JPH04207464A - Image processor - Google Patents

Abstract

PURPOSE:To allow the discrimination of specific documents regardless of the form of an input signal by providing a means for converting the image signals inputted by input means to the image signals in a prescribed color space and a means for discriminating the presence or absence of the specific documents previously registered in accordance with the image signals converted by the converting means. CONSTITUTION:The input means 100 inputs the image signal corresponding to the document from one of input apparatus 102 to 105 connected thereto. The converting means 107 converts the image signals inputted by the input means 102 to 105 to the image signals in the prescribed color space. The discriminating means 109 discriminates the presence or absence of the specific documents previously recorded in accordance with the image signals converted by the converting means 107. Processing means 108, 110 process the image signal inputted by the input means 100 in accordance with the result discriminated by the discriminating means 109. The specific documents are identified in this way regardless of the form of the input signal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to identifying a specific document in a color image processing apparatus.

[Prior Art] In recent years, with the increase in image quality and colorization of copying machines, there has been a concern that specific documents such as gift certificates and securities may be forged. On the other hand, as a method for recognizing a specific document in a copying machine, the present applicant has proposed a method of detecting the color data distribution of an input image and comparing this with the color data distribution of the specific document.

[Problems to be Solved by the Invention] However, in the above conventional examples, a color original is separated into three colors by an RGB CCD sensor.
Since discrimination is performed only by signals, for example, the image output device is connected to a host computer, etc., the computer performs image processing, and the image output device receives Y, M, C, Bk.
There is a drawback that when a signal is sent, it is not possible to detect a specific target document. That is, detection could not be performed when the input color component data and the color component data used for detection were in different color spaces.

The present invention has been made in view of the above-mentioned drawbacks of the conventional examples, and its purpose is to improve the quality of input data in, for example, normal image copying operations or when outputting images in response to signals from external equipment. The object of the present invention is to provide an image processing device that can identify a specific document regardless of the format of the signal.

[Means for Solving the Problems] In order to solve the above-mentioned problems and achieve the objectives, an image processing device according to the present invention includes an interface that is detachably connected to a plurality of input devices that handle image signals of different color spaces. an image processing apparatus having an input means for inputting an image signal corresponding to a document from one of the connected input devices, and converting the image signal inputted by the input means into an image signal in a predetermined color space. a converting means, a determining means for determining the presence or absence of a specific document registered in advance based on the image signal converted by the converting means, and an image signal input by the input means based on the result determined by the determining means. It is characterized by comprising a processing means for processing.

[Operation] According to this configuration, the input means inputs an image signal corresponding to the original from one of the connected human-powered devices, and the conversion means converts the image signal inputted by the input means into an image signal in a predetermined color space. The determining means determines the presence or absence of a specific original registered in advance based on the image signal converted by the converting means,
The processing means processes the image signal input by the input means based on the result determined by the determination means.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described in detail 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 the present invention is not limited to this, and adaptation to other devices is also possible without departing from the spirit of the present invention. In addition, specific manuscripts include everything from those that violate public order and morals to those that have specific uses.

<First Embodiment> FIG. 1 is a block diagram showing a first embodiment of a copying machine to which an image processing apparatus according to the present invention is applied.

In the figure, 101 and 101' are scanners,
The original image is read optically and R and G are read.

Converts to B signal. 102 is an image processing unit which receives R, G, and B signals from the corresponding scanner 101, converts the luminance signals into density signals, and converts the luminance signals into density signals.
Outputs C and Bk signals. 103 is a host computer which inputs R, G, and B signals from the corresponding scanner 101°, converts the luminance signals into the color system, and converts the luminance signals into the color system;
It outputs the a″b0 signal. 104 indicates a still video (hereinafter referred to as rSVJ), 105 indicates a video tape recorder (hereinafter referred to as rVTRJ), 100 is a signal processing unit, and includes an IPU 102, a host computer 103, 5V104. #112 indicates an image output device such as a printer, which is connected to the VTR 105 and other input devices, inputs an image signal in the form of a color space handled by each input device, and converts it into a print signal.

In the signal processing section 100, 106 is an arithmetic circuit having a memory, 107 is a conversion circuit, 10g is a color processing circuit,
109 is a specific original identification circuit, 110 is an inking circuit, IN
H404 indicates the identification result of the specific original identification circuit 109.

As an operation of the signal processing unit 100, a color original is separated into 83 colors of R, G, and the like by the image scanner 101.
The R9G, B signals are read digitally and the IPU1
02 and a device equipped with an image processing function, such as a host computer 103. The IPU 102 and host computer 103 perform logarithmic conversion, masking calculations, and U
The input R, G, and B signals are converted into Y, M, C, and Bk signals by the arithmetic processing performed in the image processing section of a normal digital color copying device such as CR, and the input R, G, and B signals are converted into Y, M, C, and Bk signals, and
R input to the PU 102 or host computer 103,
The G and B signals are converted to XYZ coordinates of the xyz color system, and the image signal converted to XYZ is L" a " b
The input R, G, and B signals are converted to various color spaces, such as ``converted to the color system L'a' b°.

When R, G, and B are converted to tristimulus values x, y, and Z in the xyz color system, and from tristimulus values X, Y, and Z to L'a″b1, the R, G, and B signals are converted to NTSC. According to the method, the conversion formula is expressed as the following formulas (1) and (2).

...(1) ...(2) As described above, IPL1102. host computer 10
3 and the like, image signals converted into various color space signals are output to the signal processing section 100.

On the other hand, R, G, and B signals are output from devices such as S V 1.04 and VTR 105 to signal processing section 100 .

IPU102. Host computer 103, 5V104
．． When image signals output from various devices such as the VTR 105 are sequential Y, M, C, and Bk signals, the signals are divided into two systems: one goes to the inking circuit 110, and the other goes to the inking circuit 110. It is input to the arithmetic circuit 106. In addition, the input to the image processing device 111 is Y, M, C, Bk sequentially.
If the input signal is a signal other than the signal, the input signal is sent to the arithmetic circuit 10
Sent to 6. The arithmetic circuit 106 is equipped with a memory, and when the input signal is a dot-sequential image signal, it is passed through, and when the input signal is a frame-sequential signal, it is stored in the memory and converted into a dot-sequential signal. . Arithmetic circuit 106
The signals output from are RGB, YMCBk, L” a
"b", XYZ, etc., and the signal is sent to the conversion circuit 107.
sent to. The conversion circuit 107 converts the input image signal into an image signal of a certain common color space (RGB signal in this embodiment).
Convert to The signal from the conversion circuit 107 that has been converted into an image signal in the common color space is divided into two parts and sent to the color processing circuit 10.
8. Each is sent to a specific original identification circuit 109.

FIG. 2 is a block diagram showing the configuration of the conversion circuit 107 according to the first embodiment, and FIG. 8 is a diagram illustrating the relationship between various color spaces and a common color space in the first embodiment. So,
An example will be described in which the input signals Y, M, C, and Bk are changed into RGB signals. In the same figure, 201, 202
, 203 are adders, C and Bk, M and B, respectively.
Add the k, Y and Bk signals. 204, 207, 21
0 is a multiplier, and the addition results of the adder 201 are multiplied by predetermined constants a++, az+, and as+. Multipliers 205, 208, and 211 apply predetermined constants a13, azz, and
The multiplication of ass is combined. 206, 209, and 212 are multipliers, each of which applies a predetermined constant a1 . , a2s, a, are combined. 213
, 214, 215 are adders, and each multiplier 2
Addition of outputs of 04.205.206, multiplier 207,2
Addition of outputs of 08 and 209, multipliers 210 and 211°2
12 outputs are added. Adders 213, 214.21
5 has eight R, G, and B signals.

As an operation, C, M, Y output from the arithmetic circuit 106
The signals are respectively sent to adders 201.2'02.203. The Bk signal is divided into three parts: 201, 202,
203 separately. Adders 201, 202, 2.0
3, based on the input signal, C' = C + Bk, respectively.
, M'=M+Bk.

The calculation Y'=Y+B is performed, and C', M'.

Y' is output to multipliers 204-212. Multiplier 2
The outputs of 04 to 212 are outputted to adders 213 to 215, respectively, as shown, and output as R, G, and B, respectively. This can be expressed as equation (3).

(3) This is the inverse matrix of the matrix of coefficients for masking processing performed in conventional color processing.

In other words, as shown in Fig. 8, even if the image signals are in different color spaces, or even in the same color space, the axis may be distorted due to the influence of the spectral characteristics when reading the original. In this case, signal conversion or normalization is performed to convert the image signal into a predetermined common color space.

The color processing circuit 108 receives the RGB signal from the conversion circuit 107 and performs logarithmic conversion, masking, and UCR processing.
Outputs Y, M, C, Bk signals in frame sequential order. On the other hand, the signal sent to the specific document identification circuit 109 determines whether or not a specific document exists in the input image signal by a method described later. If a specific document exists, its address data is sent to the inking circuit 110, and a black header image is output based on this address data. If a specific document does not exist in the human image signal, a signal to that effect is sent, the color processing circuit 110 is bypassed, and the color processing circuit 1
The output signal from 08 is output to the image output device 112, and the image output device 112 outputs it as a hard copy according to each method such as PWM, thermal transfer, inkjet, etc.

Next, the specific document identification circuit 109 will be explained.

3A and 3B are diagrams for explaining the relationship between a specific original and color space, FIG. 4 is a diagram for explaining the method for determining a specific original according to the first embodiment, and FIG. FIG. 6 is a block diagram showing the configuration of the specific original identification circuit 109, FIG. 6 is a diagram showing the relationship between the color space data of the specific original and data of the determination ROM 501, and FIG. 7 is a diagram showing the positional relationship between the specific original and the recognition area. FIG.

The determination ROM 501 has information written therein as to whether or not the image data of a specific document shown in FIGS. 3A, 3B, and 6 exists in the corresponding R, G, and B spaces.

If the input color signals 313, 314, and 315 match the image area of the specific document in the shaded area in the RGB space shown in FIGS. 3A and 3B, l becomes the output signal of the determination ROM 501, and if not, 0 becomes the pressure signal. becomes.

In this embodiment, the determination ROM 501 has a data width of 8
It is composed of a one-bit memory with an address width of 15 bits, and stores data corresponding to eight types of specific originals. The above judgment information outputted from the judgment ROM 501 passes through the latch circuit 502 and is then sent to the integrators 5011 to 501.
018 is input.

The integrators 5011 to 5018 are as shown in FIG. 12B.
When the input value 1 is continuous, the output value from the integrator 5011 approaches 255, and when the input value O is continuous, the output value approaches O, as shown in FIG. 12A.

Each of the comparison calculators 5001 to 5008 is an integrator 501.
Output values A1 to A8 from 1 to 5018 and register 50
Which of the constant values B1 to B of 21 to 5028 are determined in size is determined, and determination signals indicated by C1 to C8 are output. The judgment signal C1 (1≦i≦8) is expressed by the following formula (4): (ε:=8:A, U8, , (4) A + > B +.In this way, the input color If the signal continuously matches the image data of the specific original, the comparison calculator (50
The output C1 from 01 to 5008) becomes l.

The counters 521 to 528 are counters that count up only when the corresponding 8-force C1 is 1. The counters 521 to 528 calculate the number of pixels in the specific document recognition area shown in the shaded area in FIG.

The OR writing circuit 511 includes comparison calculation units 5001 to 50.
This is a circuit that OR-writes the pressure signals C1 to C8 of 08 into the RAM 521. Also, the RAM 512 is a judgment ROM 50.
FIG. 5B, which is a RAM of the same size as 1, with a bit width of 8 bits and an address width of 16 bits, is an OR write circuit 51.
1 is a block diagram showing the configuration of FIG. 5111 is an SRAM of 32 and as an address bus, A o = A I4
5-bit signals each of R, G, and B are input to , and are taken as data, and -D is the data 5021 to 5021 after the OR operation described below.
5028 is input. 5112 is a timing generation circuit that generates the timing signal shown in FIG. 5C.

In the OR operation section inside the diagonal line, the data stored in the address specified by A o "" A I 4 is converted to D according to the read enable OE at the timing of CLK'
0 to D, and latched into each latch circuit. On the other hand, the input signals 5021 to 5028 and the latched memory data are ORed in each OR circuit, and outputted from the buffer at Rio's inverter timing.

In this way, for each address defined by 5 bits each of R, G, and B, at least one of the data sequentially input by 5021 to 5028 is
The data is stored in RAM 5111.

Since D0 to Da are each stored at independent addresses,
Judgment processing can be performed in parallel on eight types of specific documents.

By measuring the number of bits of the determination result "1" stored in the RAM 512, the volume in the R, G, and B space of the shaded area, which is the observation data in FIG. 4, is calculated.

515 is a CPU that controls the entire specific document determination unit 403;
515a represents a ROM that stores programs and the like according to the flowchart of FIG. 9 for operating the CPU 515, and 515b represents a RAM used as a work area for various programs. The CPL 1515 mainly reads data in the counters 521 to 528 and the RAM 512, and determines whether a target document exists among the input documents.

The input of the integrator in FIG. 11 is indicated by X5, and the output is indicated by YI (1≦i≦8). As processing, calculation according to the following equation (5) is performed.

YI-+=β-Y, +255 (1-β)X.

(5) In the above equation (5), β is a constant that controls the integration effect of the integrator. Further, in the range of 0<β minus 1, the following relationship holds true.

0- β → 1 (small) (integral effect) (large) In other words, the integral value change curve shown in Figure 12 changes more gradually as the set value of β approaches 1, and as the set value of β approaches 0. (and vice versa, it changes rapidly. In the first example,
β=31/32.

The recognition target is assumed to be a document about the size of a banknote, but
When a smaller original image, such as a stamp, is to be recognized, a smaller value of β, such as β=7/8, is appropriate. The value of β may be arbitrarily set by a scanning unit (not shown) depending on the recognition target.

FIG. 9 is a flowchart explaining the operation by the CPU of the first embodiment.

First, when information to start reading the original is detected, the 5L20
1, the lNH404 signal is turned O at the start of document reading.
Set to . After this, in 51202, an instruction is given to read the document. At 51202, a variable n is set to 1. That is, the counter values of the n-th counter are stored in the RAM 512 in order. S 1.204, the counter of FIG. 5A, in this case counter 5 because n=1
21 is read, and the value is stored in the variable area set on the RAM 512.

51205, the variable a of the RAM 512 in FIG.
The total number of 1s stored in rea is calculated, and this value is set as the variable V
○Set to 1.

Here, the variable vol is a value indicating the volume of the shaded area in FIG. 4, that is, vol=Tjd.

51206, the value of the variable area is a predetermined constant K
Determine whether or not it exceeds.

The value of the variable area corresponds to the number of pixels in the recognition area shown in the shaded area in FIG. Therefore, by comparing and determining the size of the value of the variable area with a constant, it is determined whether or not there is a possibility that the document is a banknote document. That is, if the variable area>K, it is determined that there is a possibility that the document is a bill document.

In 51027, the variable vol set in 51205
, the observed image data in the color space expressed by the following equation (3), and the similarity r between the image data of the specific document are calculated and compared with a constant β.

In FIG. 4, Tova is image data of a specific manuscript registered in advance (hereinafter referred to as specific image data), and R
, G, B space, and indicates the volume between R, G, and B coordinates. In addition, Tjd is the image data of the read original (hereinafter referred to as observation image data), and the shaded area is the observation image data in which the output signals of the comparators 5001 to 5008 are 1, expressed in R, G, and B space. , and shows the volume in the R, G, B coordinate space.

The similarity r at this time is expressed by the following equation (6). The closer the value of similarity r is to 1, the higher the similarity between observed image data and specific image data.

Here, from Vol=Tjd, determine (gamma, that is, γ is a constant determined by experiment and indicates the matching rate in the color space: γ = 0.7), and if true, the observation It is determined that the similarity between the image data and the specific image data is high and that duplication should be prohibited.

As explained above, according to the first embodiment, by converting various input signals into common color space signals and then identifying a specific document, it is possible to identify a specific document in any system. There is an effect that can be done. Further, since the data of the specific document stored in advance only need to be data in the common color space, the memory size can be reduced.

Furthermore, when connecting to multiple types of external devices, even if the spectral characteristics of the image reading devices of the respective external devices are determined, it is possible to identify a specific document without making an erroneous determination.

Second Embodiment> FIG. 1O is an external view showing a second embodiment of a copying machine to which the image processing apparatus of the present invention is applied.

In FIG. 10, 1201 is an image scanner section, which reads an original and performs digital signal processing. Further, 1202 is a printer unit, which prints eight images corresponding to the original image read by the image scanner unit 1201 on paper in full color.

In the image scanner unit 1201, reference numeral 1200 denotes a mirror pressure plate, and an original 1204 on an original table glass (hereinafter referred to as a platen) 1203 is irradiated with a lamp 1205, guided to mirrors 1206, 1207, and 1208, and then passed through a lens 120.
9 forms an image on a 3-line sensor (hereinafter referred to as C0D) 1210, and provides full color information of red (R) and green (G).
) and is sent to the signal processing unit 1211 as a blue (B) component. Note that 1205.1206 is the speed V, and 1207.
1208 scans the entire surface of the document by mechanically moving at 1/2 V in a direction perpendicular to the electrical scanning direction of the line sensor. The signal processing unit 1211 electrically processes the read signal and converts it into magenta (M) and cyan (C).
, yellow (Y), and black (Bk), and sends it to the printer unit 1202. Furthermore, for each document scan (scanner) in the image scanner unit 1201, one component among M, C, Y, and Bk is transferred to the printer unit 1201.
202, and one printout is completed by scanning the document four times in total.

M, C, sent from the image scanner unit 1201
The Y or Bk image signal is sent to the laser driver 1212. A laser driver 1212 modulates and drives a semiconductor laser 1213 according to the image signal. The laser beam is transmitted through a polygon mirror 1214. f-theta lens 1215. mirror 12
16, the photosensitive drum 1217 is scanned.

1218 is a rotary developing device, and a magenta developing section 1219
, cyan developing section 1220. Yellow developing section 1221. It is composed of a black developing section 1222, and four developing devices alternately contact the photosensitive drum 1217 to develop an electrostatic latent image formed on the photosensitive drum 1217 with toner.

1223 is a transfer drum, and paper cassette 1224 or 1
The paper fed from 225 is transferred to this transfer drum 122.
3, and the image developed on the photosensitive drum 1217 is transferred to paper.

After the four colors M, C, Y, and Bk are sequentially transferred in this manner, the paper passes through the fixing unit 1226 and is discharged.

In the above-mentioned normal color image copying machine,
In front of the laser driver 1212, a specific original discrimination circuit 12
26 is provided. The configuration of the specific document discrimination circuit 1226 is similar to that shown in the first embodiment. This makes it possible to prevent copying of a specific document that the user does not wish to have copied.

[Effects of the Invention] As explained above, according to the present invention, there is an effect that a specific document can be identified in any system. Furthermore, since only the common color space data is sufficient as the data of the specific document to be stored in advance, the memory size can be reduced.

Furthermore, when connecting to multiple types of external devices, it is possible to identify a specific document without making a false determination even if the spectral characteristics of the image reading devices of the respective external devices are determined.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a first embodiment of a copying machine to which an image processing apparatus according to the present invention is applied, and FIG. 2 is a block diagram showing the configuration of a conversion circuit 107 according to the first embodiment. Figures 3A and 3B are diagrams explaining the relationship between a specific original and color space, Figure 4 is a diagram explaining the method for determining a specific original according to the first embodiment, and Figure 5A is the same as that shown in Figure 1. FIG. 5B is a block diagram showing the configuration of the OR writing circuit; FIG. 5C is a timing chart of the timing generation circuit; FIG. 6 is the color space data of the specific document and the judgment ROM 501. 7 is a diagram showing the positional relationship between a specific document and the recognition area. FIG. 8 is a diagram showing the relationship between various color spaces and the common color space in the first embodiment. 9 is a flowchart explaining the operation by the CPU of the first embodiment, FIG. 10 is an external view showing a second embodiment of a copying machine to which the image processing apparatus of the present invention is applied, and FIG. 11 is a block diagram showing an integrator, and FIGS. 12A and 12B are diagrams explaining the integration effect. In the figure, 100... signal processing section, 101, 101°...
- Scanner, 102... IPU, 103... Host computer, 104 - S V, 105 - V T
R1106... Arithmetic circuit, 107... Conversion circuit, 1
08... Color processing circuit, 109... Specific document identification circuit, 110... Inking circuit, 112... Image output device, 201-203. 213-215... Adder, 20
4 to 212... Multiplier, 501... Judgment ROM, 5
02,513.514...Flip-flop, 511
...OR writing circuit, 512...RAM, 515
...CPU, 515a-ROM, 515b-RA
M, 521-528... Counter, 1201... Image scanner section, 1202... Printer section, 120
3...Platen, 1204...Original, 1205...
・Lamp, 1206° 1207.1208...Mirror, 1209...Lens, 121'O...3 line sensor, 1211...Signal processing section, 1212...Laser driver, 1213...Semiconductor laser , 1214・
...Polygon mirror, 1215...f-theta lens, 1
216... Mirror, 1217... Photosensitive drum, 12
18...Rotating developer, 1219...Mazeng developing section, 1220...Cyan developing section, 1221...Yellow developing section, 1222...Black developing section, 1223...
...Transfer drum, 1224.1225...Paper cassette, 1226...Fixing unit, 1306...LU
T, 1307...Counter, 1308...Comparator, 4001.4008...Selector, 4011.
4018... Integrator, 4021.4028... Register, 5001-5008... Comparison calculation circuit, 501
1-5018... Integrator, 5021-5028...
It is a register.

Claims (2)

[Claims] (1) In an image processing apparatus having an interface for connecting to a plurality of input devices handling image signals of different color spaces, an input means for inputting an image signal corresponding to a document from one of the connected input devices; a conversion means for converting an image signal inputted by the input means into an image signal in a predetermined color space; a determination means for determining the presence or absence of a specific original registered in advance based on the image signal converted by the conversion means; An image processing device comprising processing means for processing an image signal inputted by the input means based on a result determined by the determination means. (2) The discrimination means compares the discrimination information stored in the storage means with the image signal converted by the conversion means with a storage means storing discrimination information for discriminating the image signal converted by the conversion means. and a matching means, the processing means invalidates and outputs the image signal input by the input means when the matching means obtains a match, and when the matching means obtains a matching match, the processing means invalidates and outputs the image signal input by the input means. 2. The image processing apparatus according to claim 1, further comprising output means for effectively outputting the image signal.