data, the monochrome image data is sent to the monochrome color conversion unit 4.

The color conversion unit 3 performs CMYK-C'M'Y'K 'color conversion using the conversion definition for the four-color image data. In the second embodiment, the input image data is C
Only in the case of MYK image data, the CMYK image data is sent, so that color conversion processing is performed as it is, and C′M′Y′K ′ image data is output.

The monochrome color conversion unit 4 performs gradation processing on the monochrome image data sent from the input image data recognition unit 1, and outputs monochrome image data. The monochrome color conversion unit 4 may be any function as long as it is a function of one input and one output. For example, the monochrome color conversion unit 4 can be configured by a one-dimensional LUT. This one-dimensional LUT is called a mono LUT.

With this configuration, color conversion processing (and gradation conversion processing) can be performed regardless of whether CMYK image data is input or monochrome image data is input. In addition, since monochrome image data is converted by the monochrome color converter 4 using only a single color, the output image data is also guaranteed to be a single color. Furthermore, high-speed processing is possible because the processing is for only a single color.

However, when the monochrome color conversion section 4 is provided separately from the color conversion section 3 as described above, the conversion result of the monochrome image data by the monochrome color conversion section 4 and the dummy image data of another color are added to the monochrome image data. May be different from the result of the color conversion processing performed by the color conversion unit 3 as image data of four colors. For example, assume that when the value Ki is input as monochrome image data, the conversion result by the monochrome color conversion unit is Ki ′. CM equivalent to Ki
(C, M, Y, K) which is YK image data = (0, 0,
0, Ki), the conversion result by the color conversion unit 3 does not become (0, 0, 0, Ki ′), and one or more elements of C, M, Y do not become 0. Color materials are added. Even when only the K component is compared, it differs from Ki '. As described above, it is desired that substantially the same result is obtained when a monochrome image is input and when CMYK image data equivalent to the monochrome image data is input.

In the second embodiment, the case where the monochromatic image data is subjected to the monochromatic color conversion processing (gradation conversion processing) as described above, and the case where the n-color image data equivalent to the monochromatic image data is performed And a case in which color conversion processing is performed on the n-color image data so that substantially equivalent results can be obtained.
Set the conversion definition to be used in the single color conversion process. That is, in the configuration shown in FIG. 2, the mono LUT used in the monochrome color conversion unit 4 may be set as described above.

Here, a method of generating a mono LUT will be described.
An example will be briefly described. Even in the case of monochrome, the concept of relative colorimetric matching and absolute colorimetric matching can be considered. The simplest colorimetric measure in the case of monochrome is one-dimensional physical characteristics such as lightness, reflectance, density, brightness, saturation, and color difference from paper. Here, it is assumed that lightness L ^* is used as a scale, image data on the input side is data used when printing with a monochrome printer, and image data on the output side is data used when printing with a monochrome printer. I do. The monochrome printer referred to here may be a color printer. Monochrome may be reproduced by three colors of CMY, may be reproduced by using a single color of K, and furthermore, a quaternary color of CMYK may be reproduced. It may be reproduced with. However, for a monochrome image signal, it is common to output a K single color, so here, the case of outputting in a K single color will be described.

FIG. 3 is a block diagram showing an example of a configuration when a mono LUT is generated. In the figure, reference numeral 11 denotes a mono-order prediction unit, 12 denotes a mono inverse prediction unit, and 13 denotes a mono LUT generation unit. The mono-order predicting unit 11 uses the K gradation characteristic in the input-side device, that is, the L ^* value characteristic when an image printed by giving the K value to the input-side device is used to obtain a given K. Get L ^* value from value.

The mono inverse prediction unit 12 uses the K gradation characteristic of the output side device, that is, the L ^* value characteristic when the image printed by applying the K value to the output side device is measured. Conversely, the K ′ value is obtained from the obtained L ^* value.

The mono LUT generation unit 13 associates the given K value with the K ′ value acquired by the mono inverse prediction unit 12 and makes it one entry of the mono LUT. By obtaining corresponding K 'values for a plurality of K values, a mono LU
T can be generated.

The operation of the configuration shown in FIG. 3 will be described using a specific example. FIG. 4 is a graph showing an example of the gradation characteristics of the input device and the output device. In this graph, the device-dependent signal value (K value) is shown on the horizontal axis, and the lightness L ^* value is shown on the vertical axis, and shows the characteristics of the devices on the input side and the output side. Print the characteristics of the monochrome printing device, which is the device on the input side.
The gradation characteristics and the characteristics of the monochrome printer as the output device are shown as printer K gradation characteristics.

As shown in FIG. 4, a coordinate A on an arbitrary horizontal axis
Is obtained on the print K gradation characteristic curve. This operation is performed by the mono-order predicting unit 11. The value on the vertical axis of point B (L ^*
Is obtained, the mono-inverse prediction unit 12 obtains a point C on the printer K gradation characteristic curve that is equal to the value (L ^* value) on the vertical axis of this point B, and on the horizontal axis of this point C. Is obtained. At this time, the correspondence between the coordinates A and the coordinates D is a conversion definition when L ^* is matched. This conversion definition is called a mono conversion definition. Usually, the coordinates A may be cut at regular intervals, and the coordinates D at that time may be sequentially calculated and corresponded to generate an LUT. For 8-bit processing, 256 LUTs
It is convenient to configure as

In the drawing, there is a case where no intersection exists when finding an intersection G with the printer K gradation characteristic curve, such as E, F, G, and H. In such a case, white (0
%) Or solid (100%) direction.
What is necessary is just to be saturated to white or solid respectively.

The above-described method is similar to the L-butting.
In addition, the reproduction is an absolute colorimetric match. Even in the case of monochrome, if the relative L ^* a ^* b ^* is calculated in advance, monochrome relative colorimetric matching is possible. Of course, partial colorimetric matching is possible, but a mono LUT with absolute colorimetric matching
It is not preferable to reset only one point because a false contour easily occurs. In this case, an operation of expanding or contracting a part or the whole of either curve in the Y-axis direction is added in advance so that the white point of the print K gradation characteristic curve or the printer K gradation characteristic curve matches. Then, the mono LUT may be obtained as described above.

The mono LUT generated in this way may be set in the monochrome color conversion section 4 in FIG. 2 in advance, and then color conversion (gradation conversion) of the monochrome image data may be performed.

The above-described method of generating a mono LUT is the most basic method. Usually, such a method is sufficient to create only a mono LUT. Further, there is an advantage that even if there is no color conversion definition of n colors, there is only a colorimetric value for creating a mono LUT.

In particular, when the conversion definition for the n-color image data is reset or changed by the creator's intention, the same conditions as those for creating the conversion definition for the n-color image data are used. Mono LU under the conditions
It is desirable to create T. Hereinafter, a method of creating the mono LUT in this case will be described.

FIG. 5 is a block diagram showing an example of a configuration in the case where a mono LUT is created under the same conditions as those for creating a conversion definition for n-color image data. In the figure, 21 is a color conversion unit, 22 is a forward prediction unit, 23 is a mono inverse prediction unit, and 24 is a mono LUT generation unit. In this example, an example of a configuration for providing Ki as an input to the mono LUT and generating a corresponding output Ki is shown. In addition, like each of the above-described examples,
It is assumed that four colors of CMYK are used.

The color conversion section 21 converts, for example, printing CMYK into CMYK of a printer. The conversion definition for CMYK image data is 4
It is assumed that it is composed of one one-dimensional LUT, four-dimensional DLUT, and four one-dimensional LUTs. The configuration of the conversion definition for the n-color image data is only 4DLUT, or 4 1D LUT and 4D DLUT, or 4D D
Other configurations such as an LUT and four one-dimensional LUTs may be used. The conversion definition for the n-color image data is also referred to herein as a color conversion definition. The mono LUT is for K single color, and is 8 bits (256), and is device-dependent CMY represented by 0 to 100%.
The description will be made assuming that the value of K is standardized to 0 to 255.

The color conversion unit 21 receives Ki as an input value of the mono LUT, and receives other colors, that is, C,
For M and Y, dummy image data or dummy data having a value of 0 is input. Originally, since a mono LUT is obtained, the LUT need not always be dummy image data, but may be dummy data. The difference between the dummy image data and the dummy data is that the dummy image data is a one-dimensional LUT.
While the quantization error accumulates each time the data passes through the 4DLUT or the 4DLUT, the dummy data of the one-dimensional LUT is a floating-point operation by interpolation, and the addressing and interpolation operation of the 4DLUT itself is also a floating-point operation. The final mono LU is also used as a floating-point operation for operations based on models.
The point is that the quantization error during calculation can be minimized by rounding off to an integer when generating T. Also, only the color conversion unit is used as an image processing system using dummy image data,
It is also possible to adopt a configuration in which after changing the dummy image data to the dummy data, the forward color prediction model is subjected to a floating-point operation and finally rounded. In this example, in order to generate a mono LUT, the case where all floating-point operations are performed with emphasis on accuracy is treated as dummy data. In this example, a mono LUT
The purpose of this is to generate the image data, and it is meaningless whether the data format is image data or simple data, except for the accuracy. Therefore, in the following description, the dummy data including the dummy data will be referred to as dummy image data. A color signal (C, M, Y, K) = (0, 0, 0, Ki) is input as the dummy image data. Then, the color conversion unit 21 performs a color conversion process on the input CMYK image data including the dummy image data, and outputs CMYK image data of the printer, which is output-side image data. At this time, C, M, and Y of the CMYK image data of the printer often have values other than 0. Note that the same configuration as the configuration shown in FIG. 1 can be applied to the configuration up to this point.

The forward predicting section 22 obtains L ^* a ^* b ^* values from the CMYK image data converted by the color converting section 21 using a forward color predicting model in a printer which is an output device.

The mono inverse prediction unit 23 reversely deduces the printer K gradation characteristic curve of the printer from the L ^* value of the L ^* a ^* b ^* values obtained by the forward prediction unit 22, and obtains the K corresponding to the L ^* value.
Find i '.

The mono LUT generation unit 24 associates the input Ki in the printing press with the printer Ki ′ obtained by the inverse mono prediction unit 23 and registers it as an entry of the mono LUT. A mono LUT is created based on the correspondence between a plurality of Ki and Ki '.

FIG. 6 is a flowchart showing an example of a creation method when a mono LUT is created under the same conditions as the conversion definition for n-color image data.

In S31, a counter i for updating the value of K is initialized to 0. For example, when 0 ≦ Ki ≦ 255, i may be changed in order from 0 to 255 with Ki = i.

In S32, the CMYK image data of the printing press, which is the input side image data, is the CMYK image data corresponding to the K monochrome image data (C, M, and C).
Y, K) = (0, 0, 0, Ki), (0 ≦ Ki ≦ 25
5) is generated. Then, in S33, the CMYK image data (0, 0, 0, Ki) of the printing press generated in S32
Is converted by the color conversion unit 21 using the color conversion definition, and CMYK image data (C ′, M ′, Y ′, K ′) of the printer, which is image data on the output side, is obtained. At this time, C ', M', and Y 'of the CMYK image data of the printer are also 0.
It is often a value other than.

At S34, the forward prediction unit 22 sets S3
The printer's forward color prediction model is applied to the CMYK image data of the printer obtained in step 3 to obtain L ^* a ^* b ^* values. Either give relative L ^* a ^* b ^* as raw data of the printer given to the forward color prediction model or absolute L ^* a ^* b ^*
Is determined according to the conditions at the time of generation of the color / color conversion coefficient. Then, among the obtained L ^* a ^* b ^* values, only the L ^* value is obtained.

At S35, the mono inverse predicting unit 23 determines the Ki 'value of the printer from the L ^* value obtained at S34. In determining the Ki ′ value, the printer K gradation characteristic curve may be reversed. At this time, the K gradation characteristic curve is created with the relative L ^* or the absolute L ^* according to the conditions at the time of generating the color conversion coefficient as in S34. Also, the inverse color prediction model is modified to obtain K by constraining it with L ^* , a ^* , b ^* , C, M, and Y, and the obtained printer L ^*
K may be obtained by constraining a ^* b ^* and C = 0, M = 0, Y = 0.

The printer K (S
The correspondence between Ki) generated at step S32 and printer K (Ki ′ determined at step S35) is a mono LUT to be determined,
The mono LUT generation unit 24 generates a mono LUT.
K obtained in S35 as a value corresponding to Ki of the mono LUT
i 'may be set.

In S36, it is determined whether or not the counter i has exceeded a predetermined number of times.
Then, the counter i is incremented and updated, and the process returns to S32. As a result, the Ki 'value of the corresponding printer can be obtained while sequentially changing Ki. When the process is repeated a predetermined number of times, the process ends. by this,
A mono LUT of a predetermined number of entries is completed.

By the above procedure, the detailed conditions at the time of creating the color color conversion definition, absolute colorimetric match, partial absolute colorimetric match, relative colorimetric match, presence / absence of K storage, reset condition, etc. are all taken into consideration. Regardless of whether the image data is monochrome image data or four-color image data, the final output image is L ^*
Is equivalent.

In order to further increase the consistency with the four-color color conversion definition, if white reset has been performed in the color color conversion definition, the mono LUT also performs white reset.
If the solid reset of 0% has been performed, the solid LUT may be also reset. This is because the color is not completely 0% or 100% due to the use of the forward color prediction model or L ^* butting.

In the above description, the color conversion definition is CM
Although described as four colors of YK, it is also applicable to printing of n colors or a printer. In addition, although the single color has been described as K,
Similarly, a conversion definition of a single color can be created for other colors. In addition, the method shown in S32 to S35 in FIG. 6 is a mono-conversion definition that matches with the multi-dimensional input. For C, M, and Y, a mono LUT for monochrome processing can be created in the same manner. However, with respect to Y, it is better to perform abutting with C ^* instead of L ^* .

FIG. 7 is an explanatory diagram of an example of a format of a profile in which a conversion definition is recorded. The example shown in FIG. 7 shows a format in which a conversion definition for four-color conversion and a conversion definition for single-color processing are stored in the same file. The header information includes management information such as where and in what format the color conversion definition for four-color conversion and the color conversion definition for single-color processing are described in the file. Of course, the format is not limited to such a format, and any format or management method may be used as long as the conversion definition for four-color conversion and the conversion definition for single-color processing can be managed in association with each other.

The created conversion definition is stored, and a profile designated through, for example, a GUI (not shown) is read and interpreted in advance, and the color conversion unit 3 in FIG. 1 and the color conversion unit 3 in FIG. This is set in the monochrome color converter 4.

FIG. 8 shows a computer program or a color conversion definition when the functions or the image processing method of the image processing apparatus of the present invention or the functions or the color conversion definition creating method of the color conversion definition creating apparatus are realized by a computer program. FIG. 4 is an explanatory diagram of an example of a storage medium that stores the information.
In the figure, 101 is a program, 102 is a computer, 1
11 is a magneto-optical disk, 112 is an optical disk, 113 is a magnetic disk, 114 is a memory, 121 is a magneto-optical disk device, 122 is an optical disk device, and 123 is a magnetic disk device.

The functions in the configurations shown in the above embodiments of the image processing apparatus and the image processing method of the present invention, or the functions in the configurations shown in the respective examples of the color conversion definition creating apparatus and the color conversion definition creating method are as follows. It can also be realized by a program 101 executable by a computer. In that case, the program 101 and the data used by the program can be stored in a computer-readable storage medium. Also,
The color conversion definition (profile) created by the configuration and operation shown in each example of the color conversion definition creating apparatus and the color conversion definition creating method of the present invention can be stored in a computer-readable storage medium. is there. A storage medium is a type of signal corresponding to a change state of energy such as magnetism, light, electricity, etc., caused to a reading device provided in a hardware resource of a computer in accordance with a description content of a program. Thus, the program description can be transmitted to the reading device. For example, there are a magneto-optical disk 111, an optical disk 112, a magnetic disk 113, a memory 114, and the like. Of course, these storage media are not limited to portable types.

The program 101 is stored in these storage media, and these storage media are mounted in, for example, the magneto-optical disk device 121, the optical disk device 122, the magnetic disk device 123, or a memory slot (not shown) of the computer 102. Reading the program 101 from the computer and executing the functions described in the embodiments of the image processing apparatus and the image processing method of the present invention, or the functions in each example of the color conversion coefficient creating apparatus and the color conversion coefficient creating method. Can be. Alternatively, the profiles are stored in a storage medium, and these profiles are stored in the magneto-optical disk device 121, the optical disk device 122, the magnetic disk device 123, or a memory slot (not shown) of the computer 102, for example. And the functions of the image processing apparatus and the image processing method of the present invention can be executed using the read profile. In addition to storing the program 101 and profile in advance in the storage medium, the storage medium is mounted on the computer 102 in advance, and the program 101 and profile are transferred to the computer 102 via a network or the like, and are stored in the storage medium. The program 101 and the profile may be stored and executed.

[0090]

As is apparent from the above description, according to the present invention, it is possible to perform color conversion processing on either monochrome image data or n-color image data. In particular, in the configuration having the single-color image processing means, there is an effect that high-speed processing can be performed while ensuring that the processing result of the single color becomes a single color. At this time, in both the n-color image processing means and the mono-color image processing means, the result of processing the mono-color image data by the mono-color image processing means and the n-color image data equivalent to the mono-color image data are processed by n The configuration can be made so that the result of processing by the color image processing means is substantially equivalent, and an equivalent result can be obtained regardless of which processing is performed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a first embodiment of an image processing apparatus according to the present invention.

FIG. 2 is a block diagram illustrating a second embodiment of the image processing apparatus according to the present invention.

FIG. 3 is a block diagram illustrating a configuration example when a mono LUT is generated.

FIG. 4 is a graph showing an example of gradation characteristics of an input device and an output device.

FIG. 5 is a block diagram illustrating an example of a configuration when a mono LUT is created under the same conditions as those for creating a conversion definition for n-color image data.

FIG. 6 is a flowchart illustrating an example of a creation method when a mono LUT is created under the same conditions as those for creating a conversion definition for n-color image data.

FIG. 7 is an explanatory diagram of an example of a format of a profile in which a conversion definition is recorded.

FIG. 8 is a diagram illustrating a computer program or a color conversion definition when the functions or the image processing method of the image processing apparatus of the present invention or the functions or the color conversion definition creating method of the color conversion definition creating apparatus are realized by a computer program. FIG. 3 is an explanatory diagram of an example of a medium.

[Explanation of symbols]

1. Input image data recognition unit 2. Dummy data addition unit
3 ... color conversion unit, 4 ... monochrome color conversion unit, 11 ... mono forward prediction unit, 12 ... mono reverse prediction unit, 13 ... mono LUT generation unit,
21: color conversion unit, 22: forward prediction unit, 23: mono inverse prediction unit, 24: mono LUT generation unit.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 1/407 H04N 1/40 101E 1/46 1/46 Z F term (Reference) 2C087 AA15 AA16 AB05 BA03 BA07 BA12 BD36 2C262 AA24 AA29 AB11 AC03 BA01 BC19 EA12 EA17 5B057 AA11 BA25 CA01 CB01 CE11 CE17 CH07 CH11 DB06 5C077 LL16 LL19 MP08 PP15 PP31 PP33 PP36 PP38 PP66 PQ12 PQ23 TT08 5C079 HB03 HB02 NA12 HB03 MA03

Claims (34)

[Claims] 1. An image processing apparatus for processing n-color image data and monochromatic image data consisting of one of n colors, wherein when the monochromatic image data is input, a color other than the single color is used. An adding unit for adding dummy color plate image data; n-color plate image data composed of input n-color plate image data or input single-color plate image data and color plate image data added by the adding unit An image processing apparatus comprising an n-color plate image processing means for performing a color conversion process on the image data. 2. An image processing apparatus for processing n-color image data and single-color image data of one of n colors, wherein the n-color image processing device performs a color conversion process on the n-color image data. Image processing means, and monochromatic image processing means for performing a gradation conversion process on the monochromatic image data, wherein the n-color image data is input when the n-color image data is input. A color conversion process is performed by the n-color plate image processing unit, and when the single-color plate image data is input, a gradation conversion process is performed on the single-color plate image data by the single-color plate image processing unit. Image processing apparatus. 3. An image processing apparatus for processing n-color image data and monochromatic image data of one of n colors, wherein the n-color plate performs a color conversion process on the n-color image data. Image processing means, and monochromatic image processing means for performing a gradation conversion process on the monochromatic image data, wherein the n-color image data is input when the n-color image data is input. The n-color image processing means performs a color conversion process, and when the monochrome image data is input, performs a tone conversion process on the monochrome image data by the monochrome image processing means, The monochrome image processing unit adds dummy color plate image data for the color other than the monochrome to the monochrome image data to obtain an output result substantially equivalent to an output result that would be obtained through the n-color image processing unit. To get An image processing apparatus for performing a gradation conversion process on the monochrome image data. 4. The image processing apparatus according to claim 1, wherein the n-color plane image data includes black. 5. The image processing apparatus according to claim 1, wherein the monochrome image data is black image data. 6. The n-color plane image processing means, based on CMYK four-color plane image data input to a first output device,
Four colors of CMYK for inputting to the second output device so that a color substantially equivalent to the color of the image formed in the first output device is formed in the second output device by the color image data. The image processing apparatus according to any one of claims 1 to 5, wherein four-input and four-output color conversion for converting into plate image data is performed. 7. A color conversion means for adding dummy image data to monochromatic gradation image data to convert a color signal of an input device to a color signal of an output device, and a color signal of the output device to a device. Forward color prediction means for converting into an independent color signal, an index derived from the device-independent color signal or a part of the device-independent color signal or the device-independent color signal, and the output-side device Inverse prediction means for associating monochromatic gradation characteristics, and conversion definition generating means for generating a conversion definition for converting monochromatic input image data to monochromatic output image data based on the result of association by the inverse prediction means A color conversion definition generation device, characterized in that: 8. A color conversion means for adding dummy data to single-color gradation data to convert a color signal of an input device to a color signal of an output device, and a device independent of the color signal of the output device. Forward color predicting means for converting into a color signal; a color signal independent of the device or a part of a color signal independent of the device or an index derived from the color signal independent of the device; Inverse prediction means for associating tonal characteristics, and conversion definition generation means for generating a conversion definition for converting monochromatic input image data to monochromatic output image data based on the result of association by the inverse prediction means. Characteristic color conversion definition generation device. 9. A color conversion means for converting n-color image data obtained by adding dummy image data to single-color gradation image data from an n-color signal of an input-side device to an n-color signal of an output-side device; Forward color prediction means for converting the n-color signal of the device into a device-independent color signal; and a device-independent color signal or a part of the device-independent color signal or a device derived from the device-independent color signal. Inverse prediction means for associating an index with a single-color gradation characteristic of the output side device, and a conversion definition for converting monochromatic input image data to monochromatic output image data based on a result of the association by the inverse prediction means. A color conversion definition generation device, comprising: 10. A color conversion means for converting n-color plane data obtained by adding dummy data to single-color gradation data from an n-color signal of an input device to an n-color signal of an output device, and n conversion means for the output device. Forward color prediction means for converting a color signal into a device-independent color signal, and an index derived from the device-independent color signal or a part of the device-independent color signal or the device-independent color signal; Inverse prediction means for associating the monochromatic gradation characteristics of the output side device, and a conversion definition for generating a conversion definition for converting monochromatic input image data to monochromatic output image data based on the result of association by the inverse prediction means A color conversion definition generation device comprising a generation unit. 11. The conversion definition for the monochrome image data generated by the conversion definition generating means can be stored as one recording format together with the conversion definition used in the color conversion means. The color conversion definition generation device according to claim 9. 12. The conversion definition for monochrome image data generated by the conversion definition generation means and the conversion definition used in the color conversion means can be stored as a single file. The color conversion definition generation device according to any one of claims 11 to 11. 13. The color conversion definition generation device according to claim 9, wherein the n-color plane image data or the n-color plane data includes black. 14. The color conversion unit according to claim 5, wherein the color conversion unit converts the CMYK four-color plate image data input to the first output device into a color of an image formed in the first output device by the four-color plate image data. CMY for inputting to the second output device such that an equivalent color is formed at the second output device
10. A color conversion is performed based on a 4-input / 4-output conversion definition for converting into K 4-color image data.
The color conversion definition generation device according to any one of claims 13 to 13. 15. The color conversion definition generation device according to claim 7, wherein the single color is black. 16. An index derived from a color signal independent of the device is at least one of lightness, reflectance, chroma, color difference, color difference based on white of paper, and optical density. The method according to any one of claims 7 to 15, wherein
The color conversion definition generation device according to the section. 17. An image processing method for processing n-color plate image data and single-color plate image data consisting of one of n colors, wherein when the single-color plate image data is input, dummy data for colors other than the single color is used. To add the color image data
An image processing method, wherein color conversion processing is performed on n-color plane image data as color plane image data. 18. An image processing method for processing n-color plate image data and single-color plate image data consisting of one of n colors, wherein when the n-color plate image data is input, the input n A color conversion process is performed on the color image data, and when the monochrome image data is input, a dummy color for the color other than the monochrome is added to the monochrome image data. Add plate image data and add
An image processing method, wherein a gradation conversion process is performed so as to be substantially equal to a result obtained when the color conversion process is performed as color plane image data. 19. An image processing method for processing n-color plate image data and single-color plate image data consisting of one of n colors, wherein the n-color plate image data is input when the n-color plate image data is input. With respect to the color image data, the second output device outputs a color substantially equivalent to the color of the image formed by the first output device using the n-color image data to the second output device. A color conversion process is performed on the n-color plate image data for input, and when the single-color plate image data is input, for the single-color plate image data, the color other than the single color is added to the single-color plate image data. An image processing method, wherein a gradation conversion process is performed so that a result obtained by performing a color conversion process as n-color plate image data by adding dummy color plate image data is substantially equal to the result. 20. The image processing method according to claim 17, wherein the n-color plane image data includes black. 21. The image processing method according to claim 17, wherein the monochrome image data is black image data. 22. Addition of dummy image data to monochromatic gradation image data to convert a color signal of an input device into a color signal of an output device, and converting the color signal of the output device into a color signal independent of a device. And associates the device-independent color signal or a part of the device-independent color signal or an index derived from the device-independent color signal with the monochromatic gradation characteristics of the output-side device. Generating a conversion definition for converting single-color input image data to single-color output image data based on the result of (1). 23. Converting a color signal of an input-side device into a color signal of an output-side device by adding dummy data to monochromatic gradation data, and converting the color signal of the output-side device into a device-independent color signal. And associating the device-independent color signal or a part of the device-independent color signal or an index derived from the device-independent color signal with the monochrome gradation characteristics of the output-side device, and associating the result. Generating a conversion definition for converting monochromatic input image data into monochromatic output image data based on the color conversion definition. 24. Converting n-color plane image data obtained by adding dummy image data to single-color gradation image data from an n-color signal of an input-side device to an n-color signal of an output-side device; The signal is converted into a device-independent color signal, and the device-independent color signal or a part of the device-independent color signal or an index derived from the device-independent color signal and the monochrome of the output side device A color conversion definition generation method, which relates a gradation characteristic and generates a conversion definition for converting monochromatic input image data into monochromatic output image data based on a result of the association. 25. An n-color plate data obtained by adding dummy data to monochromatic gradation data from an n-color signal of an input-side device to an n-color signal of an output-side device, and converting the n-color signal of the output-side device into a device. The color signal independent of the device, a color signal independent of the device or a part of the color signal independent of the device or an index derived from the color signal independent of the device and the monochromatic gradation characteristics of the output side device And generating a conversion definition for converting single-color input image data to single-color output image data based on the result of the association. 26. A conversion definition for converting generated single-color input image data into single-color output image data is used when performing color conversion processing on the n-color plane image data or the n-color plane data. 26. The color conversion definition generation method according to claim 24 or 25, wherein the color conversion definition can be stored as one recording format together with the conversion definition. 27. A conversion definition for converting the generated single-color input image data into single-color output image data, and a conversion definition used for performing color conversion processing on the n-color image data or the n-color data. 27. The color conversion definition generation method according to claim 24, wherein the conversion definition can be stored as a single file. 28. The color conversion definition generation method according to claim 24, wherein the n-color plane image data or the n-color plane data includes black. 29. The color conversion processing for the n-color image data or the n-color image data is performed by converting the CMYK four-color image data input to the first output device into the first color image data using the four-color image data. 4 input for converting into CMYK four-color image data for input to the second output device so that a color substantially equivalent to the color of the image formed in the output device is formed in the second output device. 4. A color conversion process based on a -4 output conversion definition.
29. The color conversion definition generation method according to any one of claims 4 to 28. 30. The color conversion definition generation method according to claim 22, wherein the single color is black. 31. An index derived from a color signal independent of the device is at least one of lightness, reflectance, chroma, color difference, color difference based on paper white, and the like, and optical density. 31. The color conversion definition generation method according to claim 22, wherein: 32. The function of the image processing apparatus according to any one of claims 1 to 6, or the function according to any one of claims 17 to 21, in a storage medium readable by a computer. A storage medium storing a program for causing a computer to execute an image processing method. 33. The computer-readable storage medium according to claim 7, wherein the function of the color conversion definition creating apparatus according to any one of claims 17 to 16 or the function according to any one of claims 22 to 31 is provided. A storage medium storing a program for causing a computer to execute the described color conversion definition creating method. 34. The computer-readable storage medium according to claim 7, wherein the color conversion definition creating apparatus is configured to execute the color conversion definition creation apparatus according to any one of claims 22 to 31. A storage medium storing a conversion definition generated by a color conversion definition creating method.