JP3371741B2 - Color signal adjustment device and adjustment 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 signal adjusting device and an adjusting method, and more particularly to a color signal adjusting device and an adjusting method in a color reproducing device such as a scanner, a monitor and a printer.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram showing an example of a printing system when a sublimation printer is used. In the figure, for example, from the color image scanner 1 to the central processing unit (CP
U) Color image data consisting of three-dimensional color signals input to a personal computer (hereinafter referred to as a personal computer) 2 equipped with 3 is displayed on a color display monitor 4 using a cathode ray tube (CRT), while a personal computer It is processed in 2 and supplied to the printer 5.

The printer 5 receives the image data from the personal computer 2 as an input signal in the central processing unit (CPU) 6 and supplies it to the color conversion processing circuit 7, while controlling the image memory 8 to perform color conversion. After the image data color-converted by the processing circuit 7 is stored in the image memory 8, the CPU 10
After the signal processing necessary for printing is performed in the print processing unit 9 having the above, the same color image as the color image displayed on the color display monitor 4 is printed on the paper.

Here, in the above system, it is necessary that the color image displayed on the color display monitor 4 and the color image of the printed hard copy be in desired desired color reproduction states. Is. In this case, if the color image read by the scanner 1 and supplied to the color display monitor 4 is printed as it is without being processed by the printer 5, desired good color reproduction cannot be obtained.

Therefore, conventionally, as shown in FIG. 6A, a three-dimensional color signal corresponding to a color of the first color system read by a first device such as a scanner is converted into a second color signal of a CRT or the like. The color signal processing is performed when the image is displayed by the second device of the color system, and the first signal read by the first device such as the scanner in the color conversion processing circuit 7 as shown in FIG. 6B. When a three-dimensional color signal corresponding to the color of the color system is input to the second device of the second color system, which is a printer, at least the three-dimensional color corresponding to the color of the second color system. There is known a color signal adjusting device that converts a signal and adjusts a color signal.

That is, conventionally, the color conversion processing circuit 7 shown in FIG. 5 is used.
As shown in FIG. 7, input lookup tables (hereinafter referred to as LUTs) 20R, 20G and 20B, and 3D.
It is composed of an LUT 21 and output LUTs 22C, 22M and 22Y. In FIG. 7, color signal data corresponding to the colors of the first color system, red (R), green (G), and blue (B), are input to the input LUTs 20R, 20G, and 20B to adjust their values. After that, it is input to the 3DLUT 21,
Here, the color signal data corresponding to the colors of the second color system (here, for example, cyan (C), magenta (M), and yellow (Y)) are converted. The color signal data corresponding to the color of the second color system is the output LUT 22 corresponding to each color.
It is supplied to C, 22M and 22Y, and the value is adjusted and output.

The printer 5 has input LUTs 20R to 20B, 3DLUT 21, and output LUT 2 which are color conversion tables.
The color of the print result can be changed by adjusting 2C to 22Y. Therefore, the printer 5 uses the input LU in the color conversion processing circuit 7 to support various devices.
T20R to 20B, 3DLUT21, output LUT22C
In most cases, each LUT data of ~ 22Y is supplied from the outside.

Therefore, conventionally, when a color to be adjusted is designated, a problematic color is first found by looking at the print result of the printer 5. Then, when the color signal data corresponding to that color is input to the input LUTs 20R to 20B of FIG.
2Y input color signal data is adjusted for a portion near that value.

[0009]

However, conventionally, since the change in the value due to the input LUTs 20R to 20B and the 3DLUT 21 is not taken into consideration, the correction position is deviated, and the user has to decide the correction position based on his experience and intuition. There is a problem.

The present invention has been made in view of the above points,
Provided is a color signal adjusting device and an adjusting method capable of easily adjusting the correction position of an output LUT in consideration of a change in value by an input LUT and a 3DLUT (or a change in value by an input LUT and a 4DLUT). The purpose is to do.

[0011]

In order to achieve the above object, the apparatus of the present invention performs at least color conversion after processing the first color signal corresponding to the color of the first color system by the input look-up table. Second using a lookup table for
Output to a printer that converts the second color signal corresponding to the color of the color system of FIG. 1 and adjusts the value of the second color signal with an output look-up table to output as a color signal for printing. A color signal adjusting device for adjusting a color signal by externally setting table data of an up table, wherein the same table data as an input look-up table, a look-up table for color conversion, and an output look-up table are separately provided. 1st, 2nd to hold
And a third storage unit, and a calculation unit that calculates color data of the designated area by designating an arbitrary area in the same image as the print result of the printer displayed on the screen for color signal adjustment, Based on the lookup table data from the first and second storage units, a simulation unit that performs color conversion simulation of the color data from the calculation unit, and a simulation result of the simulation unit is output as a lookup from the third storage unit. The display processing means generates a display signal to be displayed on a graph showing the input / output characteristics of the output lookup table created based on the table data, and the display device to display the display signal on the screen.

In the method of the present invention, the same table data as the input look-up table, the look-up table for color conversion, and the output look-up table are separately held, and the print result of the printer displayed on the screen is stored. The color data of an arbitrary area in the same image where the color signal is to be adjusted is calculated, and the color conversion simulation is performed on the calculated color data based on the held input lookup table and lookup table data for color conversion. ,
The simulation result is displayed on a graph showing the input / output characteristics of the output lookup table created based on the held output lookup table data.

In the apparatus and method of the present invention, the color signal corresponding to the color of the first color system of the arbitrary designated area of the display image is input to the output look-up table of the printer, and the color signal is adjusted. A simulation for converting into a color signal corresponding to the color of the second color system can be performed, and the simulation result can be displayed as an input value on the graph of the input / output characteristics of the output lookup table of the printer.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described. FIG. 1 shows a block diagram of an embodiment of a color signal adjusting apparatus according to the present invention. This embodiment is shown in FIG.
It is realized by the CPU 3 in the personal computer 2. In addition, in order to make color signal adjustment easy for anyone to understand, FIG.
The adjustment status is displayed on the monitor 4 of FIG.

Particularly, the relationship between the input color signals and the output color signals of the output LUTs 22C to 22Y is shown by displaying the graphs shown in FIGS. 3 (A) to 3 (D) on the monitor 4. The image data stored in the image data storage unit 37 of FIG.
The image is printed by the printer 5 through the print processing unit 38 and is displayed on the monitor 4 through the display processing unit 41 and the display frame buffer 42, and the color of the portion of the image to be corrected is displayed as shown in FIG. The input value can be obtained by specifying the area.

Input LUTs 20R-2R in the printer of FIG.
0B, 3DLUT21, and output LUTs 22C to 22Y.
Input LUT data storage unit 34, 3DLUT data storage unit 35 and output LUT of FIG.
Each is stored in the data storage unit 36. These input LUT data storage unit 34, 3D LUT data storage unit 3
5 and the respective stored LUT data of the output LUT data storage unit 36, the input LUT data adjustment processing unit 31, the 3DLUT data adjustment processing unit 32, and the output LUT data adjustment processing unit 3
3 are independently adjusted and stored again, and are also output to the external printer 5 through the print processing unit 38 and input L in the printer 5.
It can be set as UT data, 3DLUT data, and output LUT data.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG. As shown in FIG. 7, the color signal data corresponding to the colors of the first color system output from the input LUTs 20R to 20B is converted into 3DLUT.
When converting to color signal data corresponding to the color of the second color system by 21, it is realized by general 8-point interpolation (method of interpolating the desired color in the color space from eight surrounding points). It is possible.

In FIG. 7, the output of the 3DLUT 21 is described as three color signal data of C, M and K, but here, the 3DLUT is C, M, Y and K (black).
The four types of color signal data are output (however, in this embodiment, the 3DLUT 21
It is needless to say that the present invention can also be applied to a 3-output 3D LUT like the above. ).

For example, the image data of RGB is printed by the printer 5 in the current 3 input LUT, 3D LUT, and 4 output LUT. Looking at the print result, the same area as the problematic color is designated as shown by 16 on the image 15 to be printed displayed on the screen 14 of FIG. 4 (corresponding to the screen of the monitor 4 of FIG. 5). . Then, the designated area 16 is input to the designated area color data calculation unit 43 through the display frame buffer 42 and the display processing unit 41 of FIG. 1, and here, the color data corresponding to the color of the first color system of the designated area 16 is input. (So,
Here, RGB color data) is calculated.

On the other hand, the simulation unit 39 of FIG.
From the input LUT data storage unit 34, the same input LUT data as the current input LUT data in the printer, and the 3DLUT
The RGB color data of the designated region 16 calculated by the color data calculation unit 43 of the designated region, which receives the same 3DLUT data as the current 3DLUT data in the printer from the data storage unit 35 (steps 101 and 102). Is input (step 103).

As a result, the simulation unit 39
First, the RGB color data of the designated area 16 is input L
The color data R ', G', B'when passing through the input LUT based on the UT data is calculated (step 104), and further based on the calculated color data R ', G', B'and the above 3DLUT data, 8 Simulate by point interpolation 3DL
The CMYK color data corresponding to the color of the second color system that has passed through the UT is calculated (step 105), and this is temporarily stored in the simulation result storage unit 40 of FIG.

Next, the same output LUT data as the current output LUT data in the printer is input from the output LUT data storage unit 36 (step 106) and passed through the 3DLUT read from the simulation result storage unit 40 and passed through C.
It is input to the display processing unit 41 together with the MYK color data.
The display processing unit 41 performs processing for displaying a vertical line according to the input value for each color of the CMYK color data, supplies the display data to the monitor 4 of FIG. 5 through the display frame buffer 42, and displays it. Step 107).

As a result, the screen of the monitor 4 is shown in FIG.
As shown in (A), (B), (C) and (D), C,
On the graph of the output LUT for each color of M, Y and K, an image showing the values of the color data obtained by the simulation by vertical lines I, II, III and IV is displayed. Note that in FIGS. 3A to 3D, the horizontal axis corresponds to the input data value of the output LUT, and the vertical axis corresponds to the output data value of the output LUT (here, an example of 256 gradations). Shown). Since the values indicated by the vertical lines I, II, III and IV correspond to the input color signal data of the output LUT when the color signal data of the designated area 16 is obtained, anyone can easily change the correction position of the output LUT. And, it can be grasped objectively.

Subsequently, when color adjustment is performed, the personal computer 2
Is operated to cause the output LUT data adjustment processing unit 36 to perform a desired value adjustment, the output LUT data is stored in the output LUT data storage unit 36, and further output to the printer 5 through the print processing unit 38. The output LUT data of is rewritten to the adjusted output LUT data. Thereafter, the print result of the printer 5 is checked to determine whether the designated area 16 has a desired color. Thereafter, the output LUT data is adjusted until the color of the designated area 16 becomes a desired color in the same manner as described above. During this time, since only the output LUT data is changed, the position of the vertical line indicating the correction position for adjusting the output LUT data displayed on the screen of the monitor 4 shown in FIGS. Not changed

The input LUT data, the 3DLUT data, and the output LUT data are stored in the input LUT data storage section 34, the 3DLUT data storage section 35, and the output LUT data storage section 36 of the personal computer 2, respectively. Even if the data and the 3DLUT data are modified, the result can be reflected in the vertical line.
Also, the corrected input LUT data, 3DLUT data,
Since the output LUT data can be set in the color conversion processing circuit 7 through the CPU 6 in the printer 5 of FIG. 5, it can be reflected in the print result.

If the above color adjustment is not sufficient, the direct mapping process described in Japanese Patent Laid-Open No. 3-244292 is used as a simulation of the 3DLUT process of the simulation unit 39. In this direct mapping process, the data of the three-dimensional color signal corresponding to the color of the first color system is divided into upper n bits and lower m bits, and the divided upper n bits of color signal data are 3DL.
UT is used to convert into the main data of the three-dimensional color signal corresponding to the color of the second color system, and the interpolation coefficient is read out, and the interpolation coefficient and the above-mentioned divided lower m-bit color signal data are calculated. Then, after generating interpolation data for interpolating between the main data which is data at intervals of 2 ^m , the interpolation data and the main data are added to each other to generate a color corresponding to the color of the second color system. This is a method for generating three-dimensional color signal data.

It should be noted that the simulation unit 39 has four inputs L
In the case of 4DLUT processing from UT, the following method can be mentioned as a simulation of 4DLUT processing. First, the CMY color data of the input CMYK color data is the output CMYK color data.
A simulation is performed by 8-point interpolation, which corresponds to the CMY color data of the color data. Regarding K output, even if an LUT is prepared separately, K for input CMYK color data
The printer circuit supports the above. A color conversion table showing correspondence is also prepared. Therefore, the CMY color data is extracted by 8-point interpolation, and K is the K for the input CMYK color data.
Extract according to the correspondence table of.

[0028]

As described above, according to the present invention,
The color signal corresponding to the color of the first color system of any specified area of the display image is input to the output look-up table of the printer and corresponds to the color of the second color system for which the color signal is adjusted. A color signal is adjusted by adjusting the table data of the output look-up table because a simulation is performed to convert the color signal to The value of the input data of the output lookup table (correction position for color signal adjustment) can be easily and objectively grasped even by a person who is unfamiliar with the color signal adjustment, so that the correction position can be positioned. Anyone can do it accurately and in a short time. Further, since the accuracy is increased, the number of times of repeating correction and printing can be reduced as compared with the conventional case.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of a device of the present invention.

FIG. 2 is a flowchart of an embodiment of the method of the present invention.

FIG. 3 is a diagram showing an example of a screen displayed by the present invention.

FIG. 4 is a diagram illustrating image area designation according to the present invention.

FIG. 5 is a block diagram of an example of a printer system to which the present invention is applied.

FIG. 6 is a conceptual diagram of correspondence from colors of a first device to colors of a second device.

7 is a schematic block diagram of an example of a color conversion processing circuit in FIG.

[Explanation of symbols]

1 scanner 2 Personal computer (personal computer) 3, 6, 10 Central processing unit (CPU) 4 Color display monitor using CRT 5 printers 7-color conversion processing circuit 8 image memory 9 Print processing unit 31 Input LUT data adjustment processing unit 32 3DLUT data adjustment processing unit 33 Output LUT data adjustment processing unit 34 Input LUT data storage 35 3DLUT data storage 36 Output LUT data storage 37 Image data storage 38 Print processing unit 39 Simulation Department 40 Simulation result storage 41 Display processing unit 42 Display frame buffer 43 Color data calculation part of designated area

Front page continuation (51) Int.Cl. ⁷ Identification code FI G09G 5/02 H04N 9/00 D 5/06 9/64 Z 5/36 510 1/40 D H04N 1/46 B41J 3/00 B 9 / 00 G06F 15/68 310A 9/64 H04N 1/46 Z (56) Reference JP-A-2-119466 (JP, A) JP-A-9-224158 (JP, A) JP-A-9-321999 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04N 1/60 H04N 1/46

Claims (3)

(57) [Claims] 1. A first color signal corresponding to a color of the first color system is processed by an input look-up table, and then a color of the second color system is processed using at least a look-up table for color conversion. Is converted into a second color signal corresponding to
Output to the printer that adjusts the value with the output lookup table and outputs it as the color signal for printing.
A color signal adjusting device for adjusting a color signal by externally setting table data of the output lookup table, wherein the input lookup table in the printer, the lookup table for color conversion, and the output lookup table. And the first, second and third storages that respectively hold the same table data, and an arbitrary area for which color signal adjustment in the same image as the print result of the printer displayed on the screen is to be adjusted. A calculation unit that calculates color data of the specified area by designation; and a simulation unit that performs color conversion simulation of the color data from the calculation unit based on the lookup table data from the first and second storage units. , The simulation result of the simulation means,
Display processing means for generating a display signal to be displayed in a graph showing the input / output characteristics of the output lookup table created based on the output lookup table data from the third storage section; and displaying the display signal on a screen. A color signal adjusting device, comprising: a display device. 2. The display processing means displays a graph showing the input / output characteristics of the output lookup table for each color forming the color of the second color system, and displays the simulation result in the graph. The color signal adjusting device according to claim 1, wherein the color signal adjusting device displays the line. 3. A first color signal corresponding to a color of the first color system is processed by an input look-up table, and then a color of the second color system is processed using at least a look-up table for color conversion. Is converted into a second color signal corresponding to
Output to the printer that adjusts the value with the output lookup table and outputs it as the color signal for printing.
A color signal adjusting method for adjusting a color signal by externally setting table data of the output lookup table, the same table as the input lookup table, the color conversion lookup table, and the output lookup table, respectively. While holding the data separately, calculate the color data of any area to be adjusted color signal in the same image as the print result of the printer displayed on the screen,
Based on the held input lookup table and the lookup table data for color conversion, color conversion simulation of the calculated color data is performed, and the simulation result is based on the held output lookup table data. A method for adjusting a color signal, which is characterized by displaying in a graph showing the input / output characteristics of the created output lookup table.