JPH04343568A - Image processor - Google Patents

Abstract

PURPOSE:To easily discriminate a pattern image indicating information such as a machine number newly added to a copying object without confusing it. CONSTITUTION:An image scanner part 201 reads out an original to which a pattern image is added and inputs color signals R, G, B and an added pattern image correcting circuit 101 discriminates the area of the added pattern image from the inputted signal B and erases the pattern contents of the discriminated area. A pattern adder 102 adds a new pattern image to the area from which the old pattern contents are erased and a printer 202 prints out the original in the added state of the new pattern image.

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, and more particularly, to an image processing apparatus having a function of adding a specific pattern.

0002

2. Description of the Related Art Conventionally, in order to prevent the misuse of copies, it has been considered to identify the copying machine that made the copy by adding a machine number to the copied image.

[0003] This method has the disadvantage that the image quality of the copy is degraded because an image that was not present in the original document is added to the copy.

In recent years, in order to solve the above problems, attempts have been made to add equipment numbers as a pattern that is difficult for the human eye to discern. In particular, it has been effective to add a pattern image using light-density yellow line drawings, taking advantage of the fact that it is difficult for the human eye to distinguish light-density yellow characters drawn on a white background.

[0005]

[Problem to be Solved by the Invention] However, in the above-mentioned conventional example, when the above-mentioned pattern is added to the original, the conventional addition pattern and the current addition pattern are mixed on the copy, and it is difficult to identify the equipment number. The drawback was that it was difficult to do.

The present invention has been made in view of the above-mentioned drawbacks of the conventional example, and its object is to provide an image processing device that can add a pattern indicating equipment numbers, etc., to a copy to facilitate identification. The point is to provide the following.

[0007]

[Means for solving the problem] Solving the above problems,
In order to achieve the object, an image processing apparatus according to the present invention includes an input means for inputting color image data obtained from a document to which a pattern image has been added, and a determination unit for determining the area of the pattern image from the input color image data. means and
The apparatus includes a changing means for changing the pattern contents of the area determined by the determining means, and an output means for outputting color image data with the pattern contents changed by the changing means.

[0008]

[Operation] According to this configuration, the input means inputs color image data obtained from a document to which a pattern image has been added, the determination means determines the area of the pattern image from the input color image data, and the changing means determines the area of the pattern image. The pattern content of the area determined in is changed, and the output means outputs color image data with the pattern content changed by the changing means.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. In the following embodiments, a copying machine is shown as an example of application of the present invention, but it is needless to say that the present invention is not limited to this and can be applied to various other apparatuses.

FIG. 2 is a side sectional view showing an example of a copying apparatus to which the image processing apparatus according to the present invention is applied. In FIG. 2, 201 is an image scanner unit that reads a document,
This is the part that performs digital signal processing. A printer unit 202 prints out an image corresponding to the original image read by the image scanner unit 201 on paper in full color.

In the image scanner section 201, 20
0 is a mirror pressure plate, and the platen glass (hereinafter referred to as "platen")
The original 204 on the 203 (referred to as ) is irradiated by a lamp 205, guided by mirrors 206, 207, and 208, and then passed through the lens 2.
09, 3 line sensor (hereinafter referred to as "CCD") 2
The image is formed on the signal processing unit 211 as full-color information red (R), green (G), and blue (B) components.
sent to. In addition, 205 and 206 are the speed v, and 20
7, 208 scans the entire document by mechanically moving in a direction perpendicular to the electrical scanning direction of the line sensor at 1/2v. The signal processing unit 211 electrically processes the read signal, decomposes it into magenta (M), cyan (C), yellow (Y), and black (Bk) components, and sends them to the printer unit 202. Also, for each document scan (scanner) in the image scanner unit 201, M, C, Y
, Bk is sent to the printer unit 202, and one printout is completed by scanning the document four times in total.

M, C, Y or Bk image signals sent from the image scanner section 201 are sent to a laser driver 212. The laser driver 212 modulates and drives the semiconductor laser 213 according to the image signal. The laser beam is transmitted through a polygon mirror 214, an f-theta lens 215, and a mirror 2.
16, the photosensitive drum 217 is scanned.

Reference numeral 218 denotes a rotary developing device, which includes a magenta developing section 219, a cyan developing section 220, and a yellow developing section 221.
, a black developing section 222, and four developing devices alternately contact the photosensitive drum 217 to develop an electrostatic latent image formed on the photosensitive drum 217 with toner. A transfer drum 223 winds the paper fed from the paper cassette 224 or 225 around the transfer drum 223, and transfers the image developed on the photosensitive drum 217 onto the paper.

After the four colors M, C, Y, and Bk have been sequentially transferred in this manner, the paper passes through the fixing unit 226 and is discharged.

FIG. 3 shows CCD(R) 301, CCD(G)
302 and CCD (B) 303 are diagrams showing relative sensitivities according to wavelengths of light.

FIG. 4 shows the image scanner section 2 shown in FIG.
FIG. 2 is a block diagram illustrating the configuration of 01. In the figure, 316 is a counter, and the 3-line sensor 210
A main scanning address 102 that specifies the main scanning position for line sensors 301 to 303 constituting the main scanning area is output. That is, when the horizontal synchronization signal Hsync is "1", it is set to a predetermined value by a CPU (not shown) and incremented to a pixel by a clock signal CLK.

The image formed on the 3-line sensor 210 is photoelectrically converted by the 3 line sensors 301-303, and is output as read signals of the R component, G component, and B component to the amplifiers 304-306 and the sample-and-hold circuit. 307 to 309 and A/D converters 310 to 312, each color receives an 8-bit digital image signal 313 (corresponding to R), a digital image signal 314 (corresponding to G),
It is output as a digital image signal 315 (corresponding to B).

FIG. 1 is a block diagram showing the configuration of the signal processing section (image processing unit) 211 shown in FIG. 2. As shown in FIG. In the figure, 204 is a document, 101 is an additional pattern image correction circuit, 102 is a pattern addition circuit, and 103 generates and outputs the vertical synchronization signal (VSYNC), horizontal synchronization signal (HSYNC), and clock (CLK) signals. a control unit to
402 is a color signal processing unit, 104 is a CPU that controls the entire apparatus, 104a is a ROM that stores programs for operating the CPU 104, and 104b is a RAM used as a work area for each program in the ROM.

Next, the operation of the above signal processing section 211 will be explained.

Color image signals (R, G, B) read by the image scanner section 201 are input to the additional pattern image correction circuit 101. Additional pattern correction circuit 1
In step 01, light yellow characters are determined and removed from the image signal. The color signal processing unit 402 generates print cutter signals (Y, B) from input color (R, G, B) signals.
M, C, K).

The pattern adding circuit 102 adds the equipment number to the image signal during yellow printing. The control unit 103 is a circuit unit that generates a synchronization signal, and
The c signal is a sub-scanning section signal, and is a signal indicating the sub-scanning image output section. The Hsync signal is a main scanning synchronization signal, and is a signal that synchronizes the start of main scanning. CLK is a basic clock for image processing.

CPU 104 is a microprocessor and outputs a frame sequential signal CNO shown in FIG. The laser color printer used in this example is M (magenta).
C (cyan), Y (yellow), and Bk (black) are printed in this order. The frame sequential signal CNO is a signal indicating the print color currently being printed.

FIG. 5 is a circuit block diagram of the additional pattern image correction circuit 101. In the figure, 501 is a line drawing determination section, 502 is a color determination section, 503 is a NAND circuit, and 50
4 to 506 are OR circuits, and 507 to 510 are line buffers for one line delay.

Next, the operation of the additional pattern image correction circuit 101 will be explained.

A line drawing determination unit 501 determines whether the pixel in question is a line drawing portion. The color determination unit 502 determines whether the pixel is a light yellow color. The outputs of the line drawing determining section 501 and color determining section 502 are subjected to a logical AND operation and the output signal is inverted using a NAND 503, and the inverted signal is ORed.
In circuits 504, 504, and 506, an OR operation is performed on each of the R, G, and B signals. As a result, when the pixel is pale yellow and is in a line drawing area, the NAND5
The output of 03 becomes "0", and the outputs of OR circuits 504 to 506 become pure white (R=255, G=255, B=255); otherwise, the image signal is output without being changed.

FIG. 6 is a block diagram showing the configuration of the color determining section 502. In the same figure, 601 is a Lab conversion circuit;
602 and 604 are comparators that compare different threshold values C0 and C1 with L, 603 is a look-up table (hereinafter referred to as "LUT"), and 605 is an AND circuit.

Next, the operation of color determination section 502 will be explained.

The Lab conversion circuit 601 has inputs R, G, B.
3× converting the signal into a luminance signal L and color component signals a and b
This is a 3-product-sum calculator. The comparison calculators 602 and 604 are
The luminance signal L is within a predetermined value range (C0 < L < C
1). LUT603 is ROM
It is a memory and outputs "1" when the color component signals a and b are in a specific value range, that is, the yellow component, and otherwise outputs "0".

FIG. 7 is a block diagram showing the configuration of the line drawing determining section 501, and FIG. 8 is a diagram explaining the operation of the line drawing determining section 501.

In order to detect a yellow line drawing, the line drawing determination unit 501 extracts the line drawing portion using a B signal that is sensitive to a yellow image.

In FIG. 7, 701 is an edge amount calculation circuit, 702 and 703 are line buffers that delay one pixel line, and 704 is a predetermined constant P and edge amount calculation circuit 7.
01, and 705 indicates a register storing the constant P. Note that the constant P stored in the register 705 may be provided so as to be given from another unit, thereby allowing the register 705 to be omitted.

Here, FIGS. 9 and 10 are block diagrams showing the configuration of the edge amount calculation circuit 83. Figures 9 and 10
91-1 to 91-9 are latches that hold data for one pixel, and 92-1 to 92-4 are latches 91-1 to 91-9.
A computing unit inputs two data from 91-9 and calculates the average, 93-1 and 93-2 are computing units 92-1 to 9, respectively.
2-4 is an arithmetic unit that inputs two data and outputs the maximum value and minimum value. 94 is a comparison unit that inputs the maximum value from the arithmetic units 93-1 and 93-2 and outputs the larger one as the maximum value. 95 is a comparator that inputs the minimum value from the arithmetic units 93-1 and 93-2 and outputs the smaller one as the minimum value; 96 is the difference between the maximum and minimum values output from the comparators 94 and 95; The subtracters used to calculate .

In the edge amount calculation circuit 83, the input data lines X, which are delayed by line buffers 702 and 703,
Pixel data from Y and Z are stored in nine latches 91-1 to 91.
-9 to form a 3x3 window. For this, the calculation shown in FIG. 8 is performed, and the edge amount signal O
UT is output. The circuit in FIG. 10 shows a configuration for performing the calculation in FIG.

Returning to the explanation of FIG. 7, when the edge amount calculation circuit 701 calculates the edge amount from the 3×3 pixel matrix with the pixel in question as the center, the edge amount signal OUT indicating the edge amount is sent to the comparator 602. The magnitude is compared with the constant P. As a result, the edge amount signal OUT becomes constant P
If it is larger, the edge amount signal OUT is output as a line drawing amount area signal indicating that the edge amount signal OUT is a line drawing area.

FIG. 11 is a block diagram showing the configuration of the pattern adding circuit 102. In the figure, 1101 is a sub-scanning counter, 1102 is a main-scanning counter, and 110
3 is a lookup table ROM (hereinafter referred to as "LUT"); 1104, 1107, 1109 are AND gates;
1105 is a flip-flop, 1106 is a register, 1
108 is an adder.

Here, the sub-scanning counter 1101 receives the main-scanning synchronization signal Hsync, and the main-scanning counter 1102 receives the pixel synchronization signal CLK, each having a width of 9 bits, that is, 512 bits.
Count repeatedly in cycles. Furthermore, LUT1103 is
This is a read-only memory (hereinafter referred to as ROM) in which a pattern to be added is held, and a sub-scanning counter 1101,
The lower 6 counter values of each main scanning counter 1102
Bit by bit is input. The output of ROM1103 is 1
Only the bits are referenced, and an AND gate 1104 performs an AND operation with the upper three bits of the main scanning counter 1101 and sub-scanning counter 1102. The flip-flop 1105 synchronizes with the CLK signal. The 2-bit field sequential signal CNO is “
After being logically ANDed with both the inverted signal of "0" and CNO being "1", it is sent to AND gate 1107. This is a valid signal only when CNO=2, i.e. currently printing in yellow. .

On the other hand, a value P1 is held in the register 1106, and a pattern is added to the input signal V by an adder 1108 via an AND gate 1107.
' is output. Therefore, when CNO=2, that is, when yellow is currently being printed, the pattern held in the ROM 1103 is repeatedly read out and added to the signal to be output. The pattern added here is added using only yellow toner so that it is difficult for the human eye to discern, but this takes advantage of the fact that the human eye has a weak ability to discern patterns drawn with yellow toner. This is what I did.

In order to visually observe the additional pattern image on the copy, it can be confirmed, for example, by looking at it through a blue translucent film.

[0039] Here, the flow of the first embodiment will be summarized.

FIG. 12 is a diagram showing the image processing process according to the first embodiment.

In FIG. 12, step (1) shows an image when a document is read by the image scanner section 201. In this step, an existing additional pattern image 1202-1 and an image 1203 other than the additional pattern image coexist on the read original image 1201-1.

In the next step (2), the output image 1 after the correction process is performed in the additional pattern image correction circuit 101.
201-2 is shown. In this step, the existing additional pattern image 1202-1 is removed, leaving only the original 1203.

In the following steps (3) and (4), output images 1201-3, 1201-4, 5 and 6 are shown. Y output image 120
1-3, a new additional pattern image 1202-2 is added, while M, C, and BK output images 1203-4
, 5, and 6 are output without adding any additional pattern images. 1203-1, 2, 3, 4 are Y, M, C, B respectively
An image of K is shown.

As explained above, according to the first embodiment, when copying a document to which a pattern image is added in a manner that is difficult for the human eye to discern, the additional pattern image on the document is identified; By signal conversion of the pixel signal, that is, by deleting the existing additional pattern image and adding a new pattern image, it is possible to confuse the identification of the pattern image indicating information such as the equipment number newly added to the copy. It can be easily done without any problems.

<Second Example> Next, a second example will be described.

FIG. 14 is a circuit block diagram of an additional pattern image correction circuit 101 according to a second embodiment of the present invention. Components similar to those in FIG. 5 are given the same reference numerals and explanations will be omitted. In the first embodiment, the additional pattern image on the document is deleted and a new pattern image is added, but in the second embodiment, the additional pattern image on the document is deleted as a new additional pattern image. By copying with a lower density, the new additional pattern image and the original additional pattern image are identifiably mixed on the copy.

In FIG. 14, 1407 is an AND gate, 1401 to 1403 are selectors, and 1404 to 1406 are
indicate registers storing constants P0, 255, and 255, respectively. When the output from the AND gate 1207 is 0, the input R, G, and B signals are selected, and when the output from the AND gate 1407 is 1, the register 1404,
Select values 1405 and 1406. register 1404
, 1405, and 1406 are 8-bit registers whose values are set by the CPU 104. The value of P0 is set to be lower than the yellow signal value P1 of the additional pattern image when a yellow print signal is generated.

With the above circuit configuration, it is possible to create a copy of an additional pattern image on a document with a density lower than that of a newly added additional pattern image.

As described above, according to the second embodiment, by reproducing the additional pattern on the original at a specific density, it is possible to identify the newly added pattern image and the existing additional pattern image on the original. It can be made possible.

The present invention may be applied to a system made up of a plurality of devices, or to a device made up of one device. It goes without saying that the present invention can also be applied to cases where the present invention is achieved by supplying a program to a system or device.

[0051]

[Effects of the Invention] As explained above, according to the present invention,
It is possible to easily identify a pattern image indicating information such as an equipment number newly added to a copy without confusion.

[Brief explanation of drawings]

[Figure 1] Signal processing unit (image processing unit) shown in Figure 2
211 is a block diagram showing the configuration of the device 211.

FIG. 2 is a side sectional view showing an example of a copying apparatus to which an image processing apparatus according to the present invention is applied.

[Figure 3] CCD (R) 301, CCD (G) 302, C
It is a figure showing the relative sensitivity according to the wavelength of light of CD (B) 303.

4 is a block diagram illustrating the configuration of an image scanner section 201 shown in FIG. 1. FIG.

FIG. 5 is a circuit block diagram of an additional pattern image correction circuit 101.

FIG. 6 is a block diagram showing the configuration of a color determination section 502.

FIG. 7 is a block diagram showing the configuration of a line drawing determining section 501.

FIG. 8 is a diagram illustrating the operation of the line drawing determination unit 501.

FIG. 9 is a block diagram showing the configuration of an edge amount calculation circuit 83.

FIG. 10 is a block diagram showing the configuration of an edge amount calculation circuit 83.

FIG. 11 is a block diagram showing the configuration of the pattern adding circuit 102.

FIG. 12 is a diagram showing an image processing process according to the first embodiment.

FIG. 13 is a diagram illustrating a frame sequential signal CNO.

FIG. 14 is a circuit block diagram of an additional pattern image correction circuit 101 according to a second embodiment of the present invention.

[Explanation of symbols]

101 Additional pattern image correction circuit 102 Pattern addition circuit 103 Control unit 104 CPU 104a ROM 104b RAM 200 Mirror pressure plate 201 Image scanner unit 202 Printer unit 203 Platen 204 Original 205 Lamps 206, 207, 208 Mirror 209 Lens 210 3-line sensor 211 Signal Processing section 212 Laser driver 213 Semiconductor laser 214 Polygon mirror 215 f-theta lens 216 Mirror 217 Photosensitive drum 218 Rotating developer 219 Magenta developing section 220 Cyan developing section 221 Yellow developing section 222 Black developing section 223 Transfer drum 224, 425 Paper cassette 226 Fixing units 301-303 CCD 304-306 AMP 307-309 S. H 310-312 A/D 316 Address counter 501 Line drawing determination section 502 Color determination section 503 NAND 504-506 OR circuit 507-510, 702, 703 Line buffer 6
01 Lab conversion circuit 602, 604, 704 Comparator 603 LUT 605 AND gate 701 Edge amount calculation circuit 705 Registers 91-1 to 91-9 Latches 92-1 to 92-4, 93-1, 93-2 Arithmetic unit 9
4,95 Comparator 96 Subtractor 1101 Sub-scanning counter 1102 Main-scanning counter 1103 LUT 1104, 1107, 1109 AND gate 110
5 Flip-flop 1106 Register 1108 Adder 1201-1 Original image 1201-2 to 1201-6 Output image 1202-1
, 1202-2 Additional pattern image 1203, 120
3-1 to 1203-4 Image 1407 AND gates 1401 to 1403 Selectors 1404 to 1406 Register

Claims (4)

[Claims] 1. An input means for inputting color image data obtained from a document to which a pattern image has been added; a determination means for determining an area of the pattern image from the input color image data; and an area determined by the determination means. An image processing apparatus comprising: a changing means for changing pattern contents; and an output means for outputting color image data whose pattern contents have been changed by the changing means. 2. The changing means includes erasing means for erasing the pattern contents of the area determined by the determining means, and addition means for adding a new pattern image different from the pattern contents to the area after erasing by the erasing means. The image processing device according to claim 1, further comprising: 3. The changing means includes a switching means for switching to a certain density for the area determined by the determining means, and an adding means for adding a new pattern image different from the pattern contents to an area other than the area. The image processing device according to claim 1, further comprising: 4. The image processing apparatus according to claim 3, wherein the certain density is a value lower than the density of the pattern image added by the adding means.