JPH0410869A - Color erasure - Google Patents

Abstract

PURPOSE:To improve the color erasure accuracy and the copying speed by erasing a color area according to a detection signal from a chromatic color detection means detecting a color area other than white/black color by means of an erasure means. CONSTITUTION:A picture read means (a) reads a color picture of an original and obtains three color data subjected to color separation. Moreover, a chromatic color detection means (e) generates chromatic color information from the three color data to detect a color area other than white/black color on the original. Then an erasure means (d) erases a color area according to a detection signal from the chromatic color detection means (e). Thus, designation of type of color is not required in comparison with color erasure by the application of color conversion function and the erasure of the color area on the original is attained simply by one operation. Thus, the color other than white/black color on the color picture is erased at a fast speed with high accuracy by a simple color designation operation.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a color erasing device used in digital color copying, color facsimile, etc. for erasing color areas from a color image original. Copying machine (Dai) In addition to functions for faithfully copying color information, it is equipped with a variety of editing functions.

For example, it is a color conversion function that performs color discoloration such as marking on a document copied by a conventional black-and-white copying machine or the like, or converts a specified color on the document to a different color.

- A new requirement has arisen to erase color areas for original documents that have been discolored or stamped with approval stamps, etc. Conventional devices do not have a function to meet this requirement, and color conversion can be applied to erase colors. An example of the above-mentioned conventional color erasing device will be described below with reference to the drawings. FIG. 4 shows a basic configuration diagram of a conventional color image processing apparatus. In FIG. 4, 201 is an image reader ratio, 202 is a position specifying means, 203 is a detection half-submerged device, and 204 is a color conversion means.

Regarding the color image processing device configured as above,
The operation will be explained below.

An image reading unit 201 reads a color image of a document using an image sensor such as a CCD (charge-coupled device), and outputs color-separated three-color color data (digital data). The position specifying means 202 is composed of a digitizer or the like, and by specifying an arbitrary point within a substantially constant density area of a color image, it is possible to input the position data of the pixel at that point.

Detection means 203 ζ table Detects and stores the maximum and minimum values of color data of three colors for N×N pixels around the pixel designated by the position designation means 202, respectively. The color conversion means 204 compares the maximum value and minimum value detected by the detection means 203 with the three color data supplied from the image reading device 201, determines whether or not they are within the specified density range, and outputs the determination result. Color erasing: This can be achieved by specifying the color on the document that you want to erase and specifying the converted color as white.
Problems to be Solved by the Invention (For example, Japanese Patent Laid-Open No. 62-192862) However, in the above method, when there are a plurality of colors to be erased, it is necessary to repeat the color designation operation several times.

In addition, there is a problem in that color areas that cannot be erased due to density range restrictions such as the maximum density basket and minimum density value of the target color exist within the specified erase area 1 or a certain target color target area. ,,
When using a color printer that forms colors by side-by-side magenta and black, the color will be erased in the four processes of copying a color original, and if the purpose is only for the color erasing function, the copying speed will be lower. In view of the above problem, the present invention aims to provide a color erasing device that can erase colors other than black and white parts on a color image with high precision and at high speed by a simple color specifying operation. The purpose is

Means for Solving the Problems In order to solve the above problems, the color erasing device ζ of the present invention is used.
Solving means 1 includes an image reading unit that separates a color original into multiple colors to generate color image data, a monochrome generation unit that generates monochrome image data from the color image data, and a chromatic color area from the color image data. and an erasing means that erases only the chromatic color area obtained from the detection means out of the monochrome image data output from the monochrome generation means.

Solution 2 includes an image reading unit that separates a color document into multiple colors to generate color image data, and a yellow scanner that is necessary to form a color image from the color image data.
, an image processing means for generating image forming data of magenta, cyan, and black; a detecting means for detecting a chromatic region from the color image data; and an image forming data output from the image processing means. It consists of an erasing means for erasing only the chromatic color area obtained from the image.

Solution means 3 includes an image reading means that separates a color document into multiple colors to generate color image data;
, magenta, cyan, and black image forming data.

Solving means 4 includes an image reading unit that separates a color original into multiple colors to generate color image data, a monochrome generation unit that generates monochrome image data from the color image data, and a color image formation from the color image data. an image processing means for generating yellow, magenta, cyan, and black image forming data necessary for image forming; a detection means for detecting a chromatic color area from the color image data; and a designation of a color erasure area on the color document. An erasing area specifying means into which area position data can be input by means of the above, and the setting of the erasing area specifying means selects the monochromatic image data output from the monochrome generating means for the area to be color erased, and does not perform color erasing. The area is comprised of erasing means for selecting the output of the image processing means, and the erasing means erases only the chromatic color area obtained from the detection means out of the monochrome image data output from the monochrome generation means.

Effect of the Invention With the above-described configuration, the image reading means reads a color image of a document and obtains color separated three-color data. The chromatic color detection means generates chromatic color information from the three-color color data and detects color areas other than black and white on the document. The erasing means can erase the color area according to the detection signal from the chromatic color detection means. Therefore, compared to the case of color erasing by applying the color conversion function, there is no need to specify which color to use, and it becomes possible to easily erase a color area on a document by a -degree operation.

Color erasure accuracy is improved because color erasure is performed depending on whether the color is chromatic or achromatic without detecting a specific color density range.

In addition, the monochrome generation means that generates monochrome data from color image data is used as image data to the printer in areas other than color areas.It is possible to copy to the printer by forming an image once, that is, by forming only black, and the copying speed is high. It becomes possible to perform

Furthermore, by using the black image formation data of the image processing means, it is possible to copy to a printer with just one image formation, increasing the copying speed,
Furthermore, since no means of detecting the chromatic color area is used, it is possible to reduce the cost.

The erasure area specifying means makes the color area signal of the chromatic color detection means valid only for a desired area on the color document, and replaces the color area other than the color area detected by the chromatic color detection means with monochromatic data. It is possible to accurately erase chromatic colors from a desired color erasing area on a document.

Embodiment Hereinafter, a color erasing device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows the overall configuration of a color erasing device in one embodiment of the present invention.

In Fig. 1, a denotes an image reading means as a means for generating color image data, which reads the color image of the original with an image sensor such as a charge-coupled device, and generates color-separated three-color color data (digital data). ) is output. b is a color image processing means that generates yellow, cyan, magenta, and black, which are image forming colors for a color printer, etc., from color-separated three-color data (digital data); C is three-color color data ( A monochrome generator t that generates monochrome data from digital data);
d is the color image processing means b based on the color information from the chromatic color detection means e and the erasure area from the erasure area designation means f.
, or erasing means for erasing the output data from monochrome generating means C, e is color data of three colors (digital data)
chromatic color detection means for detecting a chromatic color area on a document from
f is an erasing area specifying means for specifying an erasing area on a document for the erasing means d.4 Regarding the color erasing device configured as above, the first
The basic operation will be explained using @ and FIG.

Figure 3 shows operation explanatory diagrams to explain the color erasure function. (a) shows the case where the erasure area is not specified, and (b) shows the case where the erasure area is specified on the same original as (a). In FIG. 3(a), 101 indicates black letters A and B.

For example, blue markings are painted on C and D with a marker pen, etc. 102 has black letters E, FG, H
For example, an enemy with a green underline
For example, 103 shows an example in which a red approval seal is stamped.

In FIG. 3(b), the erased area (Xi, X2°X3.
X4) shows an example in which the underline 102 is the object to be erased on gl.The erase area (Yl, Y2.Y3.Y4) shows an example in which the recognition mark 103 is the object to be erased.

The case where area specification is not performed will be described.

In FIG. 3(a), the operator marks 101,
An example of an operation when it is desired to erase the underline 102 and the approval mark 103 from a document will be described.

(Example 1) A first operational example will be described.

As a configuration, an image reading means a, a monochrome generating means C2, an erasing means d, and a chromatic color detecting means e are used. Using said means,
Set the copy mode to monochrome copy mode.

When the operator executes the color erasing function using the operation panel, etc., the color original is separated into three colors by the image reading means a.
This becomes color data and is output to the monochrome generating means C. The monochrome generating means C generates monochrome data from the color data of the three colors and outputs it to the erasing means. On the other hand, the chromatic color detection means e detects the chromatic color areas on the color document, namely the marking 101, underline 102, and approval mark 103 areas, and outputs a detection signal to the erasing means d. The erasing means d erases one of the output data of the monochromatic color generating means C, the chromatic color area signal portion on the color document outputted from the chromatic color detecting means e, and outputs it to a color printer or the like. Color printers are in monochrome copying mode and form images in black only.

(Example 2) A second operational example will be described.

The configuration includes an image reading means a, a color image processing means b,
Erasing means d and chromatic color detecting means e are used.

The copy mode is set to color copy mode using the above means. When the operator executes the color erasing function using the operation panel or the like, the color original is separated into three color data by the image reading means a, and is output to the color image processing means. The color image processing means outputs yellow, which is an image forming color, to a color printer from the color data of the three colors.
Generates and erases cyan, magenta, and black
Output to. On the other hand, the chromatic color detection means e detects the chromatic color areas, the markings 101, the underlines 102, and the recognition marks 103 on the color document, and outputs a detection signal to the erasing means d. The chromatic color area signal portion on the color document outputted from the chromatic color detection means e is erased and outputted to a color printer or the like. Color printers form images in color copying modes: yellow, cyan, magenta, and black. Color erasure is performed in the process of forming a color image.

(Example 3) A third operational example will be described.

As a configuration, an image reading means a and a color image processing means are used. Using the above means, the copy mode is set to monochrome copy mode. When the operator executes the color erasing function using the operation panel or the like, the color original is separated into three color data by the image reading means a, and is output to the color image processing means. The color image processing means outputs only black data to the color printer. As a result, only the achromatic color area is output to a color printer or the like.

Color printers are in monochrome copying mode and form images in black only. Further, the black data is a signal generated by a full black method (100% UCR).

By the operation of the above-described first embodiment, second embodiment, and third embodiment, the chromatic colored portions on the color document shown in FIG. It will be done.

Next, the case of specifying an area will be described.

In FIG. 3(b), an example of the operation will be described in which the operator wants to erase the marking 101, the underline 102, and the underline 102 and the recognition mark 103 from the document.

(Example 4) A fourth operational example will be described.

The configuration includes an image reading means a, a color image processing means b,
A monochrome generating means C1, an erasing means d, a chromatic color detecting means e, and an erasing area specifying means f are used. In the above configuration, the copy mode is set to color copy mode.

In this case, for example, as shown in Figure 3(b), the underline 102 of the erasure area (Xi, X2.X3°X4) is to be erased. and erase area (Yl,
Y2. Y3. When the recognition mark 103 of Y4) is targeted for erasing (Y4), the erasure area specifying means f uses a coordinate input device etc. to select the erasure area (XI, X2°X3.X4) and (Yl
, Y2. Y3. The coordinates of Y4) are input and an erase signal at the desired position is output to the eraser d based on the address information. The erasing means d makes the color region pressure signal of the chromatic color detecting means e valid only in the color erasing region according to the output of the erasing region specifying means f, and erases the color region portion within the effective region.

Furthermore, the image data within the effective area is used to select the output data of the monochrome generation means, and the area outside the effective area is operated to select the output data of the color image processing means. The image reading means a, the color image processing means b, and the monochrome generation means C perform the same operations as in the first and second embodiments.

By the above-described operation of the fourth embodiment, the chromatic portion in the area specified in FIG. 3(b), ie, the underline 102 and recognition mark 103 area, is erased from the original.

FIG. 2 shows a block diagram of the color erasing device in one embodiment of FIG. 1. In FIG. It outputs a signal. A/D converter 2 (Yo)
Converts to 8-bit digital signal L. Expresses 256 gradations for each color.

Complementary color converter 3 (Table Density conversion (＼ Signals Y1, Ml representing the amount of three color inks of yellow, cyan, and magenta)
, C1. The UCR/inking circuit 4 performs undercolor removal (OCR) and inking processing.

Masking circuit 5 (main) This circuit performs color correction and removes the cloudy components of the color separation filter of the human power sensor 1 and the cloudy components of the ink of the color printer 11.

20 is a microprocessor (hereinafter simply referred to as CPU).
, 21 is read-only memory (hereinafter simply referred to as ROM), random access memory (hereinafter simply referred to as RAM).
Say. ), 24 is an input/output port for outputting setting values from the CPU 20, and 24 is a bus.

The selector 64 outputs each output signal C3, M3, Y3 of the masking circuit 5 according to the setting signal 31 from the CPtJ20.
This circuit selects 2 as the output signal of the UCR/inking circuit 4.

The selector 7 converts the output data 41 (GX) of the selector 6 and the monochromatic signal 44 (
This is a circuit for selecting Vd).

The erasing circuit 8 is a circuit that erases a color region within a desired region according to the control signal 34 of the region setting circuit 12 and the color region signal 33 of the chromatic color detection circuit 100.

Luminance color difference conversion circuit 9i This is a circuit that generates a luminance signal V and color component signals I and Q based on the RGB signals, and outputs a monochromatic signal Vd subjected to density conversion for the luminance signal (2).

The chromatic color determination circuit 10 is a circuit that determines a color region based on the color component signals I and Q from the luminance/color difference conversion circuit 9 and the determination level value 36 set by the CPU 20.

The area setting circuit 12 is a circuit that sets a color erasure area based on coordinate position information from the coordinate input device 23.

22 is an operation panel consisting of various input keys and a display, and displays copy start input, set number of copies, and error display.
Performs operations such as copy mode (color copy/single color copy), displays settings, etc.

23 is a digitizer which is a coordinate input device, and when the operator presses a desired area on the document for color erasing with a position pen, the coordinate position information (address information) in the main scanning direction and sub-scanning direction of that position is transferred to the bus. 24 to the CPU 20.

The color printer 11 is, for example, a color laser beam printer (hereinafter simply referred to as a color LBP) using an electrophotographic process.
Say. ) to take the image data sent as an example.
i Y, M, C, and K are sequentially formed on a photosensitive drum and developed by developing units Y, M, C, and K, respectively, thereby reproducing a multicolor overlapping color image.

Regarding the color erasing device configured as above, the following is a second section.
The operation will be explained using figures.

In Fig. 2, the input sensor 1 outputs a three-color color separation signal RGB.
The A/D conversion circuit 2 converts these into 8-bit digital signals R1, G1, and B1, which are then converted into C1, M1, and Yl by the complementary color converter 3. Then, the UCR-inking circuit 4 performs undercolor removal and inking processing. In other words, K1=min (Yl, Ml, CI)...
(1) is calculated to obtain the minimum value signals of Yl, Ml, C1, and the signals C2, M2 . Y2, K
Get 2.

Y2=Y1- (α×Kl-β) M2=M1-(αXKI-β) C2=CI-(αXKI-β) K2-αK 1-β α, β are constants, α=1. 10 when β=0
0% OCR (full black method). Then, the masking circuit 5 uses the following equation (3) to perform color correction on the signal Y3. M3. Output C3.

Y2-α11・Y2+α21-M2+α31-C2M2
=α12・Y2+α22・M2+α32・C2C2−α
13・Y2+α23・M2+α33・C2... (3
) α, β, α11 to α33 (Dai) These are parameters determined experimentally.

Luminance/color difference conversion circuit 9i1Based on the RGB signals, the luminance component (■) of the image, the color component signals I and Q, and the monochromatic signal Vd are calculated based on the formula (4), for example.4 V = 0.30x R1 + 0.59x G 1 +0
．． llx B II =0.60x R1-0,28
x G 1-0.32x B IQ =0.21x
Rl -0,52x G 1 +0.31x B 1V
d=-LOG (V) . . . (4) The color component signals I and Q are signals that become 0 when the color is achromatic, and the signal Vd is a signal with a large dark blur value.

An example of a circuit is a look-up table (LTJT).
Consists of etc.

The chromatic color determination circuit 10 receives the color component signal 1. Q signal level value and judgment level value 36 set from CPU 20
The color area is detected by comparing the size of the two using a comparison circuit. The determination level value 36 is a parameter determined experimentally. By determining color detection based on whether it is a chromatic color or an achromatic color, it becomes unnecessary to specify a color when performing color deletion, and the number of setting operations can be reduced. Ma? = There is no need for the operator to make judgments based on delicate colors, and there is also no need to detect colors at specified positions, making it possible to improve operability and copy speed.

In the color copy mode, the selector 6 selects each output signal C of the masking circuit 5 in response to the operation in which the color printer overlaps Y, M, C, and K image data in a field-sequential manner.
3, M3. Y3 and UCR - 2 to the output signal of inking circuit 4
are sequentially selected according to the setting signal 31 from the CPU 20.
Image data 42 is output.

When the color copy mode is set by the setting signal 32 from the CPU 20, the selector 7 normally selects the output data 41 of the selector 6. However, when the operator uses the color erasing function by specifying a region, the control signal 35 from the region designation circuit 12 is inputted.
Accordingly, the erased area is a monochrome image. That is, the color printer 11 converts the monochrome signal 44 of the luminance/color difference conversion circuit 9 into a black image (K).
It is configured so that it is selected only when forming images, and outputs 0 data when forming other Y, M, and C images within the erase area. With this configuration, chromatic colors will not be printed within the erased area. Mat:,, control signal 3
It is also possible to erase chromatic colors using only the erasing circuit 8 without using the eraser 5.

Further, when the monochrome copy mode is set by the setting signal 32 from the CPU 20, the selector 7 selects the monochrome signal 44 of the luminance/color difference conversion circuit 9. In this case, the control signal 35 of the area setting circuit 12 is configured to be ignored. Since color erasure can be realized in monochrome copying mode, copying speed can be improved.

The erasure circuit 8 detects the color region signal 33 of the chromatic color detection circuit 10 within the erasure region in the control signal 34 of the region setting circuit 12.
This is a circuit that erases a color area according to the following. When the area is not specified (the control signal 34 becomes invalid, it is of course possible to erase the color area according to the color area signal 33). In this case, the area setting circuit 12 may be omitted (the area setting circuit 12 is valid only when specifying an area, and the control signal 34 is output based on the address information from the coordinate input device 23 according to the setting mode from the operation panel 22.
, outputs a control signal 35.

Since it is possible to specify an area, the operator can set the erasing area in any rectangular area on the document, improving the operability of the fire color erasing function.

When using 2 as color erasing data (black) in the output data of the UCR/inking circuit 4, control signals 34 and 35 are used.
, selector 7, and erase circuit 8 are disabled, and signals 41 and 43 become the same signal.

The data selected by the selector 6 is directly output to the color printer 11.

Effects of the Invention Since the present invention is configured as described above, it produces the effects described below.

The image reading means reads the color image of the document and obtains color data of three separated colors. Chromatic color detection means are 3
Chromatic color information is generated from color data to detect color areas other than black and white on a document. The erasing means can erase the color area according to the detection signal from the chromatic color detection means. Therefore, compared to the case of color erasing by applying a color conversion function, there is no need to specify which color to use, and the operation of -degrees is required. Color areas on a document can be easily erased by using this method.

Since color erasing is performed depending on whether the color is chromatic or achromatic without detecting a specific color density range, color erasure accuracy is improved, and there is no need to know the color density range at a specified position through pre-scanning, etc. It gets faster.

In addition, the monochrome generation means that generates monochrome data from color image data is used as image data to the printer in areas other than color areas.It is possible to copy to the printer by forming an image once, that is, by forming only black, and the copying speed is high. It is possible to perform conversion.

Sara's turn! By using the black image formation data of the image processing means, it is possible to copy to a printer with just one image formation, similar to the monochrome generation means, which increases the copying speed, and also allows for erasure, semi-immersion, and detection of chromatic color areas. The erasing area specifying means effectively applies the color area signal of the chromatic color detection means only to the desired area on the color document, and the erasure area specifying means effectively stores the color area signal of the chromatic color detection means only for the desired area on the color document. Replace non-color areas with monochromatic data The operator can erase chromatic colors with high precision in the desired color erasing area on the document.

[Brief explanation of drawings]

Fig. 1 is the basic configuration of a color erasing device in an embodiment of the present invention @ Fig. 2 is a block diagram showing an embodiment of Fig. 1 Fig. 3 is an explanation of the operation of the color erasing device in an embodiment of the present invention Figure 4 is a basic configuration diagram of a conventional color erasing device.Momo 4...UCR/inking circuit 6...Selekku 7.
... Select Kyu 8... Erasing circuit 9... Luminance color difference conversion circuit, 10... Chromatic color determination circuit, 12...
・Name of area setting representative Patent attorney Shigetaka Awano Haka1 Meister Mei Ken

Claims (5)

[Claims] (1) An image reading unit that separates a color original into multiple colors to generate color image data, a monochrome generation unit that generates monochrome image data from the color image data, and detects a chromatic region from the color image data. Among the monochromatic image data output from the detection means for detecting and the monochromatic generating means,
A color erasing device comprising: erasing means for erasing only the chromatic color area obtained from the detection means. (2) An image reading unit that separates a color original into multiple colors to generate color image data, and generates yellow, magenta, cyan, and black image forming data necessary for forming a color image from the color image data. an image processing means, a detection means for detecting a chromatic region from the color image data, and an erasing means for erasing only the chromatic region obtained from the detection means out of the image forming data output from the image processing means; A color erasing device characterized by having: (3) An image reading unit that separates a color original into multiple colors to generate color image data, and generates yellow, magenta, cyan, and black image forming data necessary for forming a color image from the color image data. 1. A color erasing device comprising: an image processing means, and performing color erasure by using only black image forming data of the image processing means. (4) The color erasing device according to claim (3), wherein the black image forming data of the image processing means is generated by a full black method. (5) an image reading unit that separates a color document into multiple colors to generate color image data; a monochrome generation unit that generates monochrome image data from the color image data; and a unit for forming a color image from the color image data. an image processing means for generating necessary yellow, magenta, cyan, and black image forming data; a detection means for detecting a chromatic color area from the color image data; An erasing area specifying means into which position data can be input, and the setting of the erasing area specifying means select the monochromatic image data outputted from the monochromatic generating means as the area where color erasing is to be performed, and select the area where no color erasing is to be performed. and erasing means for selecting the output of the image processing means, and the erasing means erases only the chromatic color area obtained from the detection means out of the monochrome image data output from the monochrome generation means. Characteristic color erasing device.