KR950015051A - Color Halftoning Method and Circuit for Printer Model in Uniform Color Space - Google Patents

Abstract

The present invention relates to a color halftoning method and a circuit for a printer model in a uniform color space, wherein the color output device outputs a color signal inputted with natural colors through a limited color in a limited color. A color converting unit for converting an input color signal into a standard color coordinate matching a human visual characteristic, and an adder for forming a target color by adding up a sum of an input color signal output from the color converting unit and an error propagated from surrounding pixels And a color matching unit for matching a target color output from the adder with a limited color, a model for dot of the target color output from the color matching unit, and a database for combining color values of respective partial regions. In order to quantify the error caused by the overlap between the printer dot modeling unit and the printer dot, Consists of a group and the output color and a subtracter for obtaining the difference between the error of the printer output color dot model portion, the error filter for dispersing a pixel neighboring the quantification error output from the subtracter of. Therefore, there is an advantage that high quality of color printed images can be realized by accurately evaluating and correcting color distortion errors occurring in printing in a uniform color space consistent with human viewing characteristics.

Description

Color Halftoning Method and Circuit for Printer Model in Uniform Color Space

Since this is an open matter, no full text was included.

2 is a block diagram according to an embodiment of a color half-running circuit for a printer model in a uniform color space according to the present invention.

3 is an exemplary view of an error filter in FIGS. 1 and 2.

4 is an illustration of color matching for an eight color palette.

5 is a flowchart illustrating a color halftoning method for a printer model in a uniform color space according to the present invention.

6 is an exemplary diagram of overlapping of ideal pixels with actual dots.

7 is an exemplary diagram for area division of dots.

Claims (4)

A color output device for outputting a color signal having a natural color through an image input device in a limited color, the color output device comprising: a first step of converting the input color signal in standard color coordinates into standard color coordinates in accordance with human viewing characteristics; A second step of forming a target color by adding up the sum of the input color signal converted by the first step and the error propagated in neighboring pixels; A third step of matching a target color defined with the target color formed in the second step; A fourth step of quantifying an error due to overlap of printer dots after performing the third step; And a fifth step of distributing the error quantified by the fourth step to neighboring pixels. 5. The method of claim 1, wherein the fourth step comprises: a first step of obtaining an average diameter of the printer dots by measuring a color patch; A second step of obtaining a target area after performing the first step and obtaining an area for each segment; And a third process of determining a color value for each segment of the database after performing the second process, and performing a database into a uniform color space. A color output device for outputting a color signal input with a natural color through a picture input device in a limited color, the color output device comprising: a color conversion unit for converting the input color signal in standard color coordinates into standard color coordinates in accordance with human visibility; An adder for forming a target color by adding a sum of an input color signal output from the color converter and an error propagated from neighboring pixels; A color matching unit for matching a target color and a limited color output from the adder; A printer dot modeling unit for modeling a dot of a target color output from the color matching unit and constructing a database combining color values of respective partial regions; A subtractor for obtaining an error that is a difference between an output color of the adder and an output color of the printer dot modeling unit to quantify an error due to overlap of printer dots; And an error filter for distributing the quantified error output from the subtractor to neighboring pixels. The color matching unit of claim 3, wherein the color matching unit outputs, as a matching color of the target color, a color having a minimum spatial distance from the target color output from the adder among the colors of the color output device. Color halftoning circuit for printer models in space. ※ Note: The disclosure is based on the initial application.