JPH07175923A - Method for processing image and device therefor - Google Patents

Abstract

PURPOSE:To more exactly detect a specified image. CONSTITUTION:In each of ROM 1041 to 1043, the information showing the hues of image original obtained by reading the image originals whose surface states are different (old and new) in specified originals of the same kind(for instance, paper money whose denomination is the same) is preliminarily stored. Next, th address to be specified by the value of inputted RGB image is imparted to the ROM 1041 to 1043 and whether the hue of an inputted image and the hues of the specified images stored in the ROM 1041 to 1043 match or not is investigated. The results are outputted to OR circuit 1180 to 1187, and if it is judged that any one of the decision results obtained from the ROM 1041 to 1043 matches with the specified image, the inputted image is decided as the specified 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 method and an apparatus thereof, and more particularly to an image processing method and an apparatus thereof for detecting a specific image using an input color image signal.

[0002]

2. Description of the Related Art Since the reproducibility of read originals has been remarkably improved with the development of color copying machines in recent years, there is a need for a technology for preventing counterfeiting of bills and securities using such copying machines. ing. As one of the technologies, the following technologies have been proposed.

That is, information of a specific image such as a bill or securities is expressed as data of a certain color space, and this is registered in the copying machine in advance. Then, when the copying machine attempts to copy the image original, the distribution of the input image data in the color space is compared with the distribution of the specific original data registered in advance. Further, as a result of the comparison, it is determined whether the distributions of the two image data are substantially the same, and the specific original is determined.

Next, the structure of a color copying machine to which the above technique is applied will be described.

(1) Overview of Overall Configuration (FIG. 9) FIG. 9 is a block diagram showing an overview of the overall configuration of a conventional color copying machine. In FIG. 9, the mechanism of the scanning unit that mechanically scans the platen on which the image original is placed and the scanner is omitted.

In FIG. 9, 101 is a CCD color sensor, 102 is an analog amplifier, 103 is an A / D converter,
Reference numeral 104 denotes a shading correction circuit for correcting variations in brightness depending on the reading position of the image signal, and 1105 denotes input color signals R (red), G (green), B (blue) for Y (yellow), M (magenta), and C. (cyan),
A print signal generation circuit for converting into a Bk (black) signal. Further, the print signal generation circuit 105 has a built-in delay circuit for compensating the time required for determining a specific image, which will be described later. The print signal output from this circuit is modulated by the real-time correction signal f.

Reference numeral 106 is a color space matching determination circuit for calculating in real time the similarity of the distribution of the read image data and a specific original document (for example, bills or securities) in the three-dimensional color space, and 107 is a real time correction signal. A real-time correction signal generation circuit for generating f, and a read synchronization signal generation circuit for generating a read cycle signal.
This circuit includes a main scanning section signal (HS) 109, a pixel reading basic clock signal (CLK) 110, and a section signal (VS) 11 indicating an effective area in the sub scanning direction for reading an original.
2 is generated. A color printer unit 110 prints out the input image original.

It should be noted that the shading correction circuit 104 corrects the distortion of brightness and tint due to the position of the original, and the shading-corrected color signal output from this circuit is used to change the position of the input original. However, the similarity determination in the color space can be accurately performed, but since this circuit is publicly known, detailed description thereof will be omitted.

(2) Configuration of Color Space Matching Determination Circuit (FIGS. 11 to 17) FIG. 10 is a block diagram showing a detailed configuration of the color space matching determination circuit 106. In FIG. 10, reference numeral 1201 denotes an upper 5-bit signal of the 8-bit R signal output from the shading correction circuit 1104, 1202 denotes a higher 5-bit signal of the 8-bit G signal output from the shading correction circuit 1104, and 1203 It is a signal of the upper 5 bits of the 8-bit B signal output from the shading correction circuit 1104. Reference numeral 1205 denotes a timing generation circuit that generates various timing signals described later, and 1209 denotes S
The RAM 1270 is an address generator that sequentially generates all the addresses of the SRAM 1209.

Reference numeral 1204 denotes a ROM that stores information regarding the tint of a plurality of types of specific originals. When a 5-bit RGB signal is input to the address (A _{0 to} A ₁₄ ) of the ROM, the input RGB signal is output. Judgment signals (X _{0 to} X) that indicate whether or not the colors match a plurality of types of specific originals.
₇ ) is output from the data output terminals (D _{0 to} D ₇ ).

Reference numerals 1220 to 1227 denote smoothing circuits that perform smoothing operations based on the determination signals (X _{0 to} X ₇ ) output from the ROM 1204. Reference numerals 1240 to 1247 show the similarity between specific image data and an input color signal in RGB space in real time. The color space similarity determination signal (MK _{0 to} MK
_This is a color space determination circuit that calculates ₇ ).

1271-1272 are S according to the address signal generated by the address generator 1270 when the sub-scanning section signal (VS) 112 is "0 (LOW)".
It is a selector used for clearing the RAM 1209 to zero.

FIG. 11 is a diagram conceptually showing the information regarding the tint of a specific document stored in the ROM 1204.
The tint information of the specific document is represented by a three-dimensional space having RGB color components as coordinate axes, as shown in FIG. Figure 1
In No. 1, the shaded area in the three-dimensional space corresponds to the tint of the specific document. Then, whether or not the input RGB signal is a region corresponding to the tint is determined by a combination of RGB coordinate values corresponding to the value of the input RGB signal. Is "1", otherwise the output value is "0"
The input / output relationship of the ROM 1204 is configured so that In other words, it can be said that the ROM 1204 stores a table having an output value of 0 or 1 corresponding to the value of the input RGB signal. The RAM 12 has eight data output terminals (D _{0 to} D ₇ ).
This is because the tint information regarding 8 types of specific originals is stored in 04, and each terminal corresponds to one of 8 types of specific originals.

FIG. 12 is a diagram showing the relationship between the input data and the output data for the data relating to the tint of a plurality of specific originals stored in the ROM 1204. First, of the input addresses (A _{0 to} A ₁₄ ), A _{0 to} A ₄ are 5-bit B signals, A _{5 to} A ₉ are 5-bit G signals, and A ₁₀ to A 4 are.
A 5-bit R signal is input to A ₁₄ . The value of the input address (A _{0 to} A ₁₄ ) is specified by this input signal, and the output value for the tint of the eight kinds of specific originals corresponding thereto is determined. Then, for the input 5-bit RGB data corresponding to each pixel, a data output terminal (D ₀
From to D _7), the determination signal relating to eight different colors for a particular document (X ₀ ~X ₇₎ are output in parallel.

FIG. 13 is a circuit diagram showing the circuit configuration of the smoothing circuits 1220 to 1227. In FIG. 13, 160
Reference numerals 1 and 1602 denote multipliers, 1603 denotes an adder, 1604 denotes a latch circuit, and 1605 denotes a comparator. Multiplier 1
The weighted average of the input data and the previous data is obtained by the 601, 1602, and the adder 1603, and it is possible to make a determination considering continuity as shown in FIG.

FIG. 14 is a diagram showing the relationship between the input value (X _i ) to the smoothing circuit and the smoothed calculation value (Y _i ). According to the circuit configuration shown in FIG. 13, when the input value (X _i ) is “1” continuously, the smoothed operation value (Y _i ) is generated as shown in FIG.
Has the property that the value of increases. Therefore, when the input RGB signals continuously match the tint of the specific original, the output signals (C _{0 to} C ₇ ) of the smoothing circuit become 1, and more accurate determination is made without being affected by noise or the like. Is possible.

In FIG. 15, the similarity between the specific image data and the input color signal is calculated in real time in the RGB space as shown in FIG. 16, and the color space similarity determination signal (M
The color space judgment circuit for calculating the K ₀ ~MK ₇₎ 1240~1
It is a block diagram which shows the structure of 247.

With the circuit shown in FIG. 15, the SRAM 12
Data (D_i : i = 1,8) and smoothing circuit
Output signal (C_i : i = 1,8) is the logical sum (OR) operation
Then, the result is written in the SRAM 1209 again.
In addition, the data (D_i ) Transitions from 0 to 1 only
The counter 1301 is counted up. Counter 1
301 is the rising edge of the sub-scanning section signal (VS) 112.
Cleared. Output value of counter 1301 (Z_i ) And
The constant δn of the transistor 1303 is the comparator 1302
The size relationship is compared and Z_i > Δ_i In case of, MK_i = 1
Become, Z_i ≤ δ _i In case of, MK_i = 0. δ_i The value of the
U shown in FIG._ORG Value of 1% is set
(Eg l = 90).

Δ _i = (l / 100) × U _ORG where U _ID is each coordinate axis in consideration of possible values of 5-bit input RGB data in the RGB coordinate space, as shown in FIG. Is a numerical value in which a unit volume is a cube formed by partitioning into 32 with a predetermined unit length. On the other hand, U
_ORG is the volume of the region formed in the RGB coordinate space by the data representing the tint of the specific image registered in the device.

By the above processing, the observed image data, that is, the data of the input color signal sequence is converted into the specific image data and the RGB image data.
When the shapes are substantially the same in the color space, the color space similarity determination signals (MK _{0 to} MK ₇ ) are “1”.

(3) Control signal time chart (see FIG. 1)
7) FIG. 17 shows the timing generated by the timing generation circuit 1205.
It is a figure which shows the ringing signal. In Figure 17, VS is a side run
Check section signal, CLK is the basic clock, and CLK4 is the basic clock.
Clock signal obtained by dividing the lock (CLK) by 4, OE is the signal
Output of SRAM 1209 through line 1208
SRAM1209 applied to enable (OE) terminal
, WE is a signal for controlling the output from
To the write enable (WE) terminal of SRAM 1209
Controls the writing of data to the applied SRAM 1209.
Signal. Also, C_i , C_i ′, D_i ″, ENB,
D _i , D_i ′ Is the control signal or the control signal shown in FIG.
Indicates the mutual relationship between the input and output signals.

(4) Configuration of Real-Time Correction Signal Generation Circuit (FIG. 18) FIG. 18 is a block diagram showing the configuration of the real-time correction signal generation circuit 107. As shown in FIG. 18, this circuit is composed of a latch circuit, an OR circuit, and an AND circuit. When it is determined by this circuit that any one of the plurality of specific originals registered in the ROM 1204 matches the input image data in the RGB color space, the real-time correction signal f is “1 (High)”. Become.

(5) Configuration of print signal generation circuit (see FIG. 1)
9) FIG. 19 is a block diagram showing the configuration of the print signal generation circuit 105.

In the masking UCR operation circuit 2101,
Normally, each color component YMCB of the density signal rather than the input RGB signal
When the input color signal is determined to match the specific original, the masking UCR calculation circuit 2102 generates the k signal and changes the tint (for example, strengthens the red tint) to generate each color component YMCBk signal of the density signal. To do. Then, the selector 2103 selects and outputs the signal from the masking UCR operation circuit 2101 or 2102 according to the real-time correction signal f.

As a result, it is possible to change the tint and print out only the area where the input image original is determined to match the specific original.

A LOG conversion circuit for converting the RGB signal, which is a 2104 luminance signal, into the YMC signal, which is a density signal.

[0027]

However, in the above-mentioned conventional example, since the color space of the specific color original for checking the similarity of the tint is generated based on one type of device or one type of the specific color original. When copying an image original using a plurality of devices, the determination of a specific color original may be affected by a difference in performance between the apparatuses or stains on the specific color original, resulting in variations in the determination results. There was a problem.

The present invention has been made in view of the above-mentioned conventional example, and an object thereof is to provide an image processing method and an apparatus therefor capable of more accurately determining the similarity of tint.

[0029]

In order to achieve the above object, the image processing apparatus of the present invention has the following configuration. That is, a storage unit for storing in advance a plurality of image data representing the tint of the specific image obtained by reading the same type of specific image under different conditions, an input unit for inputting an image original, and the input unit. The comparison means for comparing the obtained image data with the plurality of image data stored in the storage means, and the image data obtained by the input means based on the comparison result by the comparison means is the specific image. And an image processing device that has a determination unit that determines whether or not

According to another aspect of the invention, a storage step of storing a plurality of image data representing the tint of the specific image obtained by reading the specific image of the same type under different conditions in a storage medium in advance; An input step of inputting a document, a comparison step of comparing the image data obtained in the input step with the plurality of image data stored in the storage medium,
An image processing method comprising: a determination step of determining whether or not the image data obtained by the input step represents the specific image based on the comparison result by the comparison step.

[0031]

According to the present invention having the above-described structure, it is possible to determine whether the input image data represents a specific image by determining the tint of the specific image obtained by reading the same specific image under different conditions. This is performed based on the result of comparison between the plurality of image data items represented and the input image data.

[0032]

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.

<First Embodiment> [General Description of Apparatus] FIG. 1 shows a configuration of a color space matching judgment circuit incorporated in a color copying machine which is a typical embodiment of the present invention and used for detecting a specific image. It is a block diagram shown. In the constituent elements of the circuit shown in FIG. 1, elements common to those of the conventional circuit shown in FIG. 10 are designated by the same reference numerals, and description thereof will be omitted here. Here, only the characteristic parts of this embodiment will be described. In this embodiment, this circuit is incorporated in the color copying machine shown in FIG. 9, and is used. In the explanation related to the entire apparatus, the constituent elements shown in FIG. 9 will be referred to.

In FIG. 1, 1101 is a signal of the upper 5 bits of the 8-bit R signal output from the shading correction circuit 1104, and 1102 is a signal of the upper 5 bits of the 8-bit G signal output from the shading correction circuit 1104. Reference numeral 1103 denotes a shading correction circuit 1104.
It is a signal of the upper 5 bits of the 8-bit B signal output from.

Reference numerals 1041 to 1043 denote ROMs that store information regarding the tint of a plurality of different types of specific originals. Addresses A _{100 to} A of ROM 1041
₁₁₄ and addresses A _{200 to} A ₂₁₄ of the ROM 1042,
When 5-bit RGB signals are input to the addresses A _{300 to} A ₃₁₄ of the ROM 1043, the ROM
From 1041 to 1043, determination signal data (D) indicating whether or not the tint of a plurality of types of specific originals corresponding to the address specified by the value of the input RGB signal is matched
_{10 to} D ₁₇ , D _{20 to} D ₂₇ , D _{30 to} D ₃₇ ) are output.

The ROMs 1041 to 1043 respectively include
Information about the tint of the specific original is stored as in the case shown in FIG. 11. If the input image signal matches the tint of the specific original, 1 is output, and otherwise 0 is output as determination signal data. It Also, like the conventional example, three R
Each of the OMs outputs determination signal data corresponding to eight types of specific originals.

Reference numerals 1180 to 1187 denote the ROM 104.
It is an OR circuit that obtains the logical sum of the outputs of 1 to 1043.

FIG. 2 is stored in the ROMs 1041 to 1043.
Data on the color of multiple specified originals
FIG. 3 is a diagram showing the relationship between input data and output data. Well
Input address (A₁₀₀ ~ A₁₁₄, A₂₀₀ ~ A₂₁₄, A
₃₀₀ ~ A₃₁₄ ), Of which A₁₀₀ ~ A ₁₀₄, A₂₀₀ ~ A₂₀₄, A
₃₀₀ ~ A₃₀₄ Is a 5-bit B signal,₁₀₅ ~ A₁₀₉,
A ₂₀₅ ~ A₂₀₉, A₃₀₅ ~ A₃₀₉ 5-bit G signal for
But A₁₁₀ ~ A₁₁₄, A₂₁₀ ~ A₂₁₄, A₃₁₀ ~ A₃₁₄ In
A 5-bit R signal is input. Depending on this input signal
The ROM input address value is specified and
The output values for the colors of the eight specific originals are determined.
It Then, a 5-bit RG corresponding to each input pixel
Data output terminal (D_Ten~ D₁₇, D₂₀
~ D₂₇, D₃₀~ D₃₇) To 8 different specific manuscripts
The determination signal data relating to the tint is output in parallel.

When a specific color original is detected by a generally known determination method, for example, when the information about the color space to be stored in the ROM 1204, which is considered in the conventional example, is generated, only once for one specific original. Data was acquired and color space information was generated based on the data. Therefore, when trying to determine another specific original of the same type in that color space, as shown in FIG. 3, the original is older and dirty than the original used when the data of the color space is created,
If the original used when creating the data of the color space is older and dirty than the original to be judged, the tints of the two have changed and cannot be detected.

[ROM Data Generation Procedure] FIG. 4 is a diagram showing an outline of the ROM data generation procedure according to the present embodiment.

First, in step S311, a banknote A which is a specific original document.
-1 is used to input the data of the specific document, and the next S321
Then, color space data to be ROM data is created from the image data based on the bill A-1. Then, the created data is stored in the ROM 1041. Next, in S312, the data of the specific document by the banknote A-2, which is the specific document, is input, and in the next S322, the color space data serving as ROM data is created from the image data based on the banknote A-2.
Then, the created data is stored in the ROM 1042. Similarly, in step S313, the data of the banknote A-3 is input, and in step S323, the color space data is created, and the color space data is set to R.
Stored in OM1043.

The data thus stored in the ROM is used for detecting the specific original.

The above description is for the case of three ROMs, but the procedure for preparing and storing ROM data relating to a specific original having n ROMs and changing n kinds of conditions is also the same.

Next, S321 to S323 (generally S
A detailed procedure for creating color space data in 32n) will be described. In this embodiment, in order to reduce the amount of data stored in the ROM, the upper 5 bits of the image data input in 8 bits are used to generate the ROM data.

First, 8-bit data for each of the RGB color components is input to a register (not shown) (data input is performed by reading a specific document from the CCD of the color copying machine), and the upper 5 bits from the register. Take it out. Therefore, the RGB three-dimensional color space treated here is
A color of 5 bits × 5 bits × 5 bits (32 × 32 × 32) can be represented. Also, the entire color space is ROM
It is expanded as a 15-bit address space (a ₁₄ (MSB) to a ₀ (LSB)) in consideration of the input addresses 1041 to 1043, and the R value and a _{9 to} a ₅ of 5 bits a _{14 to} a ₁₀ The value of G is stored in 5 bits, and the value of B is stored in 5 bits of a _{4 to} a ₀ , and one value in RGB color space coordinates is represented by the value indicated by the 15 bits (a _{14 to} a ₀ ). When there is no point represented in the RGB color space, "0" is set as the value of the point represented by the color space coordinates (the value of the address specified by the input address of the ROM 1041 to 1043), while RG is set.
When there is a point represented in the B color space, "1" is set as the value of the point represented by the color space coordinates.

In this way, the ROMs 1041 to 104
When the ROM data relating to the specific original document is prepared in No. 3, the ROM data is read using a known ROM writer (not shown).
It is stored in M1041 to 1043.

By the above processing, for example, the bill A
-1 is a new bill with a certain face value, and bill A-2 is bill A.
If a slightly old banknote with the same face value as -1 and an older banknote with the same face value as banknote A-1 are used for banknote A-3, the ROM in the apparatus will have different conditions even if they are of the same kind ( Information of three types of specific image originals (with different paper surfaces) is stored. Further, as described in the prior art, each ROM can store color information of eight types of specific images. Therefore, if each ROM stores color information of different types of banknotes, this apparatus can be used. Then, it is possible to perform the tint determination for 24 (8 types × 3 paper surface states) different specific images.

[Determination of Specific Image] Here, a process of determining whether the input image data is a specific image using the three ROMs described above will be described with reference to FIG.

FIG. 5 is a diagram conceptually showing the tint determination processing of the specific image according to the present embodiment. As shown in FIG. 5, in the present embodiment, for specific image determination, determination data based on a new specific original document, determination data based on a specific original document of the same type but a little old, and determination data of the same type but considerably old. The three types of color space information including the determination data based on the original are stored in the ROMs 1041, 1042, and 1043, respectively.

Then, when input image data based on a slightly old image original is input in parallel to the ROMs 1041 to 1043, determination information regarding the tint of the specific original is output from each ROM. In the example shown in FIG. 5, the ROM 1041
From 1043 and 1043, the judgment result that the tint does not match is the ROM
From 1042, a determination result that the tints match can be obtained. This output is the OR of D ₁₀ , D ₂₀ , and D ₃₀ , as shown in FIG.
In the circuit 1180, D ₁₁ , D ₂₁ , and D ₃₁ are OR circuits 1181.
, D ₁₇ , D ₂₇ , D ₃₇ are input to the OR circuit 1187, and the three ROMs take the logical sum of the determination information determined under different conditions for the same specific original. Figure 5
In the example shown in (1), the output of the OR circuit has the same tint, which means that the specific image is detected.

In this way, the same specific document is stored in the ROM.
Any one of 1041 to 1043 that is determined to have the tint of the specific original will be determined to have the tint of the specific original regardless of the output results of the other ROMs. The outputs of the OR circuits 1180 to 1187 are smoothing circuits 1
220 to 1227. The subsequent processing is the same as in the conventional example.

Therefore, according to the present embodiment, since the specific image data obtained by changing several kinds of conditions for the same type of specific image original document and the input image data are compared to detect the specific image, the input original document Even if the surface is dirty and the state of the original is different, the specific image can be detected more accurately. This makes it possible to suppress variations in detection results.

In the present embodiment, the information of the same type of image originals under different conditions is stored in three ROMs and used for detecting the specific image, but the present invention is not limited to this. Needless to say, more ROMs may be used to store image information under many conditions.

Further, in this embodiment, the information read from the CCD of the same device is used as the data for detecting the specific image, but the present invention is not limited to this. For example, in order to compensate for variations in device characteristics (for example, CCD sensitivity), information of a specific image read by another device may be stored in the ROM of this device and used. This makes it possible to cope with differences in characteristics between devices.

<Second Embodiment> In the first embodiment, a plurality of R
The OM is used to store image information of the same type but with different conditions on the surface of the original, and this is used as information for detecting the specific image. However, in this embodiment, the number of ROMs and the scale of the circuit configuration are increased. An example in which the circuit configuration is suppressed as in the conventional example in order to suppress the cost increase due to the above will be described.
Therefore, when referring to circuits in the following description, the device reference numbers for the devices and circuits described in the conventional example are used as they are. The description of the processing common to that already described in the first embodiment will be omitted. Similarly, in the description of the drawings, common parts to those of the first embodiment will be referred to by using common drawing reference numerals, and description thereof will be omitted.

FIG. 6 is a diagram showing an outline of the ROM data creation procedure according to the present embodiment. Here, unlike the first embodiment, as shown in S31n and S32n, n sheets (A-1 to
It is considered to create color space data from the bill input of An) and image data based on the bill. This image data is performed by reading a specific original from the CCD of the color copying machine. Then, in S720, the logical sum of the color space data created based on the image data obtained by changing the condition of n (the surface condition of the original, etc.) in the same type of specific document is obtained, and the color space data to be the ROM data is created. .
Then, the created data is stored in the ROM 1204. The data thus stored in the ROM is used for detecting the specific original.

Creation of color space data in S321, S322, ..., S32n is the same as in the first embodiment.

Next, referring to FIG. 7, of the color space data created based on the image data in which the condition of n (such as the surface condition of the original) is changed in the specific original of the same type shown in S720 of FIG. A process of obtaining a logical sum, creating color space data to be ROM data, and storing the color space data in the ROM 1204 will be described in detail.

In this embodiment, an external connection type data writing device 700 as shown in FIG. 7 is used so as not to change the circuit structure of the conventional color copying machine, but this may be built in the color copying machine. Needless to say. The data writing device 700 includes a read buffer 701 for temporarily storing data read from a ROM, an OR circuit 702 for obtaining a logical sum of newly input image data and data read from the ROM, and a known ROM writer. have.

Here, for the specific image determination, a new specific original, then a specific original of the same kind but a little old, and a specific original of the same kind but rather old are read, and the data is used by the data writing device 700. ROM1
Write to 204. At this time, when a slightly older specific original is read, an OR is taken with the determination data based on the new specific original already written in the ROM 1204, and the result is written in the ROM.
Similarly, when a very old specific document is scanned,
O with the data already written in ROM1204
R is taken and the result is written to ROM 1204.

In this way, the information reflecting the n different images even if they are the same specific image is stored in the ROM 1
It is stored in 204. That is, in the n pieces of color space data created in S321 to 32n, the coordinates where "1" is set in any one of them are set in the corresponding addresses of the ROM 1204.

Hereinafter, the detection of the specific image, the processing by the smoothing circuit, the color space determination, etc. are performed according to the conventional technique.

Therefore, according to this embodiment, even if one ROM is used, the specific image is detected by using the information reflecting the n different images even for the same type of specific image. Even if the surface of the input document is dirty and the state of the document is different, the specific image can be detected more accurately. Further, there is an advantage that the device cost does not increase due to the increase in ROM.

Further, in this embodiment, the information read from the CCD of the same device is used as the data for detecting the specific image, but the present invention is not limited to this. For example, in order to compensate for variations in device characteristics (for example, CCD sensitivity), an image memory is provided in the data writing device 700, and information of a specific image read by another device is stored in the image memory, and later, It may be stored in the ROM of this apparatus and used. This makes it possible to cope with differences in characteristics between devices.

<Third Embodiment> In the first and second embodiments, the case where a specific image is detected using a plurality of types (eight types) of image data having different surface states of the original document has been described. An example of more accurately detecting a specific document when only one type of specific document is to be detected will be described.

In the conventional example, eight types of specific originals (A to H)
In order to store the tint information of the RO, as shown in FIG.
It has an M address configuration. As a result, eight types of specific documents can be detected at the same time. On the other hand, when only one type of specific document needs to be detected, the areas for storing the remaining seven types of image information are unnecessary.

In this embodiment, the ROM is used by utilizing this.
As shown in FIG. 5, the ROM is effectively used by storing the image data in which the surface state of the original and the reading direction are different for the same specific original.

That is, with respect to the data output terminals (D _{0 to} D ₇ ), (1) in the data area output from the data output terminals (D ₀ ), the specific original A whose paper surface is new is CC of this apparatus.
Image data (pattern A) obtained by reading from D
(2) In the data area output from the data output terminal (D ₁ ), the image data (pattern B) obtained by reading the specific original document B of the same type as the specific original document A but the old paper surface from the CCD of this apparatus is read. , (3) In the data area output from the data output terminal (D ₂ ), the image data (pattern C) obtained by rotating the specific original A by 90 ° and reading it from the CCD of the apparatus is used. ) Is rotated in the data area output from the data output terminal (D ₃ ) by (4) and the image data ( Pattern D) is added to the data area output from (5) data output terminal (D ₄ ).
The image data (pattern E) obtained by reading the specific original A from the CCD of another device is (6) Data output terminal (D
_{In the} data area output from ( ₅ ), the image data (pattern F) obtained by reading the specific document B from the CCD of another device is added to the data area output from (7) the data output terminal (D ₆ ). Is 90 ° compared to the case of (1) for the specific document A.
Image data (pattern G) obtained by rotating and reading from the CCD of another device is (8) Data output terminal (D ₇ )
In the data area output from the ROM 1204, the image data (pattern H) obtained by rotating the specific document B by 90 ° as compared with the case of (2) and reading it from the CCD of another device is stored.
To store.

In this way, when it is determined that the input image data matches any one of the eight color space data stored in the ROM, the tint is changed as described in the conventional example. Instead, it is possible to print out from the color printer 110.

Therefore, according to the present embodiment, the resources of the ROM are effectively used to deal with the variations in the device characteristics, the differences in the input conditions of the same type specific original, and the variations in the determination result due to the differences in the orientation of the original. It is possible to accurately detect the specific document.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of one 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.

[0072]

As described above, according to the present invention, whether or not the input image data represents a specific image is determined by reading the specific image of the same kind under different conditions. Since the comparison is performed based on the comparison result of a plurality of image data representing the tint of the image and the input image data, the comparison between the specific image and the input image can be performed in a more versatile manner, and the specific image can be more accurately determined. The effect is that you can. As a result, it is possible to comprehensively determine the specific image including the variation in the device characteristics and the variation in the reading due to the newness and oldness of the specific document itself.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a color space matching determination circuit incorporated in a color copying machine which is a typical embodiment of the present invention and used for detecting a specific image.

FIG. 2 is a diagram showing a relationship between input data and output data with respect to data relating to tint of a plurality of specific originals stored in ROMs 1041 to 1043.

FIG. 3 is a diagram illustrating a reason why a specific document cannot be detected when a conventional example is followed.

FIG. 4 is a diagram showing an outline of a ROM data creation procedure according to the first embodiment.

FIG. 5 is a diagram conceptually showing a tint determination process for a specific image according to the first embodiment.

FIG. 6 is a diagram showing an outline of a ROM data creation procedure according to the second embodiment.

FIG. 7 is a diagram conceptually showing ROM data creation according to the second embodiment.

FIG. 8 is a ROM 12 showing data relating to the tint of a specific original obtained under the same type but under a plurality of conditions according to the third embodiment.
It is a figure which shows a mode stored in 04.

FIG. 9 is a block diagram showing an outline of the overall configuration of a conventional color copying machine.

FIG. 10 is a color space matching determination circuit 11 shown in FIG.
It is a block diagram which shows the detailed structure of 06.

FIG. 11 is a diagram conceptually showing information relating to the tint of a specific document stored in the ROM 1204 shown in FIG.

FIG. 12 is a diagram showing a relationship between input data and output data with respect to data regarding the tint of a plurality of specific originals stored in the ROM 1204 shown in FIG.

13 is a diagram illustrating a smoothing circuit 1220 to 1227 shown in FIG.
3 is a circuit diagram showing a circuit configuration of FIG.

FIG. 14 is a diagram showing a relationship between an input value (X _i ) to a smoothing circuit and a smoothed calculation value (Y _i ).

FIG. 15 is a block diagram showing a configuration of color space determination circuits 1240 to 1247 that calculate color space similarity determination signals (MK _{0 to} MK ₇ ).

FIG. 16 is a diagram showing color characteristics of a specific image and an input image expressed in an RGB coordinate space.

FIG. 17 is a diagram showing a timing signal generated by a timing generation circuit 1205.

FIG. 18 is a block diagram showing the configuration of a real-time correction signal generation circuit 1107.

FIG. 19 is a block diagram showing a configuration of a print signal generation circuit 1105.

[Explanation of symbols]

 1041-1043 ROM 1180-1187 AND circuit 1205 Timing generation circuit 1209 SRAM 1220-1227 Smoothing circuit 1240-1247 Color space determination circuit 1270 Address generator 1271-1272 Selector

Front Page Continuation (72) Inventor Koichi Ishimoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (6)

[Claims] 1. A storage unit for pre-storing a plurality of image data representing the tint of the specific image obtained by reading the same type of specific image under different conditions; an input unit for inputting an image original; The image data obtained by the input means is based on the comparison result by the image data obtained by the input means and the plurality of image data stored in the storage means, and the comparison result by the comparison means. An image processing apparatus, comprising: a determination unit that determines whether or not the specific image is represented. 2. The image processing apparatus according to claim 1, wherein the storage unit has a plurality of ROMs that store the plurality of image data, respectively. 3. The image processing apparatus according to claim 1, wherein the storage unit has a ROM that stores the plurality of pieces of image data in an overlapping manner in one color space. 4. The image processing apparatus according to claim 1, wherein the specific image includes an image representing banknotes and securities. 5. The control means for controlling the output of the image data obtained by the input means according to the determination result of the determination means, and the image data obtained by the input means according to the control by the control means. The image processing apparatus according to claim 1, further comprising output means. 6. A storage step of preliminarily storing a plurality of image data representing a tint of the specific image obtained by reading the same specific image under different conditions in a storage medium, and an input step of inputting an image original. And a comparison step of comparing the image data obtained by the input step with the plurality of image data stored in the storage medium, and obtained by the input step based on the comparison result by the comparison step. An image processing method comprising: a determination step of determining whether or not image data represents the specific image.