JPS63151268A - Color edge processor - Google Patents

Abstract

PURPOSE:To reduce color slurring at an edge part and color decision errors by reading color information at the edge part of a color character or a graphic to decompose the information into three primary colors, converting the colors to a hue and lightness information, detecting the edge and obtaining its direction, and deciding the color of the edge part. CONSTITUTION:Generally in case a multicolor original 102 whose saturation is high is used, the three stimulus value color information (R, G, B) read by a three color decomposition system 101 are not directly used, but instead they are subjected to a color conversion by a color conversion means 103, and thus converted to a hue/ lightness/saturation information. Among these three bits of information, the saturation information is not used, and the lightness signal or the hue signal is transmitted to a processing part 105, thus an edge is detected and the direction of the edge is extracted through a color information memory 104. A color decision means 106 retrieves the color information of a suitable color element in the memory 104 as a color information detection signal based on thus obtained edge-direction information, then replace it as a color information of the edge part. As a result, color slurring or color-decision errors at the edge part of a multicolor character or a graphic can be drastically reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a color edge processing device for making clear reproductions of multicolor text and graphic originals.

Conventional technology When performing image input for multicolor text and figure dokeymentation, as shown in Fig. 4, a multicolor original 401 is read with a TV camera, scanner, etc., and separated into three colors. The device 402 decomposes it into three-dimensional information (R (red), G (green), B (blue)), or to (cyan), M (magenta), Y (yellow)).

If the multicolor original 401 has N colors, the color separation means 4
In 03, based on the statistical properties of N colors, color separation into N colors using characteristic parameters of N colors (color masking calculation processing)
It is commonly done. Next, the color-separated information is supplied to a color recording device 404 (C!,
A copy 405 is obtained using ink of M, Y, B).

Problems to be Solved by the Invention When inputting an image for multicolored text or graphic documentation, if the resolution is sufficient, the information of the original image will not be lost, but if the image is input in three colors as shown in Figure 4, the information in the original image will not be lost. In a system that reads and duplicates a multicolor original 401 using the decomposition device 402, color information including halftones is produced at the edges of colored characters due to the perforation diameter (aperture), resulting in color shift and color distortion. Discrimination errors are likely to occur.

In view of the above-mentioned prior art, the present invention has been developed by adjusting the reading aperture (aperture) at the edge portion of the above-mentioned colored characters and figures.
This reduces color shift and misjudgment of colors.

Means for Solving the Problems The present invention includes a three-color separation system that reads color information in the edge portions of colored characters and figures and separates them into three primary colors, and converts the output signals of the three-color separation system into hue and brightness information. color conversion means;
a processing section that detects edges and determines their directions from the output information of the color conversion means;
The image forming apparatus is provided with a storage means for accumulating color information of pixels (N and M are integer values) and a color discrimination means for discriminating the color of the edge portion.

Effects of the present invention With the above configuration, by performing color conversion and using hue and brightness information, it is possible to extract edge direction components and accumulate color information easily and easily, and it is also possible to easily and easily extract edge direction components and store color information in multicolor characters and figures. Color shift and color discrimination errors at edge portions can be reduced.

51.-/ Example An example of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a color edge processing apparatus according to an embodiment of the present invention.

In FIG. 1, 101 reads a multicolor original 102 using a TV camera, scanner, etc.
, M, Y), etc., 3-color separation system, 10
3 is the three primary colors (R, G,
A color conversion means 104 that performs color conversion from B), (0, M, Y), etc. to information on hue, brightness, and saturation;
105 is a color information memory that temporarily stores the hue and brightness information sent from the color conversion means 103; 105 is a color information memory 104;
A processing section 106 inputs hue or brightness information from the processing section 105 to perform edge detection and direction extraction. This is a color discrimination means that replaces the color information of a portion.

The operation of the above configuration will be explained below.

6...-7 First, when using a multicolor original 102 with generally high saturation,
Tristimulus value color information (R, G) read by the 3-color separation system 101
, B) without using it as is, the color conversion means 103
The color is converted into hue, brightness, and saturation information. Among these three pieces of information, the saturation information is not used, and the brightness signal or the hue signal is sent to the processing unit 105 to detect edges and extract the edge direction via the color information memo IJ 104. Further, hue and brightness information are stored one after another in the color information memory 104 of N×M pixels adjacent to the edge portion. This color information memo IJ 104 is set so that the reading port (aperture) of the input device (TV camera or scanner) of the three-color separation system 102 accumulates color information on both sides of the edge portion, as shown in FIG. .

When the processing unit 104 detects an edge and sends information for extracting the edge direction to the color discrimination means 106, the color discrimination means 106 extracts the edge direction from the color information memory 10 based on the edge direction information.
The color information of the appropriate pixel No. 4 is searched as the color information detection signal and replaced with the color information of the edge portion.

7 l-7 Next, more specific embodiments of the present invention will be described.

As shown in FIG. 3, the three-color separation signal 100 sent from the three-color separation system 101 as shown in FIG. The converted and calculated data is stored in ROM (read-only memory IJ) 2
00, the color conversion signal (hue signal 101, brightness signal 102) corresponding to the three color separation signal 100 is output, the color information is distributed by the multiplexer 210, and 5 x 5 neighboring pixels are accumulated around the edge part. 1% AM (read/write free memory) 201. In this embodiment, it is assumed that the reading aperture completely crosses the edge with 5×5 pixels in the vicinity. The brightness information of R, A M 201 is input into a processing unit 203 that performs edge detection and direction extraction for a portion of eight pixels adjacent to the read pixel, and a detection signal 103 and edge direction information 104 for the edge portion are calculated. . When a reading pixel hits an edge portion, the detection of the edge is transmitted to the color discrimination device 202 using the edge detection signal 103. Appropriate color information is extracted from the RAM 201 using the edge direction information 104, and the color information 105 of the edge portion is transmitted to the color discrimination device 202. replace.

Effects of the Invention As described above, the present invention provides a three-color separation system that reads color information at the edge of a color character or figure and separates it into three primary colors, and a color separation system that converts the output signal of the three-color separation system into hue and brightness information. A conversion means, a processing section that detects edges and determines the direction from the output information of the color conversion means, and N×M (N.

By providing a storage means for accumulating color information of pixels (M is an integer value) and a color discrimination means for discriminating the color of the edge portion, it is possible to prevent color shift and color misalignment at the edge portions of multicolored characters and figures. Discrimination errors can be greatly reduced.

[Brief explanation of the drawing]

FIG. 1 is a block wiring diagram of a color edge processing device according to an embodiment of the present invention, FIG. 2 is a conceptual diagram showing the multicolor document reading state of the device, and FIG. 3 is a block diagram showing a more specific configuration of the device. Wiring diagram: Fig. 4 is a block wiring diagram of a conventional image processing device. 101...Three color separation system, 103...Color conversion means, 1
04... Color information memory, 105... Processing unit, 106
... Color discrimination means.

Claims (5)

[Claims] (1) a three-color separation system that reads color information in edge portions of color characters and figures and separates it into three primary colors; and a color conversion means that converts the output signal of the three-color separation system into hue and brightness information;
a processing unit that detects edges and determines their directions from the output information of the color conversion means;
1. A color edge processing device comprising: storage means for accumulating color information of pixels (N, M are integer values); and color discrimination means for discriminating the color of the edge portion. (2) The color edge processing device according to claim 1, wherein the processing section performs edge detection and edge direction using either hue information or brightness information output from the color conversion means. (3) The storage means for accumulating color information of N×M pixels adjacent to the edge portion stores the color information separately into hue information and brightness information. 1
The color edge processing device described in Section 1. (4) For the color information of N×M pixels adjacent to the edge area, N and M are set so that the reading port of the three-color separation system includes color information on both sides of the edge area. A color edge processing device according to claim 1, characterized in that: (5) Using the edge detection signal and direction signal output from the edge detection and direction processing unit, search for color information from among the color information of N×M pixels adjacent to the edge portion. The color edge processing device according to claim 1, wherein the color information is the color information of the edge portion.