JPH0837595A - Specific image judging device - Google Patents

Abstract

PURPOSE:To conduct judgement whether or not an input image is a specific image correctly and at high speed. CONSTITUTION:Specific image data corresponding to the state of a specific image judging device 80 or a copying machine loading the same representing whether or not an input original should be sent by using an ADF(auto document feeder) 70, whether or not the ambient temperature of a CCD line sensor 16 exceeds 30 deg.C, and whether or not density correction is applied in a density conversion circuit 23 is stored in memory 87. The state of the specific image judging device 80 or the copying machine loading the same is detected by an ADF using detecting means 81, a temperature snesor 82 and the density correction detecting part 24 of the density conversion circuit 23, and the specific image data corresponding to such state is read out from the memory 87 by a CPU 88, and it is compared with input image data ID by a comparator 85, and it is judged whether or not the input image is the specific image from a comparison result by a judging circuit 86.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention determines whether an input image is a specific image, such as determining whether an input document is a specific document such as a bill or securities in a color copying machine. Regarding the device.

[0002]

2. Description of the Related Art As the image quality of color copiers increases, it is feared that counterfeit specific documents such as banknotes and securities will be forged. Therefore, a device for determining whether or not the input document to be copied is the specific document as described above is mounted, and when the input document is determined to be the specific document, copying is blocked. A copying machine that is capable of taking the above measures is being considered.

Such a determination device is specifically described in advance in Japanese Patent Laid-Open No. 4-205274, Japanese Patent Laid-Open No. 4-227365, Japanese Patent Laid-Open No. 4-352028, etc. The specific image data indicating the specific image that is a part or all of the pattern is stored in the memory as dictionary data, and the specific image data and a part or the whole of the input document obtained by reading the input document are read. Compare the input image data showing the input image that is a pattern by a method such as pattern matching,
Based on the comparison result, it is determined whether or not the input image is the specific image, that is, whether or not the input document is the specific document.

By the way, the content of the input image data changes depending on the state of the above-mentioned judgment device or a copying machine equipped with the judgment device. For example, when reading an input document, CC is generally used.
Although the D line sensor is used, as shown in FIG. 5, between the temperature and the reading value when a specific density pattern is read, the reading value becomes “thinner” (lower) as the temperature rises. ) There is a relationship.

When an input document is fed by an automatic document feeder (hereinafter referred to as an ADF) and the belt of the ADF has a black color, if the paper of the input document is thin, the black of the belt will be black. , C when a specific density pattern is read relative to when the ADF is not used or when the color of the ADF belt is white.
The reading value of the CD line sensor becomes “dark” (high).

Therefore, as the specific image data,
In the case of having only one data that does not take into consideration the state of such a judging device or a copying machine equipped with this, whether the input image is a specific image or not depending on the state of the judging device or the copying machine equipped with this. There is an error in that decision.

Therefore, as the specific image data, a plurality of data in consideration of the state of the determination device or the copying machine equipped with the determination device are stored, and the input image data is sequentially compared with the plurality of specific image data, When it is recognized that the input image data is close to any specific image data within a certain range, it is determined that the input image is a specific image, and it is recognized that the input image data is not close to any specific image data within a certain range. It may be possible to determine that the input image is not a specific image.

That is, for example, an ADF having a black belt color is used as the specific image data, and a CCD is used.
Data D1 when the temperature of the line sensor is high
1. Data D12 when the above ADF is used and the temperature of the CCD line sensor is low, the above AD
The data D21 that is obtained when F is not used and the temperature of the CCD line sensor is high, and the data D22 that is obtained when the temperature of the CCD line sensor is not used and the temperature of the CCD line sensor is low are stored in the memory. Let's leave it to Figure 6
As shown in FIG.
11 is read and compared with the input image data ID, and then it is determined in step 202 whether or not the input image is the specific image based on the comparison result. When it is determined that the input image is the specific image, the determination process is terminated. If it is determined that the image is not the specific image, then in step 203 the specific image data D1
2 is read out and compared with the input image data ID, and then it is determined in step 204 whether or not the input image is the specific image based on the comparison result. When it is determined that the input image is the specific image, the determination process is terminated. If it is determined that the image is not the specific image, then in step 205 the specific image data D21
Is read out and compared with the input image data ID, and the comparison judgment is performed.

[0009]

However, as described above, the input image data is sequentially compared with a plurality of specific image data in consideration of the state of the determination device or the copying machine equipped with the determination device, and the input image data is If it is recognized that the input image is close to the specific image data within a certain range, the input image is determined to be the specific image, and if the input image data is not close to any specific image data within the certain range, the input image is specified. When it is determined that the input image is not the image, for example, in the example shown in FIG. 6, it is necessary to perform the comparison determination four times at the maximum, and thus it is possible to determine whether or not the input image is the specific image. There is a disadvantage that it takes time.

Therefore, the present invention makes it possible to accurately and quickly determine whether or not the input image is a specific image.

[0011]

According to the present invention, when the reference numerals of the embodiments described below are made to correspond to the specific image determining apparatus, a plurality of specific image determining apparatuses 80 or a plurality of specific apparatuses in consideration of the state of the device in which the specific image determining apparatus 80 is mounted are considered. Image data D111 to D22
2 is detected, and the state of the specific image determination device 80 or a device equipped with the same is detected, and the specific image data corresponding to the state is detected as the data holding device 8 described above.
7, detection selection means 81, 82, 83, 24,
88 is provided, and comparison and determination means 85 and 86 for comparing the selected specific image data with the input image data ID to determine whether or not the input image is the specific image.

[0012]

In the specific image determining apparatus of the present invention having the above-described structure, the comparison determining means 85 and 86 include the plurality of specific image data D1 held in the data holding means 87.
Detection selection means 81, 82, 8 of 11 to D222
Only those selected by 3, 24 and 88 are compared with the input image data ID to determine whether or not the input image is the specific image. Therefore, it is fast to determine whether or not the input image is the specific image. Made in.

Moreover, the detection selecting means 81, 82, 83,
Since the specific image data selected by 24 and 88 is in accordance with the state of the specific image determining device 80 or the device mounting the same, the input image is changed depending on the state of the specific image determining device 80 or the device mounting the same. There is no error in determining whether or not is a specific image.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of a specific image judging apparatus of the present invention, and FIG. 2 shows an example of a color copying machine equipped with the specific image judging apparatus.

First, the overall structure of the color copying machine will be described with reference to FIG. The color copying machine of this example includes an image reading unit (image input unit) 10, an image processing unit 20, an image output unit (image forming unit) 30, a user interface 40, a system control unit 50, a paper tray 60, and an ADF 70.
Mainly for the image processing unit 20, the specific image determination device 80
Is provided.

The image reading unit 10 reads an input document and converts the image into input image data. Specifically, light from a light source 11a such as a halogen lamp attached to the full speed carriage 11 illuminates an input document (not shown) placed on the platen glass 12 or sent by the ADF 70. , The reflected light is reflected by the reflection mirror 11b attached to the full-speed carriage 11 and the reflection mirror 13 attached to the half-speed carriage 13.
a, 13b, a lens 14, and a color filter 15 separates the light into red, green, and blue color lights, and the respective color lights are incident on a CCD line sensor 16 which is divided for each color light, and input. The original image is read.

Further, as shown in FIG. 1, after red, green, and blue input image signals from the CCD line sensor 16 are amplified by the analog amplifier 17, they are A / D converted by the AD converter 18, and then the AD converter. 18 to red,
Multi-tone input image data R, G, B for green and blue respectively
Is obtained.

As will be described later, the image processing section 20 processes the input image data R, G, B from the image reading section 10 and converts the image information of the input image into image information for transfer onto a sheet. .

The image output section 30 transfers the input image onto a sheet according to the image information from the image processing section 20. As will be described later, the on / off binarized toner signals of black, yellow, magenta, and cyan are finally obtained in order from the image processing unit 20, and the image output unit 30 specifically describes the on / off binarized toner. Laser light scanner 3 by signal
1 is driven to convert the on / off binarized toner signal into an optical signal, and the laser light is charged by the charger 33 via the polygon mirror 31b, the F / θ lens 31c and the reflection mirror 32. The formed photosensitive drum 34 is scanned to form an electrostatic latent image on the photosensitive drum 34.

Further, the latent image is black, yellow,
A toner image is formed by a two-component magnetic brush phenomenon on the rotary developing device 35 to which magenta and cyan toners are supplied, and the toner image is transferred from the paper tray 60 and transferred onto the paper adsorbed on the transfer drum 36. It After the transfer, the photosensitive drum 34 is cleaned of excess toner by the cleaner 37. This process is repeated in the order of black, yellow, magenta, and cyan, so that the toner images are multiple-transferred onto the paper. After that, the paper is transfer drum 3
The toner is fixed on the fixing device 38, and the toner is fixed by the fixing device 38 and discharged to the outside of the copying machine.

The user interface 40 includes an operation unit having a copy button and the like, and a display unit having a light emitting diode and the like. The user selects a desired function and gives an instruction to execute the function, and the operation status of the copying machine. Is displayed.

The system controller 50 controls the entire copying machine system.

The ADF 70 has a black belt color in this example. Therefore, as described above, when the input document is sent using the ADF 70, the reading of the CCD line sensor 16 is relatively performed as compared with the case where the input document is placed on the platen glass 12 without using the ADF 70. The value becomes "darker" (higher).

The copying machine, as shown in FIG.
It has a DF use detecting means 81, that is, a means for detecting whether or not the input document is sent using the ADF 70.

Further, as shown in FIG. 1, the image reading unit 1
For the CCD line sensor 16 of 0, a temperature sensor 82 such as a thermistor that detects the ambient temperature of the CCD line sensor 16 is provided, and the output of the temperature sensor 82 is supplied to the comparator 83 and compared with the reference voltage Vr. As a result, the binary temperature detection signal Sc whose on / off state differs depending on whether the ambient temperature of the CCD line sensor 16 is 30 ° C. or higher is obtained from the comparator 83.

In the image processing unit 20, the image reading unit 1
0 input image data R, G, from the AD converter 18
B is subjected to shading correction by the shading correction circuit 21 and further subjected to gap correction by the gap correction circuit 22, and then L ^* a ^* in the density conversion circuit 23 ^.
b ^* Image data L ^* , a ^* , b ^* represented in a uniform color space
Is converted to.

At the same time, the density conversion circuit 23 performs density correction to remove the background and background of the input document. Specifically, the overall density of the input image is detected from the input image data R, G, B after the gap correction,
When the detected value is greater than or equal to a predetermined value, the image data L ^* , a ^* , b ^* are set so as to reduce the overall density of the output image ^.
Is corrected.

Image data L from this density conversion circuit 23
^* , A ^* , b ^* , on the other hand, image data L ^* , a ^* , b ^*
The primary colors of toner are black, yellow, magenta,
The image data is supplied to the color conversion circuit 25 for converting it into cyan image data K, Y, M, C, and is also supplied to the comparison circuit 85 as input image data ID to be compared with specific image data described later.

The specific image determination device 80 has a memory 87 as a data holding means for holding the specific image data. Then, as shown in FIG. 3, the memory 87 stores the addresses A0, A1, A2, A3, A4, A5, A6.
A7 includes specific image data D111, D112,
D121, D122, D211, D212, D221,
D222 is stored.

Here, the data D111 uses the ADF 70 and the ambient temperature of the CCD line sensor 16 is 30 ° C.
The above is a specific image when the density conversion circuit 23 performs the density correction described above.
2 shows a specific image when the ADF 70 is used, the ambient temperature of the CCD line sensor 16 is 30 ° C. or higher, and the density is not corrected.

The data D121 uses the ADF 70,
If the ambient temperature of the CCD line sensor 16 is less than 30 ° C,
In addition, the data D122 shows the specific image when the density correction is performed. The data D122 is the specific image when the ambient temperature of the CCD line sensor 16 is less than 30 ° C. and the density correction is not performed, using the ADF 70. It is shown.

The data D211 shows a specific image when the ambient temperature of the CCD line sensor 16 is 30 ° C. or higher and the density is corrected without using the ADF70, and the data D212 uses the ADF70. No, C
It shows a specific image when the ambient temperature of the CD line sensor 16 is 30 ° C. or higher and the density is not corrected.

Further, the data D221 does not use the ADF 70 and the ambient temperature of the CCD line sensor 16 is 30 °.
It shows a specific image when the temperature is less than C and the density correction is performed. The data D222 does not use the ADF 70, the ambient temperature of the CCD line sensor 16 is less than 30 ° C., and the density correction is not performed. The specific image at this time is shown.

In the specific image determination device 80, the binary ADF use detection signal Sa and the comparator 83 from the above-mentioned ADF use detection means 81, which are different in on / off state depending on whether the input document is sent using the ADF 70, are output from the comparator 83. Of the above-mentioned binarized temperature detection signal Sc and the concentration conversion circuit 23
The binarized density correction detection signal S whose on / off state differs depending on whether the above-described density correction from the density correction detection unit 24 is performed.
e is a CPU 88 that constitutes a selection unit for the specific image data
Is supplied to.

Then, the CPU 88 outputs the signals Sa and S.
The states of c and Se are judged, and C is judged according to the judgment result.
A selection signal of the specific image data is obtained from the PU 88 as address data of the memory 87, the memory 87 is accessed by the address data, and the specific image data is read from the memory 87.

The specific image data read from the memory 87 is supplied to the comparison circuit 85, and the density conversion circuit 2 is supplied.
The input image data ID from 3 is compared by a method such as pattern matching, and the determination circuit 8 is determined from the comparison result.
At 6, it is determined whether the input image is a specific image.

FIG. 4 shows a series of operations in the CPU 88, the memory 87, the comparison circuit 85, and the determination circuit 86. The CPU 88 first performs the binarization AD in step 101.
It is determined whether or not the F use detection signal Sa is on. If it is determined to be on, then in step 102, if it is determined to be off, then in step 103, the binary temperature detection signal Sc, respectively. It is determined whether or not is on.

When it is determined in step 102 that the signal Sc is on, then in step 104, when it is determined that it is off, in step 105, it is determined whether or not the binarized density correction detection signal Se is on. Judge whether
If it is determined in step 103 that the signal Sc is on, then in step 106, if it is determined to be off, then in step 107, it is determined whether or not the binarized density correction detection signal Se is on. To do.

If it is determined in step 104 that the signal Se is on, then in step 108 the address A0 of the memory 87 is accessed to read the specific image data D111 from the memory 87, then in step 109 the comparison circuit 85 Input specific image data D111 as input image data ID
Then, in step 110, the determination circuit 86 determines whether the input image is the specific image.

When it is determined in step 104 that the signal Se is off, then the specific image data D112 is determined in step 111, and when it is determined that the signal Se is on in step 105, the specific image data D121 is determined in step 114. If it is determined in step 105 that the signal Se is off, then the specific image data D122 is determined in step 117, and if it is determined in step 106 that the signal Se is on, then the specific image data D211 is determined in step 120. When it is determined that the signal Se is OFF in 106, the specific image data D212 is then determined in step 123, and when it is determined that the signal Se is ON in step 107, the specific image data D221 is determined in step 126 and step 107 is determined. When it is determined that the signal Se is off The specific image data D222 in step 129, read from the respective memories 87, followed by step 112,115,118,121,124,1
At 27 and 130, the comparison circuit 85 causes the specific image data D112, D121, D122, D211 and D21, respectively.
2, D221 and D222 are compared with the input image data ID, and then steps 113, 116, 119, 122,
At 125, 128 and 131, the determination circuit 86 determines whether or not the input image is the specific image.

When the determination circuit 86 determines that the input image is not the specific image, the determination output outputs the image data L ^* , a ^* , b ^* from the density conversion circuit 23 to the toner in the color conversion circuit 25. Image data K, Y, M, and C of primary colors black, yellow, magenta, and cyan are converted. Furthermore, the image data K, Y, M, C
After being gamma-corrected by the gamma correction circuit 26, D
The A / D converter 27 performs D / A conversion into a process color gradation toner signal, and the process color gradation toner signal is converted into an on / off binarized toner signal by the binarization circuit 28 and output to the image output unit 30. Then, the input image is transferred onto the sheet in the image output unit 30 as described above.

When the determination circuit 86 determines that the input image is a specific image, the determination output outputs the image data L ^* , a ^* , b ^* from the density conversion circuit 23 in the color conversion circuit 25. The image data Ca is converted so that the image has only one color of cyan. Therefore, the DA converter 27 obtains a gradation toner signal which makes the output image one color of cyan, and the binarization circuit 28 obtains the on / off binary toner signal which makes the output image one color of cyan. In the image output section 30, an output image in which only one color of cyan is obtained is obtained.

According to the above-mentioned example, the specific image judging device 8
In the case of 0, the input image data ID is C, whether or not the input original is sent using the ADF 70 in which the belt color is black, and C
Depending on whether the ambient temperature of the CD line sensor 16 is 30 ° C. or higher and whether the density conversion circuit 23 performs density correction, the specific image determination device 80 or the state of a copying machine equipped with the specific image determination device 80. Since it is determined whether or not the input image is the specific image by comparing the input image with the specific image data, there is no error in determining whether or not the input image is the specific image.

For example, the specific manuscript is a banknote (Bank of Japan note)
A red stamp printed or imprinted on it (for Japanese banknotes, regardless of the face value of 10,000 yen, 5,000 yen, 1,000 yen,
Circular red stamps of a predetermined size are printed on the front and back, respectively) as the specific image, when determining whether the input image, which is a partial pattern of the input document, is the specific image,
Since the red mark which is a specific image also has a thin portion, when the density correction circuit 23 performs the above-described density correction, it is possible that the input image data ID lacks the thin portion. As the image data, the data with the thin portion missing is prepared and stored in the memory 87. When the above-described density correction is performed, the specific image data with the thin portion missing is stored in the memory 8
By reading from 7 and comparing with the input image data ID, an error does not occur in the determination of whether or not the input image is the specific image.

In addition, according to the above-mentioned example, the input image data ID is assigned to the plurality of specific image data D11 in consideration of the state of the specific image determining device 80 or the copying machine equipped with the same.
1, D112, D121, D122, D211, D21
2, D221, D222 are not sequentially compared, but only the one selected according to the state of the specific image determination device 80 or the copying machine equipped with this is compared to determine whether the input image is the specific image. Therefore, it is possible to quickly determine whether or not the input image is the specific image.

In the above-mentioned example, there is only one type of specific image of the specific document whose copy should be prevented, but there are various types of specific document which should be protected from copying, including various securities. If it is necessary to consider a plurality of types as the above, the above-mentioned specific image data D111 to D222
As a result, a plurality of pieces of data are stored in the memory 87, and the data D111 to D222 are set as a data group including a plurality of pieces of specific image data.
It is only necessary to select one of the data groups depending on 0 or a copying machine equipped with the data and to sequentially compare a plurality of specific image data among them with the input image data ID.

As for the ADF, the ADDF is used as the specific image data, not whether the input original is sent using the ADF 70 in which the belt color is black as in the above-described example.
A when F is not used and when ADF is used
Data for each color of the DF is stored in the memory 87, whether or not the input original is sent using the ADF, and what color of the ADF is used when the ADF is used. May be detected, the specific image data corresponding thereto is read from the memory 87, and compared with the input image data ID.

The ambient temperature of the CCD line sensor 16 is not divided into two as to whether it is 30 ° C. or higher as in the above-mentioned example, but is divided into more temperature regions,
The specific image data in each temperature region may be stored in the memory 87, read from the memory 87, and compared with the input image data ID. In that case, whether or not the input image is the specific image is determined. Can be judged even more correctly.

Regarding the density correction in the density conversion circuit 23 as well, when multivalued or continuous correction is performed instead of the binary correction as in the above-mentioned example, similarly, the density correction of a large number of values is performed. The specific image data at each time may be stored in the memory 87, read from the memory 87, and compared with the input image data ID.

In the above example, when the input image is determined to be the specific image, the output image is a single color of cyan. However, copying itself is blocked or the input image is clearly visible to the human eye. It is also possible to take a method such as copying by adding a special pattern that can be identified.

[0051]

As described above, according to the present invention, it is possible not only to correctly determine whether or not the input image is the specific image, but also to perform it at high speed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a specific image determination device of the present invention.

FIG. 2 is a diagram showing the overall configuration of an example of a color copying machine equipped with the specific image determination device of the present invention.

FIG. 3 is a diagram showing a storage state of specific image data on a memory in an embodiment of the specific image determining apparatus of the present invention.

FIG. 4 is a flowchart showing operations of a CPU, a memory, and a comparison / determination unit in an embodiment of the specific image determination apparatus of the present invention.

FIG. 5 is a diagram showing a relationship between a temperature of a CCD line sensor and a read value when a specific density pattern is read.

FIG. 6 is a flowchart showing a possible example of a method of determining whether or not an input image is a specific image.

[Explanation of symbols]

 80 Specific Image Judgment Device 81 ADF Use Detection Means 82 Temperature Sensor 24 Density Correction Detection Unit 88 CPU 87 Memory 85 Comparison Circuit 86 Judgment Circuit ID Input Image Data D111 to D222 Specific Image Data

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masato Tsuji 2274 Hongo, Ebina City, Kanagawa Prefecture Fuji Xerox Co., Ltd.

Claims (1)

[Claims] 1. A data holding means for holding a plurality of specific image data in consideration of a state of a specific image determination device or a device mounting the specific image determination device, and detecting a state of the specific image determination device or a device mounting the specific image determination device. It is determined whether or not the input image is a specific image by comparing the selected specific image data and the input image data with a detection / selection unit that selects specific image data corresponding to the state from the data holding unit. A specific image determination device comprising: comparison determination means.