JP3209053B2 - Color reproduction device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color reproducing apparatus, and more particularly, to a color reproducing apparatus which reproduces an output color in a color printing or a television to be equal to a color of an input original image.

[0002]

2. Description of the Related Art In recent years, color reproduction has been improved in order to exhibit and explain using colors, and to evaluate and arrange colors.
There is a color output device (such as a color hard copy device or a television) with general colors for forming a reproduced image on paper or a screen from an original image recorded on a color original. This color output device is provided with a device-specific color conversion device for realizing color reproduction. The color output device obtains color information values input as original images of color originals and color information values of original images obtained by scanning with a scanner. A reproduced image is formed on a screen, paper, or the like by a color reproducing device.

However, since a general color output device is intended for an inexpensive and small-scale mass production type, the accuracy of color reproduction is sacrificed. Therefore, ΔE ^* _ab = 30 (color difference between target color and print color, The color reproducibility was poor, such as about (corresponding to 100 for black). Further, it is difficult for such a general color output device to improve the color reproduction accuracy by the user.

In recent years, for example, in the field of design, there has been an increasing demand for a color reproduction device capable of faithfully reproducing required colors for color design evaluation.

[0005] The color of the original image is represented by chromaticity coordinates represented by tristimulus values X, Y, Z of the color according to the CIE standard XYZ color system, which is a well-known international color representation. If the spectral distribution I (λ) of reflected light or transmitted light from an object or the like can be measured as a standard by specifying where on the chromaticity diagram it is located, tristimulus values X, Y, and Z can be obtained. it can.

In a color output device for specifying a color using such tristimulus values, a YM obtained by measuring the color of an original image is used.
A color is captured using color information values such as RGB signals corresponding to the C color or the three primary colors, and the color information values are used as a color material of a predetermined color (for example, R material, G
The material is converted into color material data representing the amount of the material, and the amount of each color material according to the color material data is mixed to form and output a reproduced image.

That is, color material values obtained by measurement of an original image or the like are converted into the above-described color information values of the XYZ color system, and color material data that can obtain the converted color information values of the XYZ color system. Ask for. This makes it possible to obtain color material data of a color whose original image is to be reproduced as a reproduced image, and to form a reproduced image with high color reproducibility.

However, in the color formation by the subtractive color mixing method such as the color output device for realizing the color reproduction by the above-mentioned tristimulus values, the conversion between the color information value and the color material data becomes non-linear. The color information value of the original image must be obtained from the color material data for forming a color reproduction image. To obtain color information values of an original image from color material data for forming a reproduction image of a desired color (ie, to solve a so-called inverse problem) requires a huge amount of color information values and color material data. The used high-load arithmetic processing is required, which is not practical.

In order to solve the above problem, the present applicant has proposed a color reproduction method capable of reproducing a required color with only a simple process using a small amount of known data (for example, color information value and color material data). (JP-A-7-5076).
No. 0). In this technique, a relative relationship between a predetermined number of input values (color information values of each of R, G, and B colors) and output tristimulus values is determined, and arbitrary tristimulus values X, Y, and Z are obtained. The input value closest to the output color represented by is obtained by interpolation processing. Thereby, a reproduced image with high color reproducibility can be formed.

[0010]

However, in order to reproduce colors from an original image to a reproduced image by a color reproduction method for reproducing a required color by a simple process using a small amount of known data as described above, it is necessary to use color reproduction. The control algorithm must be changed to an algorithm according to the above technique. Therefore, it is difficult to easily obtain a good reproduced image with a color output device in which it is difficult to change the algorithm.

An object of the present invention is to provide a color reproducing apparatus capable of obtaining an output color that matches an input color in consideration of the above fact.

[0012]

In order to achieve the above-mentioned object, a color reproducing apparatus according to the present invention is adapted to cope with a photometric light quantity at the time of photometry.
The color information value of each of a plurality of predetermined colors and the color information value of each output color from the color output device when each of these colors is used as an input color by using a colorimetric device capable of obtaining a color information value to be obtained. more together determine the relationship between, with including the input color
By including colors other than the input color, the predetermined
The relationship between the color information value corresponding to each of a large number of colors exceeding a few colors and the color information value of each output color from the color output device when each of the multiple colors is set as an input color. , The multiple colors
The relationship between the color information value of the input color and the color information value of the output color for
A predetermined number of color information values of the adjacent output colors based on the
Calculating a color information value of an input color corresponding to the color information value equally divided by the above, thereby obtaining a correspondence relationship between an input color and an output color in the color output device; and Calculating means for obtaining a color information value of a provisional input color such that the color information value of the input color matches the color information value of the output color with respect to the input color to be reproduced, based on the obtained correspondence; Using the color information value of the input color and the color information value of the temporary input color corresponding to the input color to be reproduced, the temporary input color is reproduced as the input color to be reproduced so as to be input to the color output device. Correction means for correcting the color information value of the input color to be reproduced or the input color to be reproduced.

The color output device includes a scanner that scans and measures the input color, and the correction unit is provided on a scanning side of the scanner and has a transmittance that can be changed according to an input signal. The input color to be reproduced using the color information value of the input color to be reproduced and the color information value of the temporary input color corresponding to the input color to be reproduced is scanned and measured by the scanner as a temporary input color. Filter control means for controlling the filter means as described above.

Further, the color output device includes an information reading device for reading a color information value of an input color, and the correction means is provided on an input side of the information reading device and includes color information of an input color to be reproduced. Using the value and the color information value of the temporary input color corresponding to the input color to be reproduced, the color information value of the input color to be reproduced can be converted into the color information value of the temporary input color. The plurality of colors may be predetermined colors of a plurality of color patches. Further, the filter means changes the transmittance uniformly according to an input signal within a predetermined range, and the filter control means determines a color of a temporary input color corresponding to the input designated color. Information values can be used.
Further, the filter means changes transmittance in accordance with an input signal for each minute area, and the filter control means can control the filter means for each minute area. Further, the filter unit is a wavelength filter having a predetermined spectral transmittance, and the filter control unit includes:
It can be converted into a color information value of a provisional input color controlled by the spectral transmittance of the wavelength filter.

[0015] When a reproduced image is formed on paper or a screen from an original image recorded on a color original by a color output device, improving color reproducibility is achieved by matching input colors and output colors in the color output device. It is to make it. However, although the conventional color output device forms a reproduced image in a color corresponding to the color of the color original, the output color does not match the input color.

Therefore, in the color reproduction device of the present invention, the correspondence between the input color and the output color in the color output device is obtained in advance by the calculating means. This correspondence is, first, that it has photometry
Using a colorimetric device capable of obtaining a color information value corresponding to the amount of light measured at the time, the color information values of each of a plurality of predetermined colors and each of the colors from the color output device when each of these colors is used as an input color. A plurality of relations between the output color and the color information value are obtained. With this,
Color information values corresponding to each of a large number of colors including colors other than the input color, that is, colors including the input color and colors other than the input color
Including a number exceeding the predetermined plurality of colors.
The relationship between the color information value corresponding to each of the multiple colors and the color information value of each output color from the color output device when each of the multiple colors is set as the input color is represented by the input colors for a plurality of colors. Color of
Neighbors based on the relationship between the report value and the color information value of the output color
The color information value of the output color is divided into a predetermined number of equal color information values.
Many are obtained from the color information values of the corresponding input colors . The colorimetric device does not need to be an expensive measuring device that accurately measures light intensity, but a colorimetric device with good reproducibility, in which the measured value monotonically increases as the light intensity increases, is sufficient. For example, a color camera can be used for the colorimetric device.
When the relationship between each color information value of multiple colors and the color information value of the output color from the color output device is obtained using the colorimetric device, the color information values of multiple colors including colors other than the input colors are obtained. And the color information values of the colors output from the color output device. In this way, the correspondence between the input colors and the output colors in the color output device can be obtained.

The color information value includes a value corresponding to a device signal which is an input signal of the color output device, an intermediate transmission density value for each color, a value representing each of the three primary colors, and an image pickup device such as a color camera. There is an output value of the obtained color component and a tristimulus value obtained by performing color measurement.

Further, the relationship between the color information value of the input color and the color information value of the output color for obtaining the correspondence between the input color and the output color in the color output device, for example, the sample is the whole of the color output device. Any number that can be grasped is acceptable.

If the correspondence between the input colors and the output colors in the color output device is obtained, that is, if the overall state of the color output device can be grasped, many relationships between samples can be obtained by interpolation processing.

In the arithmetic means, based on the correspondence obtained by the calculating means, the color information of the tentative input color such that the color information value of the input color matches the color information value of the output color for the input color to be reproduced. Find the value. That is, if the correspondence between the input color and the output color in the color output device is determined, the difference between the color information value of the output color and the color information value of the input color is compared, and the color information value of the output color is determined by the input color. A color information value of a provisional input color that matches the color information value can be obtained.

In order to obtain the color information value of the provisional input color, the calculation for obtaining the color information value of the input color to be input to the color output device from the color information value of the output color is performed, for example, as disclosed in The color reproduction method described in JP-A-50-5060 can be employed.

As described above, the color information value of the provisional input color for matching the output color to the input color is obtained, and if the color information value of the provisional input color corresponding to the input color is determined, the color output device If the color information value of the tentative input color corresponding to the input color is used when the color information value of the input color is input to the color output device, the input color matches the output color in this color output device. Therefore, the correcting means uses the color information value of the input color to be reproduced and the color information value of the temporary input color corresponding to the input color to be reproduced to determine the temporary input color as the input color to be reproduced. The input color to be reproduced or the color information value of the input color to be reproduced is corrected so as to be input to the output device.

Therefore, when an input color to be reproduced is output as it is by the color output device, the output color changes from the input color. In the present invention, however, the color output device corresponds to the color information value of the input color to be reproduced. The output color is output from the color output device according to the color based on the color information value of the tentative input color to be reproduced as the output color, so that extremely high color reproduction accuracy can be obtained.

When the color output device includes a scanner that scans and measures the input color, a filter that changes the transmittance can be used as a means for forming a temporary input color. That is, a correction means is provided on the scanning side of the scanner and has a transmittance which varies according to an input signal; a color information value of an input color to be reproduced and a temporary information corresponding to the input color to be reproduced. Filter control means for controlling the filter means so that the input color to be reproduced using the color information value of the input color is scanned and measured by the scanner as a temporary input color. According to this configuration, the input color transmitted through the filter unit is supplied to the color output device as a temporary input color, and the output color is output from the color output device with good reproducibility.

When the color output device has an information reading device for reading the color information value of the input color, the correction means is provided on the input side of the information reading device and has the input color to be reproduced. The color information value of the input color to be reproduced is converted into the color information value of the temporary input color by using the color information value of the input color to be reproduced and the color information value of the temporary input color corresponding to the input color to be reproduced. Good. With this configuration, the color information value of the input color is converted into the color information value of the provisional input color, supplied to the color output device, and the output color is output from the color output device with good reproducibility.

[0026]

Embodiments of the present invention will be described below in detail with reference to the drawings. The first embodiment of the present invention relates to a color input device of a scanner input type that reads a color original and forms a reproduced image on paper or the like in order to improve color reproduction when forming a reproduced image from an original image. The color reproduction device of the present invention is applied for reproduction.

As shown in FIG. 1, the color reproduction device 10
It comprises a V camera 12, a wavelength filter 20, a personal computer 16 and a color output device 18. The personal computer 16 includes a keyboard for inputting data, commands, and the like, a computer body for calculating and outputting data for outputting a desired color from the color output device 18 according to a program stored in advance, and a calculation result of the computer body. , Etc., which are displayed on the display.

The personal computer 16 includes a TV camera 12 as an image input device for outputting color data (for example, R, G, B output signals) as color information values of an original image of a color original 14 taken. It is connected. This TV
A general-purpose 8 mm video camera can be used as the camera 12.

The color output device 18 includes a scanner 24, a color conversion device 26, and a printing device 28 (see FIG. 2).
The color output device 18 exposes the original image of the color original 14 with light emitted from a light source (not shown) of the scanner 24, and reproduces the color unique to the device based on the output signal of the scanner 24 in the color conversion device 26. After performing color conversion, the printing device 2
In 8, color printing is performed based on the output signal of the color conversion device 26 to obtain a printed matter 22.

The color output device 18 includes a device that performs full-surface exposure, a device that scans slit exposure over the original image, and a device that scans the light beam vertically and horizontally within the range of the original image.

On the exposure surface 18A of the color output device 18, the transmission density of light of a predetermined wavelength can be uniform or can change for each pixel (for example, a minimum printing element: pixel) according to the magnitude of the applied voltage. A wavelength filter 20 is provided. The wavelength filter 20 is connected to the personal computer 16. The color original 14 is placed on the wavelength filter 20. Therefore, the color output device 18 exposes the original image of the color original 14 via the wavelength filter 20 with light emitted from a light source (not shown) provided inside the device, performs color control unique to the device, and Is output (see FIG. 3).

FIG. 4 is a processing routine showing a flow of a series of processing for color reproduction of a desired color in an original image of the present embodiment into a reproduction image. Although details of each process will be described later, in step 100 of FIG.
In order to obtain a reproduced image (printed material 22) having high color reproducibility from 4), the correspondence between an arbitrary input color and an output color of a color output device is calculated in advance. In the next step 102, a correction value is obtained for each color of the original image of the color original 14 to be subjected to color reproduction using the correspondence obtained in step 100. In the next step 104, a device value of the wavelength filter 20 for performing color correction substantially corresponding to a correction value to be applied to the color output device 18 is obtained.
Supply this device value. After supplying the device values, in the next step 106, the original image scanned by the scanner 24 via the wavelength filter 20 is printed (copied).
The processing from step 102 to step 106 is repeatedly executed until the printing of the color document 14 is completed.

To determine the correspondence between the input color and the output color of the color output device in step 100, the correction value for each color of the original image corresponding to the color of the arbitrary reproduced image is determined. You may do so. This step 10
The process of determining the correspondence between the input color and the output color of the 0 color output device corresponds to a calculating unit. Step 102
Is a process for correcting the color of an arbitrary original image into a transparent color for matching the color output from the color output device. The provisional process is performed such that the color information value of the output color matches the color information value of the input color. Corresponds to an operation means for calculating the color information value of the input color of the above. further,
Step 104 is a process for performing color correction so that a reproduced image having a color that matches the original image is substantially obtained from the color output device 18, and corresponds to a correction unit.

In the present embodiment, in order to reproduce the color from the original image to a reproduced image of a color corresponding to the color of the original image, the color output device 18 controls the color original 1 viewed through the wavelength filter 20.
A reproduction image of the printed matter 22 is formed from the original image of No. 4. Hereinafter, for the sake of simplicity, the color notation in each part is as follows.

The color of an image is defined as a color expression object (color original 14).
Color data (R, G, B) as color information values of a plurality of predetermined colors (for example, three primary colors) obtained when the TV camera 12 captures an image of the printed material 22 or the like.
Notated as color Vc. As the color Vc, a value of an output signal of the TV camera 12 or a value of an image digital output signal can be used. A certain color of the original image of the color original 14 is described as a color Vc ^(1), and a certain color of the original image transmitted through the wavelength filter 20 is described as a color Vc ^(2). The color output device 18 assumes that a color with
The color of the printed matter 22 obtained from is described as a color Vc ⁽³⁾ (see FIG. 3).

Next, the details of step 100 in FIG. 4 will be described. The process of step 100 is to execute a preparatory process routine shown in FIG. 5 in the personal computer 16.

In step 110 of FIG. 5, a color chart for color correction for reproducing the color of the original image and obtaining a reproduced image is prepared as follows. For simplicity of explanation, the color output device 18 prints, for example, four colors of inks of Ye, Mg, Cy, and K (yellow, magenta, cyan, and black) and prints 22.
Is formed. This printed matter 22 is stored in the scanner 2
4. The density of each of the colors Ye, Mg, Cy, and K changes in accordance with the color data (internal device values, for example, voltage values) of each of the colors Ye, Mg, Cy, and K corresponding to the output signal from No. 4. And

[0038] First, the yellow Ye, the color data D _Y by using the color data is changed in turn, the relationship between the color data D _Y, and tristimulus values Y _Y brightness of the color of the printed material to be formed Ask for. That is, the yellow Y whose size gradually increases from 0
By input to the color output device 18 as sequentially output signals of the scanner 24 color data D _Y of e, the color output device 1
The printed matter 22 on which a reproduced image of a color corresponding to the color data D _Y input from the printer 8 is formed is output. Then, the printed material 22 subjected to colorimetry by spectrometer such as a spectrophotometer, determine the tristimulus values Y _Y brightness of the color of the printed matter which is formed corresponding respective color data D _Y. Accordingly, the tristimulus value Y _Y for each color data D _Y is obtained. FIG. 7 shows color data D _Y and
It showed characteristic 30 representing the relationship between the tristimulus values Y _Y brightness of the color of the printed material to be formed.

Next, using the obtained characteristics 30, the magnitude of the brightness tristimulus value Y _Y is divided by a predetermined number. The magnitude of each of the divided tristimulus values is equivalent,
The intervals are equal on the characteristic diagram of FIG. The tristimulus value Y _Y is divided into (n-1) equal parts, and the color data D _Y corresponding to the tristimulus values at the divided boundary portions is D _Y0 , D _{Y1 ,.
Let it be Yn-1} .

In the same manner, magenta Mg, cyan Cy, and black K other than the above-mentioned yellow Ye, D _M0 , D _M1 , D _M2 ,..., D _Mn-1 D _C0 , D _C1 , D _C2 , .., D _Cn-1 D _K0 , D _K1 , D _K2 ,..., D _Kn-1, and color data corresponding to the tristimulus values at the divided boundary portions is obtained.

In this embodiment, as an example, n = 5 and 4
When divided, D _Yi, D _Mi, D _{Ci , and} D _Ki (i = 0,
1,..., 4) colors formed by a combination of all colors,
That it is assumed to be 5 ^four colors. These colors as color chart, the signals obtained by each color chip is captured by the TV camera _{12 (R j, G j,} B j) ( _{where, j} =
The color represented by 1, 2,..., 5 ⁴ )
_j (= (R _j, G _j, B _j )). Thus, n color patches are prepared.

A plurality of correspondences between the color Vc _j of the color chart and the colorimetric values of the color Vc ⁽³⁾ of the printed matter 22 are obtained in advance and stored in a table or stored as a function and calculated and calculated. Or ask for it.

Next, in step 112 in FIG. 5, the color 22 (color Vc _j ) is passed through the wavelength filter 20 and the printed matter 22 printed by the color output device 18 is measured. Using a plurality of correspondences between the color data of the color Vc _j of the color chart and the colorimetric values of the color Vc ⁽³⁾ of the printed matter 22, the following step 11 is performed.
In step 4, a color Vc ⁽²⁾ transmitted through the wavelength filter 20 is determined such that an arbitrary color Vc ⁽³⁾ is used as the color of the printed matter 22.

Steps 112 and 114
Is a process for obtaining a color transmitted through the wavelength filter 20 such that an arbitrary color is used as the color of the printed matter 22. The output color corresponding to the input color when a color other than the predetermined color is input to the color output device This is a process for calculating a color information value.

More specifically, since the number of color patches is n, the color Vc _j of the n color patches is defined as a color Vc _j ^{(2 ).} Scanner 24
The color placed on the top and printed as it is is referred to as a color Vc _j ⁽³⁾ .
An input color Vc that outputs an arbitrary color Vc ⁽³⁾ by a method of solving a well-known inverse problem from the n correspondences.
⁽²⁾ can be obtained. As a method for solving this inverse problem, there is a color reproduction method described in Japanese Patent Application Laid-Open No. 7-50760, which has already been filed by the present applicant. In this color reproduction method,
The relative relationship between a predetermined number of input values (R, G, B values) and the tristimulus values of the output color is determined, and the output color represented by any of the tristimulus values X, Y, Z is determined. Since the closest input value can be obtained by interpolation processing, an input color Vc ⁽²⁾ that outputs an arbitrary color Vc ⁽³⁾ can be obtained from the above n correspondences. .

[0046] Color Vc ⁽³⁾ of the next in step 116 any of the original image color Vc ⁽¹⁾ and the reproduced image and for matching the,
The transmission color Vc ^{(2) *} of the wavelength filter 20 is obtained, and in the next step 118, the color Vc ⁽¹⁾ of an arbitrary original image is converted to the transmission color Vc ^{(2) *.}
The voltage value Vv of the wavelength filter 20 for correcting the voltage is estimated.

This step 116 is a process for correcting the color of an arbitrary original image into a transparent color to match the color output from the color output device, and the color information value of the output color is changed to the color information value of the input color. This is a process for obtaining a color information value of a provisional input color that matches with. .

That is, the color output device 18 above the scanner
A wavelength filter 20 whose spectral transmittance changes according to the voltage is brought into close contact with the exposure surface 18A, and the original image is placed on the wavelength filter 20. When an arbitrary color of the original image is set as a color Vc ⁽¹⁾ , Vc
⁽³⁾ A transmission color Vc ^{(2) *} is determined so that = Vc ^(1), and a voltage Vv is applied to the wavelength filter 20 such that the color Vc ⁽¹⁾ becomes the transmission color Vc ^{(2) *.} Is applied. As a result, the color Vc ⁽¹⁾ of the original image is corrected to the transmission color Vc ^{(2) *} and supplied to the color output device 18, so that a reproduced image having a color that matches the color of the original image is formed. Can be.

Specifically, the voltage V applied to the wavelength filter 20 is
When v is supplied, the spectral transmittance of the wavelength filter 20 changes. In the present embodiment, it is assumed that the applied voltage Vv supplied to the wavelength filter 20 is composed of predetermined color components (R, G, B in the present embodiment) as shown in the following equation (1).

Vv = (v _R, v _G, v _B ) (1) where v _R : a value representing the R color component of the applied voltage v _G : a value representing the G color component of the applied voltage v _B : A value representing the B color component of the applied voltage

One color Vc _j ⁽¹⁾ (j = 1, 2,... ⁾
.., N) change to a certain color Vc _j ⁽²⁾ when the applied voltage Vv is applied to the wavelength filter 20. Here, the values v _R , v _G , and v _B representing the components of each color of the applied voltage correspond to integer values of 0, 1, 2,..., N _V (the maximum value of the values representing the color components). Then, the applied voltage Vv becomes
There are many (m in this embodiment), which can be expressed by the following equation (2).

M = (n _V +1) ³ (2)

At this time, the color Vc _j ⁽¹⁾ (j = 1, 2,... N) of the original image corresponding to the color of the color chart is input, and the applied voltage Vv _k (k = 1, 2,. .., m) is applied as the transmitted color Vc as the color transmitted through the wavelength filter 20
_jk ⁽²⁾ shall correspond. Therefore, the total sum of the correspondence between the color Vc _j ^{(1) of} the original image and the transmission color Vc _jk ^{(2 )} corresponding to the colors of all the color _chips is m × n. Applied voltage Vv _jk for obtaining a transparent color Vc _jk ⁽²⁾ from the original image color Vc _j ⁽¹⁾ corresponding to the color of the color chart can be expressed by the following equation (3).

Vv _jk = (Vc _j ⁽¹⁾ , Vc _jk ⁽²⁾ ) (3)

Therefore, from the color Vc _j ⁽¹⁾ to the transmitted color Vc _jk ⁽²⁾
Since there are m × n correspondences of the applied voltage Vv _jk to obtain the desired voltage, an arbitrary transmission from an arbitrary color Vc ^{(1) is performed} by using a known inverse problem by using the m × n correspondences. Color Vc
The applied voltage Vv for obtaining ⁽²⁾ can be obtained.
A method for solving the inverse problem can be realized by applying the color reproduction method described in Japanese Patent Application Laid-Open No. 7-50760 filed by the present applicant. That is, the relative relationship between the input value of this color reproduction method and the tristimulus value is replaced by the correspondence between the color Vc _j ⁽¹⁾ and the transmitted color Vc _jk ^(2), and the interpolation process is performed by replacing the tristimulus value with the applied voltage. Thus, the applied voltage Vv for obtaining an arbitrary transmitted color Vc ⁽²⁾ from an arbitrary color Vc ⁽¹⁾ can be obtained.

As described above, by obtaining the applied voltage Vv, when the color Vc ⁽¹⁾ is given, the color output device 18
The color Vc ^{(3) of the} printed matter 22 output from the
c The transmitted color Vc to the color output device 18 that matches ^(1)
(2) can be obtained, and the spectral transmittance of the wavelength filter 20 is such that the color Vc ⁽¹⁾ is corrected to the color Vc ⁽²⁾ .
The applied voltage Vv of the wavelength filter 20 can be obtained in advance.

Next, details of steps 102 and 104 in FIG. 4 will be described with reference to FIG. In the following description, the color of the n color chart Vc _j is color reproduction on a printed material ^{22 (Vc (3) = Vc} j) and applied voltage applied voltage Vv of the wavelength filter 20 when the Vv _j ^* I do.

Here, the color correction of the original image using the wavelength filter 20 differs depending on the characteristics of the wavelength filter 20.
That is, the wavelength filter 20 can change the spectral transmittance only uniformly as a whole, and can change the spectral transmittance for each minute region (pixel) using a liquid crystal device or the like. Therefore, in the present embodiment, the color output device 1
Characteristic information representing the characteristics of the wavelength filter 20 closely contacted with 8 is stored in the personal computer 16 in advance. Note that this characteristic information may be determined by an input using a keyboard.

At step 120 in FIG. 6, by reading the characteristic information of the wavelength filter 20, it is determined whether or not the wavelength filter 20 can change the spectral transmittance for each minute area (pixel). If the wavelength filter 20 that has been brought into close contact with the wavelength filter 20 cannot change the spectral transmittance for each minute region, the process proceeds to step 122, and the process proceeds to a process of correcting the original image with the same filter color. Goes to step 128.

In the case of forming a color-reproduced reproduced image, if the original image is corrected with the same filter color, not all colors of the original image are reproduced, but at least the main colors determined by the user are corrected. By performing color reproduction in this manner, a reproduced image substantially intended by the user can be formed.

Therefore, in step 122, a color whose color reproduction is important among the colors of the original image is determined. For this determination, a predetermined color may be read, or a color input by the user may be used. The input color by the user directly, the value of the color Vc _S (or TV camera 1
2) may be input, and the TV camera 12
May be color values Vc _S extracted by extracting colors contained in the area specified by the user in the captured original image is input by. In the next step 124, as the color reproduction of a specific color Vc _S determined among the colors of the original image (or color near the color Vc _S) is important,
To enhance the color reproducibility of color Vc _S (or color near the color ^{_{Vc S) (Vc (3)}} = Vc S to become like), the wavelength filter 20 colors for changing the (spectral transmittance) Applied voltage Vv
^Ask for _S ^* . That is, the process from any correspondence between colors and the applied voltage obtained in (5), the color Vc _S color Vc ⁽¹⁾
When supplied as the application voltage Vv _S ^* is determined that the primary colors Vc _S color Vc ⁽³⁾ the original image of the reproduced image matches.
The above processing corresponds to the correction value calculation processing of the original image in step 102 in FIG.

The next step 126 is step 1 in FIG.
04 is equivalent to the original image correction process.
The determined applied voltage Vv_S ^*Is supplied to the color output device 18. Obedience
Therefore, the voltage Vv applied to the wavelength filter 20_S ^*Supply
If a reproduced image is formed by the color output device 18 from the
Step 106), at least the main color Vc of the original image _STo
Thus, accurate color reproduction is performed.

In the above description, one main color is defined as one color.
As described above, if multiple colors are determined to be the main colors,
It is also possible. That is, p features of the colors of the original image
Fixed color (Vc_S1, Vc_S2, ..., Vc_Sp) Color reproducibility
Is determined to be important for each color
And a weight coefficient h determined in advance or specified by a user.
_h(H₁+ H_Two+ ... + h_p= 1, h_h≧ 0)
The applied voltages for the main colors are calculated as shown in the following equation.
Just turn it on.

[0064]

(Equation 1)

[0065] By applying the weight thus the applied voltage for each color, according to the magnitude of the weighting factor h _h, it is possible to improve the color reproducibility of each color.

Next, a description will be given of a process in which the wavelength filter 20 makes a correction based on a change in the color (spectral transmittance) of each pixel corresponding to the color of each pixel of the original image when the determination is affirmative in step 120 in FIG. I do. In the wavelength filter 20 capable of changing the color (spectral transmittance) of each pixel having a very small size, the original image can be reproduced by correcting the original image with the filter color of each pixel. Can be formed.

In step 128 of FIG. 6, the color of each area corresponding to the pixel size of the wavelength filter 20 is extracted from the original image. For this extraction, signals of respective regions corresponding to the pixel size of the wavelength filter 20 in the original image captured by the TV camera 12 can be used. In the next step 130, as the color reproduction of a specific color Vc _S (or color near the color Vc _S) is important for each of the regions corresponding to the pixels of the original image, color Vc _S (or color Vc _S
(Vc ⁽³⁾ = V ⁾
c _S ), and an applied voltage Vv _S ^* for changing the color (spectral transmittance) of the wavelength filter 20 is obtained in the same manner as in the above processing (step 124). As a result, the color Vc ⁽³⁾ of the reproduced image and the main color V
the applied voltage and c _S matches Vv _S ^* is obtained. The above processing corresponds to the correction value calculation processing of the original image in step 102 in FIG.

The next step 132 is step 1 in FIG.
04 is equivalent to the correction processing of the original image, and supplies the respective applied voltages Vv _S ^* obtained above in correspondence to the position of the wavelength filter 20 pixels to the wavelength filter 20. Therefore, by forming the reproduced image in the color output device 18 while supplying an applied voltage Vv _S ^* to the wavelength filter 20 (step 106 in FIG. 4), the major color Vc _S of the original image for each pixel,
Color reproduction is accurate.

Next, a second embodiment will be described. Although the first embodiment corrects the color of the original image using a wavelength filter whose spectral transmittance can be changed, the second embodiment converts the original image using a wavelength filter having a predetermined spectral transmittance. The present invention is applied to color correction and color reproduction.
Since this embodiment has the same configuration as the above-described embodiment, the same portions are denoted by the same reference numerals and detailed description thereof will be omitted. Also, the color output device of the present embodiment
It is assumed that the color value measured by the color correction can be corrected by a parameter based on the correction signal.

First, the principle of enabling color correction with a plurality of wavelength filters having a fixed spectral transmittance will be described. In the present embodiment, q wavelength filters 20 ₁ , 20 ₂ ,..., 20 _q having a predetermined spectral transmittance are used. Wavelength filter 20 ₁ to 20 _q are each the same thickness l, the respective spectral transmittance parameters _{a u (0 ≦ a u ≦} 1, u =
1, 2,..., Q), and the wavelength coefficient τ _u (λ)
Then, the spectral transmittance can be expressed by the following equation (5).

[0071]

(Equation 2)

The parameter a_uIs a_uWhen = 0
Wavelength filter becomes colorless and transparent, a _u= 1 then
It is assumed that the spectral transmittance is represented by the equation (6).

[0073]

(Equation 3)

Here, assuming that a _u = 1 for each wavelength filter, the emitted light when the light of intensity I ⁽⁰⁾ (λ) is incident is superimposed on the incident light by the influence of the transmittance of each wavelength filter. (See FIG. 8). Therefore, the transmitted light I _u (λ) from each wavelength filter can be expressed by the following equation (7).

[0075]

(Equation 4)

[0076] Accordingly, the tristimulus value _{Ex u (= X u, Y} u,
Z _u ) can be expressed by the following equation (8).

[0077]

(Equation 5)

Thus, the tristimulus value Ex _u can be expressed by the following equation (9).

[0079]

(Equation 6)

Here, q wavelength filters are overlapped, and the intensity I of transmitted light when the light of intensity I ⁽⁰⁾ (λ) is incident is obtained.
(Λ) can be expressed by the following equation (10).

[0081]

(Equation 7)

Therefore, the tristimulus value Ex (= (X, Y,
Z)) can be expressed by the following equation (11).

[0083]

(Equation 8)

Accordingly, the tristimulus value Ex is given by the following determinant: (1
2) It can be expressed by the following equation.

[0085]

(Equation 9)

Here, if the second term on the right side of the equation (12) is expressed by the following equation (13), the above equations (9) and (12) can be expressed by the following equations (14) and (15). Can be expressed.

[0087]

(Equation 10)

[0088] _{Ex u = R u · Δλ ·} M · EL u ··· (14) Ex = R · Δλ · M · EL ··· (15) In addition, the use of the transposed matrix M ^t of the matrix M, the next Of (16)
Equation (17).

[0089] _{EL u = (1 / R u} · Δλ) · (M t M) -1 · M t · Ex u ·· (16) EL = (1 / R · Δλ) · (M t M) · M ^t・ Ex ・ ・ (17)

Here, when the matrix operation on the right side of the expressions (16) and (17) is performed, the following expressions (18) and (19) are obtained.

[0091]

[Equation 11]

Accordingly, the wavelength coefficient τ relating to the transmittance and the coefficients of all the wavelength filters can be expressed by the following equations (20) and (21).

[0093]

(Equation 12)

From the equation (21), the following equation (22) is obtained.
Equation (23) is obtained.

[0095]

(Equation 13)

Therefore, as shown in FIG.
⁽⁰⁾ with light (lambda), tristimulus values by transmitted light for each filter _{(X u, Y u, Z} u) by obtaining in advance a, when overlaid all wavelength filter, the intensity I ^{( 0)} (
λ), the tristimulus value of the transmitted light when (X,
Y, Z) parameter a for each wavelength filter
_1, a _2, can be obtained., The a _q.

Next, the operation of the present embodiment will be described. Note that the flow of a series of processes for color reproduction on a reproduced image according to the present embodiment is the same as that in FIG. 4 described in the above embodiment, and thus the description is omitted. As shown in FIG. 10, the preparatory processing routine in the present embodiment, as in the above embodiment was prepared color chart color Vc _j a (step 110), the wavelength filter 20 color Vc _j of each color chip The printed matter 22 is printed and printed by the color output device 18, and the color of the printed matter 22 is measured.
That is, the exposure surface 18A of the wavelength filter 20 ₁ to 20 _q
The color of the printed matter 22 of each color chart when not placed on the top is measured (step 112). The color Vc _{j of} this color chart and the printed matter 22
Of any color Vc using the correspondence between the color Vc of ^{(3) and} the colorimetric value
A color Vc ⁽²⁾ is determined such that c ⁽³⁾ is used as the color of the printed matter 22 (step 114). As described in the above embodiment, using the color reproduction method described in Japanese Patent Application Laid-Open No. 7-50760 filed by the present applicant, which is a method for solving the inverse problem, An input color Vc ^{(2) *} that can output an arbitrary color Vc ⁽³⁾ can be obtained.

[0098] Figure for matching the color Vc ⁽³⁾ color Vc ⁽¹⁾ and the reproduced image Step any in 140 of the original image 10, any transparent color Vc ^{(2) *} tristimulus values Ex ^* In the next step 142, the tristimulus value Ex _j of the color Vc _j of each color chart is determined by a well-known color conversion method of converting RGB values to XYZ values. In the next step 144, the 20 ₁ each to 20 _q wavelength of q sheets filter, incident color Vc _j of each color chip as parameters a _u = 1, measuring the transmitted color Vc _ju of transmitted light at this time ⁽²⁾ Color and determine the tristimulus value Ex _ju .
In the next step 146, the color output device 1 above the scanner
8 wavelength filter of q sheets to the exposure surface 18A of 20 ₁ to 20 _q
Overlapping and when the incident light by the color Vc _j of each color ^{chart, Vc (3) = Vc (} 1) to become transparent color Vc ^{(2) *} of the parametrize Ea _j such that the transmitted light by the principle Ask as described. In the next step 148, from the plurality of correspondences obtained, parameters for the color Vc ⁽¹⁾ of the arbitrary original image are formed to form a reproduced color reproduction image that matches the color Vc ⁽¹⁾ of the arbitrary original image. Find Ea.

That is, the color output device 18 above the scanner
On the exposure surface 18A, the wavelength filter 20 ₁ each to 20 _q,
And all are brought into close contact with each other, and the original image is placed thereon. When an arbitrary color of the original image is set as a color Vc ⁽¹⁾ , Vc ⁽³⁾ = Vc
⁽¹⁾ become such transparent color Vc ^{(2) *} look, color the color of the original image Vc ⁽¹⁾ is transparent color Vc ^{(2) *} become as parameters E
a to the color output device 18. As a result, the color Vc ⁽¹⁾ of the original image is corrected to the transmission color Vc ^{(2) *} and interpreted by the color output device 18, so that a reproduced image having a color reproduction that matches the color of the original image can be formed. Can be.

Therefore, the color Vc_j ⁽¹⁾From the transmitted color Vc_jk ⁽²⁾
That there are many correspondences of the parameter Ea for obtaining
Use this method to solve the well-known inverse problem.
Any color Vc⁽¹⁾From any transmission color Vc⁽²⁾Got
The correspondence of the parameter Ea can be determined. this
As a method of solving the inverse problem, the applicant has already filed a special application.
The color reproduction method described in Japanese Unexamined Patent Publication No. 7-50760 is applied.
It can be realized by doing. That is, this color reproduction method
The relative relationship between the input value of the color and the tristimulus value is expressed by the color Vc. _j ⁽¹⁾And transparent
Color Vc_jk ⁽²⁾And change the tristimulus value
Data (parameters that can be described in vector format)
Any color Vc⁽¹⁾From any transmission color Vc
⁽²⁾Parameter Ea to obtain
You.

As described above, by obtaining the parameter Ea, when the color Vc ⁽¹⁾ is given, the color output device 1
The parameters for the transmission color Vc ⁽²⁾ interpreted by the color output device 18 are set in advance so that the color Vc ⁽³⁾ of the printed matter 22 output from the printer 8 matches the color Vc ^{( 1)} of the original image. You can ask.

Next, the details of step 102 and step 104 in FIG. 4 in this embodiment will be described with reference to FIG. In this embodiment, since a plurality of wavelength filters having a fixed spectral transmittance are used, color reproduction is performed not by color correction on a pixel-by-pixel basis but by a uniform filter color to form a reproduced image substantially intended by the user. A case where a reproduced image is formed will be described.

In step 150 of FIG. 11, a color whose color reproduction is important among colors of the original image is determined in the same manner as in the above embodiment. In the next step 152, as the color reproduction of a specific color Vc _S determined among the colors of the original image (or color near the color Vc _S) is important, the color Vc _S (or color Vc _S near color ) So that (Vc ⁽³⁾ = Vc _S
), The color of the wavelength filter 20 (spectral transmittance)
Is found to change the parameter Ea. That is,
From the correspondence relationship between the arbitrary color and parameters determined by the above processing (FIG. 10), color Vc _{when S} is supplied as a color Vc ⁽¹⁾ a major color Vc color Vc ⁽³⁾ the original image of the reproduced image A parameter Ea _S for matching _S is obtained. The above processing corresponds to the correction value calculation processing of the original image in step 102 in FIG.

When there are a plurality of important colors,
It can be obtained by weighting in the same manner as in the embodiment.
In other words, p specific colors (Vc_S1,
Vc _S2, ..., Vc_Sp) Color reproducibility is important
When specified, each color has a predetermined
Is the weighting factor h specified by the user_h(H₁+ H_Two+ ・ ・
・ + H_p= 1, h_h≧ 0) for the main multiple colors
What is necessary is just to determine a comprehensive parameter. First, the user
-Important colors Vc specified by_S1~ Vc_SpFor each of
About the parameter Ea_hAsk for. Parameters found
Ea_hIs calculated using the following equation (24).
Find the parameter Ea.

[0105]

[Equation 14]

The next step 156 is step 1 in FIG.
04 is equivalent to the correction processing of the original image, and supplies the parameters Ea _S calculated above to the color output device 18.
Therefore, the signal light transmitted through the wavelength filter 20 ₁ to 20 _q is converted, by forming a reproduced image with a color output device 18 (step 106 in FIG. 4), with respect to the major colors Vc _S of at least the original image In other words, accurate color reproduction is performed.

In the above description, the tristimulus values (X, Y,
Although Z) was used, the tristimulus values (X, Y, Z) and input signals (R, G, B) from a hand-held input device (8 mm video camera or digital still camera) have a one-to-one relationship. Since the mutual conversion can be performed by a method such as Japanese Patent Application Laid-Open No. 7-50760, it is not possible to calculate tristimulus values (X, Y, Z) from input signals (R, G, B) of a hand-held input device, for example. Easy.

As described above, in the above embodiment, the color original is color-reproduced as a printed matter on the color output device by mounting the wavelength filter on the color output device and controlling the spectral transmittance of the wavelength filter. Light is provided so that the color should be. Therefore, the color output device 19 can form a color-reproduced printed matter by performing a normal printing process by using a color original color-converted by a change in spectral transmittance due to a signal from the personal computer 16. Even in a color output device in which it is difficult to change the reproduction control, it is possible to easily form a printed matter having high color reproducibility desired by the user.

Next, a third embodiment will be described. In the first and second embodiments, a case has been described in which a reproduced image is formed by reproducing colors from an original image in a color input device of a scanner input type. The present invention is applied to a case where color reproduction is performed by a color output device (see FIG. 13) that forms a reproduced image by directly inputting an image signal such as an RGB signal without the provision of the image signal. Since this embodiment has the same configuration as the above-described embodiment, the same portions are denoted by the same reference numerals and detailed description thereof will be omitted.

As shown in FIG. 12, the color reproduction device 10
Image data output device 4 for outputting image data of an original image
0, a personal computer 16, a TV camera 12, and a color output device 19. Image data output device 4
Numeral 0 is for outputting image data of an original image including a color such as a color design or CAD, and is constituted by, for example, a microcomputer. Image data output device 4
0 is connected to the color output device 19 via the personal computer 16. The personal computer 16 has a color original 14 imaged in the same manner as in the above embodiment.
A TV camera 12 which is an image input device for outputting color data (for example, R, G, B output signals) of the original image is connected.

In this embodiment, the image data output device 4
0, the color data of the original image of the color original 14 (RG
The B signal or tristimulus value XYZ) is input to the personal computer 16, and the personal computer 16 outputs an RGB signal whose color is reproduced by referring to a table as described later. The color output device 19 outputs a printed matter 22 of a color corresponding to the original image of the color original 14 converted based on the RGB signals from the personal computer 16 (see FIG. 14).

Next, the operation of the present embodiment will be described. Note that the flow of a series of processes for color reproduction on a reproduced image according to the present embodiment is the same as that in FIG. 4 described in the above embodiment, and thus the description is omitted.

FIG. 16 shows a preparatory processing routine (step 100 in FIG. 4) of the present embodiment for performing preparatory preparation for color reproduction when forming a reproduced image from an original image. In step 160, a sample signal corresponding to each color Vc _j of the color chart is generated as follows.

First, the sample data 22 is generated by independently changing the image data R, G, and B as inputs of the color output device 19 from 0 to the maximum value. The brightness Y (tristimulus value) of the generated sample print is measured, and the relationship between each color R, G, B and the brightness Y is obtained. That is, the size of the image data R is gradually increased from 0, and is sequentially input to the color output device 19, and the color output device 19 outputs a printed matter 22 having a color corresponding to the input image data R. The output printed matter 22 is measured with a spectrophotometer or other spectrophotometer to determine the tristimulus value Y of the color brightness of the printed matter formed corresponding to each image data R. Thereby, tristimulus values for each of the image data R are obtained.
FIG. 15A shows a characteristic 32 representing the relationship between the image data R and the tristimulus value Y of the brightness of the color of the printed matter to be formed, and FIG. FIG. 15 (3) shows the relationship between the image data B and the tristimulus value Y of the brightness of the color of the printed matter to be formed. Is shown.

Next, using the obtained characteristic 32, the brightness
Is divided by a predetermined number. Note that this
According to the experiment of the present inventor, the number of divisions is about 5 divisions.
Results have been obtained. The magnitude of each of these divided tristimulus values
Are equivalent, and are equally spaced on the characteristic diagram of FIG.
You. The equal fraction of this tristimulus value Y is calculated in the same manner as in the above embodiment.
(N-1), corresponding to the tristimulus values at the divided boundary
Image data R ₁, R_Two, ..., R_nAnd

Similarly, image data corresponding to the boundary portion is obtained for data G and B other than the image data R (see FIGS. 15 (2) and 15 (3)).

G ₁ , G ₂ ,..., G _n B ₁ , B _{2 ,.}

The combinations of these image data are as follows. The colors generated by the image data of this combination are used as color chips (n), and R, R,
A combination of the G and B image data is referred to as a sample signal C.

[0119] ^{_{C 1 (2) = (R}} 1, G 1, B 1) C 2 (2) = (R 1, G, B 2) · · · C n (2) = (R n, G n, B _n )

The sample signal C and the color Vc can be handled as the same physical quantity, as described in the above embodiment. Let these be the colors printed by the sample signal color Vc _i ⁽²⁾ as the color Vc _i ⁽³⁾ .

In the next step 164, this sample signal
Issue color Vc_jAnd the color Vc of the printed matter 22 ⁽³⁾Vs. colorimetric values
Arbitrary color Vc using response⁽³⁾Is the color of the printed matter 22
Color Vc⁽²⁾In the next step 166
As described in the above embodiment, this is a method for solving the inverse problem.
Japanese Patent Application Laid-Open No. 7-50760 filed by the present applicant
Use the color reproduction method described in
The desired color Vc⁽³⁾Input color Vc such that^{(2) *}To
Ask.

Next, as described above, the correspondence between the sample signal and the color of the printed matter, and the input color Vc ^{(2) *} that outputs an arbitrary color Vc ⁽³⁾ could be obtained. So
In step 168, a correspondence between the color of the input signal and the color of the signal to be formed and output on the printed matter is determined. This correspondence is performed for a large number of colors, and this correspondence is stored in the personal computer 16 as a table.

As for the color of the printed matter from the color output device 19 desired by the user, the color based on the input signal is the same as the color Vc ⁽²⁾ , but refer to the table stored in the personal computer 16. Thus, the color Vc ⁽²⁾ by the input signal can be converted into a signal to be reproduced.
Therefore, the image generated by this converted signal is
The color matches the color desired by the user.

Next, the color correction of this embodiment will be described with reference to FIG.
7 (steps 102 and 104 in FIG. 4).

In step 170 of FIG. 6, a table for image data conversion stored in the personal computer 16 in advance is read. In the next step 172, the image data output device 40 is referred to while referring to the read table.
The image data of the original image output from is converted. As a result, each image data is converted into image data to be formed on a printed matter in a color corresponding to the color at the time when it is input to the personal computer 16. Next Step 17
In step 4, the converted image data is output to the color output device 19. As a result, the color output device 19 forms an image on the printed material by performing image formation based on the converted image data, by performing color reproduction that matches the color of the image data output from the image data output device 40.

As described above, in the present embodiment, after the input signal is converted into a color signal (image data) to be formed on a printed matter as a color corresponding to the input signal to the color output device 19. Supplying. Therefore, by the signal from the personal computer 16 storing the table,
In the color output device 19, it is possible to form a printed material in which color reproduction is performed by performing a normal print process, and the color reproduction device desired by the user is high even in a color output device in which it is difficult to change the color reproduction control. Printed matter can be easily formed.

The color output device 18 includes a color hard copy device of a thermal transfer system, an ink jet system, an electrophotographic system, and a silver halide photographic system for outputting a color reproduction image using RGB color system color data as input values. .

The above embodiment is preferably applied to a color printing apparatus. That is, in recent years, in the case of an ID card that easily forms a color reproduction image or a photograph such as a speed photograph, the color printing to which the above-described embodiment is applied can be performed more speedily without performing a film development process. It is possible to form a reproduced image of the original image that is reproduced more clearly and in a closer color.

In the above embodiment, an inexpensive TV camera such as an 8 mm video camera can be used as a device for measuring the color of a color original or a printed matter, and a highly accurate and expensive colorimeter is prepared. The color reproducibility can be improved without performing.

Although the embodiments of the present invention have been described above, the present invention is not limited to the colorimetry by the colorimeter, and can be rephrased as follows. First, the color reproduction device determines a relationship between a color information value corresponding to each of a plurality of predetermined colors and a color information value of each output color from the color output device when each of these colors is used as an input color. And a plurality of color information values corresponding to each of a large number of colors including colors other than the input color, based on the plurality of obtained relationships, and from the color output device when each of the multiple colors is used as an input color. Calculating means for obtaining a large number of relations between the color information values of the respective output colors, and the input color to be reproduced based on the many relations between the obtained color information values of the input color and the output color. Calculating means for obtaining a color information value of a provisional input color such that the color information value of the input color matches the color information value of the output color, and the color information value of the input color to be reproduced and the input color to be reproduced Using the color information value of the temporary input color corresponding to It comprises a correcting means for correcting the input color information value to be input color or reproduction to be reproduced as input to a color output device.

The present invention can be paraphrased as follows. First, a requirement described in the claims is a condition between a color information value corresponding to a plurality of predetermined colors S and a color information value of an output color when these colors S are input to a color output device. And a color information value of an output color corresponding to an input color when a color other than the color S is input to the color output device, based on a calculation result by the checking means for calculating the relationship in advance. And comparing the difference between the color information value of the output color and the color information value of the input color based on the calculation result of the information value calculation means and the color value of the input color. An information value correction unit that obtains a color information value of a provisional input color that matches the information value.

In this color reproduction apparatus, the color information values corresponding to a plurality of predetermined colors S are determined by the confirmation means in advance.
The relationship between the color information value of the output color when these colors S are input to the color output device is calculated. This color information value includes a value corresponding to a device signal which is an input signal of the color output device,
An intermediate transmission density value for each color, a value representing a component of each of the three primary colors,
There are output values of color components imaged by an imaging device, for example, a color camera, and tristimulus values obtained by colorimetry.
Therefore, it is possible to obtain a correspondence between the color information values corresponding to the plurality of colors S and the color information values of the output color when the reproduced image is obtained from the original image in the color output device.

If it is possible to obtain a correspondence between the color information values corresponding to the plurality of colors S and the color information values of the output color, it is necessary to perform an operation for estimating the color information values of the output colors for colors other than the plurality of colors S. Can be. Therefore, the information value calculation means calculates the color information value of the output color corresponding to the input color when a color other than the color S is input to the color output device based on the calculation result by the check means. The calculation of this color information value is described in JP-A-7-507.
The color reproduction method described in Japanese Patent Application Laid-Open No. 60-260 may be employed.

The information value correcting means compares the difference between the color information value of the output color and the color information value of the input color based on the calculation result of the information value calculating means, and sets the color information value of the output color to that of the input color. A color information value of a provisional input color that matches the color information value is obtained.

As described above, the color information value of the provisional input color for matching the output color to the input color is obtained, and if the color information value of the provisional input color corresponding to the input color is determined, the color output device If the color information value of the tentative input color corresponding to the input color is used when the color information value of the input color is input to the color output device, the input color matches the output color in this color output device. It should be noted that a correction value based on the color information value of the original image can be used so that the reproduced image has a color that substantially matches the original image.

Therefore, if the original image of the color to be reproduced is formed as it is by the color output device, the reproduced color of the reproduced image changes from the color of the original image. In the present invention, however, the input color of the original image to be reproduced is changed. The color output device obtains a color information value of a provisional input color to be reproduced as an output color by the color output device, and inputs the color information value of the provisional input color to the color output device. Reproducibility is obtained.

According to such a color reproducing apparatus, the color information value of the input color is converted into the color information value based on the relationship between the color information value corresponding to the plurality of colors S and the color information value of the output color by the confirmation means in advance. The relationship between the color information values of the output color when input to the output device is obtained, and the color information value of the tentative input color such that the color information value of the output color matches the color information value of the input color is obtained by the information value correction means. Since the color information value of the temporary input color corresponding to the input color is used when the color information value of the input color is input to the color output device, There is an effect that it is possible to provide a color reproduction device that can match colors and form a reproduced image that is faithful to the original image.

The checking means determines the plurality of correspondences between the color Vc _j of the color chart and the colorimetric values of the color Vc ⁽³⁾ of the printed matter 22 in the above-described embodiment.
0 corresponds to the process.

The information value calculating means calculates an arbitrary color of the print 22 in order to calculate a color information value of an output color corresponding to an input color when a color other than the predetermined color is input to the color output device. This corresponds to the processing of steps 112 and 114 in FIG. 5 for obtaining the color transmitted through the wavelength filter 20.

Further, the information value correcting means converts the color of an arbitrary original image into a color in order to obtain a color information value of a provisional input color such that the color information value of the output color matches the color information value of the input color. This corresponds to the process of step 116 in FIG. 5 for correcting the transmission color to match the color output from the output device.

[0141]

As described above, according to the present invention, the color information value of the output color is calculated by the calculating means based on the correspondence between the input color and the output color in the color output device previously determined by the calculating means. The color information value of the provisional input color that matches the color information value is obtained, and the input means or the color information value of the input color is corrected by the correction unit, so that the input color matches the output color by the color output device. Thus, there is an effect that it is possible to provide a color reproduction device that performs color reproduction.

[Brief description of the drawings]

FIG. 1 is an image diagram illustrating a schematic configuration of a color reproduction device according to a first embodiment.

FIG. 2 is a block diagram showing a flow until a printed matter is formed from a document only by a color output device.

FIG. 3 is a block diagram illustrating a flow until a printed matter is formed from a document in the color reproduction device according to the first embodiment.

FIG. 4 is a flowchart illustrating a processing flow in the color reproduction device according to the first embodiment.

FIG. 5 is a flowchart illustrating a flow of a preparatory process according to the first embodiment.

FIG. 6 is a flowchart illustrating a flow of an original image correction process according to the first embodiment.

FIG. 7 is a characteristic diagram illustrating a relationship between color data and brightness.

FIG. 8 is an image diagram for explaining a plurality of wavelength filters and transmitted light according to the second embodiment.

FIG. 9 is an image diagram for explaining transmitted light when a plurality of wavelength filters of the second embodiment are overlaid.

FIG. 10 is a flowchart illustrating a flow of a preparatory process according to the second embodiment.

FIG. 11 is a flowchart illustrating a flow of an original image correction process according to the second embodiment.

FIG. 12 is an image diagram illustrating a schematic configuration of a color reproduction device according to a third embodiment.

FIG. 13 is a block diagram illustrating a flow until a printed material is formed from a document only by the color output device according to the third embodiment.

FIG. 14 is a block diagram showing a flow until a printed matter is formed from a document in the color reproduction device according to the third embodiment.

FIG. 15 is a characteristic diagram illustrating a relationship between image data and brightness.

FIG. 16 is a flowchart illustrating a flow of a preparatory process according to the third embodiment.

FIG. 17 is a flowchart illustrating a flow of an original image correction process according to the third embodiment.

[Explanation of symbols]

 Reference Signs List 10 color reproduction device 12 TV camera 16 personal computer 18 color output device 20 wavelength filter

Continuation of the front page (56) References JP-A-6-169391 (JP, A) JP-A-7-50760 (JP, A) JP-A-63-254438 (JP, A) JP-A-6-152941 (JP, A) , A) (58) Fields studied (Int. Cl. ⁷ , DB name) G01J 3/00-3/52 G03F 3/08

Claims (7)

(57) [Claims] 1. Color information corresponding to a photometric amount at the time of photometry.
Using a colorimetric device capable of obtaining a value, a color information value of each of a plurality of predetermined colors and a color information value of each output color from a color output device when each of these colors is used as an input color. Are obtained, the input color is included , and the input color is included.
Exceeding the predetermined multiple colors by including colors other than
The relationship between the color information value corresponding to each of the multiple colors and the color information value of each output color from the color output device when each of the multiple colors is used as the input color is represented by the plurality of colors. about
Based on the relationship between the color information value of the input color and the color information value of the output color
Then, the color information values of the adjacent output colors are equally divided by a predetermined number.
Calculating means for obtaining a color information value of the input color corresponding to the color information value, thereby obtaining a correspondence between the input color and the output color in the color output device; andreproducing based on the correspondence obtained by the calculation means. Calculating means for obtaining a color information value of a provisional input color such that the color information value of the input color matches the color information value of the output color for the input color to be reproduced; The input color to be reproduced or the input to be reproduced so that the temporary input color is input to the color output device as the input color to be reproduced by using the color information value of the temporary input color corresponding to the input color to be reproduced. A color reproduction device comprising: a correction unit configured to correct a color information value of a color. 2. The color output device includes a scanner that scans and measures an input color, and the correction unit is provided on a scanning side of the scanner and has a transmittance that can be changed according to an input signal. The input color to be reproduced using the color information value of the input color to be reproduced and the color information value of the temporary input color corresponding to the input color to be reproduced is scanned and measured by the scanner as a temporary input color. 2. A color reproducing apparatus according to claim 1, further comprising: a filter control unit for controlling said filter unit. 3. The color output device includes an information reading device that reads color information values of an input color, and the correction unit is provided on an input side of the information reading device and includes color information of an input color to be reproduced. A color information value of an input color to be reproduced is converted into a color information value of a temporary input color using a value and a color information value of a temporary input color corresponding to the input color to be reproduced. 2. The color reproduction device according to 1. 4. The color reproducing apparatus according to claim 1, wherein the plurality of colors are colors of a plurality of predetermined color patches. 5. The filter means for changing the transmittance uniformly according to an input signal within a predetermined range, and the filter control means comprises a tentative input corresponding to the input designated color. The color reproduction device according to claim 2, wherein a color information value of a color is used. 6. The filter means whose transmittance changes in accordance with an input signal for each minute area, and wherein the filter control means controls the filter means for each minute area. The color reproduction device according to claim 2. 7. The filter means is a wavelength filter having a predetermined spectral transmittance, and the filter control means converts the color information value of a temporary input color controlled by the spectral transmittance of the wavelength filter. The color reproducing device according to claim 2, wherein