JPH0979907A - Color reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a color reproducing device to reproduce a color by making the output and input colors of the device coincident with each other by correcting the input color by finding the correcting value corresponding to an original picture from the correlation between the input color and output color. SOLUTION: A color reproducing device 10 is constituted of a TV camera 12, a wavelength filter 20, a personal computer 16, and a color copying device 18 and calculates in advance the correlation between an arbitrary input color and the output color of the copying device 18 by using the components. Then the device 10 finds the correcting value to each color of the original picture of a colored original 14 the color of which is an object to be reproduced. After finding the correcting values, the device 18 finds the device values of the filter 20 for correcting color corresponding to the correcting values to be substantially given to the device 18 and supplies the device values to the filter 20. Thereafter, the device 18 copies the original picture scanned with a scanner through the filter 20. The device 10 repeats the above-mentioned processes until the original 14 is copied. Therefore, an output color which coincides with an input color can be obtained.

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 that reproduces an output color in a color printing, a television or the like in a color equal to that 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 (color hard copy device, television, etc.) with a general color that forms a reproduced image on paper or a screen from an original image recorded on a color original. This color output device is equipped with a device-specific color conversion device for realizing color reproduction, and uses the color information values input as the original image of the color original or the color information values of the original image obtained by scanning the scanner. A color reproduction device forms a reproduced image on a screen or paper.

However, since a general color output device is intended for an inexpensive and small mass production type, it sacrifices color reproduction accuracy. Therefore, ΔE ^* _ab = 30 (color difference between target color and print color, white The color reproduction ability was poor, such as about 100 (black corresponds to 100). In addition, it is difficult for the user to improve the color reproduction accuracy of such a general color output device.

Recently, for example, in the field of design, for the purpose of color design evaluation, there is an increasing demand for a color reproduction device capable of faithfully reproducing a required color.

As is well known, the color of the original image has chromaticity coordinates expressed by using tristimulus values X, Y, Z of the color by the XYZ color system of the CIE standard, which is an international method of expressing color. If it can be specified as a standard by where it is located in the chromaticity diagram and the spectral distribution I (λ) of reflected light or transmitted light from an object can be measured, the tristimulus values X, Y, Z can be obtained. it can.

In such a color output device that specifies a color by using the tristimulus values, the YM obtained by measuring the color of the original image is obtained.
A color material of a predetermined color (for example, R material, which is used when a color is captured by color information values such as RGB signals corresponding to C color or three primary colors and a reproduced image is formed on a material such as paper, G
(Color material, B material), and the reproduced images are formed and output by mixing the color material data representing the amount of each material and mixing the respective color materials in the amounts according to the color material data.

That is, the color material data obtained by converting the color information values obtained by measuring the original image into the color information values of the XYZ color system and obtaining the converted color information values of the XYZ color system. Ask for. As a result, it is possible to obtain color material data of a color that the original image is to be reproduced as a reproduced image, and a reproduced image with high color reproducibility can be formed.

However, since the conversion between the color information value and the color material data is non-linear in the color formation by the subtractive color mixing method such as the color output device which realizes the color reproduction by the tristimulus value, it is desired. The color information value of the original image must be obtained from the color material data for forming the color reproduction image. Obtaining the color information value of the original image from the color material data for forming a reproduction image of a desired color (solving the so-called inverse problem) requires a huge amount of color information values and color material data. The high-load calculation processing used is required, which is not practical.

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

[0010]

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

The present invention has been made in consideration of the above facts, and an object thereof is to obtain a color reproducing apparatus capable of obtaining an output color that matches an input color.

[0012]

In order to achieve the above object, the color output device of the present invention has a photometric amount and a color information value of 1: 1.
Between the color information value of each color of a predetermined plurality of 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, using the color measurement device corresponding to A plurality of relationships are obtained, and color information values corresponding to each color of multiple colors including colors other than the input color, and color information values of each output color from the color output device when each color of the multiple colors is used as an input color By calculating a large number of relationships between and, based on the correspondence relationship obtained by the calculating means for obtaining the correspondence relationship between the input color and the output color in the color output device, and the calculating means,
For the input color to be reproduced, a calculation means for obtaining the color information value of the temporary input color such that the color information value of the input color and the color information value of the output color match, and the color information value of the input color to be reproduced Using the color information value of the temporary input color corresponding to the input color to be reproduced, the input color to be reproduced or to be reproduced so that the temporary input color is input to the color output device as the input color to be reproduced. A correction unit that corrects the color information value of the input color.

Further, the color output device includes a scanner for scanning and measuring the input color, and the correcting means is arranged on the scanning side of the scanner and has a filter means for changing the transmittance 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. And a filter control unit that controls the filter unit.

Further, the color output device comprises an information reading device for reading the color information value of the input color, and the correction means is arranged on the input side of the information reading device and the color information of 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 by using the value and the color information value of the temporary input color corresponding to the input color to be reproduced.

When forming a reproduced image on paper or a screen from an original image recorded on a color original by a color output device, improving the color reproducibility is to match the input color and the output color in the color output device. It is to let. However, although the conventional color output device forms a reproduced image with a color corresponding to the color of the color original, the output color does not match the input color.

Therefore, in the color reproducing apparatus of the present invention, the correspondence relationship between the input color and the output color in the color output apparatus is obtained in advance by the calculating means. In this correspondence relationship, first, using a color measuring device in which the photometric amount and the color information value have a one-to-one correspondence, the color information value of each of a plurality of predetermined colors and each of these colors are used as input colors. At this time, a plurality of relationships between the color information values of the respective output colors from the color output device are obtained. Along with this, between the color information value corresponding to each color of multiple colors including colors other than the input color and the color information value of each output color from the color output device when each color of the multiple colors is used as an input color. Ask for many relationships. The colorimetric device does not need to be an expensive measuring device that accurately measures the photometric amount, and a colorimetric device that has a good reproducibility in which the measured value monotonously increases as the photometric amount increases is sufficient. For example, a color camera can be used as the color measurement device.
In this way, if 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 color measurement device, the color information values of multiple colors including colors other than the input color are obtained. And the respective color information values of the output colors from the color output device can be obtained. In this way, the correspondence relationship between the input color and the output color in the color output device can be obtained.

The color information value is 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 color component of the three primary colors, and an image pickup device such as a color camera. There are the output value of the color component and the tristimulus value obtained by measuring the color.

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 relationship between the input color and the output color in the color output apparatus, for example, the sample is the entire color output apparatus. It is enough if there are enough numbers to understand the situation.

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

In the calculation means, on the basis of the correspondence relationship obtained by the calculation means, the color information of the tentative input color such that the color information value of the input color and the color information value of the output color match 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 obtained, 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 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 such a 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 described in, for example, Japanese Unexamined Patent Publication No. Heisei 7-96 The color reproduction method described in JP-A-50760 can be adopted.

In this way, if the color information value of the temporary input color for matching the output color with the input color is obtained and the color information value of the temporary input color corresponding to the input color is determined, the color output device If the color information value of the provisional input color corresponding to the input color is used when the color information value of the input color is input to, the input color and the output color match in this color output device. Therefore, the correction 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, and the temporary input color is the above-mentioned 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 the input color to be reproduced is directly output by the color output device, the output color that is output changes from the input color. However, in the present invention, it corresponds to the color information value of the input color to be reproduced, and the color output device Since the output color is output from the color output device by the color based on the color information value of the provisional input color to be reproduced as the output color, extremely high color reproduction accuracy can be obtained.

When the color output device includes a scanner for scanning and measuring the input color, a filter means having a variable transmittance can be used as a means for forming the temporary input color. That is, the correction means is provided on the scanning side of the scanner and the filter means whose transmittance changes according to the input signal, the color information value of the input color to be reproduced and the temporary color 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 structure, the input color that has passed through the filter means 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 reproduction.

Further, when the color output device is provided with an information reading device for reading the color information value of the input color, the correction means is arranged on the input side of the information reading device and the input color to be reproduced. If 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 Good. By doing so, the color information value of the input color is converted into the color information value of the provisional input color and supplied to the color output device, and the output color is output from the color output device with good reproduction.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. In the first embodiment of the present invention, in order to improve color reproduction when a reproduced image is formed from an original image, a color in a scanner input type color output device that reads a color original and forms a reproduced image on paper or the like. The color reproduction apparatus of the present invention is applied to reproduction.

As shown in FIG. 1, the color reproduction apparatus 10 has a T
It is composed of a V camera 12, a wavelength filter 20, a personal computer 16 and a color output device 18. The personal computer 16 has a keyboard for inputting data, commands, etc., a computer main body for arithmetically outputting data for outputting a desired color from the color output device 18 according to a prestored program, and an arithmetic result of the computer main body. It is composed of a CRT that displays the like.

The personal computer 16 is provided with a TV camera 12 which is an image input device for outputting color data (for example, R, G, B output signals) as color information values of the original image of the imaged color original 14. 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 by the light emitted from the light source (not shown) of the scanner 24, and the color conversion device 26 reproduces the color peculiar to the device based on the output signal of the scanner 24. Printing device 2
In 8, the color printing is performed based on the output signal of the color conversion device 26, and the printed matter 22 is obtained.

As the color output device 18, there are a device that exposes the entire surface, 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 exposed surface 18A of the color output device 18, the transmission density of light of a predetermined wavelength can be uniform or can be changed for each pixel (for example, the minimum printing element: pixel) according to the magnitude of the applied voltage. The wavelength filter 20 is installed. 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 through the wavelength filter 20 by the light emitted from a light source (not shown) provided inside the device, performs the color control unique to the device, and prints 22 Is output (see FIG. 3).

FIG. 4 is a processing routine showing a flow of a series of processing for reproducing a desired color in the original image into a reproduced image according to the present embodiment. Although details of each process will be described later, in step 100 of FIG. 4, the original image (color original 1
In order to obtain a reproduced image (printed material 22) having high color reproducibility from 4), the correspondence relationship with the output color of the color output device corresponding to an arbitrary input color 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 color reproduced, using the correspondence obtained in step 100. In the next step 104, the device value of the wavelength filter 20 for color correction substantially corresponding to the correction value to be applied to the color output device 18 is obtained,
Supply this device value. After supplying this device value, in the next step 106, the original image scanned by the scanner 24 via the wavelength filter 20 is printed (copied).
The above steps 102 to 106 are repeatedly executed until the printing of the color original 14 is completed.

To obtain the correspondence with the output color of the color output device corresponding to an arbitrary input color in step 100, the correction value for each color of the original image corresponding to the color of the arbitrary reproduced image is obtained. You may do it. This step 10
The process of obtaining the correspondence between the input color and the output color of the color output device of 0 corresponds to a calculating unit. Also, step 102
Is a process for correcting a color of an arbitrary original image into a transparent color for matching with a color output from a color output device, and a process for correcting the color information value of the output color to match the color information value of the input color. Corresponds to the calculation means for obtaining the color information value of the input color. further,
Step 104 is a process for performing color correction so that a reproduced image whose color matches the original image is substantially obtained from the color output device 18, and corresponds to a correction unit.

In the present embodiment, the color output device 18 reproduces the color of the original image into a reproduced image of a color corresponding to the color of the original image.
The reproduced image of the printed matter 22 is formed from the original image of No. 4. In order to simplify the description below, the notation of colors in each part is as follows.

The color of an image means a color expression object (color original 14
Or printed matter 22) and the like, which are color data (R, G, B) as color information values of each of a plurality of predetermined colors (for example, three primary colors) obtained when the TV camera 12 takes an image,
Indicated as color Vc. As the color Vc, the value of the output signal of the TV camera 12 or the value of the image digital output signal can be used. The color of the original image of the color original 14 is expressed as a color Vc ^(1), and the color of the original image transmitted through the wavelength filter 20 is expressed as a color Vc ⁽²⁾ and the original image transmitted through the wavelength filter 20. A color output device 18 that reproduces a certain color.
The color of the printed matter 22 obtained from the above is referred to as a color Vc ⁽³⁾ (see FIG. 3).

Next, details of step 100 in FIG. 4 will be described. The processing of step 100 is to execute the preparatory processing 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 the reproduced image is prepared as follows. In order to simplify the description, the color output device 18 prints a printed matter 22 by printing with four color inks of Ye, Mg, Cy, and K (yellow, magenta, cyan, and black), for example.
Shall be formed. This printed matter 22 is the scanner 2
The density of each color Ye, Mg, Cy, K changes according to the color data (internal device value, eg, voltage value) of each color of Ye, Mg, Cy, K corresponding to the output signal from 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, yellow Y whose size gradually increases from 0
By inputting the color data D _{Y of} e as the output signal of the scanner 24 in order to the color output device 18, the color output device 1
The printed matter 22 on which the reproduced image of the color corresponding to the color data D _Y inputted from 8 is formed is output. Next, this printed matter 22 is subjected to color measurement with a spectrophotometer or other spectrophotometer to obtain tristimulus values Y _Y of the color brightness of the printed matter formed corresponding to each color data D _Y. Accordingly, the tristimulus value Y _Y for each color data D _Y is obtained. In FIG. 7, color data D _Y and
The characteristic 30 showing the relationship between the color luminosity of the formed printed matter and the tristimulus value Y _Y is shown.

Next, the obtained characteristic 30 is used to divide the magnitude of the brightness tristimulus value Y _Y into a predetermined number. The size of each of these divided tristimulus values is equivalent,
On the characteristic diagram of FIG. 7, the intervals are equal. Let (n-1) equal parts of these tristimulus values Y _Y , and color data D _Y corresponding to the tristimulus values of the divided boundary portion be D _Y0 , D _Y1 ,.
_Yn-1 .

Similarly, for magenta Mg, cyan Cy and black K other than the above 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 to obtain color data corresponding to the tristimulus values of the divided boundary portion.

In the present embodiment, as an example, when n = 5, 4
When divided, D _Yi, D _Mi, D _{Ci ,} D _Ki (i = 0,
1, ..., 4) colors formed by the combination of all colors,
That is, 5 ⁴ colors are assumed. 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} =
1, 2, ..., 5 ⁴ ) is the color of the color chart Vc
_j (= (R _j, G _j, B _j )). In this way, n color chips are prepared.

A plurality of corresponding relationships between the color Vc _{j of} this color chart and the colorimetric value of the color Vc ⁽³⁾ of the printed matter 22 are obtained in advance and stored as a table or stored as a function and calculated. You can ask for it.

Next, at step 112 in FIG. 5, the color of the color patch (color Vc _j ) is passed through the wavelength filter 20 and printed on the color output device 18 to measure the color of the printed matter 22. Using the plurality of correspondence relationships between the color data of the color Vc _j of the color chart and the colorimetric value of the color Vc ⁽³⁾ of the printed matter 22, the following step 11 is performed.
In 4, the color Vc ⁽²⁾ transmitted through the wavelength filter 20 is obtained such that the arbitrary color Vc ⁽³⁾ is the color of the printed matter 22.

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

More specifically, since the number of color charts is n, the color Vc _j of the n color charts is set as the color Vc _j ^{(2 ),} and this is not passed through the wavelength filter 20 and the color output device 18 is used. Scanner 24
The color placed on the surface and printed as it is is referred to as color Vc _j ⁽³⁾ .
An input color Vc that outputs an arbitrary color Vc ⁽³⁾ by a well-known inverse problem solving method 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 already filed by the present applicant. With this color reproduction method,
The relative relationship between a predetermined number of input values (each value of R, G, B) and the tristimulus value of the output color is obtained, and the output color represented by any tristimulus value X, Y, Z is obtained. Since the closest input value can be obtained by interpolation processing, it is possible to obtain the input color Vc ⁽²⁾ that outputs an arbitrary color Vc ⁽³⁾ 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 transmitted 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 changed to the transmitted color Vc ^{(2) *.}
The voltage value Vv of the wavelength filter 20 for the correction is estimated.

This step 116 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, and the color information value of the output color is the color information value of the input color. Is a process of obtaining a color information value of a temporary input color that matches .

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

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 expression (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 : Value that represents the B color component of the applied voltage

One color of the color chart Vc _j ⁽¹⁾ (j = 1, 2, ...
.., n) changes 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 that represent the components of the applied voltage for each color correspond to 0, 1, 2, ..., N _V (the maximum value that represents the color component) that is an integer value. Then, the applied voltage Vv is
There are a large number (m in this embodiment), which can be expressed by the following equation (2).

M = (n _V +1) ³ (2)

At this time, the applied voltage Vv _k (k = 1, 2, ...) Is input with the color Vc _j ⁽¹⁾ (j = 1, 2, ... N) of the original image corresponding to the color of the color chart. .., m) is applied, the transmitted color Vc is the color transmitted through the wavelength filter 20.
_{Suppose jk} ⁽²⁾ supports it. Therefore, the sum of the correspondence between the original image color Vc _j ⁽¹⁾ and the transparent color Vc _jk ^{(2 )} corresponding to the colors of all the color _charts is m × n. The applied voltage Vv _jk for obtaining the transmission color Vc _jk ⁽²⁾ from the color Vc _j ^{(1 ) of} the original image 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 transparent color Vc _jk ⁽²⁾
Since there are m × n correspondences of the applied voltage Vv _jk for obtaining, the known inverse problem is solved by using this m × n correspondences from any color Vc ⁽¹⁾ to any transmission. Color Vc
The applied voltage Vv for obtaining ⁽²⁾ can be obtained.
A method for solving this inverse problem can be realized by applying the color reproduction method described in Japanese Patent Application Laid-Open No. 7-50760 already filed by the present applicant. That is, the relative relationship between the input value and the tristimulus value in this color reproduction method is replaced with the correspondence between the color Vc _j ⁽¹⁾ and the transmitted color Vc _jk ^(2), and the tristimulus value is replaced with the applied voltage to perform interpolation processing. Thus, the applied voltage Vv for obtaining the arbitrary transmitted color Vc ⁽²⁾ from the arbitrary color Vc ⁽¹⁾ can be obtained.

Thus, 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 is the color V of the original image.
Transmission color Vc to the color output device 18 that matches c ^(1)
(2) is 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.

Details of steps 102 and 104 in FIG. 4 will be described below with reference to FIG. In the following description, the applied voltage Vv of the wavelength filter 20 when the colors of the n color charts Vc _j are reproduced on the printed matter 22 (Vc ⁽³⁾ = Vc _j ), will be referred to as the applied voltage Vv _j ^* . To do.

The color correction of the original image using the wavelength filter 20 depends on the characteristics of the wavelength filter 20.
That is, the wavelength filter 20 includes one that can change the spectral transmittance only uniformly as a whole, and one that 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 is previously set.
The characteristic information indicating the characteristic of the wavelength filter 20 that is in close contact with the optical filter 8 is stored in the personal computer 16 in advance. Note that this characteristic information may be determined by inputting with a keyboard.

In step 120 of FIG. 6, the characteristic information of the wavelength filter 20 is read to determine whether the wavelength filter 20 can change the spectral transmittance for each minute region (pixel). If a negative determination is made that the closely attached wavelength filter 20 cannot change the spectral transmittance for each minute region, the process proceeds to step 122 to shift to processing for correcting the original image with the same filter color, and if a positive determination is made. Proceeds to step 128.

In the case of forming a reproduced image in which colors are reproduced, if the original image is corrected with the same filter color, not all the colors of the original image are reproduced, but at least the main colors defined by the user are corrected. By performing color reproduction by using the color reproduction, it is possible to form a reproduced image that is almost intended by the user.

Therefore, in step 122, of the colors of the original image, the color for which color reproduction is important is determined. For this determination, a predetermined color may be read, or a color input by the user may be used. Further, the color input by the user is directly performed by the value of the color Vc _S (or the TV camera 1).
2 signal) may be input, and the TV camera 12
The value included in the extracted color Vc _S may be input by extracting the color included in the area designated by the user from the original image captured by. In the next step 124, it is assumed that the color reproduction of the specific color Vc _S (or the color near the color Vc _S ) determined among the colors of the original image is important.
To change the color (spectral transmittance) of the wavelength filter 20 so that the color reproducibility of the color Vc _S (or a color near the color Vc _S ) is improved (Vc ⁽³⁾ = Vc _S ). Applied voltage Vv
^Ask for _S ^* . That is, from the correspondence relationship between the arbitrary color obtained in the above processing (FIG. 5) and the applied voltage, the color Vc _{S is changed} to the color Vc ^{( 1)}
, The applied voltage Vv _S ^{* at} which the color Vc ⁽³⁾ of the reproduced image matches the main color Vc _{S of the} original image is obtained.
The above processing corresponds to the correction value calculation processing of the original image in step 102 of FIG.

The next step 126 is step 1 of FIG.
This is equivalent to the correction processing of the original image No. 04.
Calculated applied voltage Vv_S ^*Are supplied to the color output device 18. Obedience
Therefore, the applied voltage Vv is applied to the wavelength filter 20._S ^*Supply
If a reproduced image is formed by the color output device 18 from the
106), at least the main color Vc of the original image _SAgainst
As a result, accurate color reproduction is achieved.

In the above description, one main color is one
As explained above, if multiple colors are determined to be the main colors,
It is also possible. That is, of the colors of the original image, p features
Fixed color (Vc_S1, Vc_S2, ..., Vc_Sp) Color reproducibility
Is determined to be important, for each color
And a weighting factor h that is predetermined or specified by the user
_h(H₁+ H₂+ ... + h_p= 1, h_h≧ 0),
Calculate the applied voltage for the major colors as shown in the following equation.
You should do it.

[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 the processing in the case where the affirmative determination is made in step 120 of FIG. 6 and the wavelength filter 20 corrects by the change of the color (spectral transmittance) of each pixel corresponding to the color of each pixel of the original image. To do. With the wavelength filter 20 capable of changing the color (spectral transmittance) of each pixel having a minute size, the original image can be corrected by the filter color of each pixel to reproduce the color. Therefore, at least for each pixel, a reproduced image almost intended by the user can be obtained. 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. This extraction can use the signal of each area corresponding to the pixel size of the wavelength filter 20 in the original image captured by the TV camera 12. 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
To improve the color reproducibility of neighboring colors (Vc ⁽³⁾ = V
c _S and such that), in the same manner as in the above process (step 124), determining the applied voltage Vv _S ^* for changing the color of the wavelength filter 20 (spectral transmittance). As a result, the color Vc ⁽³⁾ of the reproduced image and the main color V of the original image
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 of FIG.

The next step 132 is step 1 of FIG.
This is equivalent to the correction processing of the original image 04, and each applied voltage Vv _S ^* obtained above is supplied to the wavelength filter 20 in correspondence with the position of the pixel of the wavelength filter 20. Therefore, if a reproduced image is formed by the color output device 18 while supplying the applied voltage Vv _S ^* to the wavelength filter 20 (step 106 in FIG. 4), the main color Vc _S of the original image for each pixel is
Accurate color reproduction.

Next, a second embodiment will be described. In the first embodiment, the original image is color-corrected by using the wavelength filter whose spectral transmittance can be changed, but in the second embodiment, the original image is color-corrected by using the wavelength filter having a predetermined predetermined spectral transmittance. The present invention is applied to color correction and color reproduction.
Since the present embodiment has the same configuration as that of the above-mentioned embodiment, the same reference numerals are given to the same portions and detailed description thereof will be omitted. In addition, the color output device according to the present embodiment is provided with the scanner 24
It is assumed that the color value measured by means of the color correction can be performed by the parameter based on the correction signal.

First, the principle of enabling color correction by 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. The wavelength filters 20 _{1 to} 20 _q have the same thickness l, and their respective spectral transmittances are 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
The wavelength filter becomes colorless and transparent. _uWhen = 1, the next
The spectral transmittance is represented by the equation (6).

[0073]

(Equation 3)

Here, with a _u = 1 for each wavelength filter, the emitted light when light of intensity I ⁽⁰⁾ (λ) is incident is superposed on the incident light due to the influence of the transmittance of each wavelength filter. It becomes the emitted light (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)

Therefore, the tristimulus values Ex _u (= X _u , Y _u ,
Z _u ) can be expressed by the following equation (8).

[0077]

(Equation 5)

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

[0079]

(Equation 6)

Here, the intensity I of the transmitted light when q wavelength filters are overlapped and light of intensity I ⁽⁰⁾ (λ) is incident
(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)

Therefore, the tristimulus value Ex is calculated by the following determinant, (1
It can be expressed by the formula 2).

[0085]

[Equation 9]

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) are represented by the following equations (14) and (15). Can be represented.

[0087]

(Equation 10)

Ex _u = R _u · Δλ · M · EL _u (14) Ex = R · Δλ · M · EL (15) If the transposed matrix M ^t of the matrix M is used, Of (16)
Expression can be expressed by Expression (17).

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 matrix operations on the right side of the equations (16) and (17) are performed, the following equations (18) and (19) are obtained.

[0091]

[Equation 11]

Therefore, the wavelength coefficient τ regarding 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)
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)} (
The tristimulus value of the transmitted light when the light of λ) is incident is (X,
Parameter a for each wavelength filter such as Y, Z)
It is possible to obtain ₁ , a ₂ , ..., A _q .

Next, the operation of this embodiment will be described. Note that the flow of a series of processes for performing color reproduction on a reproduced image according to the present embodiment is the same as that shown in FIG. 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 through the color output device 18 after passing through, and the color of the printed matter 22 is measured.
That is, the wavelength filters 20 _{1 to} 20 _q are connected to the exposure surface 18A.
The color of the printed matter 22 of each color patch when it is not placed is measured (step 112). The color Vc _{j of} this color chart and the printed matter 22
Color Vc ⁽³⁾ using the correspondence with the colorimetric value
A color Vc ⁽²⁾ is obtained such that c ⁽³⁾ is 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 already filed by the applicant, which is a method for solving the inverse problem, from a plurality of correspondence relationships, An input color Vc ^{(2) *} that outputs 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 ^* Then, in the next step 142, the tristimulus value Ex _j of the color Vc _j of each color chart is calculated by a known color conversion method for converting RGB values into XYZ values. In the next step 144, the color Vc _j of each color patch is incident as a parameter a _u = 1 for each of the _q wavelength filters 20 _{1 to} 20 _q , and the transmitted color Vc _ju ⁽²⁾ of the transmitted light at this time is measured. Color and determine the tristimulus value Ex _ju .
In the next step 146, the color output device 1 above the scanner is
The number of wavelength filters 20 _{1 to} 20 _{q on} the exposed surface 18A of 8
When the light of the color Vc _j of each color patch is made to overlap, the parameter Ea _j is obtained by the above principle so that the transmitted light of the transmitted color Vc ^{(2) *} becomes Vc ⁽³⁾ = Vc ^(1). Ask as described. In the next step 148, a parameter for the color Vc ⁽¹⁾ of the arbitrary original image is formed from the obtained plurality of correspondences so as to form a color-reproduced 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 exposed surface 18A of each of the wavelength filters 20 _{1 to} 20 _q ,
And all are in close contact, and the original image is placed on top of it. When an arbitrary color of the original image is 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 is supplied to the color output device 18. As a result, the color Vc ⁽¹⁾ of the original image is corrected to the transparent color Vc ^{(2) *} and is interpreted by the color output device 18, so that a reproduced image in which the color is reproduced that matches the color of the original image is formed. You can

Therefore, the color Vc_j ⁽¹⁾To transparent color Vc_jk ⁽²⁾
There are many correspondences of the parameter Ea for obtaining
Using this correspondence, a well-known inverse problem
, Any color Vc⁽¹⁾To any transmission color Vc⁽²⁾Got
The correspondence of the parameter Ea for this
As a method for solving the inverse problem, the applicant has already applied for a special feature.
The color reproduction method described in Kaihei 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 _j ⁽¹⁾And transparent
Color Vc_jk ⁽²⁾And change the tristimulus value to
Data (parameters that can be written in vector format)
Any color Vc⁽¹⁾To any transmission color Vc
⁽²⁾The parameter Ea for obtaining
You.

Thus, by obtaining the parameter Ea, when the color Vc ⁽¹⁾ is given, the color output device 1
In order to make the color Vc ⁽³⁾ of the printed matter 22 output from 8 match the color Vc ^{( 1)} of the original image, the parameter for making the transparent color Vc ⁽²⁾ interpreted by the color output device 18 is set in advance. You can ask.

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

In step 150 of FIG. 11, the color of which the color reproduction is important among the colors of the original image is determined in the same manner as in the above embodiment. In the next step 152, the color reproduction of the specific color Vc _S (or the color near the color Vc _S ) determined among the colors of the original image is important, and the color Vc _S (or the color near the color Vc _S is regarded as important. ) Is improved (Vc ⁽³⁾ = Vc _S
The color of the wavelength filter 20 (spectral transmittance)
A parameter Ea for changing is calculated. That is,
When the color Vc _S is supplied as the color Vc ⁽¹⁾ from the correspondence between the arbitrary color and the parameter obtained in the above processing (FIG. 10), the color Vc ⁽³⁾ of the reproduced image and the main color Vc of the original image are obtained. A parameter Ea _S for matching with _S is obtained. The above processing corresponds to the correction value calculation processing of the original image in step 102 of FIG.

When there are a plurality of important colors, the above
It can be obtained by weighting as in the embodiment.
That is, p specific colors (Vc_S1,
Vc _S2, ..., Vc_Sp) Color reproducibility is important
When it is set, for each color
Is the weighting factor h specified by the user_h(H₁+ H₂+ ...
・ + H_p= 1, h_h≥ 0) is attached to the main multiple colors
It is only necessary to determine the total parameters to be used. First, the user
Multiple important colors Vc specified by_S1~ Vc_SpTo each of
Parameter Ea_hAsk for. Calculated parameter
Ea_hFor the final pattern, using the following equation (24),
Calculate the parameter Ea.

[0105]

[Equation 14]

The next step 156 is step 1 in FIG.
This corresponds to the correction processing of the original image 04, and supplies the parameter Ea _S obtained above to the color output device 18.
Therefore, if a reproduced image is formed by the color output device 18 by the signal obtained by converting the light transmitted through the wavelength filters 20 _{1 to} 20 _q (step 106 in FIG. 4), at least for the main color Vc _{S of the} original image. Therefore, accurate color reproduction is achieved.

In the above description, the tristimulus values (X, Y,
Z) is used, but the tristimulus values (X, Y, Z) and the input signals (R, G, B) from a handheld input device (8 mm video camera or digital still camera) have a one-to-one relationship. Since mutual conversion is possible by a method such as Japanese Patent Laid-Open No. 7-50760, for example, it is not possible to calculate tristimulus values (X, Y, Z) from input signals (R, G, B) of a handheld input device. It's easy.

As described above, in the above-described embodiment, the wavelength original is placed on the color output device and the spectral transmittance of the wavelength filter is controlled, whereby the color original is reproduced as a printed matter on the color output device. It provides the light so that it has the right color. Therefore, the color output device 19 can form a color-reproduced printed matter by performing a normal printing process with a color-converted color original due to a change in spectral transmittance caused by a signal from the personal computer 16. Even with a color output device in which it is difficult to change the reproduction control, it is possible to easily form a printed matter with high color reproducibility desired by the user.

Next, a third embodiment will be described. In the first embodiment and the second embodiment, the case where the color image is reproduced from the original image in the scanner input type color output device to form the reproduced image has been described. However, the present embodiment describes an image scanning device such as a scanner. The present invention is applied to the case where color reproduction is performed in 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. Since the present embodiment has the same configuration as that of the above-mentioned embodiment, the same reference numerals are given to the same portions and detailed description thereof will be omitted.

As shown in FIG. 12, the color reproducing apparatus 10 is
Image data output device 4 for outputting image data of original image
0, a personal computer 16, a TV camera 12, and a color output device 19. Image data output device 4
0 is for outputting the image data of the original image including the color such as color design and CAD, and is configured 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.
The TV camera 12, which is an image input device for outputting the color data (for example, R, G, B output signals) of the original image, is connected.

In this embodiment, the image data output device 4
The color data (RG
The B signal or tristimulus value XYZ) is input to the personal computer 16, and the personal computer 16 outputs a color-reproduced RGB signal 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 this embodiment will be described. Note that the flow of a series of processes for performing color reproduction on a reproduced image according to the present embodiment is the same as that shown in FIG.

FIG. 16 shows a preparatory process routine (step 100 in FIG. 4) of the present embodiment, which performs preparatory steps for color reproduction when a reproduced image is formed 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 prints 22 are generated by independently changing the image data R, G, and B, which are inputs to the color output device 19, from 0 to the maximum value. The brightness Y (tristimulus value) of the generated sample printed matter 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 input to the color output device 19 in order, and the printed matter 22 in which the color corresponding to the image data R input in the color output device 19 is formed is output. The output printed matter 22 is subjected to color measurement by a spectrophotometer or other spectrophotometer to obtain the tristimulus value Y of the color brightness of the printed matter formed corresponding to each image data R. As a result, tristimulus values for each of the image data R are obtained.
FIG. 15 (1) shows a characteristic 32 representing the relationship between the image data R and the tristimulus value Y of the color brightness of the printed matter to be formed, and FIG. 15 (2) shows the image data G and the characteristic 32. FIG. 15C shows the characteristic 34 representing the relationship between the color brightness tristimulus value Y of the printed matter and the relationship between the image data B and the color brightness tristimulus value Y of the printed matter to be formed. Characteristic 36 representing

Next, using the obtained characteristic 32, the brightness is
The size of the tristimulus value Y is divided by a predetermined number. Note that this
As for the number of divisions, about 5 divisions are sufficient according to the experiments of the present inventors.
With good results. The size of each divided tristimulus value
Are equivalent and are not evenly spaced on the characteristic diagram of FIG.
You. This tristimulus value Y is divided into equal parts as in the above embodiment.
(N-1), corresponding to the tristimulus values of the divided boundary
Image data R ₁, R₂・ ・ ・ ・ ・ ・ R_nAnd

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

G ₁ , G ₂ , ..., G _n B ₁ , B ₂ , ..., B _n

The combination of each of these image data is as follows, and the colors generated by the image data composed of this combination are color chips (n pieces), and R,
A combination of G and B image data is called a sample signal C.

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 treated as the same physical quantity, as described in the above embodiment. A color printed by the color Vc _i ⁽²⁾ of the sample signal is referred to as a color Vc _i ⁽³⁾ .

At the next step 164, the sample signal
Issue color Vc_jAnd the color Vc of the printed matter 22 ⁽³⁾Pair with the colorimetric value of
Any color Vc using correspondence⁽³⁾Be the color of the printed matter 22
Color Vc⁽²⁾The next step 166
As described in the above embodiment, it is a method for solving the inverse problem.
Japanese Patent Application Laid-Open No. 7-50760 already filed by the present applicant
By using the color reproduction method described in,
Color of intention Vc⁽³⁾Input color Vc that outputs as^{(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) *} which outputs the arbitrary color Vc ⁽³⁾ could be obtained. So
In step 168, the correspondence between the color of the signal input and the color of the signal which should be formed on the printed matter and output should be obtained. This correspondence is performed for many colors, and this many correspondences are stored in the personal computer 16 as a table.

The color of the printed matter from the color output device 19 desired by the user is the same as the color Vc ⁽²⁾ according to the input signal, but refer to the table stored in the personal computer 16. Thus, the color Vc ⁽²⁾ due to the input signal can be converted into a signal to be color-reproduced.
Therefore, the image produced by this transformed 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.
This will be described with reference to FIG. 7 (steps 102 and 104 in FIG. 4).

In step 170 of FIG. 6, the table for image data conversion stored in advance in the personal computer 16 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 in which a color matching the color at the time of being input to the personal computer 16 is to be formed on the printed matter. Next step 17
In 4, the converted image data is output to the color output device 19. As a result, the color output device 19 forms an image based on the converted image data to form a reproduced image on the printed material in which the color is reproduced and matches the color of the image data output by the image data output device 40.

As described above, in the present embodiment, after the input signal to the color output device 19 is converted into the signal (image data) of the color to be formed on the printed matter as the color corresponding to the input signal. We are supplying. Therefore, by the signal from the personal computer 16 which stores the table,
The color output device 19 can form a color-reproduced printed matter by performing a normal printing process, and the color reproducibility desired by the user is high even if the color output device is difficult to change the color reproduction control. A 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 salt photographic system, which outputs a color reproduction image by inputting color data of RGB color system. .

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

Further, in the above embodiment, a TV camera such as an inexpensive 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

Although the embodiments of the present invention have been described above, the present invention is not limited to the color measurement by the color measurement device, and can be put in other words as follows. First, the color reproduction device has 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. Based on the obtained plurality of relations, the color information value corresponding to each color of the multiple colors including the color other than the input color, and the color output device when each color of the multiple colors is set as the input color. Of the input color to be reproduced based on the calculated relationship between the color information value of each output color and a large number of relationships between the color information value of the input color and the color information value of the output color For the color information value of the input color and the color information value of the output color, the calculation means for obtaining the color information value of the provisional input color, the color information value of the input color to be reproduced, and the input color to be reproduced By 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 restated as follows. First, the requirements described in the claims are between the color information values corresponding to a plurality of predetermined colors S and the color information values of the output colors when these colors S are input to the color output device. And a 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 confirmation unit and the calculation result by the confirmation unit. The difference between the color information value of the output color and the color information value of the input color is compared based on the calculation result of the information value calculation means and the information value calculation means, and the color information value of the output color is the color 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 reproducing apparatus, the color information values corresponding to a plurality of colors S determined in advance by the confirmation means,
The relationship between these colors S and the color information values of the output colors when input to the color output device is calculated. This color information value is a value corresponding to the device signal that is the input signal of the color output device,
Intermediate transmission density value for each color, value representing the components of each of the three primary colors,
There are output values of color components picked up by an image pickup apparatus such as a color camera, and tristimulus values obtained by colorimetry.
Therefore, it is possible to obtain the correspondence between the color information value corresponding to the plurality of colors S and the color information value of the output color when the reproduced image is obtained from the original image in the color output device.

If the correspondence between the color information value corresponding to the plurality of colors S and the color information value of the output color can be obtained, the calculation for estimating the color information value of the output color for the colors other than the plurality of colors S can be performed. You can Therefore, the information value calculation means calculates the color information value of the output color corresponding to the input color when the color other than the color S is input to the color output device based on the calculation result by the confirmation means. The calculation of this color information value is described in JP-A-7-507.
The color reproduction method described in JP-A-60 can be adopted.

The information value correction means compares the difference between the color information value of the output color and the color information value of the input color on the basis of the calculation result of the information value calculation means, and the color information value of the output color corresponds to the input color. A color information value of a temporary input color that matches the color information value is obtained.

In this way, if the color information value of the temporary input color for matching the output color with the input color is obtained and the color information value of the temporary input color corresponding to the input color is determined, the color output device If the color information value of the provisional input color corresponding to the input color is used when the color information value of the input color is input to, the input color and the output color match in this color output device. It should be noted that a correction value from the color information value of the original image so that the reproduced image has a tint that substantially matches the original image can be used.

Therefore, when the original image of the color to be reproduced is formed by the color output device as it is, the reproduced color of the reproduced image changes from the color of the original image, but in the present invention, the input color of the original image to be reproduced is changed. Corresponding to the color information value, the color information value of the provisional input color to be reproduced as an output color by the color output device is obtained, and the color information value of this provisional input color is input to the color output device. Reproducibility is obtained.

According to such a color reproducing apparatus, the color information value of the input color is calculated 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 colors when input to the output device is obtained, and the color information value of the temporary 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 input color is input to the color output device, if the color information value of the provisional input color corresponding to the input color is used There is an effect that it is possible to provide a color reproduction device that can match colors and can form a reproduced image that is faithful to the original image.

The above-mentioned confirming means obtains a plurality of correspondences between the color Vc _j of the color chart and the colorimetric value of the color Vc ⁽³⁾ of the printed matter 22 in the above-mentioned embodiment, and step 11 in FIG.
This corresponds to the processing of 0.

In addition, the information value calculating means calculates an arbitrary color of the printed matter 22 in order to calculate the color information value of the output color corresponding to the input color when the color other than the predetermined color is input to the color output device. 5 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 correction means uses the color of any original image to obtain the color information value of the temporary 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 processing in step 116 of FIG. 5 for correcting the transparent 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 from the input color by the calculating means from the correspondence relationship between the input color and the output color in the color output device obtained in advance by the calculating means. Since the color information value of the provisional input color that matches the color information value is obtained and the correction means corrects the input color or the color information value of the input color, the color output device matches the input color with the output color. There is an effect that it is possible to provide a color reproduction device capable of performing color reproduction.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing a flow of forming a printed matter from a document only with a color output device.

FIG. 3 is a block diagram showing a flow from a document to a printed material in the color reproduction apparatus according to the first embodiment.

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

FIG. 5 is a flowchart showing a flow of pre-preparation processing according to the first embodiment.

FIG. 6 is a flowchart showing a flow of original image correction processing according to the first embodiment.

FIG. 7 is a characteristic diagram showing 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 according to the second embodiment are stacked.

FIG. 10 is a flowchart showing a flow of pre-preparation processing according to the second embodiment.

FIG. 11 is a flowchart showing a flow of original image correction processing according to the second embodiment.

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

FIG. 13 is a block diagram showing a flow from forming an original to a printed matter by using only the color output device of the third embodiment.

FIG. 14 is a block diagram showing a flow from a document to a printed material in the color reproducing apparatus according to the third embodiment.

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

FIG. 16 is a flowchart showing the flow of pre-preparation processing according to the third embodiment.

FIG. 17 is a flowchart showing a flow of original image correction processing according to the third embodiment.

[Explanation of symbols]

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

Claims (3)

[Claims] 1. A color measuring device in which a photometric amount and a color information value have a one-to-one correspondence is used, and a color information value of each of a plurality of colors determined in advance, and when these respective colors are used as input colors. A plurality of relations between the color information values of the respective output colors from the color output device are obtained, and the color information values corresponding to the respective colors of the multiple colors including the colors other than the input color and the respective colors of the multiple colors as the input colors. Calculating means for obtaining a correspondence relationship between the input color and the output color in the color output device by obtaining a large number of relationships between the color information values of the respective output colors from the color output device when A calculation means for obtaining a color information value of a temporary input color such that the color information value of the input color and the color information value of the output color of the input color to be reproduced match based on the correspondence relationship obtained by the means; The color information value of the input color to be reproduced and the temporary information corresponding to the input color to be reproduced. Correction for correcting the color information value of the input color to be reproduced or the input color to be reproduced so that a 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 force color And a color reproduction device including. 2. The color output device comprises a scanner for scanning and color measuring an input color, and the correction means is arranged on the scanning side of the scanner and has filter means for changing the transmittance 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. The color reproduction apparatus according to claim 1, further comprising a filter control unit that controls the filter unit. 3. The color output device comprises an information reading device for reading the color information value of an input color, and the correction means is arranged on the input side of the information reading device and the color information of the input color to be reproduced. A color information value of the input color to be reproduced is converted into a color information value of the temporary input color by using the value and the color information value of the temporary input color corresponding to the input color to be reproduced. 1. The color reproduction device according to 1.