JPH06113117A - Picture processor - Google Patents

Abstract

PURPOSE:To add an inconspicuous pattern and to prevent the pattern from being added even if a pattern addition function is present by providing a means for judging the presence or absence of a means overlapping the addition pattern with a picture signal. CONSTITUTION:The look-up table 303 of a pattern addition circuit holds the pattern to be added, and inputs the counted values of scanning counters 301 and 302. The outputs are signal-processed, are transmitted to an AND gate 309, and they become valid only when they are printed in yellow. The modulation amount of the addition pattern is stored in a register 308, and it is added to picture data in an adder 310 when it is yellow. CPU 313 controls the addition of the pattern and stores the program in ROM 314. A procedure for the addition of the pattern is stored in the program and '1' is set in a register 312 when a system is started.

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 specific information to a reproduced image.

[0002]

2. Description of the Related Art In recent years, as the performance of color copiers and color printers has improved, it has become possible to illegally use them. However, it has been almost impossible to specify which device has been used for the copy or to limit the person who made the copy based on the copied product.

In order to prevent such illegal copying, it has been considered to identify it by a color copying machine or color printer itself and forcibly prohibit illegal copying. In this case, a circuit for determining a specific original is used in a color copying machine or a color printer, but since the number of image patterns that can be registered is limited in this circuit, it is not possible to register all types of specific originals. It has the drawback of being possible.

Further, in a color copying machine or a color printer having an external interface, such a determination circuit for a specific document may not function. For example, if the image data on the external interface is the data of the three primary colors of red, green and blue, and the specifications are such that they are sent at the same time, the above-mentioned determination circuit can operate. However, the image data on the external interface is cyan,
With data specifications such as magenta, yellow, and black that match the individual characteristics of the printer, there are multiple types of color-reproducible combinations, which necessitates multiple types of image patterns for specific document determination. Further, even the determination for detecting the specific document becomes very difficult, and the number of images of the specific document that can be determined decreases. Furthermore, when the image data representing the components of each color is sent frame-sequentially for each color, the image data must be stored in the memory for determination, which increases the cost of the device. There is also a disadvantage that a large amount of money is required to judge a document.

Further, assuming that the above problem of the image data sent from the external interface has been solved, even if recognition is performed by limiting the number of target specific originals to a recognizable number, it is registered. It is unavoidable that a picture that is very similar to a specific original is erroneously determined to be a specific original, and a dirty specific original is not a specific original.

As described above, it is important to add a means for detecting a specific document to the apparatus itself, but since the detection capability of the specific document is limited, a document which should not be copied should be copied. In this case, it is important to identify the copying machine that made the copy or the person who made the copy. Based on such a background, a technique for adding a copying machine or information for identifying a person who copied the image to a document image is being studied today. The technique is to use an output color component (eg, yellow) that is the least noticeable to human eyes among the output color components (eg, magenta, cyan, yellow, black) of the copying machine, and to output the image signal of the output color component. Is modulated (for example, a constant value is added), a number or a code indicating the serial number of the copying machine, etc. is struck small and repeated at regular intervals.

[0007]

However, in the above technique, even if yellow is the output color component which is the least visible, the modulation of the image signal must be minimized. When using the machine for design purposes, it is a hindrance to see patterns that are not in the manuscript.

In the case of copying an original, even if the original has a uniform color, the image signal is not always uniform due to variations in the sensitivity of the CCD, but the external interface of the color copying machine is used. When printing out an image on a computer, CG (Computer Graphics) can be directly output, so that there is a sufficient uniform area at the image signal level. then,
When the yellow component is modulated, there is a drawback that the additional pattern becomes conspicuous particularly in a light gray or light blue uniform portion.

[0009] has been conventionally considered, and small cohesive unit pattern numbers and codes representing the additional information, the method of configuring the additional pattern repeating the unit pattern at regular intervals, just because the unit pattern is held together small It is easy to stand out, and since the human eye is more likely to recognize a regular pattern than a randomly arranged pattern, it becomes easier to stand out when the unit patterns are arranged in a grid pattern. Therefore, there is no choice but to reduce the degree of modulation of the image signal, and the additional information may not be read depending on the specific document.

Therefore, it is difficult to identify all of the output images when viewed with the eyes, and a condition having the opposite direction that it can be surely identified by a certain method in a copy such as a specific original document. It is necessary to consider such modulations and patterns. Therefore, an object of the present invention is to provide an image processing apparatus that can add information for identifying a copying machine or a person to a reproduced image of an original image in a pattern that is as inconspicuous as possible. When the device is indexed by adding a pattern to such a reproduced image, the CPU (not shown) does not add the pattern by the pattern adding unit at the time of initialization and the image (video) remains as it is. If the copying machine of a certain model is equipped with only the pattern addition function to the copying machine of the previous model, the program of the copying machine of the previous model, that is, the program ROM, is copied to the copying machine of the new model. If it is installed in and started up, a pattern will not be added and a normal image will be output. Another object of the present invention is to
An object of the present invention is to provide an image processing device capable of preventing the above-mentioned loophole.

[0011]

[Means for Solving the Problems]
In order to achieve the object, an image processing apparatus according to the present invention provides a superimposing unit that superimposes additional information on an input image signal, a determining unit that determines the presence or absence of the superimposing unit, and a determination unit that determines the presence or absence of the superimposing unit. , And control means for controlling the device.

[0012]

According to this structure, the superimposing means superimposes the additional information on the input image signal, the judging means judges the presence or absence of the superimposing means, and the control means controls the apparatus according to the judgment by the judging means. .

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. In the following embodiments, an example of a copying machine is shown as an application example of the present invention, but the present invention is not limited to this, and it is needless to say that it can be applied to various other apparatuses. In addition, each device to which the present invention can be applied is
To prevent counterfeiting, specific documents such as banknotes and securities are made symmetrical.

<First Embodiment> [Apparatus Overview] FIG. 2 is a side sectional view showing the internal structure of a color copying machine according to the first embodiment of the present invention. In FIG. 2, 201 is an image scanner unit, which is 400 dpi.
This is a part that reads a document at a resolution of (dot / inch) and performs digital signal processing. A printer unit 202 is a unit that prints out an image corresponding to the original image read by the image scanner unit 201 on a sheet with a resolution of 400 dpi in full color.

In the image scanner unit 201, 20
Reference numeral 0 denotes a mirror surface pressure plate, which is a platen glass (hereinafter referred to as “platen”).
A document 204 on a 203 is illuminated by a lamp 205, guided to mirrors 206, 207, and 208, and an image is formed on a three-line sensor (hereinafter referred to as “CCD”) 210 by a lens 209, and full-color information red ( R), green (G), and blue (B) components are sent to the signal processing unit 211. The lamp 205 and the mirror 206 have a speed v, and the mirrors 207 and 208 have a speed 1/2.
At v, the front surface of the document is scanned (sub-scanning) by mechanically moving in a direction perpendicular to the electrical scanning (main-scanning) direction of the line sensor.

In the signal processing unit 211, the read image signal is electrically processed and decomposed into magenta (M), cyan (C), yellow (Y) and black (Bk) components, and the printer unit. Send to 202. In addition, M, C, and
One component of Y and Bk is sent to the printer unit 202, and a total of four document scans completes one printout.

The M, C, Y and Bk image signals sent from the image scanner unit 201 are sent to the printer video processing unit 212. Printer video processing unit 212
The semiconductor laser 213 according to the transmitted image signal.
Drive modulation. The laser light is generated by the polygon mirror 214,
The photosensitive drum 217 is scanned via the f-θ lens 215 and the mirror 216.

Reference numeral 218 denotes a rotary developing device, which has a magenta developing section 219, a cyan developing section 220, and a yellow developing section 22.
1. The black developing section 222 is composed of four black and black developing sections 222. The four developing sections alternately contact the photosensitive drum 217 to develop the electrostatic development formed on the photosensitive drum with toner. Reference numeral 223 denotes a transfer drum, which winds the paper supplied from the paper cassette 224 or 225 around the peripheral surface and transfers the image developed on the photosensitive drum to the paper.

After the four colors of M, C, Y, and Bk are sequentially transferred in this manner, the paper passes through the fixing unit 226, the toner is fixed on the paper, and then the paper is ejected.
[Image Scanner] FIG. 1 is a block diagram showing the circuit arrangement of the image scanner unit 201 according to the first embodiment. In the figure, 210 is a CCD line sensor having spectral sensitivity characteristics of R, G and B, 101 is A / D &
S / H circuit, 102 is a shading correction circuit, 103
A connection correction circuit, 104 is an input masking circuit, 10
Reference numeral 5 is a LOG conversion circuit, 106 is a masking / UCR (undercolor removal) circuit, 107 is a γ correction circuit, 108 is an MTF correction circuit, 109 is a pattern addition circuit, and 110 is a modulation circuit.

In the above structure, the CCD line sensor 2
The image signal input from 10 is the A / D & S / H circuit 1
After being A / D converted and S / H at 01, they are output as signals of 8-bit outputs 0 to 255, respectively. further,
The shading correction circuit 102 performs shading correction and black correction. The joint correction circuit 103 performs joint correction. That is, the connection correction circuit 103
Since the CCD line sensor 210 is arranged with a constant distance, the R signal and the G signal are delayed and the spatial deviation thereof is corrected. The input masking circuit 104 corrects the NTSC signal, and the LOG conversion circuit 1
In 05, conversion from the luminance signal to the density signal is performed.
In the masking / UCR circuit 106, magenta (M), cyan (C), yellow (Y), and black (Bk) signals for output are read out from the three input signals (R, G, B). Each frame is sequentially output in a predetermined bit length (for example, 8 bits). The γ correction circuit 107 is
It is composed of M or RAM and its peripheral circuits. MTF
The correction circuit 108 performs edge enhancement or smoothing. The pattern adding circuit 109 performs a process of adding a pattern that cannot be identified by human eyes to the copied image. The modulation circuit 110 is a circuit for encryption and is composed of, for example, a ROM or a RAM. These R
For example, when the video length is 8 bits, the contents of the memory of the OM and the RAM are 0 to 255 for the input range and 0 for the output range.
˜255, it is obtained by a one-to-one correspondence function created by a known random number generation formula or the like.

[Printer Video Processing Unit] FIG. 7 is a block diagram showing the circuit arrangement of the printer video processing unit 212 according to the first embodiment. In the figure, a frequency conversion circuit 701 frequency-converts the video sent from the reader unit 201 into the image clock of the printer. A FIFO is used for the frequency conversion circuit 701. Reference numeral 702 denotes a demodulation circuit for encryption, such as ROM or R
Composed of AM. The contents of the memories of the ROM and RAM are inverse functions of the functions handled by the modulation circuit 110 described above, and the output of the demodulation circuit 702 is a video image at the time of printout. A gamma correction circuit 703 of the printer unit is composed of a ROM and a RAM. The γ correction circuit 703 corrects the density change of the printer due to environmental changes. With this control, regardless of environmental changes,
Since a constant output can be obtained, a dot pattern which cannot be discerned by the human eye at all times, but can be viewed with certainty can be obtained by using a certain method.

Reference numeral 704 is a D / A converter, which converts video into an analog signal, and 705 is a PWM (pulse width modulation) modulation circuit, which performs PWM modulation of the analog signal.
A laser driver 706 drives the semiconductor laser 213 in accordance with the M, C, Y, and Bk video signals sent from the PWM modulator 704. 213 is a semiconductor laser.

[Pattern Adding Circuit] FIG. 3 is a block diagram showing the structure of the pattern adding circuit 109 according to the first embodiment. In the figure, 301 is a sub-scanning counter, 30
2 is a main scanning counter, 303 is a look-up table RAM (hereinafter referred to as "LUT"), and 304 is an AND
A gate, 305 a flip-flop, 306 an inverter, 307 an AND gate, 308 a register, 309
Is an AND gate, and 310 is an adder.

Here, the sub-scanning counter 301 repeatedly counts the main scanning synchronizing signal HSYNC and the main scanning counter 302 repeatedly counts the pixel synchronizing signal CLK with a 7-bit width, that is, 128 cycles. Further, the LUT 303 is a random access memory (hereinafter referred to as “RAM”) in which a pattern to be added is held, and the lower 5 bits to the least significant bit of the count value of each of the sub scanning counter 301 and the main scanning counter 302 are stored. The removed 4 bits are input. Only one bit of the output of the LUT 303 is referred to, and the one bit is supplied to the main scanning counter 301 and the sub scanning counter 302 by the AND gate 304.
ANDed with the upper 2 bits of each.

This result is synchronized with the CLK signal in the flip-flop 305 and, after being ANDed with both the 2-bit CNO signal "0" and CNO signal "1" in the AND gate 307, AND gate 3
Sent to 09. Both CNO “0” and CNO “1” are set by a CPU (not shown), and M → 0, 0, C
→ 0,1, Y → 1,0, K → 1,1 are set respectively. Here, a valid signal is generated only when CNO = 2, that is, when it is currently printed in yellow.

Here, the level (modulation amount) of the pattern to be added is stored in advance in the register 308 set by a CPU (not shown), and the AND gate 309
Only when CNO = 2 (when the surface is yellow), it becomes valid and is added to the image data V by the adder 310. 31
1 is an AND gate, 312 is a register set by the CPU 313, and becomes 0 at reset. Therefore, if the pattern adding circuit is not accessed by the CPU, the input video is output with a fixed value of 0. That is, the reproduced image is blank. Reference numeral 313 is a CPU for controlling pattern addition and the like, and ROM for storing programs
314 and a RAM 315 used as a work area
It is connected to the. Here, the ROM 314 is replaceable, and it is assumed that there are an old model ROM and a new model ROM now. Since the program stored in the ROM of the old model does not have the procedure for adding the above-mentioned pattern, the procedure for setting "1" in the register 312 is not included. On the other hand, the program stored in the ROM of the new model stores the procedure for adding the above-mentioned pattern, which is stored in the register 312 when the system starts up.
1 ". Now, if the register 312 is reset when the ROM is replaced or the power is turned on, the old model ROM will be blank and the new model ROM will be normal. The pattern can be added, which can solve the above-mentioned problems.

It should be noted that the additional pattern is added only by the yellow toner so that it is difficult for the human eye to identify it, but this has a weaker identifying ability with respect to the pattern drawn by the human eye with the yellow toner. This is what was used. FIG. 4 is a diagram for explaining additional patterns according to the first embodiment. L
The UT 303 holds a dot pattern as shown in FIG. 4, that is, an additional pattern. One square in FIG. 4 corresponds to one bit held in the LUT 303, where white indicates 0 and black indicates 1. The horizontal direction corresponds to the lower 4 bits of the address, and the vertical direction corresponds to the upper 4 bits of the address, and the additional pattern is composed of 256 bits. The line in which the upper bit of the address is 0 on the left side of FIG. Further, the 6 lines of the upper 4 bits of the address which are shaded on the left side of FIG. Each of these two lines represents 16 kinds of information by hitting one or two 2 × 2 bit dots at a determined position as shown on the right side of FIG. That is, each 2 lines represent 4-bit information. There are 3 of these 2 lines under the mark, so combine 1
Two bits of information can be represented. For example, “BBB” and “12” are not separated from each other and separated from each other.
When two lines of dot arrangement are continuous like 3 ”,
This is to prevent the additional pattern from becoming conspicuous by connecting dots vertically or diagonally.

The LUT 303 shown in FIG. 3 has a CPU
It is provided so that it can be written from 313, and information for identifying the source of the copy document, such as information for identifying the copying machine, is written in the state of being converted into additional pattern data. Further, the data except for the least significant 1 bit of the main scanning counter 302 and the sub scanning counter 301 of FIG.
One bit on 303 corresponds to 2 × 2 4 pixels on the copy. This is because the printer unit 202 according to the present exemplary embodiment performs a known line number switching process in the image area, for example, and thus the resolution is low and it may be difficult to read by adding a pattern on a pixel-by-pixel basis.

[Copy Result] FIG. 5 is a diagram showing an example of the copy result according to the first embodiment, and FIG. 6 is a diagram for explaining the effect of the first embodiment. First, in FIG. 5, 501
Is an added pattern, and the contents held in the LUT 303 are added as an image. In the example shown in FIG. 5, the pattern meaning “3FC” is added in a pattern of 32 pixels × 32 pixels and is repeated for every 128 main scanning lines and every 128 sub scanning lines so that it is difficult for human eyes to identify. . Therefore, by setting this as a machine-specific serial number or a coded serial number,
By examining the copy, it is possible to limit the copying device.

Further, in the present embodiment, the pitch for adding the pattern is set to every 128 pixels (or lines) in the main scanning, but in the present embodiment, it is 400 dpi (dot / inc).
Since the resolution is h), a pattern will be added about every 8 mm. This is an interval at which the additional pattern can be easily read on the watermark of the bill and the surrounding margins.

In the method using the additional pattern described above, as shown in FIG. 6B, as in the present embodiment, rather than the method of modulating the image signal by using the numerical values as they are, With the method using a pattern as shown in FIG. 6A, it is possible to reduce the number of pixels to be modulated and make the additional pattern less noticeable. As described above, according to the first embodiment, a specific additional pattern for limiting a device or the like in a copy is composed of a mark indicating a position reference and a pattern including one or more dots. By recording on a copy, the number of pixels to be modulated is reduced and the additional pattern is made less conspicuous, so that deterioration of image quality can be reduced. Furthermore, since converting the additional pattern into a pattern of dot arrangement is a kind of encryption, it also has the effect that it is difficult for a third party to intentionally operate this pattern.

Here, another point is that the modulation circuit 110 and the demodulation circuit 702 which form an encryption circuit.
Is after the pattern adding circuit. This makes it possible to realize pattern addition independent of encryption. That is, since the modulation circuit is provided after the pattern addition circuit, the pixels of the pattern addition unit are prevented from being messed up, and since the modulation circuit and the demodulation circuit are provided after the pattern addition circuit, the encryption function is sufficiently satisfied. be able to. Second Embodiment Now, in the first embodiment described above, the PWM modulation circuit 705 in the pattern adding circuit 109 is used, but in the second embodiment, the same function as the modulation circuit 110 is used. An example is given.

FIG. 8 is a block diagram showing the structure of the main part according to the second embodiment. In the figure, reference numeral 801 is a ROM, and a circuit having the same function as the modulation circuit 110 is RO
The inverse function table is written in the demodulation circuit 702 at the address where the MSB is "1", and a table completely different from that is written at the address "0". In this way, unless a "1" is written in the register 312, an abnormal image is output. However, in this embodiment, the AND gate 311 of FIG. 3 is unnecessary. <Third Embodiment> Now, in the third embodiment, unless a predetermined value is written in a register in which a fixed value is written,
An example of fixing to “0” is given.

FIG. 9 is a block diagram showing a pattern adding circuit according to the third embodiment. The difference from FIG. 3 described in the first embodiment is that the AND gate 31
That is, the value written in the register 308 is controlled through the gate 901 without controlling 1. This embodiment is one effective method because the modulation value is usually fixed and the 8-bit structure is used, so that the possibility of accessing a predetermined value at a predetermined address is very small.

In each of the above-mentioned embodiments, the laser beam printer has been described as an example, but the present invention is not limited to this, and is applicable to an ink jet printer and a thermal transfer printer. In particular, a so-called bubble jet type printer that uses a head that ejects droplets by utilizing film boiling due to thermal energy may be used.

Further, in each of the above-mentioned embodiments, the color to be added is yellow, but the present invention is not limited to this. For example, an inconspicuous color such as yellow green or gray, or light purple or light green. It may be a color with high lightness. Also,
In each of the above-described embodiments, the original image is input by the image scanner, but the present invention is not limited to this. Still video cameras, those input by a video camera, and those created by computer graphics May be

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of a single device. Further, it goes without saying that the present invention can be applied to the case where it is achieved by supplying a program to a system or an apparatus.

[0038]

As described above, according to the present invention, even if there is a pattern addition function that occurs when there are two models that differ only in the presence or absence of the pattern addition function, a normal image is obtained without pattern addition. This has the effect of preventing a loophole that is output.

[Brief description of drawings]

FIG. 1 is an image scanner unit 201 according to a first embodiment.
3 is a block diagram showing the circuit configuration of FIG.

FIG. 2 is a side sectional view showing the internal structure of the color copying machine according to the first embodiment of the present invention.

FIG. 3 is a block diagram showing the configuration of a pattern adding circuit 109 according to the first embodiment.

FIG. 4 is a diagram illustrating an additional pattern according to the first embodiment.

FIG. 5 is a diagram showing an example of a copy result according to the first embodiment.

FIG. 6 is a diagram for explaining the effect of the first embodiment.

FIG. 7 is a printer video processing unit 21 according to the first embodiment.
It is a block diagram which shows the circuit structure of 2.

FIG. 8 is a block diagram showing a configuration of a main part according to a second embodiment.

FIG. 9 is a block diagram showing a pattern adding circuit according to a third embodiment.

[Explanation of symbols]

 101 A / D & S / H circuit 102 Shading correction circuit 103 Connection correction circuit 104 Input masking circuit 105 LOG conversion circuit 106 Masking / UCR circuit 107 γ correction circuit 108 MTF correction circuit 109 Pattern addition circuit 110 Modulation circuit 210 CCD 201 Image scanner 202 Printer 200 mirror surface pressure plate 203 platen 204 original 205 lamps 206, 207, 208 mirror 209 lens 210 CCD 211 signal processing unit 212 laser driver 213 semiconductor laser 214 polygon mirror 215 f-θ lens 216 mirror 217 photosensitive drum 218 rotary developing unit 219 magenta developing unit 220 Cyan developing section 221 Yellow developing section 222 Black developing section 223 Transfer drum 224, 225 Paper cassette 26 fixing unit

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Claims (2)

[Claims] 1. A superimposing means for superimposing additional information on an input image signal, a judging means for judging the presence or absence of the superimposing means, and a control means for controlling the apparatus according to the judgment by the judging means. An image processing device characterized by the above. 2. The image processing apparatus according to claim 1, wherein the control unit has a unit that sets the image signal obtained by the superposing unit to a fixed value. Image processing device.