JPH0458377A - Method for color picture reproduction - Google Patents

Abstract

PURPOSE:To shorten the processing time for inking and to simplify processing procedure by generating the generation processing of a black element for inking from the overlapping part of Y/M/C elements. CONSTITUTION:The picture data reproducing the color picture is color-separated into yellow (Y), Magenta (M), and cyanogen (C) by a color element separation means 5. The data in a memory 6 is printed by a printer 3. At this time, the generation processing of a black element data from the color element data of Y/M/C is performed by a black element generation means 4. Thus, the overlapping part of printed dot can be generated as the black element.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color image reproduction method in digital image processing.

[Prior art] Inking is one of the basic techniques in color image reproduction.
It is. That is, yellow (Y), magenta (M),
Reproducing black using only the cyan (C) color component may occur when the tone is different from reproducing black using the black component. For example, image reproduction using a four-color printer is Y.

In addition to reproducing colors using the M and C color components, inking is performed using the black component to improve the quality of the reproduced image.

At this time, for inking, a method is used in which the density of the black component is determined from the density of each of the Y, M, and C components.

[Problems to be Solved by the Invention] However, the above-mentioned prior art examples have drawbacks such as it takes time to determine the black component concentration and often requires large-scale equipment and complicated processing.

[Means for Solving the Problems] The present invention has been made in view of the above points. Image data for reproducing a color image is separated into yellow, magenta, and cyan, input into a memory, and the stored yellow, magenta, and cyan are input into a memory. The present invention provides a color image reproduction method that generates an overlapping portion of dots printed by each color component of cyan and cyan as a black component.

[Example] The present invention will be explained below based on preferred embodiments.

FIG. 1 is a drawing that best represents the features of the present invention. In the figure, image input means 1 such as a color scanner
Red (R), clean (G), and full (B) image data obtained by color-separating the color image are input to the memory 6, and the input color image is displayed by the display means 2.

Next, the color component separation means 5 separates the image data read from the memory 6 into Y, M, and C color component data, and inputs the data into the memory 6 again. At this time, if necessary, this color component data may also be displayed on the display 2 by the display means.

Furthermore, the data in the memory 6 is printed by the printer 3. At this time, the black component generating means 4 performs processing to generate black component data from Y, M, and C color component data.

FIG. 2 shows a specific configuration of a device for executing the image processing shown in FIG. It controls each component connected to AB, control bus CB, and data bus DB.

Address bus AB transfers address signals specifying each component to be controlled by microprocessor CPUII. The control bus CB transfers and supplies control signals for each component to be controlled by the microprocessor CPUII. The data bus DB transfers and receives data between each component device.

The ROM 12 is a read-only fixed memory, and stores procedures shown in the microprocessor CPU II, which will be described later.

RAM 13 is a writable random access memory and is used to temporarily store various data from each component.

PRT14 is a printer for printing generated images.

FIG. 3 is an example of a memory structure of Y, M, and C color component data after color component separation. In the figure, 1 bit corresponds to 1 dat of an image, which is divided into Y, M, and C and stored. For each color, from the top left: y(x+, yt), Y(x+, y2)"・y(xn
, ynLM (xs, yx) + M (xl, y2)...
・M(xn, yn).

C(x+, yt), C(Xl, 312) --
It will be expressed as −C(xn, yn) +.

FIG. 4 is an example of a flowchart of processing executed by the CPUI 1. As shown in FIG. 3, each color component data corresponding to the pixel at the same position stored in the memory is extracted (steps 21 to 23), and a logical OR is performed for each bit (step 24). The black data generated by this method is stored in memory (step 25).

FIG. 5 shows an example of generating black data according to the above procedure. In the figure, Yn represents the dot position where the Y color component is printed by the printer, Mn represents the dot position where the M color component is printed by the printer, and Cn represents the dot position where the C color component is printed by the printer. .

Furthermore, Bn represents the dot position where the black component is printed.

The printer 14 reproduces colors by printing dot patterns of each color overlappingly. That is, the Bn black dot pattern is generated by temporarily storing the MMC dot pattern in the RAM and logically ORing the dots at the overlapping dot positions of these color components. That is, the black dot is given by the following first equation.

Bn=YnORMnORCn...1 Here, Bn represents a black dot, and Yn, Mn, and Cn represent component color dots.

[Effects of the Invention] As explained above, by generating the black component for inking from the overlapping portion of the Y, M, and C components, the processing time of the inking process can be shortened and the processing procedure can be improved. It is effective in simplifying the process, reducing the cost of processing equipment, and improving the quality of reproduced images.

[Brief explanation of the drawing]

Fig. 1 is a conceptual diagram of the present invention, Fig. 2 is a block diagram of the device of the present invention, Fig. 3 is a diagram showing an example of the configuration of image data, Fig. 4 is a flowchart, and Fig. 5 is an example of data generation. 11 is CPU 12 is ROM 13 is RAM 14 is PRT yl y2 y3 n Figure 4

Claims (1)

[Claims] The feature is that the image data for reproducing a color image is separated into yellow, magenta, and cyan and input into memory, and the overlapping portion of the dots printed using the stored yellow, magenta, and cyan color components is generated as a black component. Color image reproduction method.