JP3384997B2 - Color image processing equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image processing apparatus, and more particularly to a color image processing apparatus for forming an image in which additional marks are combined on a color original.

[0002]

2. Description of the Related Art Conventionally, companies and public institutions have paid close attention to the confidentiality of important documents and drawings. However, there is no end to the problem of leaking those secret documents. In particular, those documents distributed as conference materials are often copied and taken outside.
For this reason, when distributing these documents at a meeting or the like, different marks (for example, serial numbers) are described on each of the multiple copies of the same original document, and the combination of the mark with the recipient and the mark are memorized. It is necessary to take measures such as maintaining confidentiality by clarifying the leak source. Conventionally, a dedicated image synthesizing device has been used to perform marking processing on an image. However, when overlaying a mark indicating that it is a secret document on the entire surface of the image (the part that contains information in the document), whether the information held by the document is damaged or not depending on the print density, size, and dot configuration of the mark. Even if it does not happen, readability may be significantly reduced.

Therefore, the applicant of the present invention has proposed an image forming apparatus that uses a mark having a halftone density when adding a confidentiality-preserving mark to an original image (Japanese Patent Application No. 3-37664: Japanese Patent Application Laid-Open No. Hei 5 (1999) -3664).
No. 22568).

[0004]

[Problems to be Solved by the Invention] Japanese Patent Application No. 3-37664
14 does not support color original images, and when this technique is applied to a color copying machine and a secret holding mark is added to the original image, for example, as shown in FIG.
As shown in, if the text in the original image is blue and the confidentiality mark is red, the overlapping part of the image and the mark becomes black (or gray) according to the subtractive color mixing method, and According to the color mixing method, the color becomes yellow and the original image becomes very difficult to see.

Further, it has been proposed to use complementary colors other than the gray component when printing the mark, but as shown in FIG. 15, there is a missing image at the portion where the image and the mark overlap, and only the mark is emphasized, so that the original The image becomes very difficult to see.

An object of the present invention is to add a mark to a color original so as not to impair the legibility of color original information.

[0007]

Means for Solving the Problems (1) In a color image processing apparatus for adding a mark to an image of an input color original, it is determined whether or not it is an image background based on the density of image data of the input color original. detecting area detection means (40) for generating a background detection signal representative of this; mark image de to form a color mark image data - data forming means (81); and said <br/> of a color original, the area detection Color image data only in the area where the background detection signal of the means (40) represents an image background ,
Image data synthesizing means (82, 83, 8) for changing the color mark image data formed by the mark image data forming means (81)
4,85); provided with a color image processing device.
(Example 1: FIGS. 1-5).

In order to facilitate understanding, reference numerals of corresponding elements in the embodiments shown in the drawings and described later are added for reference.

According to this, the image data synthesizing means (82, 83, 84, 8) is added to the area detected by the area detecting means (40) as the image background.
5) synthesizes the color mark image data formed by the mark image data forming means (81). Since the color mark image data is synthesized only on the image background, the information of the color original and the color mark image data do not overlap each other, and the legibility of the original information is not impaired.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION ( 2 ) Image of input color original
Oite the color image processing apparatus for adding a mark to the image, counting means for counting the number of each color pixel of the color image data of the input color document (44c); said counting means (44
Area detection means for generating a signal representing the area formed by pixels of the color with the maximum count of c) as a background color area
(40c); mark image data forming means for forming a color mark color different from the color of the background color area (81); and, the mosquito
Raa document, the color image data of only the background color area in which the signal represents the area detecting means (40c), the image data synthesizing means for changing the color mark image data to which the mark image data forming means (81) to form ( 82, 83, 84, 85); and a color image processing apparatus (Example 2:
(Fig. 9) .

(3) The mark image data forming means (81)
Forms a color mark existing in the color image data of the color original and different from the color of the background area ;
The color image processing device according to item (2) .

According to this method, the color of the largest number of pixels in the original is determined as the background color and the color mark image data of a color different from this is combined, so that the legibility of the original information is not compromised. If you try to erase the mark by applying color conversion etc. to the mark by using the color existing in the original,
Since part of the original data is erased at the same time, it is possible to deal with the mark erasing process. ( 4 ) Add a mark to the input color original image
In the color image processing device, a region detecting means (40) for generating a signal representing a region where the color of the color image data of the input color original is the set color as a background color region;
Means for forming a color mark image data (81d); input means for inputting the color of the color mark image data (33,91); Before
Color converting means for converting the color of the color mark image data serial forming means (81d) is formed on the color inputted from said input means (33,91) (82d, 83d, 84d, 85d); and, of the color original color formed color image data of only the background color area in which the signal represents the area detecting means (40), the mark image data forming means (81d) and the color conversion means (82d, 83d, 84d, 85d) by 13. An image processing device (embodiment 3: FIG. 12) , characterized by comprising image data synthesizing means (82d, 83d, 84d, 85d) for changing to mark image data.

According to this, the operator can specify the color of the mark image data according to the document information. Therefore, by specifying the color most suitable for the document information, the image output which does not impair the legibility of the document information is output. Can be obtained. ( 5 ) Add a mark to the input color original image
In the color image processing device, a region detecting means (40) for generating a signal representing a region where the color of the color image data of the input color original is the set color as a background color region;
Means for forming a color mark image data (81d); density detecting means for detecting the density of the color image data of the document (92);
Concentration detection means (92) of the detected density conversion means in response to the density of the image data to convert the density of the color mark image data (82d, 83d, 84d, 85d); and, wherein the color original, the area detection Means (40) color image data only the background color region represented by the signal, to the mark image data forming means (81d) and the density conversion means (82d, 83d, 84d, 85d) color mark image data formed by An image processing apparatus (embodiment 3: FIG. 12) characterized by comprising image data synthesizing means (82d, 83d, 84d, 85d) for changing.

According to this, since the color mark image data density is converted according to the image density of the color document information, the color mark image data and the color document information can be distinguished from each other, and the legibility of the document information is impaired. You can get no image output.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

[0016]

Embodiments-Embodiment 1-FIG. 1 shows a schematic configuration of a digital color copying machine of the present invention. The digital color copying machine shown in FIG. 1 is roughly divided into a scanner unit 1 for reading a document and a printer unit 2 for recording an image on recording paper. In the scanner unit 1, the document placed on the contact glass 3 is exposed and illuminated by the fluorescent lamp 5. The reflected light from the original 4 enters the color image sensor CCD 7 through the lens array 6 and is converted (color separation) into image signals R (red), G (green), and B (blue) by photoelectric conversion. The fluorescent lamp 5, the lens array 6, the CCD 7 and the like are mounted on a carriage 8, and a carriage drive motor 9 is used when reading a document.
As a result, the carriage 8 moves from right to left, and the entire surface of the document 4 placed on the contact glass 3 is scanned. CC
The image signal output from D7 is subjected to various image processing in the image processing unit 10 and the like, and then input to a laser diode (not shown) of the printer unit 2.

In the printer unit 2, the laser lights for Y (yellow), M (magenta), C (cyan), and Bk (black) emitted from the laser diodes energized by the image signals are respectively reflected by the polygon mirror 11. A direction perpendicular to the rotation direction (clockwise direction) of each drum-shaped photoconductor 14 via the fθ lens 12, the mirror 13, etc.
That is, the main scanning is performed in the direction along the drum axis. Photoconductor 14
The surface is uniformly charged by a charging charger 16 connected to a high voltage generator of negative voltage. Therefore, when the laser beam is irradiated, the charge on the surface of the photoconductor flows to the device ground of the drum body by the photoconductive development and disappears. Here, the laser diode is not turned on in the portion where the original density is high, and the laser diode is turned on in the portion where the original density is low. As a result, an electrostatic latent image corresponding to the density of the original is formed on the surface of the photoconductor 14. This latent image is transferred to the developing unit 1
When developed with No. 7, a toner image according to the image density is formed on the photoconductor 14.

On the other hand, the recording paper 19 stored in the paper feed cassette 18 is fed out by the paper feed operation of the paper feed roller 20 and the like, and is transferred by the registration roller 21 at a predetermined timing.
Sent to 2. While the recording paper 19 conveyed on the transfer belt 22 passes under the photoconductor 14, the toner image on the photoconductor 14 is transferred onto the recording paper 19 by the action of the transfer charger 23.
Is transcribed to. After transfer, the recording paper 19 is separated by the charger 2.
4 is peeled off by the action of 4 and sent to the fixing unit 26,
After being fixed, the sheet is discharged onto the sheet discharge tray 28 by the sheet discharge roller 27.

After the transfer, the toner remaining on the photoconductor 14 is removed by the cleaning unit 29, and the toner attached to the surface of the transfer belt 22 is cleaned by the cleaning unit 3.
It is removed at 0 and is discharged to each waste bottle 31. Also,
The residual charge on the surface of the photoconductor 17 is erased by the static elimination lamp 32.

FIG. 2 shows an outline of an electric component section of the digital color copying machine shown in FIG. The electrical component unit includes the scanner unit 1, the printer unit 2, and the image processing unit 10 described above, an operation display unit 33 for inputting and displaying various processing modes, and each of these units 1, 2, 33.
A system control unit 34, which communicates with a control unit inside to control the entire copying machine and sets the image processing unit 10.
Etc.

Color original image data optically read by the scanner 1 or color original image data input from an external device (recording medium such as a magnetic disk) 36 is input to the image processing unit 10. The image processing unit 10 is RGB
Based on the data, masking of Y, M, C, Bk and processing such as image processing and editing are performed. The image data that has been subjected to the predetermined processing in the image processing unit 10 is image-formed by the printer 2 or is output to an external device (recording medium such as a magnetic disk) 36. In this way, the copying machine body 3
5, an external device 36 can be connected to the image forming device 5, and image signals can be transmitted and received by communication between the copying machine main body 35 and the external device 36.

FIG. 3 is a block diagram showing the basic configuration of the image processing unit 10. The γ correction circuit 50 adjusts the gray balance of the data read from the scanner and converts it into a density value. Further, the delay circuit 60 adjusts the delay of the mark area detection circuit 40 in the line direction. Masking circuit 7
0 converts the R, G, B data into Y, M, C, Bk by the density masking method which has been used for a long time in plate making technology. The mark area detection circuit 40 generates a mark area signal based on the R, G, B image data and inputs it to the mark addition circuit 80. The mark adding circuit 80 adds a mark for confidentiality protection to the image data according to the mark area signal. The γ correction circuit 90 is used for the printer 2 connected to the latter stage.
(Or an external device 36) is a circuit that performs gradation conversion according to the characteristics of the device.

The mark area detecting circuit 40 and the mark adding circuit 80, which are the main parts of the present invention, will be described below.

FIG. 4 shows a schematic configuration of the mark area detection circuit 40. Even in the case of color originals, the background of the character part (text part) generally uses the base of the paper (original paper) as it is, in order to avoid consumption of ink in printing and toner in copying machines. White paper is generally used. Therefore, the mark area detection circuit 40 detects white as the background.

The comparator 41 compares the image data R input to the P terminal with the threshold value R1 input to the Q terminal,
When P> Q (R> R1), L (low level) is output. Similarly, the comparator 42 uses the image data G and the threshold value G1.
When the image data is larger than the threshold value (G> G1), the output is set to L and the comparator 43
Compares the image data B with the threshold value B1 and sets the output to L when the image data is larger than the threshold value (when B> B1). The outputs of the comparators 41, 42, and 43 are input to the gate 47, and the image data R,
The output of the gate 47 becomes H (high level) when all of G and B are larger than their respective threshold values. The output of the gate 47 becomes a mark area signal which becomes H output when the image data is judged to be white.
That is, the image data R, G, and B have a large number of components (color components) when their data values are large. Therefore, it is determined that each component is larger than the threshold value as white, and if it is smaller, it is black. I have decided.

FIG. 5 shows a schematic configuration of the mark adding circuit 80. The mark addition circuit 80 includes a mark pattern generation circuit 81 including an address generation circuit 81a and a mark data storage circuit 81b, and four data calculation circuits 8
2, 83, 84, and 85.

The address generation circuit 81a generates an address signal and supplies it to the mark data storage circuit 81b. The mark data storage circuit 81b reads the secret-holding mark data (mark data) stored in advance in synchronization with the address signal. The mark data read from the mark data storage circuit 81b is input to the data calculation circuits 82 to 85 for each color, and the data calculation circuits 82 to 85 are further input.
Then, a predetermined process is performed to form image data. In addition,
The mark data is binary (H or L) data, and H
Represents the addition of the confidentiality mark, and L represents the absence of the confidentiality mark. Further, the mark data storage circuit 81b
Stores multi-valued data as color data in addition to binary mark data.

When the mark area signal formed by the mark area detection circuit 40 is L, or when the mark area signal is H and the mark data is L, the data calculation circuits 82 to 85 directly input the input image data. Output. On the other hand, the mark area signal when the mark data is H in H outputs remain Teso to multi-value data outputted from the mark data memory circuit 81b and the image data. The mark color can be freely set by freely setting multi-valued data.

In the case where the secret-keeping marks are combined on the entire recording paper as shown in FIG. 6, if the character is blue and the secret-keeping mark is red, the secret-keeping marks are combined as shown in FIG. It At this time, the mark pattern is Y,
All of M, C and Bk are the same and are stored in the mark data storage circuit 81b so that the multi-valued data becomes red. As described above, in the first embodiment, no mark is added to a character other than white, whether red or blue.

[0030] The Contact, by storing the mark storing circuit 81b between Kudeta independently can form a mark confidentiality configured in a plurality of colors as shown in FIG. 8,
In addition, by forming the confidentiality mark composed of multiple colors, it is possible to deal with the case where only the confidentiality mark is erased by using the designated color conversion function added to the digital color copying machine. it can. In this case, it is desirable that the color interval of the confidential mark is 0.5 mm or less. Needless to say, it is difficult to erase the secret-holding mark by simply changing the multi-valued data instead of simply using R, G, B, Y, M, C, and Bk.

Second Embodiment The second embodiment is different from the first embodiment in the configuration of the mark area detection circuit 40, and the other configurations are the same.

FIG. 9 shows a schematic configuration of the mark area detection circuit 40c used in the second embodiment. Mark area detection circuit 40
c is composed of a binarization circuit 41c, an octal expansion circuit 42c, a selection circuit 43c, and a color data count circuit 44c.

First, the binarization in the binarization circuit 41c will be described. When binarizing the R, G, B image data, if each data is simply binarized, for example, R = 25
0, G = 150, B = 150 (MAX of data is 25
Both the data of 5) and the data of R = 100, G = 0, B = 0 cannot be judged to be red. Therefore, when binarizing, the maximum value, the minimum value, and the intermediate value of each pixel are calculated (between R, G, and B), and the intermediate value is regarded as the closer one of the maximum value and the minimum value. Binarization is performed.

FIG. 10 shows a flowchart of the binarization process. First, the value of each parameter is set (step S
1: Hereinafter, the word step is omitted in parentheses).
Next, image data is input (S2), and the following processing is performed on this image data. 1) White judgment (S3) (R> THR) AND (G> THG) AND (B> TH)
Those satisfying the condition of B) are white. R = H, G = H,
B = H (S4). THR, THG, and THB are preset parameters. 2) Black judgment (S5) Maximum value-minimum value ≦ (complement of maximum value) × Kk + Kc is black if it satisfies the condition. R = L, G = L, B = L (S6). Kk and Kc are preset parameters. 3) Color determination (S8) Maximum value-intermediate value> Maximum value = H, minimum value = L, intermediate value = L, if the condition of intermediate value-minimum value is satisfied, otherwise, maximum value = H, minimum Value = L, intermediate value = H (S
7, S9, S10). It should be noted that the maximum value, the intermediate value, and the minimum value are determined based on the magnitude relationship among R, G, and B in one pixel.

Referring again to FIG. 8-value expansion circuit 42c
Then, R ', G', which has been binarized by the binarization circuit 41c,
The data of B'is R, G, B, Y, M, C, Bk, W
Expands to eight values (color data) of (white). More specifically, using Table 1 below, three input values (R ', G',
Only the color data corresponding to the combination B ') is output at the H level.

[0036]

[Table 1]

The color data counting circuit 44c independently counts the number of 8 levels (color data) obtained by the 8-value expansion circuit 42c, which have become the H level. In other words, the number of R, G, B, Y, M, C, Bk and W colors (the number of pixels) is counted.

The selection circuit 43c receives the data R,
One of G, B, Y, M, C, Bk and W is selectively output by a selection signal. The color selection signal is set in advance.

The overall operation will be described. After recognizing the document size, the scanner 1 is scanned (pre-scanned) to read an image, and 8 data obtained by binarization and 8-value expansion are converted into a color data counting circuit. Count at 44c. The value of 8 data of the entire manuscript is referred to. The background color is the one with the highest count value. That is, it is used as a selection signal of the selection circuit 43c. In addition, a color other than the background color is used as the mark data when adding the secret keeping mark.

By outputting the secret-keeping mark by setting the parameters in this way, the secret-keeping mark is not invisible because it is different from the color added to the background color, and the legibility of manuscript characters can be improved. There is nothing wrong with it.

By the way, a color document has very little character information, and a color of information that is relatively small in the document due to the amount of information that is not regarded as noise can be regarded as character information. In addition, if you try to erase the mark by performing color conversion processing etc. on the mark by using the same color for the mark and the character information, the character information will also be erased at the same time, and you can handle the mark erasing process. it can. Therefore, in the present embodiment, the maximum value of the count value of the color of 8 data in the color data count circuit 44c is set as the background color during the prescan, and the noise of several% or less of the original pixels (shown in FIG. 11) is used.
By setting the color of the range that is not considered to be the color of the confidentiality-preserving mark, the color of the mark can be set to the same type of color as the information (character). Also, the same toner (ink) as the image data was used when adding the confidentiality mark.
By using the special color toner (ink) dedicated to the mark, when the same color is applied, the secret holding mark becomes easy to see because the gloss and gloss are different.

-Third Embodiment In the third embodiment, the mark adding circuit 80 is different from the first embodiment.
2 is different in configuration, and the operation display unit 33 is provided with input means for setting and inputting the mark color. Others are Example 1
It has the same configuration as.

FIG. 12 shows a schematic configuration of the mark adding circuit 80a used in the third embodiment. The operation display unit 3 is shown in FIG.
3 shows a part (mark color setting input section). The mark data stored in the mark data storage circuit 81f as mark color data and binary data arbitrarily set by the operator from among R, G, B, Y, M, C, Bk, etc. by the operation display unit 33. Mark area detection circuit 4 described in Example 1
The data calculation circuit 8 for each of Y, M, C, and Bk is the mark area signal generated by 0 and the image data.
2d, 83d, 84d and 85d are input. Y, M,
C, Bk data calculation circuits 82d, 83d, 84d, 8
In 5d, the image density of each of Y, M, C, and Bk is input and the mark density is determined by the mark density set by the mark density setting circuit 92 or the mark density held in advance. Also the color of the mark,
That is, as for the hue, the ratio of each data of Y, M, C and Bk is obtained based on the hue set by the mark color setting input means 91. Further, the image data to which the mark data formed at the obtained ratio is added is output. Here, as in the other embodiments, both the mark area signal and the mark data are H.
A mark is added only in the case of a level.

The operator presses (selects) the mark addition function 331 in the mark color setting input section shown in FIG.
By doing so, it becomes possible to input the hue of the mark. Here, the operator can select a desired mark color by pressing one of the keys 322 to 337. The color selected at this time is set as the mark color of the mark color setting input means 91.

In the third embodiment, R, G, B, Y, M, C, and Bk can be selected as the mark colors, but even when it is desired to use an intermediate color such as sky blue or orange, the image data is multi-gradated. By doing so, it becomes possible easily.

[0046]

As described above, according to the invention of the present application, for example, when the set color is white (the color of the area where the image information does not exist), the character image data is synthesized only in the background color area. , The information of the original and the character image data do not overlap each other, and the legibility of the original information is not impaired.

[Brief description of drawings]

FIG. 1 is a side view showing a schematic configuration of a digital color copying machine of the present invention.

FIG. 2 is a block diagram showing an outline of an electric component section of the digital color copying machine shown in FIG.

FIG. 3 is a block diagram showing a basic configuration of the image processing unit 10 shown in FIG. 2 according to the first embodiment of the present invention.

4 is a block diagram showing a schematic configuration of a mark area detection circuit 40 shown in FIG.

5 is a block diagram showing a schematic configuration of a mark adding circuit 80 shown in FIG.

FIG. 6 is a plan view showing an example of a color image original and an output image to which a security mark is added according to the present invention.

7 is a partially enlarged plan view of the output image shown in FIG.

FIG. 8 is a plan view showing an example of an output image to which a security protection mark is added when the security protection mark is composed of a plurality of colors.

FIG. 9 is a block diagram showing a schematic configuration of a mark area detection circuit 40c used in a second embodiment of the present invention.

10 is a flowchart showing the contents of binarization processing of the binarization circuit shown in FIG.

FIG. 11 is a plan view showing noise in a document image.

FIG. 12 is a block diagram showing a schematic configuration of a mark adding circuit 80d used in a third embodiment of the present invention.

13 is a plan view showing a part of the operation display unit used in the third embodiment of the present invention, which corresponds to a part of the operation display unit 33 shown in FIG. 2 (mark color setting input unit).

FIG. 14 is a plan view showing an example of an output image to which a security mark is added in the conventional apparatus.

FIG. 15 is a plan view showing an example of an output image to which a security mark is added in the conventional apparatus.

[Explanation of symbols]

1: Scanner 2: Printer 10: Image processing unit 33: Operation unit 40: Mark area detection circuit 50, 90: γ correction circuit 60: Delay circuit 70: Masking circuit 80: Mark addition circuit 81: Mark pattern generation circuit 82, 83 , 84, 85: data calculation circuit 40c: mark area detection circuit 41c: binarization circuit 42c: 8-value expansion circuit 43c: selection circuit 44c: color data counting circuit 80d: mark addition circuit 81d: mark pattern generation circuits 82d, 83d , 84d, 85d: data calculation circuit 91: mark color setting means 92: mark density setting means

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI H04N 1/46 H04N 1/40 D 1/60 1/46 Z (72) Inventor Yasushi Kamo 1-chome, Nakamagome, Ota-ku, Tokyo No. 3-6 Incorporated company Rico (56) Reference JP-A-2-284189 (JP, A) JP-A-2-210591 (JP, A) JP-A-61-285578 (JP, A) JP 63-141449 (JP, A) JP-A-4-14378 (JP, A) JP-A-4-77058 (JP, A) JP-A-59-45760 (JP, A) (58) Fields investigated (Int .Cl. ⁷ , DB name) H04N 1/387 H04N 1/40 H04N 1/46

Claims (5)

(57) [Claims] 1. A color image processing apparatus for adding a mark to an image of an input color original, detecting whether or not the image is a background based on the density of image data of the input color original and detecting the background. area detection means for generating a signal; mark image de to form a color mark image data - data forming means; and, wherein the color original, the color image de the background detection signal of only a region representing the image background of the region detecting means - the data,
Color image processing apparatus comprising the; image data synthesizing means for changing the color mark image data to which the mark image data forming means has formed. 2. A mark is added to the input color original image.
Pixels for each color of the input color image data of the color original in the color image processing apparatus
Counting means for counting the number ; a pixel of a color having the maximum count number of the counting means is formed
Generates a signal that represents this area as the background color area
Area detecting means; a mask for forming a color mark of a color different from the color of the background color area
Image data forming means; and the signal of the area detecting means of the color original is displayed.
The color image data of only the background color area
Color mark image data formed by the image data forming means
An image data synthesizing means for changing the color image processing device. 3. The mark image data forming means is color
The color of the background area that exists in the original color image data
Forming a color mark of a color different from that;
Placing the color image processing apparatus. 4. A mark is added to the input image of the color original document.
In the color image processing device to be added, the color of the color image data of the input color original is the set color.
Generate a signal that represents a region of
Area detection means; means for forming color mark image data; input means for inputting the color of the color mark image data ; color of the color mark image data formed by the forming means
Color conversion means for converting the color input from the input means;
And the signal of the area detecting means of the color original is displayed.
The color image data of only the background color area
A cover formed by the image data forming means and the color converting means.
An image processing apparatus, comprising : an image data synthesizing unit for changing the image data into the Lamark image data . 5. A mark is added to the input image of the color original document.
In the color image processing device to be added, the color of the color image data of the input color original is the set color.
Generate a signal that represents a region of
Area detection means; means for forming color mark image data ; density detection means for detecting the density of color image data of an original
Step: corresponding to the density of the image data detected by the density detecting means
A density converter for converting the density of color mark image data.
Stage; and the signal of the area detection means of the color original is represented.
The color image data of only the background color area
Formed by image data forming means and density converting means
Image data synthesizing method to change to color mark image data
An image processing apparatus comprising : a stage .