JPH04237261A - Color printer controller - Google Patents

Abstract

PURPOSE:To eliminate the difference of a color tone of a picture on paper printed out by a color printer from a color tone of a picture expressed on a color display device. CONSTITUTION:This controller is provided with a storage means 13 storing a prescribed number of combinations of color components representing a print color and color component conversion means 12-14 which compares the combination of color components designated by print information with the combination of color components stored in the storage means and giving a combination closest to the combination of the color component designated among the combinations of the color components to a print means in place of the color component of the print information.

Description

DETAILED DESCRIPTION OF THE INVENTION [0001]The present invention relates to a color printer control device, and more specifically, to a color printer control device for converting printing color (color component) information supplied from a computer main body etc. to a color printer. The present invention relates to a color printer control device. [0002] In the creation of color images using a computer, a color display device such as a color CRT (cathode ray tube) or a color LCD (liquid crystal display) is used to arrange colors, draw, etc. on the screen. This can be advanced by The information of the created color image is the color components "R (red), G" of each dot.
(green), B (blue)” or “Y (yellow), M (magenta)”
, C (cyan)'' and supplied to a color printer. Problems to be Solved by the Invention In many cases, there is a perceived difference between the tone of an image expressed on a color display device and the tone of an image on paper printed out by a color printer. This is due to the fact that the color resolution of color display devices is lower than that of color printers, and that the color characteristics (material characteristics) of the ink or ink sheet of color printers do not match the color characteristics of color display devices. are doing. [0004] Accordingly, in the present invention, there is provided a storage means that stores a predetermined number of combinations of color components representing printing colors, and a storage means that stores combinations of color components specified by printing information in the storage means. Color component conversion that compares the specified combination of color components and supplies the color component combination that most closely approximates the designated color component combination to the color printer instead of the color component of the print information. We will try to solve the above problems by using means. [Operation] That is, in the present invention, the number of print colors of a color printer and the combination of color components representing the colors are predetermined in accordance with the color resolution of the color display device and the color characteristics of the ink or ink sheet of the color printer. The number, for example, 108 sets (colors) is determined. Combinations of these predetermined numbers of color components are stored in the storage means. The printing color of each dot is specified in the form of a combination of color components depending on printing information supplied from the computer main body or the like. The color component conversion means compares the designated combination of color components with the combination of color components stored in the storage means, and selects a combination of color components that most closely approximates the designated combination of color components among the combinations of color components. The color components are selected and supplied to the color printer in place of the color components of the print information. [0006] The details of the present invention will be explained below based on the illustrated embodiments. In FIG. 2, reference numeral 1 denotes a computer main body, which executes so-called color graphic software and other application programs. A color CRT display 2 displays color image information supplied from the computer main body 1. 3 is a keyboard for inputting various data and functions (commands). A so-called mouse 4 controls the cursor on the color CRT display 2, selects so-called icons (inputs functions), and the like. 11 is a color printer control device, 12 is its central processing unit (CPU), and a program or read-only memory (ROM) 1 downloaded from the computer main body 1 to a random access memory (RAM) 13;
Execute the program stored in 4. 15 is LCD (
The data supplied from the CPU 12 is displayed on the liquid crystal display. 16 is a touch panel for inputting desired characters and functions (commands). A color printer 17 prints out a color image on paper 18 based on the color components of each dot supplied from the CPU 12. 19 is an input/output port, which connects the CPU 12 and each peripheral device 15 to
Data is exchanged with 17. 20 is a lithium battery that backs up the RAM 13. The apparatus of this embodiment operates as follows. First, data of a combination of color components determined by taking into consideration the characteristics of the CRT 2 and the color printer 17 is stored in the RAM 13. This color component data may be input using the LCD 15 and touch panel 16, or it may be selected from several types prepared in advance on the computer body 1 to match the characteristics of various CRTs and printers. You may also download it. Further, an IC card storing data may be selectively installed depending on the purpose. Tables 1 and 2 show data examples of color component combinations. [0009] [Table 1] [0010] [Table 2] [0011] In Tables 1 and 2, n is the number of a combination of color components (printing color). In this example, colors from red to purple are divided into 108 colors, and for these 108 colors (108 sets), the value of the color component of each set (each printing color) is determined by a numerical value with "1" as the maximum density. Ta. For example, the combination number n=0 is determined for "black", and the combination number n=62 is determined for "yellow". However, the three primary colors of light, R, G, and B, were used as color components. In addition, in this embodiment, in order to make it easier to understand, for example, whether it is "black" with n=0 or "yellow" with n=62, the color components are as "R, G, B=1" or "R,G=1
, B=0]. The value of this color component should be adjusted according to the characteristics of the color display 2 and color printer 17. For example, for "black" where n=0, "R=0"
．． 95, G=0.99, B=1.0". [0012] Conversion of color component combinations (print colors) in the print information supplied from the computer main body 1 involves developing the print information into dot data that can actually be printed, such as by developing character codes into bitmaps. Executed as needed as part of routine. Figure 1 shows the procedure. First, we will explain the definition of each variable. AR, AG, AB...R, G, and B color components specified by print information. CR, CG, CB…AR
, AG, AB color components that are temporarily held as a combination of color components close to each other. MC...Marginal approximation. Determined according to the purpose. If the degree of approximation C is larger than this, replacement is inappropriate. Rn, Gn, Bn...R, G of number n in Table 1 or Table 2,
B Each color component. DR, DG, DB...Difference between AR and Rn, difference between AG and Gn,
Difference between AB and Gn. TC...Approximation (sum of absolute values of DR, DG, and DB). The smaller the better. C...Minimum approximation degree. What is retained during processing? Minimum value of TC detected up to that point. NR, NG, NB... New R, G, B color components supplied to the color printer 17. First, in step S1, the color component combinations AR, AG, AB included in the print information are taken into a calculation buffer. Next, the temporarily held color component CR,
The initial value "0" is assigned to CG, CB, and n, and the initial value "3" is assigned to the minimum degree of approximation C. Then, "3" is substituted here for the limit degree of approximation MC (step S
2). Next, the process advances to step S3, and the contents of the minimum degree of approximation C are checked. This step S3 is for ending the process here if a combination of color components matching the color components AR, AG, and AB specified in the print information is found, and in this case, the CPU 12 does not perform a subsequent search. The CR
, CG, and CB as the converted color components NR, NG, and NB, and this process ends (step S11). This new combination of color components NR, NG, and NB is taken in by the aforementioned "routine for developing print information into dot data that can actually be printed" and is supplied to the color printer 17. When the process has proceeded from step S2 to step S3, the answer here is "yes" because the minimum degree of approximation C=3 is set in step S2. Therefore, C.P.
U12 proceeds to step S4. Here, the color combination Rn, Gn, Bn of number n is read out from Table 1 or Table 2. When proceeding here from step S2, n=0 is set in that step, so the first combination n=0 in Table 1 is "
"R=1, G=1, B=1" is read out. Then, the difference DR between the color component AR specified in the print information and Rn at this time
, Similarly the difference DG between AG and Gn, Similarly the difference D between AB and Bn
B is calculated, and the sum TC of their absolute values is calculated. The sum of absolute values TC is the set of color components AR, AG, and AB specified in the printing information and the set of color components Rn, Gn, and Bn in Table 1 at that time (here, n=0). )
represents the degree of approximation between The purpose of the processing in Figure 1 is to
The combination of color components CR, CG, CB (NR
, NG, NB) from Table 1 or Table 2. The degree of approximation TC calculated at this time in step S4 is compared with the limit degree of approximation MC. As described above, the limit approximation MC defines the limit at which color component replacement is inappropriate. In this embodiment, this is set to "3" in step S2.
”, so if this value TC were 3 or more, the answer here would be “no”. In this case, the CPU 12 proceeds to step S8, increments n, returns from step S9 to step S3, and repeats the same process for the next number n=1 in Table 1. And if for all combinations of Tables 1 and 2, the degree of approximation TC
If exceeds the limit approximation degree MC (=3), the CPU 12 determines that the replacement is inappropriate, and the CPU 12 uses the "
CR=0, CG=0, CB=0 (i.e. color "white")" is assigned to NR, NG, NB, and the process ends (step S1
0). Returning to the point in time when the process advances from step S2 to step S5. The answer in step S5 is "yes"
, that is, the degree of approximation T for the combination of color components with number n=0
When C is below the critical approximation degree MC (=3), C
The PU 12 proceeds to step S6. Here, the degree of approximation TC is compared with the minimum degree of approximation C held at this point. When proceeding from step S2, C=3 is set in step S2, so if the degree of approximation TC is lower than this, CP
U12 proceeds to step S7, and at this time Rn, Gn,
Assign Bn to CR, CG, and CB, respectively. and CPU
12 substitutes the degree of approximation TC at this time to the minimum degree of approximation C,
Proceed to step S8. Here, n is incremented. Then, the process advances to step S9 to check the contents of n. If the process comes from step S2, n is still 1, so the process returns to step S3. Step S3
The processing from to S9 is continued until n reaches 108, unless the answer is "no" in step S3 as described above. Through this repetition, the temporarily held CR, CG, and CB are replaced with color components AR, AG, and AB that are closer to those designated by the print information. At the time when n reaches 108, the CR, CG, C
B is the color component AR, AG, A specified by the print information
This is the closest approximation to B. This most approximate color component combination CR, CG, CB is substituted into NR, NG, NB when n=108 (step S
10). However, in this embodiment, the limit degree of approximation MC is set to "3".
However, other values may be used. For example, if this is set to "1", among the printing colors included in the printing information, those whose similarity degree TC for each color in Tables 1 and 2 exceeds this value will be
The color components are "NR=0, NG=0, NB=0, that is,"
It is converted to "white". Further, the number of combinations of color components in Tables 1 and 2 and the distribution of R, G, and B are arbitrary. Furthermore, if the combination of color components to be supplied to the color printer 17 instead of the color components specified by the print information is made to have the same ratio of R, G, and B components, it is possible to print in a single color. I can do it. Here, the same component ratio refers to the same color but different density, for example, n=0, 1, 2 in Tables 1 and 2.
They say things like 1, 41, 61, 101 (R, G, B
(The proportions vary depending on the color, of course). [0021] As explained above, in the present invention, the combination of color components specified by the print information is compared with the combination of color components stored in the storage means, and the combination of color components is determined. Among them, a combination of color components that is most similar to the specified combination of color components is supplied to the color printer instead of the color components of the print information. Therefore, the color tone of the image expressed on the color display device and the color tone of the image printed on paper printed by the color printer are harmonized, and no difference is perceived. Also, on the computer side, the color specification code of the image data, etc.
Although the color components are converted into RGB or CMY color components by calculation and sent out, the present invention eliminates variations in color due to calculation errors (digit loss, etc.) that occur at that time. Also, by manipulating the combination of color components that should be replaced with the color components of print information,
The color tone of the output printed matter can be changed arbitrarily. Furthermore, if this conversion is performed on the color printer side, there is no need to change the specifications of the software on the computer main body side.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing a processing procedure for color component conversion.

FIG. 2 is a block diagram showing a circuit configuration.

[Explanation of symbols]

12-14 Color component conversion means 13. Storage means

Claims (1)

[Claims] 1. A storage means that stores a predetermined number of combinations of color components representing printing colors, and a combination of color components specified by printing information is compared with a combination of color components stored in the storage means, A color printer control characterized by comprising a color component conversion means for supplying a color component combination that most closely approximates the designated color component combination to the color printer instead of the color components of the print information. Device.