JPH05244420A - Picture processor - Google Patents

Abstract

PURPOSE:To realize an excellent picture processing by preventing a color balance around a threshold level from being unbalanced. CONSTITUTION:A white level discriminator 814 outputs an 'H' level when other color exceeds threshold level data 804 while defining a minimum level among R, G, B colors as a reference level in the case the discriminator 814 is in the level other than 'L' and the discriminator outputs an L level when the level is the threshold level data 804 or below. That is, a white level point at the time of binarization can be set in threshold level data 801-803, and the binarization is implemented with a level difference between the threshold level data 804 and the minimum value, then the binarization is implemented without black level processing from a low density region to a high density region. Furthermore, color slippage hardly takes place.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus such as a copying machine, and more particularly to R (red), G (green) and B.
The present invention relates to an image processing apparatus that binarizes data that is independent for each color, such as (blue), Y (yellow), M (magenta), C (cyan), and / or K (gray).

[0002]

2. Description of the Related Art As a conventional technique related to the present invention, there is an "image processing device" disclosed in Japanese Patent Laid-Open No. 2-132963. This technique uses a circuit in which Y (yellow), M (magenta), C (cyan), and B _K (gray) are independently binarized after processing by the UCR circuit. ， It can be divided into 7 colors from low density part to high density part.

[0003]

However, in the image processing apparatus described above, it is possible to divide into seven colors from the low density portion to the high density portion, but on the other hand, each color is independently binarized. Therefore, there is a problem in that the color balance is lost in the area around the threshold value, and good image processing cannot be realized.

The above problem will be described in more detail with reference to FIGS. In the above conventional image processing, R (red), G (green), B (blue),
Alternatively, when binarizing the color data of Y (yellow), M (magenta), C (cyan), and / or K (gray), threshold values fixed independently for each color are used.

In FIG. 17, the density of a document is K (gray) is R.
FIG. 18 is a graph showing the case where the color levels are (red), G (green), and B (blue), and FIG.
The concentration of (red) is R (red), G (green), B
It is a graph showing a case where the color level is set to (blue),
In FIG. 19, the manuscript has the density of R (red) as R (red),
FIG. 20 is a graph showing the case where the color levels are G (green) and B (blue). FIG. 20 shows the original density of C (cyan) of R (red), G (green), and B (blue). FIG. 21 is a graph showing a case where the level is set, and FIG. 21 is a graph showing a case where the density of C (cyan) of the document is set to R (red), G (green), and B (blue) color levels. 22 is a graph showing the case where the original has the R (red) density set to the R (red), G (green), and B (blue) color levels. Also, other colors are R,
By changing the balance of G, B, G, B,
M and Y can also be expressed.

Here, in FIG. 17, if the threshold value for binarizing the color expressed in gray is executed by using the document density, by determining a predetermined color level, it is possible to obtain a value over a certain document density. It can be binarized such as black and white below, but R, G, B around the above threshold
A slight misalignment in the balance causes color misregistration. For example, when the threshold is 128 of 256 gradations, R = 12
When 9, G = 127 and B = 127, the gray is a halftone expression, but it becomes red when binarized.

Next, description will be made with reference to FIG. In this case as well, color shift similarly occurs around the threshold value. When the threshold value is set between the color levels b′y and by, the original density bx is red, but the ax is white. Conversely, if the threshold color level is set between a'y and ay, the document density a
Red at x, but black at bx. This ax, bx
Even though the halftone expression is reddish, it turns black in this case (this phenomenon is called blackening).

As described above, in order to avoid blackening,
It would be better to be able to express the reddish part in white, but then there was the problem that the density setting range would be narrowed.

The present invention has been made in view of the above, and it is an object of the present invention to prevent the color balance from being lost in the peripheral portion of the threshold value and to realize good image processing.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides R (red), G (green), B
(Blue), or Y (yellow), M (magenta), C (cyan), and / or K (gray). Multi-valued data input means for inputting data,
Data output means for outputting data, white level detecting means for detecting the white level of the data, level difference detecting means for detecting the level difference of each color, data obtained by the level difference detecting means, and a predetermined threshold value. The present invention provides an image processing apparatus including a binarizing unit that performs binarization based on the image processing apparatus.

Further, it is desirable that the binarizing means be based on the difference from the maximum value.

Further, it is desirable that the binarizing means be based on the difference from the minimum value.

Further, R (red), G (green), B
(Blue), or Y (yellow), M (magenta), C (cyan), and / or K (gray). Multi-valued data input means for inputting data,
A data output means for outputting data, a white level detecting means for detecting a white level of the data, a level difference detecting means for detecting a level difference of each color, and a maximum value and a minimum value are discriminated by the level difference detecting means. The present invention provides an image processing apparatus including a binarizing unit that binarizes the other data in the same manner as either one of the closer data.

Further, R (red), G (green), B
(Blue), or Y (yellow), M (magenta), C (cyan), and (or) K (gray). Multi-valued data input means for inputting data,
A data output means for outputting data, a white level detecting means for detecting a white level of the data, a level difference detecting means for detecting a level difference of each color, and a selecting means for selecting input data according to a predetermined condition, Threshold calculation means for calculating a threshold in accordance with the output from the selection means, and binarization means for performing binarization based on the data obtained by the level difference detection means and the threshold obtained by the threshold calculation means. An image processing apparatus provided is provided.

Further, R (red), G (green), B
(Blue), or Y (yellow), M (magenta), C (cyan), and / or K (gray). Multi-valued data input means for inputting data,
Data output means for outputting data, white level detection means for detecting the white level of the data, level difference detection means for detecting the level difference of each color, and color based on the level difference detected by the level difference detection means. And an image processing apparatus including a binarizing unit for binarizing by switching a threshold value to be compared with the level difference data detected by the level difference detecting unit in the determining unit. Is provided.

Further, R (red), G (green), B
(Blue), or Y (yellow), M (magenta), C (cyan), and / or K (gray). Multi-valued data input means for inputting data,
Data output means for outputting data, white level detection means for detecting the white level of the data, level difference detection means for detecting the level difference of each color, and color based on the level difference detected by the level difference detection means. There is provided an image processing apparatus comprising: a determining unit that determines the level order of 1) and a selecting unit that selects a binarizing unit that binarizes the level difference data detected by the level difference detecting unit in the determining unit. It is a thing.

[0017]

In the image processing apparatus according to the present invention, blackening is performed by the white level detecting means for determining the level (color other than white) from which the color is added and the binarizing means by detecting the level difference between the colors. Eliminate color misregistration. In addition, the above-mentioned fixed threshold value is set to the maximum value or the minimum value.

Further, the white level detecting means for determining from which level a color (other than white) is to be added, and the means for detecting the maximum value and the minimum value by detecting the level difference of each color, the maximum value with respect to the intermediate value is obtained. Value or minimum value, whichever is the closest, 2
The quantizing means eliminates blackening and reduces color misregistration.

Further, the threshold value is changed according to certain color data to prevent the binary data from becoming black.

When performing the binarization process, the threshold data is changed in accordance with the color level order in order to match the visual sensitivities.

In the binarization process, a plurality of processes are selected according to the color level order so as to match the visual sensitivity.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing a schematic configuration of an image processing apparatus according to the present invention. In FIG. 1, an image reading unit 101 that scans a document and reads the document information as digital data, an image processing unit 102 that performs predetermined processing and processing on the image data read by the image reading unit 101, and image processing The image recording unit 103 records the image data output from the unit 102.

In the image processing unit 102, for example, main scanning scaling processing, mirror processing, shadowing processing, mosaic processing, filter processing, γ correction processing, R, G, B → Y,
M, C, K conversion processing, halftone processing, etc. are executed on the read image.

FIG. 2 is a block diagram showing a detailed configuration of the image processing unit 102. The image processing unit 102 includes a binarization unit 201, a conversion data calculation unit 202, a delay circuit unit 203, and a conversion circuit 203. The data selection unit 204 is included. Hereinafter, the shadowing processing and the binarization processing executed by the image processing unit 102 will be sequentially described.

The image data R _in , G _in , B _in (multi-valued) are
It is input to the delay circuit unit 203 and the binarization unit 201. The image data R _in , G _in , and B _in are R,
Each of G and B is binarized, input to the conversion data calculation unit 202, and the determination result is output to the conversion data selection unit 204. The delay circuit unit 203 adjusts the image delay in the binarization unit 201 and the conversion data calculation unit 202.

In the binarization unit 201, the image data R _in and the threshold value 502 are compared by the comparator 501 as shown in FIG. 5, and when the image data R _in exceeds the threshold value 502, “H” is given.
The configuration that outputs (binary data R) is adopted. In addition, in FIG. 5, although R is described as an example,
The same applies to G and B. Here, binarized R, G, B
The data is output to the conversion data calculation unit 202 as described above.

The binarization process and the shadowing process will be described with reference to FIG. 3 as an example of the conversion data calculation unit 202. In the binarization process, when the region signal 1 is "H", the MODE0 is "H"
And outputs a signal called binarization processing. At this time,
The binarized data R, G, B are output as DR, DG, DB, respectively. Next, the binary data R, G, B are processed by the shadow processing unit 3
Inputting 01, the shadowing process is performed. When performing the shadowing process, the output R of the shadow processing unit 301 outputs "H". Further, KDR, KDG, and KDB are output as shadow color information. When the area signal 2 is “H”, the shadow processing unit 301
When the output of is "H", MODE1 and "H" are output. Here, the area signals 1 and 2 are controlled by an area signal generator (not shown) and have the functions shown in the table of FIG.

Next, the shadowing process will be described in detail. Figure 3
The configuration of the shadow processing unit 301 shown in FIG. 6 is shown in FIG. 6. The shadow processing unit 301 has line memories 601 to 603, and inputs binary data R, binary data G, and binary data B to KDR,
Outputs KDG, KDB and shadow data.

FIG. 7 shows the above line memories 601 to 603.
Showing the configuration of the registers 701 and 702 and the storage element 7
It is composed of 03 and. Here, data for one line is stored. And the one output is the register 701,
By delaying one pixel by 702 and repeating the data input, the movement of 45 degrees is executed for the binary data.

In the shadowing process, the binary data R, G and B are all "H" (meaning white), and the line memory 60
Somewhere in the output (movement data) from 1 to 603 is "L"
When it means (other than white), the shadowing process is executed.
Outputs from the shadow processing unit 301 are KDR, KDG, KD
B outputs color information.

FIG. 4 shows an example of R in the configuration of the conversion data selection unit 204, where 401 is color data 1, 402 is color data 2, 403 is color data 3, 404 is color data 4, and so on.
Reference numerals 405 to 407 are selection circuits. However, in the case of G, R _in is G _in , R _out is G _out , and K _{in the} figure.
DR replaces KDG and DR replaces DG. In the case of B, R _in is B _in and R _out is B _{in the} figure.
_Out , KDR is replaced with KDB, and DR is replaced with DB.

When MODE0 = H, MODE1 = L and DR = H, color data 4 (high density data) is output, and when DR is L, color data 3 (low density data) is output. Is output. As a result, R, G, B, Y, M, C, and
7 colors of B _K can be expressed.

When MODE0 = L, MODE1 = H and KDR = H, color data 2 (high density data) is output, and when DR is L, color data 1 (intermediate density data) is output. Is output. As a result, the shadowing process is performed using the R, G, B data, and the thin R, G, B, respectively.
7 colors of Y, M, C and B _K can be expressed.

Further, when MODE0 = H and MODE1 = H, it is the same as when MODE0 = L and MODE1 = H. When MODE0 = L and MODE1 = L, normal image data R is output. Here, arbitrary multivalued data may be set to the color data 1 to the color data 4401 to 404.

The binarization unit 201 shown in FIG. 5 will be described in more detail with reference to FIG. In FIG. 8, 801 to 80
3 is threshold data of R, G, B for white level detection, 804
Is threshold data for detecting a level difference between color data, 805-
Reference numeral 807 denotes a subtracter, which has an AB terminal for outputting | AB | and an F terminal for outputting a sign (+, −).
Reference numerals 808 to 813 denote comparators, which output "H" when P> Q. Reference numeral 814 is a white level judging device, which outputs "H" when it is white. Reference numeral 815 is a control unit (microprocessor) that controls the entire binarization unit 201, and 816 is a selection circuit.

Next, MAX of the control unit 815 is set to L,
A method based on the minimum value will be described. Image data R,
G and B are input to the comparators 808 to 810, and the output result is output to the white level determination unit 814. White level determiner 81
In No. 4, when the input data are all "H", "H" is output (the R, G, B data are all in a high density state, which means white).

Further, the image data is subtracted from the subtracters 805 to 807.
At, the calculation of R-G, G-B, and B-R is performed, and A-
The absolute value is output from the B terminal. Also, the + and-signs, which are the calculation results, are output from the F terminal. Further, 0 may be + or-, but here it is +.

In the comparators 811 to 813, the threshold data 10
4 is compared with the difference between R, G, and B, and if the difference is larger than the threshold value, "H" is output. The control unit 815 uses the subtractors 805 to 805.
As shown in the table of FIG. 12, the magnitude relation is determined by 807, and becomes "L" only when each color of MR, MG, and MB has the minimum value. For example, N in the table shown in the table of FIG.
o. When B is the minimum value as in the case of 1, MB =
It becomes "L" and the other becomes "H". SR, SG, S
B outputs RG, GB and BR as they are.

At the input of the selection circuit 816, the data other than the minimum value of the comparators 811 to 813 is input as it is, and only the data of the minimum value becomes "L" by the AND gate. In the selection circuit 816, the outputs R, G, B are changed to RG, by the inputs of SK, SG, SB, as shown in the table of FIG.
It is selected from GB and BR. The output of the selection circuit 816 is ORed with the output of the white level determiner 814 and output. That is, the binary data R, G, B are all "H" when the white level determiner 814 outputs "H" (white) when they are white, and are output as white.

When the white level determiner 814 is other than "L", the minimum value of R, G, B is used as a reference, and "H" is output when the other colors exceed the threshold data 804,
If the threshold data 804 or less, "L" is output. That is,
In the threshold data 801 to 803, the white level point at the time of binarization can be set, and the threshold data 80
4, it is possible to perform binarization by the level difference from the minimum value, and it is possible to perform binarization from the low density region to the high density region without blackening. In addition, color shift is less likely to occur.

Next, a method of setting MAX of the control unit 815 to "H" and using the maximum value as a reference will be described. For the sake of explanation, only the control unit 815, which is different from the above, and the portion related to the selection circuit 816 will be described. The control unit 815 uses the subtractor 805.
.About.807, the magnitude relationship is determined as shown in the table of FIG. 12, and becomes "L" only when each color of MR, MG, and MB has the maximum value. For example, No. shown in the table of FIG.
When R is the maximum value as in the case of 2, MR = L,
Others are “H”. SR, SG, SB are R
G, GB, BR are output as they are.

The input of the selection circuit 816 is the comparator 8
The data other than the maximum value of 11 to 813 is inverted and input, and only the data of the maximum value becomes "L" by the AND gate and then becomes "H" because it is inverted. However, when the data other than the maximum value is all "L", the input is input as it is and all "L". In the selection circuit 816, S
By inputting R, SG, SB, the outputs R, G, B are selected from RG, GB, BR as shown in the table of FIG.
As a result, the color at the time of binarization becomes the maximum value reference, and the same effect as the minimum value reference can be obtained.

Next, another embodiment of the binarization unit 201 is shown in FIG.
Will be explained. Reference numerals 901 and 902903 denote R, G, and B threshold value data for white level detection, 912 threshold value data for level difference detection between color data, and 904 to 906 are subtractors, which output | AB | It has a −B terminal and an F terminal for outputting a sign (+, −). 907-
Reference numeral 911 is a comparator, which outputs "H" when P> Q. Reference numeral 917 is a white level judging device, which outputs "H" when it is white. Reference numeral 918 is a control unit, and reference numerals 919 and 913 to 916 are selection circuits.

The control unit 918 determines the magnitude relation as shown in the table of FIG. 13 by the codes from the subtractors 904 to 906, and the selection circuit 913 selects the maximum value, the minimum value or a specific color. The selection circuit 914 selects the maximum value-intermediate value, the selection circuit 915 selects the minimum value-intermediate value, and the selection circuit 916 selects the maximum value-minimum value. Then, the comparator 910 determines whether the intermediate value is closer to the maximum value or the minimum value. Further, the comparator 911 determines whether the color is a gray system or other colors depending on the difference between the maximum value and the minimum value and the level of the threshold data 912. In addition, MAXR, M of the control unit 918
AXG and MAXB output RG, GB and BR as they are.

In the selection circuit 919, the comparators 910 and 91 are provided.
1, based on the information from the control unit 918, outputs R, G, B data. The output contents of the selection circuit 919 are shown in FIG.
Shown in the table. The output from the selection circuit 919 is ORed with the output of the white level determiner 917 and output.

As described above, the binary data R, G and B are
When it is white, the white level determiner 917 outputs "H", so that all the signals become "H" and are output as white.
When the white level determiner 917 is “L” (other than white), the difference between the maximum value and the minimum value of R, G, B is the threshold value data 91.
If it is 2 or less, it is output as gray, and on the contrary, the threshold value data 9
If it is 12 or more, the maximum value is "H" and the minimum value is "L". If the other intermediate values are close to the maximum value, "H" is set. As a result, the intermediate value between the maximum value and the minimum value can be binarized from the low density area to the high density area without blackening by performing the same processing as the one which is closer to the maximum value or the minimum value. Can be converted.
In addition, color shift is less likely to occur.

Further, blackening may occur in the low density region, but this is not a concern. In order to prevent blackening in the low density region, the selection circuit 913 may change the threshold value data 912 according to the maximum value, the minimum value, or the data amount of a certain color. For example, based on a certain level, the output of the threshold data (912) = reference threshold / threshold data (912)
Input × aa: coefficient formula may be used. This makes it possible to prevent blackening in the low density region. Further, the same effect can be obtained by performing the same processing on the threshold data 804 in the embodiment of FIG.

Further, another embodiment of the binarizing unit 201 will be described with reference to FIG. In the figure, 1001 to 1003 are threshold data of R, G, and B for white level detection, 1004 to
1009 is threshold value data for detecting a level difference between color data,
Subtractors 1010 to 1012 are provided with an AB terminal that outputs | AB | and an F terminal that outputs a sign (+, −). 1013 to 1018 are comparators, P
When> Q, "H" is output. Reference numeral 1023 is a white level judging device, which outputs "H" when it is white. 1024 is a control unit, 1019 and 1025 are selection circuits, and 1020 to 102
Reference numeral 2 is a data selector. When S = L, Y selects A.

Threshold data 1001 to 1003, white level judging device 1023, subtractors 1010 to 1012, comparator 1
Since 016 to 1018 are the same as those in the above embodiment, the description thereof will be omitted. The threshold data 1004 to 1009 are the threshold data 8 in the first embodiment of the binarizing unit 201.
04 is individual for each color or in the color order. The data selectors 1020 to 1022 select the threshold value data 1004 to 1009 for each color or in the color order.

The selection circuit 1025 includes the binarization unit 201.
When the input of RG, GB, BR in the first embodiment of the above is the maximum value, MA is set as the minimum value of ARG, AGB, ABR.
X is provided with MAXR, MAXG, and MAXB respectively (MAX = L and MAX = in the first embodiment of the binarizing unit 201).
H is separated). Further, the control unit 1024 determines that MAX is MAXR, MAXG,
It becomes MAXB, and PR, PG, and PB are newly increased.

The function of the selection circuit 1025 is as shown in the table of FIG. The threshold data 1004 to 1009 are stored in the selection circuit 101, as in the second embodiment of the binarization unit 201.
It has a function of changing the threshold for the data from 9.

First, the case where the threshold data 1004 to 1009 all have the same value and the data of the selection circuit 1019 is not converted will be described. This state is different in the control unit 1024 and the selection circuit 1025 in the first embodiment of the binarization unit 201.

With the above configuration, R,
The maximum value criterion or the minimum value criterion can be selected depending on the order of G and B data. Further, R, G, and B can be set independently, R can be set as a maximum value, and G and B can be set as a minimum value. Further, this is not limited to the maximum value and the minimum value, but the maximum value or the minimum value, whichever is closer, may be selected. By doing so, the balance between the colors can be corrected, and the binarization processing can be executed according to the visual sensitivity.

When the selecting circuit 1025 always selects the minimum value, the different parts of the binarizing unit 201 from the first embodiment are the threshold data 1004 to 1009 and the data selectors 1020 to 1022. At this time, the threshold data 1004 and 1009 contain the R data threshold and the threshold data 1
005 and 1006, G data threshold, threshold data 100
Input the threshold value of B data to 7, 1008, R, G,
The data selectors 1024 to 102 depending on the magnitude relation of B
By selecting 2, it is possible to set the threshold independently for R, G, and B.

Further, the threshold value data 1004 to 1009 may be further increased to change the threshold value according to the magnitude relationship of R, G, and B. Further, the threshold value may be selected according to the processing standard (maximum value or minimum value standard) of the selection circuit 1025.

By doing the above, it is possible to correct the balance between the colors, and to adjust the balance according to the visual sensitivity.
Quantization correction can be performed. These can be easily applied not only to the binarization but also to the N-valued, and can also be applied to the shadowing and the binarization processing to all that are binarized to execute the processing.

[0057]

As described above, according to the image processing apparatus of the present invention, R (red), G (green), B
(Blue), or Y (yellow), M (magenta), C (cyan), and / or K (gray). Multi-valued data input means for inputting data,
The data output means for outputting data, the white level detecting means for detecting the white level of the data, the level difference detecting means for detecting the level difference of each color, the data obtained by the level difference detecting means, and the maximum value Since it has a binarizing means for binarizing based on the threshold value of the difference or the difference from the minimum value,
Further, a multi-valued data input means for inputting multi-valued data, a data output means for outputting the data, a white level detection means for detecting a white level of the data, a level difference detection means for detecting a level difference of each color, Since the level difference detecting means discriminates the maximum value and the minimum value and binarizes the other data in the same manner as either one of the closer data, the binarizing means is provided. Multi-value data input means for inputting value data, data output means for outputting data,
A white level detecting means for detecting a white level of data, a level difference detecting means for detecting a level difference of each color, a selecting means for selecting input data according to a predetermined condition, and an output from the selecting means. Threshold calculation means for calculating the threshold,
The multi-valued data input means for inputting multi-valued data includes the binarization means for binarizing the data obtained by the level difference detection means and the threshold value obtained by the threshold value calculation means. , Data output means for outputting data,
A white level detecting means for detecting a white level of data, a level difference detecting means for detecting a level difference of each color, and a judging means for judging a color level order based on the level difference detected by the level difference detecting means. , Multi-valued data for inputting multi-valued data, further comprising binarizing means for binarizing by switching a threshold value to be compared with the level difference data detected by the level difference detecting means in the judging means. Input means, data output means for outputting data, white level detecting means for detecting the white level of the data, level difference detecting means for detecting the level difference of each color, and level difference detected by the level difference detecting means. And a binarizing unit for binarizing the level difference data detected by the level difference detecting unit in the determining unit. For having a selection means for selecting, avoiding collapse of the color balance of the threshold peripheral portion, it is possible to achieve proper image processing.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing a configuration of an image processing unit shown in FIG.

FIG. 3 is an explanatory diagram showing a configuration of a conversion data calculation unit shown in FIG.

FIG. 4 is an explanatory diagram showing a configuration of a conversion data selection unit shown in FIG.

5 is a block diagram showing a schematic configuration of a binarizing unit shown in FIG.

FIG. 6 is an explanatory diagram showing a configuration of a shadow processing unit shown in FIG.

7 is a block diagram showing a configuration of a line memory shown in FIG.

FIG. 8 is a circuit diagram showing a detailed configuration of the binarizing unit shown in FIG.

9 is a circuit diagram showing another detailed configuration of the binarization unit shown in FIG.

10 is a circuit diagram showing another detailed configuration of the binarization unit shown in FIG.

11 is a table showing functions of area signals 1 and 2 shown in FIG.

12 is a table showing a relationship between inputs and outputs of the selection circuit of FIG.

13 is a table showing output contents of the selection circuit of FIG.

14 is a table showing output contents of the selection circuit of FIG.

FIG. 15 is an explanatory diagram showing an output example corresponding to the function of the area signal shown in FIG. 11.

16 is an explanatory diagram showing an output example corresponding to the function of the area signal shown in FIG.

FIG. 17 shows that the original has a K (gray) density of R (red),
6 is a graph showing a case where color levels of G (green) and B (blue) are set.

FIG. 18 shows that the original has a density of R (red), R (red),
6 is a graph showing a case where color levels of G (green) and B (blue) are set.

FIG. 19 shows that the original has the density of R (red), R (red),
6 is a graph showing a case where color levels of G (green) and B (blue) are set.

FIG. 20 shows that the original has a C (cyan) density of R (red),
6 is a graph showing a case where color levels of G (green) and B (blue) are set.

FIG. 21 shows that the original has a C (cyan) density of R (red),
6 is a graph showing a case where color levels of G (green) and B (blue) are set.

FIG. 22 is a graph showing the density of R (red) in the original as R (red),
6 is a graph showing a case where color levels of G (green) and B (blue) are set.

[Explanation of symbols]

101 image reading unit 102 image processing unit 103 image recording unit 201 binarization unit 202 conversion data calculation unit 203 delay circuit unit 204 conversion data selection unit 301 shadow processing unit 814 white level determiner 815 control unit 816 selection circuit 917 white level determination Control unit 918 Control unit 919 Selection circuit 1023 White level determination unit 1024 Control unit 1025 Selection circuit

Claims (7)

[Claims] 1. R (red), G (green), B (blue), or Y (yellow), M (magenta), C
In an image processing device that binarizes data independent for each color such as (cyan) and / or K (gray),
Multi-valued data input means for inputting multi-valued data, data output means for outputting data, white level detection means for detecting a white level of data, level difference detection means for detecting a level difference of each color, and the level An image processing apparatus comprising: data obtained by the difference detecting means; and binarizing means for binarizing based on a predetermined threshold value. 2. The image processing apparatus according to claim 1, wherein the binarizing unit uses a difference from a maximum value as a reference. 3. The image processing apparatus according to claim 1, wherein the binarizing unit uses a difference from a minimum value as a reference. 4. R (red), G (green), B (blue), or Y (yellow), M (magenta), C
In an image processing device that binarizes data that is independent for each color, such as (cyan) and / or K (gray),
Multi-valued data input means for inputting multi-valued data, data output means for outputting data, white level detection means for detecting a white level of data, level difference detection means for detecting a level difference of each color, and the level An image processing characterized by comprising a binarizing means for discriminating the maximum value and the minimum value by the difference detecting means and binarizing the other data in the same manner as either one of the closer data. apparatus. 5. R (red), G (green), B (blue), or Y (yellow), M (magenta), C
In an image processing device that binarizes data independent for each color such as (cyan) and / or K (gray),
Multi-value data input means for inputting multi-value data, data output means for outputting data, white level detecting means for detecting a white level of data, level difference detecting means for detecting a level difference of each color, and input data Selecting means for selecting in accordance with a predetermined condition, threshold calculating means for calculating a threshold according to the output from the selecting means, data obtained by the level difference detecting means, and threshold obtained by the threshold calculating means. An image processing device, comprising: 6. R (red), G (green), B (blue), or Y (yellow), M (magenta), C
In an image processing device that binarizes data independent for each color such as (cyan) and / or K (gray),
Multi-valued data input means for inputting multi-valued data, data output means for outputting data, white level detection means for detecting a white level of data, level difference detection means for detecting a level difference of each color, and the level Binarization is performed by switching between a determination unit that determines the color level order based on the level difference detected by the difference detection unit and a threshold value that is compared with the level difference data detected by the level difference detection unit in the determination unit. An image processing apparatus, comprising: a binarizing unit for performing. 7. R (red), G (green), B (blue), or Y (yellow), M (magenta), C
In an image processing device that binarizes data independent for each color such as (cyan) and / or K (gray),
Multi-valued data input means for inputting multi-valued data, data output means for outputting data, white level detection means for detecting a white level of data, level difference detection means for detecting a level difference of each color, and the level The determination means for determining the color level order based on the level difference detected by the difference detection means and the binarization means for binarizing the level difference data detected by the level difference detection means in the determination means are selected. An image processing apparatus, comprising: