JP3015302B2 - Image processing apparatus and method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an image processing device and an image processing method.

[0002]

2. Description of the Related Art In recent years, image processing apparatuses capable of forming a color image, such as a color copying machine and a color printer, are capable of forming a high-quality color image. For this reason, there is an increasing possibility that a specific image (for example, securities, bills) that should not be copied by using this image processing apparatus is illegally created.

[0003]

However, conventionally,
When a specific document that should not be copied is originally copied, a method for obtaining specific information such as an image processing apparatus or a user who made the copy from the copy has not been specifically considered.

For example, as a method of obtaining specific information, it is conceivable to add a header or the like indicating specific information to an image formed by each image processing apparatus in the same manner as a facsimile. And it becomes impossible to visually output a high-quality image.

[0005] Further, if the user can rewrite the data like a normal FAX header, there is a possibility that the device identification information or the user information is intentionally set to the wrong one.

An object of the present invention is to provide an image processing apparatus and an image processing apparatus that solve at least one of the above-mentioned problems.

In addition, a color image formed by an image processing apparatus is effectively utilized by effectively utilizing the visual characteristics of human colors to prevent an image formed by the image processing apparatus from visually changing from an original image. It is an object of the present invention to provide an image processing apparatus and an image processing method capable of obtaining information for specifying a user based on the above.

[0008]

[0009]

According to the present invention, there is provided an image processing apparatus comprising: an input unit for inputting color image information including a plurality of color components; And an adding unit for adding information for specifying the apparatus user to the color image. It is characterized in that information for specifying the device user is added.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) [Overview of Apparatus] FIG. 2 shows an overview of an apparatus according to a first embodiment of the present invention. In FIG. 2, reference numeral 201 denotes an image scanner unit, which is 400 dpi (dots / inch).
Is a part that reads a document at a resolution of and performs digital signal processing. Reference numeral 202 denotes a printer unit which prints out an image corresponding to the document image read by the image scanner 201 in full color on a sheet at a resolution of 400 dpi.

In the image scanner 201, 20
Reference numeral 0 denotes a mirror pressure plate, and a platen glass (hereinafter, platen) 2
The original 204 on the original 03 is irradiated by a lamp 205, guided to mirrors 206, 207 and 208, and forms an image on a three-line CCD sensor (hereinafter referred to as a CCD) 210 by a lens 209. (G) and blue (B) components are sent to the signal processing unit 211. Note that 205 and 206 are speeds v, 207, 2
Reference numeral 08 scans the entire original surface (sub-scanning) by mechanically moving the line sensor in the direction perpendicular to the electrical scanning (main scanning) direction at a speed of 1/2 v.

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

Each of the M, C, Y, and Bk image signals sent from the image scanner unit 201 is sent to a laser driver 212. The laser driver 212 modulates and drives the semiconductor laser 213 according to the sent image signal. The laser light is applied to the polygon mirror 214, f
The photosensitive drum 2 via the −θ lens 215 and the mirror 216
17 is scanned.

Reference numeral 218 denotes a rotary developing unit, which includes a magenta developing unit 219, a cyan developing unit 220, a yellow developing unit 221,
The developing unit includes a black developing unit 222. The four developing units alternately contact the photosensitive drum 217, and develop the electrostatic development formed on the photosensitive drum with toner.

Reference numeral 223 denotes a transfer drum, which winds a sheet supplied from a sheet cassette 224 or 225 around the transfer drum 223, and transfers an image developed on the photosensitive drum to the sheet.

After the four colors of M, C, Y, and Bk are sequentially transferred in this manner, the sheet passes through the fixing unit 226 and is discharged after the toner is fixed on the sheet.

[Image Scanner] FIG. 1 is a block diagram of the image scanner unit 201.

Reference numerals 210-1, 210-2, and 210-3 denote red (R), green (G), and blue (B), respectively.
(CCD) sensor having a spectral sensitivity characteristic of A. The image signal read by this sensor is A
After being subjected to / D conversion, they are output as 8-bit output signals 0 to 255, respectively.

The sensor 210 used in this embodiment
-1, 210-2 and 210-3 are arranged in parallel with a certain distance therebetween, so that the delay elements 401 and 4
In 02, the spatial shift is corrected.

Reference numerals 403, 404, and 405 denote log converters, each of which is constituted by a look-up table ROM or RAM, and converts a luminance signal into a density signal. Reference numeral 406 denotes a known masking and UCR (under color removal) circuit.
Based on the three input signals, magenta (M), cyan (C), yellow (Y), and black (Bk) signals are sequentially and sequentially output with a predetermined bit length, for example, 8 bits.
Because of the surface-sequential projection, the CCD sensors 210-1 to 210-1
0-3 performs four scans.

A known spatial filter circuit 407 corrects the spatial frequency of the output signal. Reference numeral 408 denotes density conversion means for correcting the density characteristics of the printer unit 202, and is constituted by a ROM or RAM similar to the log converters 403 to 405.

On the other hand, reference numeral 414 denotes a microcomputer (hereinafter referred to as a CPU) for controlling the apparatus, and 413 denotes a CP.
An input / output port (hereinafter referred to as an I / O port) connected to the U 414, and a reference numeral 409 is a means for determining a specific document.

Here, the specific document determining means 409 determines whether the document placed on the document table is at least one of a plurality of specific documents, and a determination signal H indicating the possibility. Are output as multi-valued 2 bits. That is,
If at least one of the plurality of specific originals is most likely to be output, H = “3” is output, and if it is least likely, H = “0” is output.

The CNO signal is a 2-bit field-sequential signal, and is a control signal indicating the order of four reading operations as shown in Table 1. The CNO signal is sent from the CPU 414 to the I / O port 413.
And switches the operating conditions of the masking / UCR circuit 406.

[0025]

[Table 1]

Further, the above-described frame-sequential signal CNO is also input to the determination means 409, and the determination standard can be switched for each of the four reading operations to determine a different specific document.

Reference numeral 410 denotes a pattern adding circuit,
In accordance with the 2-bit pattern level selection signal PS specified by U414, a pattern that is difficult for human eyes to identify is added to the copied image.

[Timing Chart] FIG. 6 shows a main scanning timing chart in the present embodiment. VS
The YNC signal is a sub-scanning section signal, and is a signal indicating the sub-scanning image output section. HSYNC is a main scanning synchronization signal and is a signal for synchronizing the start of main scanning. CLK
Is an image transfer clock, which is a basic clock for various image processing in the present embodiment.

On the other hand, CLK 4 is obtained by dividing the frequency of the CLK signal by １ ／, and becomes a basic clock in the judgment means 409. The SEL signal is a timing signal used in the above-described thinning circuit 301, and is a signal shown in FIG.
Is generated by a circuit as shown in FIG. That is, the inverter 4
51, a 2-bit counter 452, an inverter 453, and an AND gate 454. 2-bit counter 4
52 is an HSYNC signal which is a main scanning synchronization signal,
After being cleared (initialized), the CLK signal is counted,
The count value is output with 2 bits. (D0, D1)
The upper bit D1 is output as the CLK4 signal, and the logical product of the inverted signal of the lower bit D0 and the upper bit D1 is output as the SEL signal.

As a result, in the circuit shown in FIG. 4A, flip-flop 4
55, 456, 457 and 461, 462, 463;
Selectors 458, 459, 460, flip-flops 464, 465, 466 holding data by CLK4 signal
As shown in FIG. 6, the R (or G, B) signal transferred by the CLK signal is thinned out at a rate of 1/4 and synchronized with CLK4 by the thinning circuit constructed as described above. R ′ (or G ′, B ′) signal can be obtained.

[Judging Means] FIG. 3 is a block diagram of the judging means 409.

Numeral 301 denotes a thinning circuit as shown in FIG. 4, which thins out data in order to reduce the load on the processing circuit of the judging means. Reference numeral 302 denotes a color matching look-up table ROM (read-only memory), which performs color matching with a plurality of types of specific originals.

The color distribution of 32 types of specific originals is checked in advance, and a result of determination as to whether or not the color of the pixel matches the color of the specific originals is stored.

That is, to the ROM 302, the CNO signal which is a frame sequential signal is input to the upper 2 bits of the address, and the upper 5 bits of the RGB color image signal thinned out to the lower 15 bits. The value of each plane sequential signal CNO 0
3 to 3 simultaneously output whether or not the color of the pixel matches the color of the eight types of specific originals in correspondence with the 8-bit data. Is determined.

303-1, 303-2,..., 303
Reference numeral -8 denotes a color determination circuit constituted by the same hardware, and includes an integrator 306, registers 307 and 308,
309, a comparator module 310, each of which determines the possibility that a specific document exists in the document by two bits. Reference numeral 309 denotes a maximum value circuit.
The maximum value of the judgment result outputs of 03-1 to 303-8 is output. That is, a determination result is output for the largest one of the eight types of specific originals.

[Integrator] FIG. 5 is a block diagram of the integrator 306.

Flip-flops 501 and 505 hold data at the rising timing of the CLK4 signal.

Reference numeral 502 denotes a multiplier which receives an 8-bit 2-input signal (A, B) and outputs an 8-bit signal (A × B / 255) as a multiplication result. A multiplier 503 receives a 1-bit input signal (A) and an 8-bit input signal (B), and outputs an 8-bit output signal (A × B) as a multiplication result.

An adder 504 receives two 8-bit input signals (A, B) and outputs an 8-bit signal (A + B) as an addition result.

As a result, in the present integrator, the 8-bit output signal y _i is expressed by the following equation with respect to the binary input signal x _i .

Y _i = (α / 255) y _i-1 + βx _i-1 where α and β are preset constants, and the characteristics of the integrator are determined by the magnitudes of these values. .

For example, FIG. 7 shows an example of input and output of the integrator when α = 247 and β = 8. That is, (a)
In response to an input x _i-1 as shown in (b), an output y _i as shown in (b) is output.

Here, inputs such as 701 and 702, which are almost "0" even though the surroundings are almost "0",
An input such as 703 whose surroundings are almost “1” but are still “0” is considered to be noise. This is processed by the integrator and the register 307 of FIG.
704 (R1), 704 ′ (R2), 704 ″ (R
By setting an appropriate threshold value as in 3) and binarizing the output y _i of the integrator with this, noise (noise) can be removed.

[Comparator Module] FIG. 8 is a block diagram of the comparator module 310. 801, 802, 80
3 is a comparator, 804 is an inverter, and 805 is AN
D gates and 806 and 807 are OR gates. In advance,
R1 is set in the register 307, R2 is set in the register 308, and R3 is set in the register 803.
>R2> R3. With this configuration, as a result, the determination result is quantized into two bits and output. That is, if R1 <(input), 11 is output, if R2 <(input) ≦ R1, 10 is output, and if R3 <(input) ≦ R2, 01 is output,
If (input) ≦ R3, 00 is output.

This output signal indicates the possibility that the input image is a specific document.

[Pattern Adding Circuit] FIG. 9 is a block diagram of the pattern adding circuit 410. Reference numeral 901 denotes a sub-scanning counter; 902, a main scanning counter; 903, a lookup table ROM; 905, a flip-flop;
3 is an AND gate, 906, 907, 908, and 909 are registers, 910 is a 4to1 selector, and 911 is AN
D gate, 912 is an adder, 913 is an AND gate, and 914 is an inverter.

Here, the sub-scanning counter 901 repeatedly counts the main scanning synchronizing signal HSYNC, and the main scanning counter 902 counts the pixel synchronizing signal CLK with a 9-bit width, that is, 512 cycles. Reference numeral 903 denotes a read-only memory (hereinafter referred to as RO) in which a pattern to be added is held.
M), the sub-scanning counter 901 and the main scanning counter 9
02 The lower 6 bits of each count value are input. The output of the ROM 903 refers to only one bit, and the AND gate 904 controls the main scanning counter 901.
The logical product of the upper 3 bits of the sub-scanning counter 902 is obtained, and the flip-flop 905 synchronizes with the CLK signal. Is logically ANDed with both the inverted signal of CNO0 and CNO1, and then sent to the AND gate 911. This is a signal effective only when CNO = 2, that is, when printing is currently performed in yellow.

On the other hand, registers 906, 907, 908,
909 holds in advance the values P1, P2, P3, and P4, and any one of P1 to P4 is selected according to the pattern level selection signal PS specified by the CPU, and the AND gate 911 is set. Thereafter, the adder 912 adds a pattern to the input signal V and outputs V ′. Therefore, when CNO = 2, that is, when the image is currently printed in yellow, the pattern held in the ROM 903 is repeatedly read and added to the signal to be output.

Here, it is set so that P1 <P2 <P3 <P4, and the selector 910 sets Y = A s = 01 when s = 00 (binary number) and Y = B s when s = 01 (binary number). = 10 (binary number) Y = C When s = 11 (binary number), Y = D is set, so that when PS = 00 (binary number), V ′ = V + P1 PS = 01 ( In the case of V ′ = V + P2 PS = 10 (binary) V ′ = V + P3 In the case of PS = 11 (binary), a pattern is added such that V ′ = V + P4.

Here, the pattern to be added is added only with yellow toner so that it is difficult for the human eye to identify it. This is based on the fact that the discrimination ability is weak. Furthermore, by changing the level of the pattern to be added according to the possibility that the specific document exists in the input image, the pattern can hardly be recognized by human eyes in a normal copy, and the specific document can be identified. The higher the possibility of the existence, the sharper the pattern is added.

[Copy Result] FIG. 10 shows an example of a copy result in the present embodiment. The pattern 1001 is the added pattern, and the contents held in the ROM 903 are added. In the example shown in FIG.
The pattern of 34 ″ is added in a pattern of 64 × 64 pixels so that it is difficult for the human eyes to recognize the pattern, and is repeated every 512 pixels in the main scan and 512 lines in the sub-scan.
Therefore, by setting this as a serial number unique to the machine or by encoding the serial number, the copied device can be identified, and the copied device can be limited.

Further, when there is a high possibility that a specific document that should not be copied is present in the read image,
You can also add a clear pattern. That is, the density of the pattern can be changed according to the possibility of being a specific document.

Further, in the present embodiment, the pitch at which the pattern is added is set to 512 pixels (or lines) in the main scan.
However, in the present embodiment, 400 dpi (d
ots / inch), so about 32.5m
A pattern is added for each m. On the other hand, the width of banknotes (Bank of Japan) in the short direction is about 76 mm, and the width of banknotes in major countries in the short direction is also about 60 mm.
Therefore, when the bill is copied, the pattern is always added to the inside of the copied bill. Therefore, even if only the bill portion is cut off and misused, the copy number can be identified by examining the copy and reading the added pattern.

[Flow chart] FIG.
4 controls the pattern level selection signal PS.
2 is a flowchart for the set of.

First, immediately after the copy start, step 1
At 102, the pattern level selection signal PS is set to "0".
Is set. Next, in step 1103, the current determination level H is compared with the value of PS. If H is larger, the value of H is set in PS in step 1104. Otherwise return to 1103. That is, according to the history of the determination signal H, the maximum value from the copy start to the present is P
Set to S.

The present invention is not limited to the above embodiment. For example, in the above-described embodiment, as the specific pattern to be added, a device-specific serial number or a coded version thereof is added. However, the information is not limited to this as long as it is information for specifying the device. .

For example, other information for specifying the apparatus, such as the manufacturing date of the apparatus, the lot number of the apparatus, and the version of the apparatus, may be used.

In the above-described embodiment, the copied device is specified. However, the embodiment of the present invention is not limited to this, and the copied person may be limited.

For example, devices that require insertion of an ID card for restricting users and devices that require input of an ID number are already known when using the device. In the device, the recognized ID number or its encoded ID number may be added as a specific pattern.

Further, the date of copying or the encoded date may be added as a specific pattern.

As described above, according to the above embodiment,
As a method for specifying the device in a copy, by adding a specific pattern that is difficult to be recognized by human eyes, when a specific document (for example, banknote) that should not be copied is copied, It can be a clue to limiting the device. Furthermore, by repeatedly adding a specific pattern at a pitch shorter than the length of the banknote in the short direction, even if a part of the copy is cut off and abused,
A specific pattern is always added to a copy, and by limiting the specific pattern, it is possible to identify or narrow down the copied device or copied person.

In the above embodiment, a laser beam printer has been described as an example. However, the present invention can be applied to an ink jet printer and a thermal transfer printer.

In particular, a so-called bubble jet printer using a head of a type that ejects droplets by utilizing film boiling caused by thermal energy may be used.

The color to be added is not limited to yellow, but may be an inconspicuous color such as yellow-green or gray or a color with high lightness such as light purple or light green.

The document is not limited to the original input by the reader, but may be an input by a still video camera, a video camera, or an image created by computer graphics.

[0066]

As described above, according to the present invention, when adding information for specifying an apparatus user to a color image represented by input color image information, a plurality of color components are added. By adding to the color components that are difficult to discern to the human eye, the image formed by the image processing device is visually changed from the original image by effectively utilizing the visual characteristics related to human colors. While suppressing
Information for specifying the user can be obtained based on the color image formed by the image processing device.

[0067]

[0068]

[0069]

[Brief description of the drawings]

FIG. 1 is a block diagram of an image scanner unit.

FIG. 2 is an external view of the apparatus according to the first embodiment.

FIG. 3 is a block diagram of a determination unit.

FIG. 4 is a block diagram of a thinning circuit and a frequency dividing circuit;

FIG. 5 is a block diagram of an integrator.

FIG. 6 is a timing chart.

FIG. 7 is a diagram showing timings of input / output signals in an integrator 306;

FIG. 8 is a block diagram of a comparator module 310.

FIG. 9 is a block diagram of a pattern adding circuit 410.

FIG. 10 is a diagram illustrating an example of a copy result according to the embodiment;

FIG. 11 is a flowchart showing a control flow.

[Explanation of symbols]

 202 Image Scanner Unit 203 Printer Unit 306 Integrator 308 Comparison Module 409 Specific Document Judgment Means 410 Pattern Addition Circuit 414 CPU

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ identification symbol FI H04N 1/46 G06F 15/66 B 1/60 H04N 1/46 Z (58) Investigated field (Int.Cl. ⁷ , DB name) ) H04N 1/38-1/393 H04N 1/40-1/409 H04N 1/46 H04N 1/60

Claims (8)

(57) [Claims] An input unit for inputting color image information including a plurality of color components; and an addition unit for adding information for specifying an apparatus user to a color image represented by the input color image information. Means for adding information for identifying the user of the apparatus to a color component which is difficult to be recognized by human eyes among the plurality of color components. apparatus. 2. The image processing apparatus according to claim 1, wherein a color component of the plurality of color components that is difficult to recognize by human eyes is yellow. 3. The image processing apparatus according to claim 1, further comprising an output unit that outputs a color image to which information for specifying the apparatus user has been added by the adding unit. 4. The image processing apparatus according to claim 3, wherein the output unit records the color image on a recording medium. 5. An image processing method in an image processing apparatus for processing input color image information, comprising: an input step of inputting color image information including a plurality of color components; An additional step of adding information for specifying an apparatus user to a color image to be performed, wherein the adding step is performed for a color component which is difficult to be recognized by human eyes among the plurality of color components. An image processing method characterized by adding information for specifying the user of the apparatus. 6. The image processing method according to claim 5, wherein a color component of the plurality of color components that is difficult to recognize by human eyes is yellow. 7. The image processing method according to claim 5, further comprising an output step of outputting a color image to which information for specifying the apparatus user has been added in the adding step. 8. The image processing method according to claim 7, wherein in said output step, said color image is recorded on a recording medium.