JPS6248876A - Color image processor - Google Patents

Abstract

PURPOSE:To convert a full color signal to three color binary-coded signals by separating inputted three groups of color picture signals to a common component and a non-common component and binary-coding inputted three groups of the color picture signals based upon each of separated signals. CONSTITUTION:The reflected light of an original 2 by the illuminating light of a light source 3 is inputted to an image sensor 4. The image sensor 4 performs a color separation on the light synchronizing with a one line section signal (a), outputting it to a quantizer 5 as a Red signal R, a Green signal G and a Blue signal B having N-number of bits respectively. The quantizer 5 quantizes these inputted signals and outputs quantization signals to each corresponding latch circuit 8, 8 or 9. The quantization signals a R, G and B are outputted to a conversion means 22 respectively by synchronizing signals, etc. from the latch circuits 7, 8 or 9. The conversion means 22 performs the conversion of the signals according to a prescribed procedure.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a color image processing device that separates colors into three color signals, binarizes each signal, and outputs multicolor signals of eight colors in total. .

BACKGROUND OF THE INVENTION FIG. 3 is a schematic diagram showing an example of a conventional color image processing apparatus.

This color image processing device inputs a glass plate 1 on which an original 2 is placed, a light source 3 that illuminates the original 2, and the reflected light from the original 2, and separates this reflected light into color information of three colors. An image sensor 4 that outputs this as a color separation signal, and latch circuits 7, 8 that latch three types of color separation signals for each color.
9, a rotary switch 19, 20, 21 for setting the slice level of each color, and comparators 16, 17, 18 for binarizing the color separation signal according to the slice level,
From these comparators 16, 17, and 18, binarized signals for each of R, (, B, as shown in FIGS. 6 and 7) were obtained.

Problems to be Solved by the Invention However, with this configuration, relative determination of the three color separation signal levels is not performed, and even if the overall density is high and the signal level is low, Since binarization is performed at a constant slice level, there is a problem in that the reproduced hues vary depending on the shade.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a color image processing device that can convert a full color signal into a three-color binary signal without being affected by differences in density. purpose.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention includes a reading optical system that separates the image information of a document into three systems of color, and a conversion means that inputs the three systems of color image signals. ing. The conversion means separates the input three systems of color image signals into common components and non-common components, and binarizes the input three systems of color image signals based on the respective separated signals.

The common component is subtracted from the color image signals of the three systems of action, and the relative level of the remaining components is calculated, and this calculated value and the magnitude of the common component subtracted at the same time are compared and determined using respective predetermined reference values. The three systems of color image signals are binarized.

Embodiment FIG. 1 is a schematic configuration diagram showing a color image processing apparatus according to an embodiment of the present invention.

This color image processing device inputs a glass plate 1 on which an original 2 is placed, a light source 3 that illuminates the original 2, and the reflected light from the original 2, and separates this reflected light into color information of three colors. It is equipped with an image sensor 4 that outputs this as a color separation signal. Note that in this embodiment, light source 3. Image sensor 4
This constitutes a reading optical system.

An H-bit quantizer 5 is connected to the image sensor 4, and latch circuits 7, 8.9 for latching the color signals of the N-bit quantizers 5KR, G, and B, respectively. Furthermore, it is connected to latch circuits 7, 8.9, inputs color signals from each, separates this color signal into common components and non-common components, binarizes the color signal based on these separated signals, and converts the color signal into two values. and converting means 22 for outputting a converted signal.

The operation of the color image processing apparatus configured as above will be explained below.

First, the image sensor 4 receives reflected light from the original 2 due to the illumination light from the light source 3 . And image sensor 4Fi,
As shown in FIG. 4, this light is color-separated in synchronization with the 1-line section signal B, and outputted to the quantizer 6 as N-bit R, G, and B signals, respectively.

The quantizer 5 quantizes these input signals, and sends these quantized signals to the corresponding Usochi circuits 7.
, 8.9.

The R, G, and B quantized signals are sent to latch circuits 7 and 8.
．． 9 to the converting means 22 using a synchronizing signal or the like.

The converting means 22 converts the signal according to the procedure shown in FIG.

First, the quantized signals input from the latch circuits 7, 8.9 are respectively set as signals R1+' 1 + B1, and (
In step (hereinafter referred to as 8T) 1), in the case of this embodiment, it is assumed that the signal "1+01+B1 is the signal shown in FIG. 6. Among these, the signal with the lowest level is extracted (Sr2 ).In the case of this embodiment, the signal G1 is the lowest level, and this is referred to as the common component X, and its level is designated as X.

Next, the common component level X is subtracted from the level R1+B1 of each of the signals R1 and B1 to calculate the non-common components R2 and B2 (this level is also 121B2 (R2<B2)) (Sr1).

Level R2+ 82 is compared with a predetermined threshold a in step ST4, and if level R2 or level B2 is thicker than threshold a, it is determined to be a chromatic color, and conversely, if both are smaller than threshold a, Determined as white or black (Sr
4). If it is determined to be white or black, it is determined whether the level X of the common component X is greater than a predetermined threshold value (Sr7).

If it is determined as YES in step ST7, RlG corresponding to each of the common components R1+' 1 + B+,
B binary signals RO, Go, and Bo are “1”, that is, “white”
(Sr8). Further, when it is determined that the signal is NO, the signal RO+GO+BO is output as 0, that is, 6 black (Sr9).

When it is determined that it is a chromatic color (that is, when it is determined as YES in step ST4), the threshold value C (C:B2X1/
N; N*1) is set, and the magnitude with respect to level R2 is determined (STs). In this determination, in either case of YES Y or NO N, the signal R2+σ2. Of B2, 'ab
, the dog's value is 1゛ from c.

Smaller values are output as "0".

In this way, the level R of the signal R1+G1+B1
1+G1+B1, and outputs a binarized signal RQ+GO+BO for each pixel.

Effects of the Invention As is clear from the above explanation, according to the present invention, the common component of color-separated three-color color signals is subtracted, and the magnitude of the remaining non-common component and the subtracted common component are both calculated. To create the binarized level of each signal from the level,
This has the advantage that color signals can be binarized without depending on density.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing a color image processing device according to an embodiment of the present invention, FIG. 2 is a flow diagram showing an example of the determination flow of the conversion means of the same device, and FIG. 3 is a conventional color image processing device. FIG. 4 is a signal waveform diagram in the image processing section of the apparatus shown in FIGS. 1 and 3, FIG. 5 is a signal waveform diagram of the main part of the apparatus shown in FIG. FIG. 7 is a signal waveform diagram of the main parts of the device shown in FIG. 3. 3...Light source, 4...Image sensor, 6...
...Quantizer, 7,8.9...Latch circuit, 22...Conversion means. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 4 Figure LJ 5 Figure Rt G+ Ih M 6 Figure 7

Claims (1)

[Claims] A reading optical system that scans a document, separates the image information of the document into three systems, and outputs color image signals; and a reading optical system that inputs the three systems of color image signals and converts each image signal into a common component. and converting means for separating the color image signals into non-common components and binarizing the three systems of color image signals based on these common component signals and non-common component signals.