JP3302103B2 - Color image forming apparatus, color image adjusting apparatus, color image adjusting method, monitor apparatus, and color image forming / displaying method - 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 image forming apparatus of a color printer for printing out a full-color image and a color image of the same color displayed on a monitor device.

[0002]

2. Description of the Related Art In recent years, computer systems for handling full-color images such as color filing systems and computer graphics have become widespread, and full-color printers have been actively developed as output devices of these systems. On the other hand, a full-color video printer for printing out television images has been developed for consumer use. In these full-color printers, the output image is often compared with a monitor device of each system such as a CRT, and an image reproduced on the monitor device is a target of color reproduction of the printer.

[0003] The monitor device of each system has a color light source of three.
While color reproduction is performed based on the principle of additive color mixture by controlling the emission luminance of the primary colors red (R), green (G), and blue (B), full color printers are complementary colors of each color light. A color based on the subtractive color mixing principle in which three color inks of cyan (C), magenta (M), and yellow (Y) are used, and depending on the printer, four colors of ink, including black (K) ink, are used as absorption filters for color light. Reproduction is performed.

[0004] However, the spectral absorption characteristics of ink that actually exist are broad, do not act as ideal absorption filters for the respective color lights, and require color correction in order to perform desired color reproduction.

A technique called masking is generally used for color correction. Equation 1 is called linear masking, in which an ink density signal (C, M, Y) for controlling a main density of ink used in a printer is converted into a three primary color density signal which is a complementary color of the three primary color luminance signals (R, G, B). signal (D _R, D
_G , D _B ) is determined by a linear matrix operation, and is widely adopted because it can be realized with a small-scale circuit configuration.

[0006]

(Equation 1)

[0007] In addition, nonlinear factors existing in the color reproduction are included.
The three primary color density signals (D_R , D_G , D _B Higher order many
Nonlinear higher-order masking that corrects with a term is also proposed.
The simplest second-order masking is shown in Equation 2.
You.

[0008]

(Equation 2)

When linear masking or nonlinear higher-order masking is used for color correction, the determination of the masking coefficient used in each masking operation is an important factor in color reproduction. We have previously proposed a method of determining a masking coefficient that minimizes the difference in color perceived by humans between the color reproduction of a standard CRT of the NTSC system and the color reproduction of a printed image, for example.

On the other hand, in each system in which a full-color printer is used, color reproduction on a monitor device used is often set as a target color, and the color reproduction of an image printed out matches the color reproduction of the monitor device. It is desired. In particular, in the case of computer graphics, an original image is an image displayed on a monitor device, and when the image is printed out, color reproduction with the same color as the monitor device is targeted.

However, commercially available monitor devices generally have unique color reproduction characteristics depending on manufacturers and models, and different color reproduction is performed even for the same input signal. That is, the target of color reproduction is not specified by the NTSC standard or the like, but the color reproduction of each monitor device used by the user is used. Since it is difficult for the printer to automatically perform color correction corresponding to all of these monitor devices, the printer is generally equipped with an image quality adjustment function, and the user can adjust the color reproduction of the image to be printed out. The color correction corresponding to the monitor device is performed by matching the color reproduction of the monitor device.

Japanese Patent Laid-Open No. 4-133 discloses an image quality adjusting device for a video printer which performs image quality adjustment while looking at a monitor device.
No. 582. A conventional technique will be described with reference to the drawings. FIG. 9 is a block diagram showing the prior art. Reference numeral 114 denotes a frame memory for storing one frame of image information; 116, a print image adjustment circuit for adjusting the image quality of the image information output from the frame memory 114;
Reference numeral 20 denotes a head driving circuit that drives the recording head 122 in accordance with the image signal output from the print image adjustment circuit 116 to record a color image on recording paper, and 124 outputs image information output from the frame memory 114 to a monitor device. Monitor image adjustment circuit for performing image adjustment when performing
Reference numeral 8 denotes a print image adjustment circuit 11 according to the operation of the operator.
6. A controller for controlling an adjustment value of the monitor image adjustment circuit 124. The print image adjustment circuit 11
6. The monitor image adjustment circuit 124 includes a plurality of look-up tables (LUTs).

[0013] In the above configuration, the user sets the luminance (B
RT), contrast (CONT), color (COLO)
R) and the tint (TINT), the controller 118 selects the LUT of the print image adjustment circuit 126 according to the respective adjustment values, and the color image displayed on the monitor device is the same as the color image on the recording paper. LUT of the monitor image adjustment circuit 124 to be in the state
Select Then, how the image printed out by the adjustment operation changes is simulated by a color image displayed on the monitor device.

[0014]

However, in the case where the printer is provided with an image adjustment function and the user adjusts the color reproduction of the printer, the user performs an adjustment operation on an image to be printed out and creates an image with the printer. Then, the image on the monitor device which is the target of color reproduction is compared with the printed out image, and if the color reproduction of the printed out image is different from that of the monitor device, the adjustment operation is performed again. Will be. That is, the adjustment operation and the printout are repeated, and there has been a problem that an enormous amount of labor and unnecessary printout are required.

Further, in the conventional technique disclosed in Japanese Patent Application Laid-Open No. Hei 4-133581, in which the image adjustment of an image to be printed out is simulated on a monitor device, the change in color reproduction due to the adjustment operation is not considered. Although it is possible to monitor the outline, it is difficult to completely grasp the degree of change in color reproduction from an image on a monitor device. Further, this prior art is not applied for the purpose of matching the color reproduction of an image to be printed out to a monitor used by a user, but to match the color reproduction of an image to be printed out to a monitor used by a user. In such a case, there is a problem that it is necessary to repeat the adjustment operation and the printout.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and it is possible to adjust the color reproduction of an image printed out to an image displayed on a monitor device used by a user without repeating unnecessary printouts. Possible,
It is another object of the present invention to provide a color image forming apparatus capable of performing optimal adjustment.

[0017]

According to a first aspect of the present invention, a color image forming apparatus uses a first image signal input for recording to form a color image based on a first adjustment parameter. First adjusting means for converting the color image into an image signal ;
Of a color correction means for color correcting the color matching purposes, the gradation recording based on at least a yellow, magenta and cyan, a recording means for forming a color image corresponding to the second image signal, a first A second adjustment unit configured to convert the image signal into a third image signal used for display on a monitor device based on a second adjustment parameter having a conversion characteristic different from the conversion characteristic of the first adjustment parameter; An adjustment parameter is set to a value of the standard state, and the color correction unit sets the adjustment parameter based on the first adjustment parameter set to the value of the standard state .
A color image is formed in a state where the color correction is operated, a second adjustment parameter is set based on the formed color image, and the first adjustment is performed based on the set second adjustment parameter. Control means for changing parameters.

According to a third aspect of the present invention, there is provided a color image forming apparatus.
3. An image signal storage device according to claim 1, further comprising: an image signal storage means for storing at least one image signal to be recorded; and a color chart signal generation means for writing a color chart signal in said image signal storage means. I do.

According to a fourth aspect of the present invention, there is provided a color image adjusting apparatus.
First adjustment of a first image signal input to perform recording
A second parameter used for forming a color image based on the parameters
First adjusting means for converting the color image into an image signal;
For the purpose of matching colors with the image of the standard monitor device
Color correction means for performing color correction, and a first image signal
Second having a conversion characteristic different from the conversion characteristic of the
Used for display on the monitor device based on the adjustment parameters of
A second adjusting unit for converting the image signal into a third image signal;
Set the adjustment parameters to the standard state, and
Corresponding to the first adjustment parameter set in
Form a color image with color correction by the correct
And a second adjustment parameter based on the color image.
Is set, and then the set second adjustment parameter is set.
Control means for changing the first adjustment parameter based on
And a step . The method for adjusting a color image according to claim 9, wherein the first image input for recording is performed.
The image signal obtained by converting the image signal based on the first adjustment parameter
2 color image by image signal and monitor as standard
Step of performing color correction for the purpose of matching colors with the image of the device
And the first adjustment parameter is set to the value of the standard state.
Corresponds to the first adjustment parameter set to the value of the standard state
Then, a color image is formed while the color correction is operated.
And a first image based on the color image
The signal is converted to a third image signal used for display on a monitor device.
Setting a second adjustment parameter for switching
And, based on the set second adjustment parameter,
Changing a first adjustment parameter.
Characterized in that was. The method for forming and displaying a color image according to claim 11, wherein the first image input for recording is performed.
A second image signal obtained by converting the image signal based on the first adjustment parameter;
Color image and the standard monitor
Correcting the color for the purpose of color matching with the image of the device,
Set the first adjustment parameter to the value of the standard state,
Based on the first tuning parameter set to the value of the quasi-state
Form a color image with the color correction operating,
Based on the formed color image, the first image signal is modeled.
To a third image signal used for display on the monitor.
Setting a second tuning parameter for
The first adjustment parameter is based on a second adjustment parameter.
Changing the first key, and changing the first key.
The first image signal to the second image signal based on the
Color image corresponding to the second image signal
Forming a color image using a color image forming apparatus; and
The second adjustment parameter is set to the standard state, and this standard
The first image signal is converted to a third image signal based on the set value of the state.
And an image corresponding to the third image signal is monitored.
And displaying using a device .

[0020]

According to the construction of claims 1, 4 , 9 and 11 ,
A color image is formed in a state in which color correction is performed on the first adjustment parameter set to the standard state, and the second adjustment parameter is set in accordance with the color image, so that an adjustment target is set. The color reproduction of the monitor device set as above is approximated to the color reproduction of the color image in the standard state. Further, since the first adjustment parameter is changed in accordance with the set second adjustment parameter, the color reproduction of an actual color image obtained by image formation is made to match the color reproduction of an actual monitor. . In addition, the standard mode is
Color-corrected to match the color of the monitor
Monitor device based on the color reproduction of the color image sample
Adjust the color image displayed on the
When adjusting the parameters of the color image forming apparatus based on
In both cases, the monitor must be
Color reproduction of the image printed out to the color reproduction of the monitor
Match the present.

According to the third aspect of the present invention, the control means creates a color chart signal corresponding to the information of the image signal in the image signal storage means by the color chart signal generation means based on the program stored in the control means. The control unit adjusts the color image displayed on the monitor device based on the color reproduction of the color image sample created by the recording unit in response to the color chart signal, and prints out the color reproduction of the monitor device. Match the color reproduction of the image.

[0022]

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the color image forming apparatus of the present invention will be described in which a full-color image is formed by a sublimation type thermal transfer type recording process using three color inks of yellow, magenta and cyan. γ corrected RGB
An example in which the luminance signal is used as an input image signal and applied to a color image forming apparatus that aims to reproduce colors that are the same color as an image displayed on a CRT will be described.

FIG. 1 is a block diagram of the color image forming apparatus of the first embodiment. Reference numeral 11 denotes a first adjustment unit that performs conversion according to a first adjustment parameter on a first image signal to be recorded and outputs a second image signal. Reference numeral 12 denotes an output of the first adjustment unit 11. A recording unit that forms a full-color image by a sublimation-type thermal transfer recording process in accordance with a certain second image signal, performs conversion on the first image signal in accordance with a second adjustment parameter, 3
A second adjusting means 14 for outputting an image signal of the CRT, a signal converting means for converting a third image signal output from the second adjusting means 13 into an input signal of the CRT, Reference numeral 15 denotes a second signal in response to an input operation signal.
Is set, and the first adjustment parameter corresponding to the set second adjustment parameter is set to the first adjustment parameter.
Control means for setting the adjusting means 11 of the recording means 1;
Reference numeral 17 denotes a full-color image sample created in 2 and a CRT used in the present embodiment, which reproduces the color of a full-color image using the output of the signal conversion means 14 as an input signal.

In the present embodiment, the control means 15 is
U, RAM, ROM, I / O, etc., and also controls the sequence of the image forming operation of the recording unit 12.

The full-color image forming apparatus according to the present embodiment uses a CRT γ-corrected R as an image signal to be recorded.
For inputting digital data of a GB luminance signal,
Each means was constituted by a digital circuit.

With the above configuration, the color image forming apparatus of the present embodiment sets the CRT 17 used by the user as a color reproduction target, performs adjustment so as to perform color reproduction equivalent to the CRT 17, and records a full-color image on the image receiving paper. Things.

Next, the recording means 12 in this embodiment will be described. In this embodiment, the recording means 12 is a sublimation type thermal transfer recording type in which thermal energy is applied to three color ink sheets of yellow, magenta, and cyan in a face-sequential manner, and a full-color image is recorded on an image receiving paper by overlap recording. Using. FIG. 2 shows a detailed block configuration diagram of the recording means 12.

Reference numeral 21 denotes a signal switching means for switching the RGB luminance signal of the image signal in accordance with an input switching signal for recording in a frame-sequential manner, and reference numeral 22 denotes an inverse γ correction means for performing an inverse γ correction of a CRT. The γ characteristic of a normal CRT is 2.2
In this embodiment, the calculation of the inverse γ correction is a calculation in which the input x and the output y are expressed by Equation 3 because of the power characteristic.

[0030]

(Equation 3)

Reference numeral 23 denotes a complementary color conversion means for converting an additive color system luminance signal into a subtractive color system density signal. If the maximum reproducible density is Dmax, the input x and the output y are calculated by the equation (4). Is what you do.

[0032]

(Equation 4)

Numeral 24 is a sheet γ correcting means for correcting a non-linear sheet γ characteristic of energy (pulse width) applied to the ink sheet and reproduced density and outputting pulse width data for reproducing a desired density. And outputs pulse width data corresponding to the γ characteristic of each of the yellow, magenta, and cyan ink sheets in response to the input switching signal.

25 is a pulse width modulation means for implementing pulse width modulation according to the pulse width data output from the sheet gamma correction means 24 to control the applied energy by pulse width modulation;
A thermal head 26 applies thermal energy to an ink sheet (not shown) in accordance with the output of the pulse width modulation means, and forms a color image on an image receiving paper (not shown).

In this embodiment, the result of performing both operations of the CRT inverse γ correction means 22 and the complementary color conversion means 23 is tabulated, and a LUT for inputting a γ-corrected luminance signal of the CRT and outputting a density signal is provided. And stored in the ROM.

With the above configuration, the recording means 12 in the present embodiment performs gradation recording in accordance with an input CRT gamma-corrected luminance signal by using inks of yellow, magenta, and cyan (not shown). This is to form a full-color image sample 16 on an image receiving paper (not shown).
The sequence of the image forming operation such as motor control for transporting the image receiving paper and generation of a switching signal is controlled by the CPU constituting the control means 15.

Next, adjustment of an image signal in this embodiment will be described. In the present embodiment, two parameters of “brightness of halftone” and “bluishness of the image” are used as parameters for adjusting the image quality, and the first adjusting unit 11 and the second adjusting unit 13 are each set to 8 bits. A ROM was used as an output LUT. FIG. 3 shows the first adjusting means 1.
1 shows the connection of the ROM used in the second adjusting means 13.
As shown in FIG. 3, the control means 1 uses the lower 8 bits of the ROM address as input data and the upper bit for table selection.
5 is connected to the output. Here, GAM is a parameter corresponding to “brightness of halftone”, and k is a parameter corresponding to “bluishness of the image”, each of which is a 4-bit signal.

Assuming that the input RGB luminance signal has a value of 0.0 to 1.0 for the "halftone brightness", the adjustment parameters are converted as shown in Equation 5 using GAM, and R'G ' B ′ is output.

[0039]

(Equation 5)

FIG. 4 is a graph when GAM = 0.8 and GAM = 1.2. When a value smaller than 1.0 is used as the GAM, the halftone is adjusted so as to be bright, and when a value larger than 1.0 is used, the halftone is adjusted so as to be dark. .

The first adjustment parameter relating to “brightness of halftone” is GAM1, and the second adjustment parameter is GAM2.
In this embodiment, the standard value is set to 1.0 for both GAM1 and GAM2, and GAM2 of the second adjustment parameter is set to 1.0.
Was set to GAM2 = 0.8 to 1.2 in increments of 0.05, and the value of GAM1 was set so as to have the opposite characteristics. Table 1 shows the addresses of the first adjustment unit 11 and the second adjustment unit 13 and the stored values of GAM1 and GAM2 of the LUT. As shown in Table 1, data is stored in the LUTs of the first adjustment unit 11 and the second adjustment unit 13 so that parameter values having opposite characteristics when the same A8 to A11 are given are selected. The control means 15 sets the same value in the first adjustment means 11 and the second adjustment means 13 according to the operation signal.

[0042]

[Table 1]

"Bluish image" means that the B signal is set to 0.0 to 1.B with respect to the B (blue) signal of the input RGB luminance signal.
When the value is set to 0, the conversion represented by Expression 6 is performed using the adjustment parameter k.

[0044]

(Equation 6)

FIG. 5 shows a graph when k = 0.8 and k = 1.2. When the value of k is larger than 1.0, RG
Since the value of B is larger than the value of, the bluish tone of the reproduced image becomes stronger. Conversely, if the value of k is smaller than 1.0, the bluish tone of the image becomes weaker and the yellowish tone becomes stronger.

Assuming that the first adjustment parameter relating to “bluishness of the image” is k1 and the second adjustment parameter is k2, in this embodiment, the standard values of both k1 and k2 are 1.0, and
The second adjustment parameter k2 is set to k2 = 0.8 to 1.2 in increments of 0.05, and k1 is set to have the inverse characteristics.
Was set. Table 2 shows the addresses of the first adjustment unit 11 and the second adjustment unit 13 and k1 of the stored LUT.
And the value of k2. As shown in Table 2, the same A1 is set in the LUTs of the first adjustment unit 11 and the second adjustment unit 13.
The data is stored so that parameter values having the opposite characteristics when 2 to A15 are given are selected.
Is to set the same value to the first adjusting means 11 and the second adjusting means 13 according to the operation signal.

[0047]

[Table 2]

Next, the operation of performing image adjustment in the color image forming apparatus of this embodiment will be described. First, as an unadjusted state, the control unit 15 sets the first and second adjustment parameters to the values of the standard state (GAM1) so that both the second image signal and the third image signal are equal to the first image signal.
= 1.0, GAM2 = 1.0, k1 = 1.0, k2 =
1.0) is set.

Under this setting, when a full-color image such as a person image is input as a first image signal,
Since the first adjustment parameter is in the standard state, a second image signal equal to the first image signal is input to the recording unit 12 through the first adjustment unit 11. Then, the image sample 1 corresponding to the second image signal is recorded by the recording unit 12.
Create 6. Since the second adjustment parameter is also in the standard state, the second adjustment means 13 and the signal conversion means 1
4, a full-color image corresponding to the first image signal is reproduced on the CRT 17.

Next, the second adjustment parameter is operated by the operation signal to change the color reproduction of the image reproduced on the CRT 17, and the operation signal is compared with the image reproduced on the CRT 17 and the image sample 16. To set the second adjustment parameter. Then, the adjustment operation is completed by setting the second adjustment parameter so that the reproduced image on the CRT 17 reproduces the color closest to the image sample 16.

The control means 15 sets the second adjustment parameter according to the operation signal, and sets the first adjustment parameter corresponding to the set second adjustment parameter in the first adjustment means 11. The first image signal is converted into a second image signal according to the set first adjustment parameter, and is input to the recording unit 12. When recording is performed by the recording unit 12 in this state, an image sample 16 corresponding to the adjustment operation is created.

As a result of performing the adjustment using the human image as the image signal in the above operation, the second adjustment parameter is set to GAM.
When 2 = 1.15 and k2 = 0.85, the reproduced image on the CRT 17 became the color reproduction closest to the image sample 16 created in the standard state (GAM1 = 1.0, k1 = 1.0). . Compared to the image sample 16 created in the standard state, the CRT 17 is darker in halftone and stronger in yellow.
By adjusting the color reproduction of the CRT 17, the color reproduction of both becomes the closest state. Conversely, in order to approach the color reproduction of the CRT 17 in the standard state, the halftone of the image sample 16 is made bright and the bluish is increased. It is only necessary to make such adjustments. In the present embodiment, when the above adjustment is performed, the control unit 15 sets GAM1 =
0.870 and k1 = 1.176 are set. And
Using this first adjustment parameter, the first adjustment means 11
Converts the first image signal into a second image signal, and creates an image sample 16. As a result, an image closest to the CRT 17 in the standard state with respect to the standard image of the person image to be adjusted could be obtained. .

As described above, the color image forming apparatus according to the first embodiment of the present invention creates an image sample using the first adjustment parameter as a standard state, and compares the created image sample with the color reproduction of a CRT. Since the second adjustment parameter of the image adjustment is set while changing the color reproduction of the CRT, the color reproduction of the CRT used for the color reproduction of the image sample can be performed by one image sample creation and adjustment operation. It is now possible to set the adjustment parameters to be closest to

Next, a second embodiment relating to the color image forming apparatus of the present invention will be described. The color image forming apparatus according to the second embodiment includes image signal storage means for storing an image signal to be recorded for one image, and means for writing a pattern signal in the image signal storage means, and adjusts image quality. At this time, the adjustment operation can be performed using an image sample obtained by recording the pattern signal created in the image signal storage means.

FIG. 6 shows a block diagram of the color image forming apparatus of the second embodiment. Reference numeral 31 denotes an image signal storage unit for storing one image of the RGB luminance signal of γ-correction of the CRT for each image of 8 bits for each color of RGB. In this embodiment, the image signal storage unit is configured using an SRAM.

Reference numeral 32 writes a pattern signal to the image signal storage means 31 and, in accordance with an input operation signal,
Control means for outputting the first adjustment parameter and the second adjustment parameter. In this embodiment, the color chart signal generation means 31a
Also serves as. In this embodiment, the CPU, RAM, R
It is composed of OM, I / O, etc., and stores a pattern generation program in ROM. The CPU creates a pattern signal in accordance with the program and writes it to the image signal storage unit 31.

The first adjusting means 33, the recording means 34, the second
The adjusting means 35 used was the same as that of the color image forming apparatus of the first embodiment. An operation of performing adjustment in the color image forming apparatus of the present embodiment will be described.

First, when an operation signal for generating a pattern is input to the control means 32, the CPU constituting the control means 32 stores the pattern signal in the image signal storage means 31 in accordance with the pattern generation program stored in the ROM. Create.

When a pattern signal for one image is created in the image signal storage means 31, the control means 32 sets the first and second adjustment parameters to the values of the standard state (GAM1 = 1.0, G
AM2 = 1.0, k1 = 1.0, k2 = 1.0).

Under this setting, the first adjusting means 33 outputs to the recording means 34 a second image signal equal to the pattern signal output from the image signal storing means 31. And
The recording unit 34 creates a full-color image sample 37 using yellow, magenta, and cyan inks according to the input pattern signal. Further, since the second adjustment parameter is also in the standard state, the second adjustment means 35,
Through the signal conversion means 36, a full-color image corresponding to the pattern signal output from the image signal storage means 31 is reproduced on the CRT 38.

Next, the second adjustment parameter is operated by the operation signal to change the color reproduction of the image reproduced on the CRT 38, and the operation signal is compared while comparing the image reproduced on the CRT 38 with the image sample 37. To set the second adjustment parameter. Then, the adjustment operation is completed by setting the second adjustment parameter so that the reproduced image on the CRT 38 reproduces the color closest to the image sample 37.

The control means 32 sets the second adjustment parameter in accordance with the operation signal, and sets the first adjustment parameter corresponding to the set second adjustment parameter in the first adjustment means 33. The first image signal is converted into a second image signal according to the set first adjustment parameter, and is input to the recording unit 34. When recording is performed by the recording unit 34 in this state, an image sample 37 corresponding to the adjustment operation is created.

Next, the pattern image used for adjusting the image quality in this embodiment will be described. In this embodiment, the CRT γ
Four types of signal levels are set for each of the corrected RGB luminance signals, and the signal levels are combined to form 64.
A pattern image in which one color chart signal is included in one image was used. FIG. 7 shows a color chart signal. In FIG. 7, each signal level is R0 = G0 = B0 = 0/255 and R1 = G1
= B1 = 85/255, R2 = G2 = B2 = 170/2
55, R3 = G3 = B3 = 255/255. For example, the color chart at the upper right of the pattern image is R = R0 = 0/255,
This is a (R, G, B) color chart signal of G = G3 = 255/255 and B = B1 = 85/255.

When the colors of the respective color patches of the pattern image created based on the above color patch signals were measured, the colors of these color patches were located almost uniformly in the entire color space. When adjustment was performed on these color patches so as to be equal in color on average, the second adjustment parameter was GAM2 =
At 1.10 and k2 = 0.90, the reproduced image of the CRT 38 became the color reproduction closest to the image sample 37 created in the standard state (GAM1 = 1.0, k1 = 1.0).
By adjusting the color reproduction of the CRT 38 so that the halftone is darker and the yellowish color is more intense than the image sample 37 created in the standard state, the color reproduction of both becomes the closest state. In order to approximate the color reproduction of the CRT 38 in the standard state, it is necessary to perform adjustment such that the halftone of the image sample 37 is bright and the bluish color is strong. In this embodiment, when the above adjustment is performed, GAM1 = 0.909,
k1 = 1.111 is set. Then, using the first adjustment parameter, the first adjustment means 33 converts the pattern signal stored in the image signal storage means 31 into a second image signal, and creates an image sample 37.
An image closest to the standard CRT 38 in color reproduction could be obtained.

Further, the first adjustment parameter (GA
M1 = 0.909, k1 = 1.111), various images were created by the recording means 34, and the color reproduction was compared with that of the CRT 38. I got it.

As described above, in the color image forming apparatus according to the second embodiment of the present invention, the image signal storing means 31 for storing one image signal and the means for writing the color chart signal in the image signal storing means 31 are provided. When adjusting the image quality, the adjustment operation is performed using an image sample created in accordance with the color chart signal. In the case where a plurality of color chart signals are generated, it is possible to set adjustment parameters that can be applied to many images on average with a single adjustment.

Next, a third embodiment relating to the color image forming apparatus of the present invention will be described. The color image forming apparatus of the third embodiment has the same overall configuration as that used in the first embodiment shown in FIG. When the first adjustment parameter is a standard value, color correction is performed so as to reproduce colors in the same color as a standard monitor device.

FIG. 8 shows a block diagram of the recording means of the color image forming apparatus of this embodiment. 41a, 41b, 41
c is a CRT inverse γ correction means that performs CRT inverse γ correction on the γ-corrected luminance signals (R, G, B) of the CRT and outputs (R ′, G ′, B ′) In this embodiment, the correction represented by Expression 7 is performed.

[0069]

(Equation 7)

[0070] 42a, 42b, 42c are complementary converting means, the concentration signal based CRT inverse γ correction means 41a, 41b, the output of 41c to subtractive color mixing principle (D _R, D _G, D
_B ), respectively, and in this embodiment,
Was performed.

[0071]

(Equation 8)

Reference numeral 43 denotes a color correction means, which is a complementary color conversion means 4
In which the second output of the density signal _{(D R, D G, D} B) enter the outputs yellow used, magenta, ink density signals for controlling the concentration of the cyan inks (C, M, Y) and is there.

Reference numeral 44 denotes sheet γ correction means, 45 denotes pulse width modulation means, and 46 denotes a thermal head. In this embodiment, the color correction means 43 corrects the color turbidity at the time of color mixture caused by the spectral characteristics of the broad ink, and performs a non-linear masking operation for the purpose of performing color reproduction with a standard monitor device. Is used to perform color correction, and the details will be described below.

First, the density signals (D _R , D _G , D _B ) are converted into signals (C ′, M ′, Y ′) corresponding to the color material amount of the ink. Specifically, assuming that a constant (a> 1) representing the nonlinear degree of the relationship between the color material amount and the density of the ink is three primary color density signals obtained by the complementary color conversion by the first nonlinear conversion shown in Expression 9. Each of (D _R , D _G , D _B ) is nonlinearly converted into a signal (C ′, M ′, Y ′) corresponding to the color material amount of ink.

[0075]

(Equation 9)

Subsequently, the output (C ′, M ′, Y ′) of the first non-linear conversion is converted into (C ″, M ″, Y ″) by the linear matrix operation of equation (10).

[0077]

(Equation 10)

Further, it is an inverse function of the first nonlinear transformation, and (C ″,
M ", Y") are converted to ink density signals (C, M, Y).
Convert to

[0079]

[Equation 11]

The color correcting means 43 of this embodiment performs the above-described non-linear masking in consideration of the fact that the addition rule of density is not satisfied. Further, in this embodiment, since the standard monitor device which is the target of color correction is a CRT defined by NTSC, ten correction coefficients a, a _{11 to} a ₃₃ used in Expressions 9 to 11 are recorded by a recording means. 34 output and NT
A CRT that performs color reproduction specified by SC and that has been determined so that the color difference in the Luv-based uniform color space is minimized on average for many color patches.

The color correcting means 43 realizes high-precision color correction for the purpose of reproducing colors of the same color as a CRT defined by NTSC by the above-mentioned nonlinear masking and correction coefficients. That is, by providing the color correction unit 43, the first adjustment parameter is set to the standard value (GAM1 = 1.0, k1 =
1.0), the image sample 16 created is NTS
This realizes color reproduction with the same color as the CRT specified in C with high accuracy.

From this, the image sample 16 and the CRT 1 created when the first adjustment parameter has a standard value are obtained.
The color reproduction difference 7 is equivalent to the color reproduction difference between the CRT specified by NTSC and the CRT used by the user. This difference in color reproduction can be corrected with high accuracy using “halftone brightness” and “image bluishness” used as image adjustment parameters in the present embodiment, similar to the first embodiment. By the above adjustment operation, it is possible to realize color reproduction of the same color as the CRT 17 to be used with very high accuracy.

The embodiment relating to the color image forming apparatus of the present invention has been described above. In this embodiment, the parameters for adjusting the image quality are “brightness of halftone” and “bluishness of the image”, and the first and second adjusting means for performing the adjustment use the ROM storing the LUT. However, the present invention is not limited to the parameters to be adjusted and the specific configuration of the adjusting means. For example, when parameters for adjusting hue, saturation, and lightness are used, adjustment for performing color matching with a CRT used by a user can be performed with higher accuracy. In addition, as the number of adjustment parameters increases, the number of repetitions of the adjustment operation and printout increases in the related art, making it difficult to perform optimal adjustment. However, in the color image forming apparatus of the present invention, the color reproduction of the CRT is changed. Since the adjustment parameters are set while the number of adjustment parameters is large, optimal adjustment can be performed without repeating printout.

In this embodiment, a recording means which performs a recording process of a sublimation type thermal transfer recording system is used.
It is apparent that the color image forming apparatus of the present invention is not limited to a recording process, and can be applied to, for example, an apparatus that forms a full-color image by a recording process of an electrophotographic system, an inkjet system, or a silver halide photographic system. is there.

In the second embodiment, a plurality of color chart signals generated by the color chart signal generating means 31a in the image signal storing means 31 are positioned almost uniformly in the entire color space. Is not limited to the color chart signal
If there is a color to be emphasized in the adjustment, a large number of color patches of the color in the vicinity may be created. For example, when a large number of color patches close to the skin color are created, it is possible to accurately adjust the flesh color of the person.

Further, in the third embodiment, the color correction means 43 performs the non-linear masking operation shown in Equations 9 to 11, but the present invention is not limited to the color correction operation. For example, linear masking, which is widely used in general, can also be applied when a correction coefficient is determined so as to reproduce colors that are the same color as a standard monitor device.

[0087]

According to the first, fourth, ninth and eleventh aspects of the present invention, a color image is formed in a state where color correction is performed on the first adjustment parameter set to the standard state, and the color image is formed. By setting the second adjustment parameter in response to the above, the color reproduction of the monitor device to be adjusted can be approximated to the color reproduction of the color image in the standard state. Further, since the first adjustment parameter is changed corresponding to the set second adjustment parameter, the color reproduction of the actual color image obtained by the image formation is changed to the color reproduction of the set actual monitor device. Can be matched. As a result, the color reproduction of the color image obtained by the user can be matched with the color reproduction of the monitor device seen by the user without repeating the adjustment operation and the image formation. Also, the color correction operation allows the standard monitor
-Color created by color correction so that it matches the device
Display on the monitor device based on the color reproduction of the image sample
Adjust the color image shown and make adjustments based on the adjustment result.
To adjust the parameters of the color image forming apparatus
In order to adjust the monitor device to the standard state,
-Color reproduction of the image printed out to the color reproduction of the device
Can be matched. As a result,
Of the reproduced image and the color reproduction of the monitor device used by the user
The difference is that the standard monitor device and the monitor used by the user
-It is equivalent to the difference in color reproduction of the device, and
Because it is equivalent to the difference in color reproduction, a large-scale circuit
Unnecessary adjustment parameters allow user
To match the color reproduction of the monitor device used.
Can be adjusted.

According to the third aspect of the present invention, based on the program stored in the control means, the control means creates the color chart signal corresponding to the information of the image signal in the image signal storage means by the color chart signal generation means. The control means adjusts the color image displayed on the monitor device based on the color reproduction of the color image sample created by the recording means in response to the color chart signal, and prints out the color reproduction of the monitor device. Since the color reproduction of the same image is the same, if the color chart signals are located evenly in the entire color space, it is possible to make optimal adjustments to the colors in the entire color space. Applicable adjustment parameters can be set by one adjustment operation. In addition, when a large number of color chart signals close to the color to be emphasized in the adjustment are generated, the adjustment can be performed with the color being emphasized.

[0089]

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a color image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a recording unit of the embodiment.

FIG. 3 is a configuration diagram of first and second adjusting means of the embodiment.

FIG. 4 is a graph of input / output relating to an adjustment parameter (halftone brightness).

FIG. 5 is a graph of input and output regarding an adjustment parameter (bluishness of an image).

FIG. 6 is a configuration diagram of a color image forming apparatus according to a second embodiment of the present invention.

FIG. 7 is a pattern diagram of a color chart signal of the embodiment.

FIG. 8 is a configuration diagram of a recording unit according to a third embodiment of the present invention.

FIG. 9 is a configuration diagram of a conventional color image forming apparatus.

[Explanation of symbols]

 11, 33 First adjustment means 12, 34 Recording means 13, 35 Second adjustment means 15, 32 Control means 31 Image signal storage means 31a Color chart signal generation means 43 Color correction means

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-48885 (JP, A) JP-A-4-1333582 (JP, A) JP-A-4-343391 (JP, A) JP-A-3-343 171877 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H04N 1/40-1/409 H04N 1/46-1/64

Claims (12)

(57) [Claims] 1. A a first adjusting means for converting the second image signal used for forming a color image based on the first image signal input for recording to the first adjustment parameter, the color image And the standard monitor image
Has a color correction means for color correcting the color for the purpose, the gradation recording based on at least a yellow, magenta and cyan, a recording means for forming a color image corresponding to the second image signal, a first image signal Adjusting means for converting a first adjustment parameter into a third image signal used for display on a monitor device based on a second adjustment parameter having a conversion characteristic different from the conversion characteristic of the first adjustment parameter; It was set to a value in the standard state, the target
Based on the first tuning parameter set to the value of the quasi-state
A color image is formed in a state where the color correction by the color correction unit is operated, and a second adjustment parameter is set based on the formed color image.
A control unit for changing the first adjustment parameter based on the adjustment parameter. 2. The method according to claim 1, wherein the control means changes the first adjustment parameter such that the conversion using the second adjustment parameter and the conversion using the first adjustment parameter have a relationship of inverse characteristics to each other. The color image forming apparatus as described in the above. 3. An image signal storing means for storing at least one image signal of an image signal to be recorded, and a color chart signal generating means for writing a color chart signal in the image signal storing means. The color image forming apparatus according to any one of the above. 4. A first image signal input for recording.
To form a color image based on the first adjustment parameter
A first adjusting unit for converting the color image into a second image signal to be used, a color correcting unit for performing color correction for the purpose of matching colors between the color image and an image of a standard monitor device, and a first image signal, A second adjustment unit that converts the first adjustment parameter into a third image signal used for display on the monitor device based on a second adjustment parameter having a conversion characteristic different from the conversion characteristic of the first adjustment parameter; Set to the standard
Corresponding to the first tuning parameter set to the state value,
With the color correction by color correction
Forming an image, and a second adjustment parameter based on the color image.
Setting the meter, and then setting the second adjustment parameter
Changing the first adjustment parameter based on a meter
A color image adjusting device, comprising:
Place. 5. The control means uses a second adjustment parameter.
Conversion and the conversion using the first adjustment parameter are opposite to each other.
The first adjustment parameter is changed so as to have a characteristic relationship.
The color image adjustment device according to claim 4 . 6. An image signal of at least one image to be recorded.
Image signal storage means for storing the
5. A color chart signal generating means for writing a vote signal.
A color image adjusting apparatus according to claim 5 . 7. Modification by the control means according to claim 4.
According to the second image signal based on the first adjustment parameter
Color image, at least yellow, magenta and sheer
Color image adjustment device formed by 8. The control means according to claim 1 or 4,
A third image signal based on the set second adjustment parameter
Monitor device that displays images according to the issue. 9. A first image signal input for recording
Image obtained by converting based on the first adjustment parameter
Color image by signal and standard monitor image
Performing a color correction for the purpose of achieving color matching with the image; setting a first adjustment parameter to a value of a standard state;
Corresponding to the first adjustment parameter set to the value of the quasi-state,
While operating the color correction, to form formed a color image
And a step of monitoring a first image signal based on the color image.
For converting to a third image signal used for display
Setting the first adjustment parameter; and setting the first adjustment parameter based on the set second adjustment parameter.
And a changing step of changing the adjustment parameters of
And a method for adjusting a color image. 10. The method according to claim 10, wherein the changing step includes a second adjusting parameter.
Conversion using data and conversion using the first adjustment parameter
And the first adjustment parameter so that
10. The method for adjusting a color image according to claim 9, wherein the meter is changed.
Law. 11. A first image signal input for recording.
Image converted based on the first adjustment parameter.
The color image by the image signal and the standard monitor
Correcting the color for the purpose of matching the color with the image; setting the first adjustment parameter to a value in a standard state;
Based on the first tuning parameter set to the value of the quasi-state
Form a color image with the color correction operating,
Based on the formed color image, the first image signal is modeled.
To a third image signal used for display on the monitor.
Setting a second adjustment parameter for adjusting the first adjustment parameter based on the second adjustment parameter.
A step of changing a parameter and a first image based on the changed first adjustment parameter.
Converting the image signal into a second image signal;
A color image corresponding to
And setting the second adjustment parameter to a standard state.
The first image signal is converted to the third image based on the set value of the quasi-state.
And the image corresponding to the third image signal is monitored.
Displaying using a monitor device.
A method of forming and displaying a color image. 12. The method according to claim 11, wherein the changing step changes the first adjustment parameter such that the conversion using the second adjustment parameter and the conversion using the first adjustment parameter have characteristics opposite to each other. Item 13. Formation of a color image according to item 11.
-Display method.