JPH0927906A - Image processing unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow the processing unit to be mounted on all color image processing units, to detect a circular image at a comparatively low cost and to discriminate a paper note or the like. SOLUTION: A concentric circle image detection circuit 70 detects a concentric circle image of an original face and stores patterns each represented by a diameter of or a chordal pitch and a chordal distance from a center of a detected concentric circle, and a concentric circle discrimination circuit 71 compares the detected pattern with the chord pattern of a concentric circle having been stored in advance in the buffer memory 72, and discriminates the detected pattern is that of a specific concentric circle when they are coincident. A discrimination result output circuit 73 provides an output of the discrimination result. Since the pattern represented by the chord pitch and distance of a chord is used for the discrimination of the concentric circle in this way, identification of patterns in existence at a prescribed interval is facilitated and the storage capacity for information required for the detection of the pattern is considerably reduced. Thus, the processing unit is realized at a low cost and the real time image processing is attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus having an abusive copy prevention function for preventing a color document such as banknotes or securities from being faithfully copied.

[0002]

2. Description of the Related Art In recent years, with the improvement of the performance of color copiers, it is necessary to develop a copier having a function of preventing copying of securities such as banknotes, stock certificates, bonds, commuter pass tickets, event tickets, and cash vouchers. The nature is higher. The technology related to the copy protection function of conventional copiers is roughly divided into
The technique is divided into a technique of providing a function of preventing normal copying on the document side and a technique of providing a function of detecting a copy-inhibited document by the image reading / detecting device and preventing a normal copying operation.

As the function of preventing the normal copying on the original side, for example, metal powder is mixed into the original to form a copy image based on metal powder other than the original image by the metal powder of the original image surface irradiation lamp. Selenium photoreceptor, selenium photoconductor, background pattern of document recorded image, moire caused by halftone dots during copying, processed by holography, or fluorescent color that cannot form clear image on ink There are known techniques such as a technique of using blue ink that is difficult to reproduce in a copying machine using. The latter image reading / detecting device detects a copy-inhibited document and adds a function to prevent normal copying operation by comparing the read data of the document with the basic data in the memory.
A method is known in which it is determined whether or not a document is good for copying, and processing is performed such as prohibiting copying, unfixing the output paper, and changing the output state of the paper from the normal state. For example, Japanese Patent Application Laid-Open No. 2-223498 discloses a technique for preventing counterfeiting by including one or more detectable concentric circles in a bill or other document. In addition, JP-A-2-21059
No. 1 discloses an image having a function of detecting the position state of a document, extracting image data of a specific portion in the document, determining the degree of similarity with a pattern registered in advance, and determining the specific document from the result. A processing device is disclosed.

[0004]

However, any of the above-mentioned prior art technologies for preventing abuse copying of originals have advantages and disadvantages.
Not widely spread. In addition, the normal copy protection function of the image reading / detecting device requires a memory having an enormous capacity for storing basic data of a specific document and a means for comparing and judging the read document image. There was a drawback that it became expensive. Further, in the method for determining a specific original document disclosed in Japanese Patent Laid-Open No. 210510/1990, since image data of a specific portion is compared, the memory capacity for storing the image data becomes large, the cost of the apparatus becomes high, and the image is registered. It takes time to determine the degree of similarity with the pattern. For example, Japanese Patent Application Laid-Open No. 2-223498 discloses recognition of concentric circles, but the concentric circles are recognized as a whole, that is, whether the concentric circles as a whole are concentric or not. As a result, there are problems that it is difficult to identify the pattern, and the storage capacity of information in the pattern detection is large.
Therefore, an object of the present invention is to provide an image processing device that can be installed in all color image processing devices and that can detect a circular image at a relatively low cost, and more specifically, to provide an image processing device that can perform determination of bills and the like in real time processing. It is to be.

[0005]

The above object of the present invention is achieved by the following constitution. That is, in an image processing apparatus that reads a document image in units of pixels with a scanner, processes the read image, and outputs the image, a concentric-circle image detection unit for detecting a concentric-circle image on the document surface and a concentric-circle image detection unit If the pattern consisting of the pitch and the interval of the chords at a distance from the center or the diameter of the detected concentric circles is stored, and the pattern of the chords corresponding to the concentric circles stored in advance is stored, this detected circle is detected. An image processing apparatus provided with a concentric image determination mechanism that is configured to determine that an image is a specific concentric circle, or

In an image processing apparatus for reading a document image in units of pixels with a scanner and processing and outputting the read image, a concentric image detecting means for detecting a concentric image of the document surface and a concentric image detecting means are provided. The diameter of the concentric circles detected by or the distance between the intersections with a plurality of concentric circles on the chord at a position away from the center by a constant distance is detected and stored, and when the distance information corresponds to the previously stored distance information corresponding to the concentric circles. An image processing device having a concentric circle image determination mechanism including means for determining that the detected circular image is a specific concentric circle, or

In an image processing apparatus for reading a document image in a pixel unit with a scanner, processing the read image and outputting the image, a concentric image detecting means for detecting a concentric image of the document surface and a concentric image detecting means are provided. When a pixel is detected, a main scanning direction detection signal thinning means for thinning the detection pixel signal on the main scanning direction line, and a diameter of a circle from the detection signal thinned by the main scanning direction detection signal thinning means A main scanning direction predetermined distance pitch signal detecting means for detecting a circle image signal on a line in the main scanning direction at a considerable specific distance pitch position, and a detection for storing image information detected by the concentric circle image detecting means. Both detection pixel signals detected by the image storage means, the main scanning direction detection signal thinning means and the main scanning direction predetermined distance pitch signal detection means are both the diameter of the circle. A center position calculating means for calculating the center position of the circle when it is assumed to correspond to the position, and at least one of an oblique direction and a sub-scanning direction rotated by a predetermined angle from the main scanning direction about the center position of the circle. Diagonal predetermined distance pitch signal detecting means for detecting that the detected image signal information of the circles corresponding to the positions on both sides of the diameter of the circle on the line in the direction is within the stored image information of the detected image storage means, When image information is detected by the oblique direction predetermined distance pitch signal detecting means, a circle pixel number counting means for counting the number of concentric circle pixels in the circle of the stored image information of the detected image storage means, and the circle pixel number When it is compared and judged that the count value of the counting means is within a range of a specific number stored in advance in the storage means, the images detected by the series of detection means are formed from specific concentric circle images. An image processing apparatus having a concentric image determination mechanism comprising that the determining concentric image determination means.

The concentric image determination mechanism of the image processing apparatus can be provided in the image output apparatus to which the image reading signal from the external scanner is input. Further, the detection of the specific concentric circle by the concentric image determination mechanism can be performed a plurality of times by rotating it by a predetermined angle. The object of the present invention is also achieved by the following configurations. That is, it is an image processing apparatus including the concentric circle image determination mechanism and a magnetism detector for detecting the magnetism on the side of the document arranged in the platen cover. The concentric circle code has a color and regularity that can be detected by an optical bar code sensor which is widely used at present, and this optical bar code sensor may be built in the image processing apparatus.

[0009]

According to the above construction, the pattern consisting of the pitches and the intervals of the chords on the diameter of the concentric circles or at a position apart from the center by a certain distance, that is, the distance between the intersections of a plurality of concentric circles on the chord is stored. If the pattern of the chord corresponding to the concentric circle stored in advance matches, the detected circular image is determined to be a specific concentric circle. As a result, if the document can be identified, then the image processing apparatus may be provided with the abuse image processing prevention function. The function of preventing abused image processing is to prohibit image processing, prohibit fixing, etc., to change the original writing timing from the normal state, to change the color of image processing toner from the original color, or to fade. Adds functions such as image processing with a neutral toner. Since the pattern consisting of the pitches and intervals of the strings is used to determine the concentric circles in this way, it is possible to easily identify patterns at regular intervals without performing detection by the conventional mark angle, and to detect patterns. Since the storage capacity of the information can be markedly reduced, the cost of the device can be reduced and the real-time processing can be performed.

A procedure for detecting a document on which a concentric code is printed by another image processing apparatus of the present invention will be described with reference to FIG. First, when an image signal is detected in the main scanning direction by the concentric circle detecting means (FIG. 8 (1)), even if the image signal consists of a plurality of pixel signals, the main scanning direction detection signal thinning means makes one line. The pixel signal is thinned. The thinning of the detection signal is performed by the main scanning direction predetermined distance pitch signal detecting means detecting a pixel signal in the main scanning direction that is a predetermined distance ahead corresponding to the diameter (for example, d ₀ mm) of the circle on the line in the main scanning direction ( This is to make FIG. 8 (2)) effective. That is, even when the circle is continuously detected from the first detection of the circle pixel signal (FIG. 8 (1)) to the point beyond the pitch of d ₀ mm, the first circle pixel signal shown in FIG. If the circle pixel signal of (1) is thinned, the pixel detection signal is also detected by the pitch signal detecting means for the predetermined distance in the main scanning direction ahead by the pitch of d ₀ mm (FIG. 8 (2)), which corresponds to the diameter of the circle. Therefore, it is not erroneously detected as an image signal of a specific color having a pitch of d ₀ mm.

When the image signal is detected by the concentric circle detecting means, the image information of the image signal is stored in the detected image storing means on a pixel-by-pixel basis, so that the pixel is detected by the predetermined distance pitch signal detecting means in the main scanning direction. When done (Fig. 8
(2)), both detection pixel signals (FIG. 8 (1) and FIG. 8 (2)) detected by the main scanning direction detection signal thinning means and the main scanning direction predetermined distance pitch signal detection means are circular. Concentric circles corresponding to both side positions corresponding to the diameter d ₀ mm of the circle on the diagonal line rotated by a predetermined angle from the main scanning direction around the center position x ₀ of the circle assuming that it corresponds to both end positions of the diameter. The detected pixel signal information of is searched for in the stored information in the detected image storage means.

A predetermined distance pitch signal detection in the oblique direction indicates that there are detection pixel signals of a specific color corresponding to both side positions corresponding to the diameter d ₀ mm of the circle on the oblique line in the stored image information of the detected image storage means. When the means detects (Fig. 8
(3)) The circular image determining means can determine that the circular image is formed from concentric images. Further, by detecting the predetermined distance pitch signals in both the sub-scanning direction and the oblique direction, more accurate determination can be made.

Further, when the circular image determining means detects the image information by the diagonal predetermined distance pitch signal detecting means, the circle of the stored image information of the detected image storing means counted by the in-circle pixel number counting means. When it is compared and determined that the number of specific color pixels in the specific color pixel is within the range of the specific number stored in advance in the storage means, the circle detected by the series of detection means is formed from a specific concentric circle image. Can be determined. In this way, a specific concentric circle code can be identified by repeating the determination of the concentric circles having the respective preset diameters d ₀ mm.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 21 shows an overall configuration diagram of a digital color copying machine which is an example of an image processing apparatus to which this embodiment is applied. In the color copying machine shown in FIG. 21, the base machine 30 has a platen glass 3 on which an original is placed.
1, an image input device 32, an electric system control housing 33, an image output device 34, a paper tray 35, and a user interface (U / I) 36, and optionally an edit pad 61 and an automatic document feeder (AD).
F) 62, sorter 63, and film projector (F
/ P) 64 and a mirror unit (M / U) 65.

The image input device 32 comprises an imaging unit 37, a wire 38 for driving the imaging unit 37, a drive pulley 39, and the like. The color filters in the imaging unit 37 allow the primary colors B (blue), G (green) of light, The image information of a color original which is color-separated into R (red) and read using a CCD line sensor is converted into a multi-gradation digital image signal BGR and output to an image processing apparatus. The image processing device is housed in the electrical system control housing unit 33, receives a BGR image signal, and performs various conversion, correction, and editing processes to improve color, gradation, definition, other image quality, and reproducibility. Are converted into primary colors Y (yellow), M (magenta), C (cyan), and K (black or black) of the toner based on the processed signal, and a gradation toner signal of a process color is obtained. Is converted into an on / off binarized toner signal and output to the image output device 34. The image output device 34 has a scanner 40 and a photosensitive material belt 41, and converts an image signal into an optical signal in a laser output unit 40a.
A latent image corresponding to the document image is formed on the photosensitive material belt 41 via the polygon mirror 40b, the F / θ lens 40c, and the reflection mirror 40d, and the image is transferred to a sheet conveyed from the sheet tray 35 to discharge a color copy. Things.

In the image output device 34, the photosensitive material belt 41 is driven by a drive pulley 41a, and a cleaner 41b, a charger 41c, each developing device 41d of YMCK and a transfer device 41e are arranged around the photosensitive material belt 41. A transfer device 42 is provided so as to face each other. And paper tray 3
5, the paper fed through the paper transport path 35a is added, and in the case of four-color full-color copying, the transfer device 4
2 is rotated four times to transfer each of the YMCK latent images onto the sheet, and then the sheet is fixed from the transfer device 42 via the vacuum carrying device 43 by the fixing device 45 and discharged. The SSI (single sheet inserter) 35b can selectively supply paper manually to the paper transport path 35a.

The user interface 36 is used by the user to select a desired function and instruct execution conditions thereof. The user interface 36 is provided with a color display 51 and a hard control panel 52. Further, an infrared touch board 53 is combined with the soft button on the screen. You can directly instruct. The electric system control storage unit 33 includes the image input device 3 described above.
2. a plurality of control boards configured separately for each processing unit such as an image output device 34, a user interface 36, an image processing device, a film projector 64, etc .; further, an image output device 34, an automatic document feeder 62, a sorter An MCB board (machine control board) for controlling the operation of a mechanism such as 63, and a SYS board for controlling the whole thereof are housed therein.

Further, the control device of the copying machine of FIG. 21 is shown in FIG.
Shown in The image input unit 100 has a reduced sensor composed of three line sensors of R, G, and B arranged at right angles in the sub-scanning direction (page sync direction), and is synchronized with a timing signal from the timing generation circuit 12. The image is read by being scanned. The read image data is subjected to shading correction for the balance between pixels due to various factors by the shading correction circuit 11, and then the gap correction circuit 13 performs gap correction between the line sensors. This gap correction is for delaying the image data read by the FIFO 14 by an amount corresponding to the gap so that R, G, and B image signals at the same position can be obtained at the same time.

ENL (Equivalnt Neutral Lightness) 1
5, the gray balance is performed, and the negative-positive inversion signal from the editing processing unit 400 for performing color conversion, color editing, region generation, pixel density conversion, etc. reverses the way gray is taken for each pixel to perform negative-positive inversion. For example, the negative / positive can be reversed only in a certain designated area. Also, the matrix circuit 16a
Then, in order to facilitate the interface with the outside, the gray-balanced R, G, B image signals are converted into L ', a', b'image signals by a control signal from the edit processing unit 400. In the selector 17, the matrix circuit 1
The output of 6a or the image data from the memory system 200 which is an interface with an external computer is selectively taken out. The selector 17 is connected to a background removal circuit 18 for skipping pixels having a background density or less to improve copy quality and a document detection circuit 19 for detecting and storing a document size.

In the matrix circuit 16b, the L ', a', and b'image signals color-edited by the editing processing section 400 are converted into Y, M, and C toner colors, and the pictographic character separating circuit 20 is converted.
Then, the color-edited image data is divided into a plurality of pixels to identify regions of color characters / black characters / patterns (characters / halftones). The under-color removing circuit 21 generates the black board, and outputs the same amount of Y, M, and C in accordance with the monochrome / full-color mode signal and black.
Is performed, the image data of the process color is output, and the hue is determined to generate the hue signal (Hue). The hue signal is temporarily stored in the FIFO 22a, and the image data composed of the halftone image signal of the picture and the character image signal of black characters and color characters is stored in the FIFO 22b.
Is stored once. This hue signal is transmitted to the pictogram separation circuit 20.
The signal is decoded by the area decoder 24 together with the signal based on the result of the pictogram separation from the CPU, and the respective processing units of the filter 25, the multiplier 26 and the TRC 27 operate based on this control signal, and the processing of the image data output from the FIFO 22b is executed. You.

The expansion / contraction circuit 23a expands / contracts so that the execution area of the area control information for the image does not shift even if there is a reduction / enlargement, and the area expansion / decoding control circuit 24 decodes the expansion / contraction area control information as necessary. It is then processed for each part. The area decoder 24 generates a signal for switching each parameter from the editing command, the area identification, and the hue. The image data reduced or enlarged by the enlargement / reduction circuit 23b is subjected to moire removal and edge enhancement by the filter 25, and the multiplier 26 and the TRC 27 appropriately select a coefficient and a conversion table for each color component. , Color adjustment and density adjustment are performed, and the multiplier 26 calculates the image data to correct the conversion table of the TRC 27. The TRC 27 is for adjusting the density in accordance with the characteristics of the IOT 34. The PAL 29 is capable of switching the conversion table of the TRC 27 by a development process or area identification, and the prepared image data is stored in the memory system or the ROS 300. The dot is developed by the screen generation unit 28, and is output as a halftone image.

Next, in the present embodiment, the function of not performing normal copying when the document is recognized as a banknote by reading the red stamp of the banknote using the color copying machine will be described. FIG. 1 shows a control block diagram of a bill red seal determining mechanism for that purpose. As described above, the banknote issued by the Bank of Japan has a circular red stamp printed on both the front and back sides. The red stamp on the front side has a diameter of 14.5 mm and the red stamp on the back has a diameter of 13.5 mm regardless of the face value of the banknote. The pattern of the red seal is different on the front side and the back side. It is assumed that the bill red seal has a circular shape shown in FIG.

First, a red stamp on the surface of a bill will be taken as an example to explain the outline of the procedure until the determination is made. First, scanning of the original surface with a CCD line sensor (not shown) for reading the original image of the copying machine is started. However, since there is no red printing near the red mark of the bill, the main scanning direction (CC
13. After the reading of the document surface in the scanning direction (D) starts, the detection of the red pixels starts and corresponds to the diameter of the red seal on the bill surface.
If a red pixel equivalent to a 5 mm pitch is detected, it can be assumed that it is based on a red circle with a diameter of 14.5 mm. At this time, the detection of the red pixels corresponding to the 14.5 mm pitch may be performed continuously during this time, or the circle corresponding to the line at the diameter position of the outer circle of the bill red seal and the circle in the circle may be used. Any of the cases where the ON state is discontinuous due to the character may be used.

Then, from the center position (x ₀ , y ₀ ) of a circle having a diameter of 14.5 mm, a predetermined distance pitch (Lmm
Pitch) See if red pixels can be detected at the intersection with the circle at a position shifted by a considerable amount. Here, the value of L is an arbitrary value having a radius of less than 7.25 mm of the red seal. If a red pixel is detected at the position corresponding to the intersection of the circles on the Lmm pitch line, it is correct to assume that the detected red pixel signal is circular. Further, a predetermined distance (am) of the center of the dmm pitch line within the circle on the Lmm pitch line
m) Count the number of times N corresponding to ON. This predetermined distance a
mm is set so as to correspond to a print area of a character such as “The Bank of Japan” in the bill red seal (a ≦ d). This dm
The number of pixels (number of ONs) N in the amm pitch on the m pitch line is equivalent to the number of pixels on the d pitch line corresponding to a character such as, for example, "The Bank of Japan" in the banknote red seal stored in the buffer memory in advance. Then, the detected circular red information can be determined to be a red seal of a bill.

In the block diagram of the bill red stamp determination mechanism shown in FIG. 1, the pixel density conversion circuit 1 has a pixel density of 400d.
When the red detection circuit 2 detects the red mark, the 14.5 mm pitch line detection circuit 3 detects red in the main scanning direction 14.5 mm pitch ahead. Further, in order to detect a red pixel on a line separated by L mm in the sub-scanning direction, Lmm in FIG.
The standby time for 2.5 mm in this embodiment is 2.5 mm
It is controlled by the Wait circuit 4. Then, after waiting for 2.5 mm in the sub-scanning direction, dmm in FIG.
(3.6 mm) pitch line detection is performed by a 13.6 mm pitch line detection circuit 5. The number N of ONs at a predetermined distance (amm) at the center of the 13.6 mm pitch line is ON / OF.
The count number N is compared with a corresponding numerical value in a buffer memory (not shown) by a comparison / judgment circuit 7, and the count number N is set to a threshold value th.
If it is within the range of ₁ and th ₂ , it is determined that this red signal is a red stamp of a bill. The determination result is the determination result output circuit 8
To output.

Further, the number of times of ON is N _1, and other ON / O
If the number of FF changes N _{2 is} also obtained and N is obtained by N = wN ₁ + (1-w) N ₂ , the accuracy of the determination is further improved. In the case of a red stamp on the surface of a banknote issued by the Bank of Japan, L = 2.5 mm, w =
At 0.1, the count number N = 5 to 25. In the present embodiment, the buffer memory of the banknote red stamp determination mechanism uses the above-mentioned ON / OF.
Since only the memory capacity for the F count number thresholds th ₁ and th ₂ is required, it is possible to provide a low-cost detection device.

FIG. 3 shows a flow chart for the above-mentioned bill red stamp determination. The red seal determining mechanism of the present embodiment is not operated, for example, when copying a monochrome document or during monochrome copying of a color document image. It is desirable to be able to do so. Therefore, the operation of the banknote red seal determination function may be limited to full-color copying or three-color copying.

Further, when magnetic ink is used for the bill, when the original is set on the platen, the original is detected by a magnetic detector installed in the platen cover, and this and the bill. It can be combined with the red stamp judgment mechanism. At this time, when the magnetic detection signal of the bill is first received by the magnetic detector, and the bill red seal judging mechanism is operated for the first time, the copying operation that is frequently performed without abuse of the original can be quickly performed. . In addition, the mechanism for judging the red seal of the banknote to be performed after the detection of the magnetism is as follows.
It is possible to judge a banknote with a sufficiently high probability simply by judging a circle having a pitch of 5 mm or simply judging a circle having a pitch of 14.5 mm. It is not necessary to dispose the magnetic detector on the entire surface of the platen cover, and it is sufficient to dispose the magnetic detector at a required position at an interval slightly shorter than the printing width of the magnetic ink.

Further, when the magnetic detector in the platen cover reacts, it is possible to prevent copying at the same magnification (100%) without the need to activate the red stamp determination mechanism for bills. In addition, when the magnetic detector responds, the paper quality of the paper is detected by a sensor etc. installed in the paper tray, and if the paper can be misused as a banknote, the operation of the copier is stopped. Can also. Further, at this time, it may be possible to perform processing such as changing the color of only the color area used for the banknote and output it, or to output with a smelled toner. Of course, a plurality of these operations can be combined.

Also, by increasing the gloss of the paper to be copied by a method such as combining with the above operation and outputting it, or by checking the presence or absence of printing on the back side near the registration roll with a photo sensor or the like during double-sided copying (especially during manual operation). Alternatively, the friction (sliding) of the feed roller may be detected in the determination of double-sided copying, and when there is a risk of misuse copying, the operation may be stopped such as copying stop. Further, a histogram of a density or a print pattern unique to a document such as a bill, for example, the number of detection pixels in each density region of a plurality of density regions is stored in a memory, and based on this, the document to be detected is a bill or the like. It is also effective to check whether or not the document should not be abused. At this time, the histogram can be applied to a specific area or an entire area of the document.

Similarly, a density peculiar to a document such as a banknote or a profile of a print pattern, for example, a density change in a direction orthogonal to each coordinate axis in the longitudinal direction of the document is stored in a memory and detected based on this. It is also effective to check the target manuscript. At this time, the profile can be applied to a specific area or an entire area of the document. In addition, a feature may be provided in which a feature point of a specific person image of a bill is stored in a memory, and when read information on the feature point is input, the bill is determined to be a bill. In the case of bills, since the watermark has a characteristic, the characteristic point of this watermark may be processed in the same manner as the above-mentioned person image.

Further, the bill red stamp determination mechanism of this embodiment is shown in FIG.
When provided on the image output means as described above, not only the scanner signal inside the image reading means, but also the scanner signal transmitted from an external device directly transmitted to the image output means, the bill red seal determining mechanism Can be passed through. In addition, when the bill red seal determining mechanism of the present embodiment determines the red seal of a bill, the writing timing of the front and back of the copy paper can be randomly performed using a random number table or the like. This is to make use of the fact that creation of counterfeit banknotes becomes impossible if the writing start timing changes unpredictably on the front and back of the copy sheet.

Further, when the banknote red stamp determination mechanism of the present embodiment determines that the banknote has a red stamp, the copy paper will always be unusable as a banknote, for example, a logo such as "copy" or "unusable". If the mark is automatically printed on at least the front side or the back side of the copy paper, the copy of the bill cannot be abused. In addition, such a logo mark is put on the paper immediately after copying or at the time of standby of the copying machine by printing the logo mark of a copying machine maker or the like by a printing mechanism.
If it is specified that the paper is copied from a manuscript, it is possible to prevent abuse copying of bills and the like. By printing a logo mark of a copier maker or the like on all copies, it is useful for copyright protection. In particular, high-performance color copiers have made it easy to obtain copies of the same quality from photo books, etc., so it is meaningful to print the logo on the copies. is there.

In the present embodiment, the means for preventing the illegal copy of the original document was described centering on the bill red stamp determination mechanism, but the present invention is not limited to the bill red stamp determination mechanism, and one or a plurality of the various original document illegal copy preventing means described above may be used. The optimum combination can be selected according to the purpose by combining. Next, a description will be given of a document for preventing image processing which has been specially printed in order to prevent faithful copying of a color document such as banknotes and securities, and an image processing apparatus for preventing abusive image processing of the document.

FIG. 5 shows an example of the concentric circle code. In the concentric code, at least one of the line thickness of each circle, the interval between the lines, and the diameter of each circle has a certain regularity. If the regularity can be identified on the copying machine side, the abuse of the document can be easily prevented. If the rules applied to optical barcodes, which are currently widely used, are applied to the concentric codes as they are, a document misuse prevention function that can be accepted worldwide can be established. In order to identify the concentric code of the document, the copier may be provided with the following concentric code determination function. Since the circular image of the present embodiment can be read as a circular image regardless of the direction in which the original is set on the original reading surface of the copying machine, attention is paid to the fact that the means for identifying the image can be configured relatively easily. It is. FIGS. 6 and 7 show block diagrams of a control circuit which is a concentric code judging mechanism.

The concentric circle determination mechanism shown in FIG. 6 is provided with a concentric image detecting circuit 70 for detecting a concentric image of the document surface, and a diameter of the concentric circle detected by the concentric image detecting circuit 70 or a position separated from the center by a certain distance. If a pattern consisting of the pitches and intervals of the strings is stored and matches the pattern of the strings corresponding to the concentric circles stored in the buffer memory 72 in advance, it is determined that the detected circular image is a specific concentric circle. It is composed of a concentric circle determination circuit 71 and a determination result output circuit 73 which outputs the determination result. The concentric circle determination circuit 71 detects and stores the diameter of the concentric circle or the distance between the intersections with a plurality of concentric circles on the chord at a position separated by a certain distance from the center, and stores the distance in the buffer memory 72 corresponding to the previously stored concentric circle. , The detected circular image can be determined to be a specific concentric circle.

Further, an outline of a procedure for performing concentric circle code determination when the concentric circle determination mechanism shown in FIG. 7 is used will be described.
First, an image (not necessarily a concentric image) is obtained by reading and scanning the original surface in the main scanning direction (CCD scanning direction).
Is started, the image information to be detected thereafter is stored in the buffer memory 2. When the pixels at the two positions corresponding to the diameters of the concentric circles are detected, the pixels are assumed to have detected the two points at the diameters of the circle, respectively, and the center position is calculated. If circular information is stored in the buffer memory 2 at both ends of the diameter rotated by a predetermined angle from the main scanning direction, the assumption that the detected pixel signal is circular is correct.

Further, since there are concentric circles with different line intervals, line thicknesses, etc. in the circle, the number N of pixels in the circle which is the stored image in the buffer memory 2 is counted, and the number N of pixels is preset. If the calculated number of pixels corresponding to the concentric circles matches, it can be determined that the detected circular image is due to a specific concentric circle. When the concentric circle detection circuit 70 detects an image in the control block diagram of FIG. 7, the image is stored in the buffer memory 72. At the same time, the main scanning direction detection signal thinning circuit 71-1 thins the detection signal in the main scanning direction. For this thinning, signal detection is easily performed by the next main scanning direction d ₀ mm pitch signal detection circuit 71-2. Further, in the buffer memory 72 in which the circular pixel information is stored, when the d ₀ mm pitch signal in the main scanning direction is detected, the memory required for detecting the d ₀ mm pitch signal in the sub scanning direction and the diagonal direction is sufficient. The capacity of the buffer memory 72 may be very small, and the cost of the buffer memory 72 can be reduced.

Concentric circle detection circuit 70 and main scanning direction d ₀ mm
When the pitch signal detection circuit 71-2 detects a pixel, it is assumed that the pixels detected by the detection means 70 and 71-2 of the two are both ends of the diameter of the circle, and the center x ₀ of the circle is the center of the circle. The position calculation circuit 71-6 calculates the position. A circle corresponding to a circumferential position with a pitch of d ₀ mm at a position rotated by a predetermined angle from the center x ₀ (FIG. 8) of the circle with respect to the main scanning direction, for example, a sub-scanning direction or a 45 ° oblique direction from the main scanning direction. The d ₀ mm pitch signal detection circuit 71-3 in the diagonal direction or the sub-scanning direction detects whether the pixel information is stored in the buffer memory 72. When the circular pixel information is also detected in the diagonal direction d ₀ mm pitch signal detection circuit 71-3, the in-circle pixel count circuit 71-4 counts the number of pixels in this circle, and the number of concentric circle pixels stored in advance. It is compared and judged by the comparator 71-5. If the number of pixels determined by the comparator 71-5 is within the upper and lower threshold values (th ₁ and th ₂ ), the determination result output circuit 73
Output that is a set concentric circle.

FIG. 9 shows a flowchart for concentric circle determination by the concentric circle determination mechanism of FIG. Further, in the bills and the like used in the automatic money changer, since the bill setting position is specified, the thickness of the line of each circle of the concentric code, the line spacing of each circle, the size of the diameter of each circle In addition to or in addition to changing the notch, providing a notch in each circle, further limiting the notch position to a specific location, etc., so that the notch can be detected further, Abuse of the original such as bills can be prevented.

In the above, an example in which a concentric circle code is printed on an original and the image is read by the image processing apparatus has been described. However, in addition to the concentric circle code, the following functions can be added to the original.
Prevents misuse of manuscripts. (1) A watermark in the form of a tracing paper is attached. This watermark portion utilizes the fact that copying is impossible. (2) Perform special color printing. An image printed with ink of gold, silver, pale pink, or the like utilizes the fact that the color cannot be faithfully reproduced at the time of copying. (3) Apply gloss to the printing surface. Gloss utilizes the fact that it cannot be copied. (4) Attach magnetic tape or print magnetized iron powder or iron powder, or print transparent or white magnetic ink on paper. If a magnetic detection sensor is provided on the platen cover side of the copying machine, an abuse copy prevention function of the document can be activated when the document is set on the platen. (5) The paper itself can be copied only by the paper specified by the copier maker, or the paper can be copied only by printing a specific logo on the back of the paper.

Copying is made impossible by, for example, making it possible to convey only the specific sheet in the copying machine. For example, at the time of copying a monochrome document or at the time of monochrome copying of a color document image, by not operating the function for red seal determination, the intended copy can be quickly performed when the concentric circle determination mechanism is unnecessary. Is desirable. When it is determined that the image is a circular image of the document, a density histogram in a concentric circle stored in advance or a histogram calculated from a density of ON pixels in a circle of the document stored in the buffer memory and a density profile is stored. Alternatively, the concentric code can be determined in association with the density profile.

When magnetic ink is used for the original, when the original is set on the platen, the original is detected by the magnetic detector installed in the platen cover. It is possible to combine the concentric circle code judgment mechanism of. At this time, when the magnetic detection signal of the original is first received by the magnetic detector and the concentric circle determination mechanism of the original is actuated for the first time, the copying operation which is frequently performed without abuse of the original can be quickly performed. .
In addition, the concentric circle determination mechanism of the document, which is performed after the magnetic detection, determines the concentric circles with a pitch of d ₀ mm or simply d ₀ m.
The original can be determined with a sufficiently high probability only by determining the circles of m pitches. It is not necessary to dispose the magnetic detector on the entire surface of the platen cover, and it is sufficient to dispose the magnetic detector at a required position at an interval slightly shorter than the printing width of the magnetic ink.

Further, when the magnetic detector in the platen cover reacts, it is not necessary to activate the concentric circle determination mechanism for the original document, and copying at the same magnification (100%) may be prohibited. In addition, when the magnetic detector responds, it is possible to detect the paper quality of the paper by a sensor or the like installed in the paper tray, and to stop the operation of the copying machine if the paper is for originals. . Further, at this time, it may be possible to perform processing such as changing the color of only the color area used in the document and output the image, or output the image using scented toner. Of course, a plurality of these operations can be combined.

Also, by increasing the gloss of the paper to be copied by a method such as combining with the above operation and outputting it, or checking the presence or absence of printing on the back side near the registration roll with a photo sensor or the like during double-sided copying (especially during manual operation). Alternatively, the friction (sliding) of the feed roller may be detected in the determination of double-sided copying, and when there is a risk of misuse copying, the operation may be stopped such as copying stop. Furthermore, the density of the original or the histogram of the print pattern, for example, the number of pixels detected in each of the plurality of density areas is stored in the memory, and based on this, the original to be detected is copied to the abuse of the original. It is also effective to check whether a document should not be printed. At this time, the histogram can be applied to a specific area or an entire area of the document.

Similarly, the density or print pattern profile peculiar to the original document, for example, the density change in the direction orthogonal to each coordinate axis in the longitudinal direction of the original document is stored in the memory,
Based on this, it is also effective to check the document to be detected. At this time, the profile can be applied to a specific area or an entire area of the document. In addition, a feature may be provided in which characteristic points of a person on a document on which a specific person image is printed are stored in a memory, and when read information on the characteristic points is input, the document is determined to be a document. . In the case of bills, since the watermark has a characteristic, the characteristic point of this watermark may be processed in the same manner as the above-mentioned person image. Further, when the concentric circle determination mechanism of this embodiment is provided in the image output means IOT as shown in FIG. 10, not only the scanner signal inside the image input means IIT but also the external signal transmitted directly into the image output means IOT. The scanner signal transmitted from the device can also be passed through the document concentricity determination mechanism. IPS is an image processing means, P
C is a personal computer.

Further, when the concentric circle judging mechanism of the present embodiment judges the concentric circles of the original, the writing timing of the front and back sides of the copy paper can be randomly performed using a random number table or the like. This is to make use of the fact that creation of a forged manuscript becomes impossible if the writing start timing on the front and back of the copy paper changes without predictability. Further, if the concentric circle judgment mechanism of the present embodiment judges the concentric circle of the original, the copy paper cannot be used as the original without fail, for example, "copy".
If a configuration is adopted in which a logo mark such as "unusable" is automatically inserted at least on the front or back of a copy sheet, it is impossible to abuse a copy of the document.

It is to be noted that such a logo mark is clearly copied from the original by inserting the logo mark of the copier maker or the like on the paper immediately after copying or during standby of the copier by the printing mechanism. Then, it is possible to prevent the misuse of the original document. By printing a logo mark of a copier maker or the like on all copies, it is useful for copyright protection. In particular, high-performance color copiers have made it easy to obtain copies of the same quality from photo books, etc., so it is meaningful to print the logo on the copies. is there. Although the present embodiment has described the abuse copy prevention means by the copying apparatus centering on the abuse copy prevention manuscript and the concentric circle judging mechanism, the present invention is not limited to this. By combination, the optimal one according to the purpose can be selected.

Next, an embodiment of an image processing apparatus having a document abuse image processing prevention function, in which specific pattern information is added to the read digital image data and printed, will be described. FIG. 11 shows a copy sheet on which pattern information is printed. On the copy paper processed by the image output means, a pattern information print area is provided so as to overlap a copy image forming area for forming a copy image, and the pattern information built in the apparatus is printed on the pattern information print area. Is done. Here, whether the pattern information print area is set as a copy image formation area to be added to all of the read image data and printed, or a specific area is set in the copy image formation area according to the device specification. You can choose. For example, as a specific area,
The range may be limited to only a specific density range of the digital image data.

Explaining the mode of the pattern information, the pattern information is character information or coded information, the character information is composed of a combination of numbers and symbols, and the coded information is composed of significant information by a combination of dots. To be done. In the case of character information, any of meaningless information in which the combined specific numerical value, symbol, or the like has no meaning or significant information in which the meaning itself is given may be used. These pieces of information are constituted by an area or density below the detection limit of the human eye, that is, below the visual limit, or a combination of the area and the density. For example, the area and density of each dot used for the encoded information are set to be equal to or less than the visual limit.

Since a color copier is usually printed with a plate of four colors of yellow, magenta, cyan and black at the same time as printing, a specific color among them is, for example, a single color or a combination of a plurality of colors. Print pattern information. Preferably, the specific color is yellow which is most difficult to detect by human eyes. Further, when the pattern information enters a white background, it tends to be noticeable depending on the specific color used. Therefore, it is necessary to control the density of the pattern information with high precision. Therefore, by adopting a configuration in which the specific color used in the digital image data is added only to the inconspicuous specific density area, that is, the area other than the white area, the density control of the pattern information becomes easy.

The coded information is code-converted from a character string, converted into pattern information represented by one row of bit strings, and added to the digital image data. For example, in the pattern information shown in FIG. 12, a character string is converted into an ASCII code,
The byte code is converted into pattern information represented by one row of bit strings. One bit is represented by a dot pattern of two pixels in the main scanning direction and one pixel in the sub scanning direction, and the density is set to the maximum density that can be reproduced by the image output device. In this example, as encoding information, only alphanumeric is used, 7-bit character information of 8-bit ASCII code is inserted, and the remaining 1 bit (most significant bit MSB) is error correction information (of odd parity). Check) That is, FFh is set in the first line as a guide for the digit positions in the second and subsequent lines. Bits of ASCII are placed in the 2nd to N-1th rows. Data for a parity check in the vertical direction is placed in the Nth row. According to the present embodiment,
Since the dot pattern can be recognized with an extremely small dot area, the dot pattern can be made inconspicuous as compared with the character information. In addition, since dot identification is less affected by density than character information, density control becomes easier.

Next, image processing for preventing partial misuse of the copy paper on which the pattern information is printed will be described. FIG. 13 shows a copy sheet on which periodic pattern information is printed. A large number of pieces of pattern information are arranged vertically and horizontally on a copy sheet at a predetermined area and at predetermined intervals. With such a configuration, the pattern information to be printed enters the entirety of the copy sheet finely, so even if an attempt is made to use the portion of the copy sheet, the printed pattern information enters there. Therefore, partial abuse of the copy sheet can be prevented. FIG. 14 shows encoded information having periodicity. In this example, encoded information having an area of 320 dots vertically and 160 dots horizontally is provided with periodicity, and the encoded information is arranged in a mesh pattern.

FIG. 15 shows a hardware configuration of an image processing system for adding pattern information. The system configuration for reading a document image by a scanner in pixel units and performing image processing on the read image data and outputting the processed image data is the same as the configuration shown in FIG.
The pattern adding device adds the above-described pattern information to the digital image data processed by the image processing device. Next, an embodiment of the pattern adding apparatus will be described in which encoded pattern information is added. FIG. 16 shows a hardware configuration of an apparatus for adding a pattern of encoded information having periodicity.

The block interval setting section 80 sets the repetition cycle of the pattern information. The dot interval setting unit 81
The interval between the dots constituting the pattern information is set. The register 82 holds a dot interval set value written by the CPU and ON / OFF of the dot. The counter selector 83 controls dot printing or non-printing based on the interval set by the dot interval setting unit 81 and the dot ON / OFF information of the register 82. Selector 8
4 selects whether to output the video data (Video Data) as it is or to output the pattern information.
In the present embodiment, for all of the digital image data read, it is configured to add pattern information, but the image data is collated with image data stored in advance that should not be faithfully copied, The pattern adding device may be configured to operate only when they match.

Next, the addition control or addition prohibition control of a specific pattern based on the detected value will be described. FIG. 17 shows a basic configuration of an image processing apparatus having a function of switching the shape and density of a specific pattern according to a detected density value. After the image signal read by the image reading device is processed by the image processing device, the image is written on the photoconductor by the laser light converted by the laser writing device LD. The density-controlled image is transferred based on the detected density information, and the developed image is transferred to a transfer drum and output.
In the present embodiment, in the density control of image processing, switching control of an additional pattern is performed using the detected output density. That is, in order to check the output density of the image, the toner image (batch) formed on the photoconductor is transferred to a transfer drum, and the density of the transferred batch is detected by the image density (ADC) sensor 5.

The additional pan selection device is the ADC sensor 10
A specific pattern is selected based on the detected density value from 0, and this switching signal is sent to the pattern adding device 4. The pattern adding device determines a pattern from a plurality of specific patterns prepared in advance by a switching signal from the additional pattern selecting device, and sends the pattern signal together with the image signal from the image processing device to the image writing device LD. Add a specific pattern to the processed image. As a plurality of specific patterns prepared in the pattern adding device,
A description will be given using encoded information as an example. FIG. 18 shows a sheet on which an encoded pattern is printed. FIG. 19 is an example of an encoding pattern switched according to the output density of an image. A specific coded pattern is image-processed and printed on paper, and since this coded pattern tends to be printed dark when the output density is high, for example, printed with small dots, When the output density is low, printing is performed with large dots. In the illustrated example, a specific pattern is formed by one dot when the output density is high and by two dots when the output density is low.

By the way, although it is not noticeable by humans,
When adding a pattern that can be read by a scanner and image processing to an image, if the density of the pattern to be added is too high, it is recognized as fog by the human eye, and if it is too low, the pattern cannot be read by the scanner and image processing. There is
According to the present embodiment, since a pattern having an optimum shape and density is added according to the detected output density, abuse image processing of a document can be prevented without deteriorating image quality.

FIG. 20 shows the basic structure of an image processing apparatus having a pattern addition prohibiting function that prevents a specific pattern from being added according to the type of transfer paper. Here, as a transfer paper for which addition of a specific pattern is prohibited, an OHP sheet,
Targets a specific color paper. The pattern addition prohibition judging device judges OHP or a specific color sheet based on a detection signal from the OHP detection sensor 101 and / or the sheet detection sensor 102, and sends the result to the pattern addition device. When OHP or a specific color sheet is detected, the pattern adding device does not add a pattern to the image processed by the image processing device in response to the pattern addition prohibition signal from the pattern addition prohibition judging device. Therefore,
The image is output as it is. When plain paper or a color paper other than the above is detected, pattern addition is not prohibited. Therefore, the pattern adding device adds a pattern to the processed image and outputs the image.

In the present embodiment, the OHP detection sensor and the paper detection sensor for detecting the paper of a specific color are provided in combination, but it may be configured with only one sensor. In addition, by combining these sensors and the ADC sensor, a configuration having both functions of switching a specific pattern and prohibiting the addition of a pattern according to the type of transfer paper can be provided.
By the way, there is a problem that even an added pattern that is not noticeable by humans can be seen at the time of projection on an OPH sheet, or can be seen by humans on colored paper,
According to the present embodiment, control is performed so as not to add a pattern in the above case, so that such a problem can be solved. Manuscripts that are the subject of the present invention are bills, securities such as stock certificates and bonds, commuter passes, admission tickets for events, and cash vouchers. The image processing apparatus of the present invention can be applied to not only a copying machine but also a facsimile and a printer.

[0061]

As described above, according to the present invention, a memory only needs to have a minimum capacity, and a circular image can be detected at a relatively low cost. In particular, a red mark such as a bill is detected. it can. Therefore, a normal image processing prevention function can be obtained at a relatively low cost, so that a function to prevent abuse of the image processing apparatus, such as copying bills, can be added to a low-cost color image processing apparatus. it can. Further, by printing a circular image composed of a plurality of specified concentric circles on a document, it is possible to prevent the image processing of the document being abused, and the printing can be performed relatively easily. Further, the concentric code of the document can be detected by the image processing device of relatively low cost.

[Brief description of drawings]

FIG. 1 is a block diagram showing a banknote red stamp determination mechanism according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram for detecting a circle.

FIG. 3 is a flowchart of a bill determination process.

FIG. 4 is a diagram illustrating a hardware configuration of an image processing apparatus including a bill red seal determining mechanism.

FIG. 5 is a diagram showing concentric circles according to another embodiment of the present invention.

FIG. 6 is a block diagram of a concentric circle determination mechanism.

FIG. 7 is a block diagram of a concentric circle determination mechanism.

FIG. 8 is a conceptual diagram for detecting concentric circles.

FIG. 9 is a flowchart of a document determination process.

FIG. 10 is a diagram illustrating a hardware configuration of an image processing apparatus including a concentric circle determination mechanism.

FIG. 11 is an explanatory diagram of a copy sheet on which pattern information is printed according to another embodiment of the present invention.

FIG. 12 is an explanatory diagram of a copy sheet on which encoding information is printed as pattern information.

FIG. 13 is an explanatory diagram of a copy sheet on which periodic pattern information is printed.

FIG. 14 is an explanatory diagram of a copy sheet on which encoded information having periodicity is printed.

FIG. 15 is a diagram illustrating a hardware configuration of an image processing apparatus having a pattern information adding function.

FIG. 16 is a diagram illustrating a hardware configuration of a pattern adding apparatus.

FIG. 17 is a diagram illustrating a hardware configuration of an image processing apparatus having an additional pattern selection function.

FIG. 18 is an explanatory diagram of a copy sheet on which an encoding pattern corresponding to an output density is printed.

FIG. 19 is a diagram illustrating a specific example of an encoding pattern according to an output density.

FIG. 20 is a diagram illustrating a hardware configuration of an image processing apparatus having a pattern addition prohibition function.

FIG. 21 is an overall configuration diagram of a color copying machine according to an embodiment of the present invention.

FIG. 22 is a control block diagram of a color copying machine.

[Explanation of symbols]

1 .... pixel density conversion circuit, 2 .... red detection circuit, 3 .... 14.
5mm pitch line detection circuit, 4 ... 2.5mm Wait
Circuit, 5 ... 13.6mm pitch signal detection circuit, 6 ... ON
/ OFF frequency counting circuit, 7: comparison judgment circuit, 8: judgment result output circuit, 70: concentric circle detection circuit, 71: concentric circle judgment circuit, 71-1: main scanning direction detection signal thinning circuit,
71-2 ... Main scanning direction d ₀ mm pitch signal detection circuit, 7
1-3 ... Diagonal direction d ₀ mm pitch signal detection circuit, 71-
4 ... circle pixel count circuit, 71-5 ... comparator, 71
-6: circle center position calculation circuit, 72: buffer memory,
73: determination result output circuit, 80: block interval setting unit,
81: dot interval setting unit, 82: register, 83: counter / selector, 84: selector, 90: additional pattern selecting device, 92: pattern addition prohibition judging device, 100 ...
ADC sensor, 101: OHP detection sensor, 102: paper detection sensor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Swiren 2274 Hongo, Ebina City, Kanagawa Prefecture, Fuji Xerox Co., Ltd. (72) Inventor, Koji Aikawa, 2274 Hongo, Ebina City, Kanagawa Prefecture, Fuji Xerox Co., Ltd. (72) Inventor Koichiro Shinohara 2274 Hongo, Ebina City, Kanagawa Prefecture, Fuji Xerox Co., Ltd. (72) Inventor Fumio Nakatani, 2274 Hongo, Ebina City, Kanagawa Prefecture, Fuji Xerox Co., Ltd.

Claims (6)

[Claims] 1. An image processing apparatus for reading a document image in units of pixels by a scanner, processing the read image and outputting the image, and a concentric image detecting means for detecting a concentric image of a document surface, and the concentric image detection. By storing a pattern consisting of the diameter and the pitch of the chords at a distance from the center of the concentric circles detected by the means, and a pattern, and matching with the pre-stored chordal pattern corresponding to the concentric circles, An image processing apparatus comprising a concentric circle image determination mechanism including means for determining that the detected circular image is a specific concentric circle. 2. An image processing apparatus for reading a document image in a pixel unit by a scanner, processing the read image and outputting the image, and a concentric circle image detecting means for detecting a concentric circle image of the document surface, and the concentric circle image detecting means. The diameter of the concentric circles detected by the means or the distance between the intersections with a plurality of concentric circles on the string at a distance from the center is detected and stored, and distance information corresponding to the concentric circles stored in advance is stored. An image processing apparatus comprising a concentric circle image determination mechanism including a unit for determining that the detected circular image is a specific concentric circle when they match. 3. A concentric circle image detecting means for detecting a concentric circle image of a manuscript surface in an image processing apparatus for scanning a manuscript image in units of pixels by a scanner, and processing and outputting the read image, and the concentric circle image detecting means. When the pixel is detected by the means, the main scanning direction detection signal thinning means for thinning the detection pixel signal on the main scanning direction line, and the diameter of the circle from the detection signal thinned by the main scanning direction thinning means Main scanning direction predetermined distance pitch signal detecting means for detecting a circular image signal on a main scanning direction line of a considerable specific distance pitch position, main scanning direction detection signal thinning means and main scanning direction predetermined distance pitch signal detection The center position of the circle for calculating the center position of the circle assuming that both detection image signals detected by the means correspond to the both ends of the diameter of the circle, and the center position of the circle. The detected image signal information of a circle corresponding to positions on both sides of the diameter of the circle on a line in at least one of the oblique direction and the sub-scanning direction rotated by a predetermined angle from the main scanning direction is the detected image storage means. Of the diagonal direction predetermined distance pitch signal detecting means for detecting that it is in the stored image information, and when the diagonal direction predetermined distance pitch signal detecting means detects the image information, When comparing and determining that the number of pixels in a circle for counting the number of concentric circle pixels in the circle and the count value of the number of pixels in the circle are within a range of a specific number stored in advance in the storage means The image detected by the series of detection means is provided with a concentric circle image determination means for determining that the image is formed from a specific concentric circle image, and a concentric circle image determination mechanism is provided. Image processing device. 4. The image processing apparatus according to claim 1, wherein the concentric image processing determination mechanism is provided in an image output apparatus to which an image reading signal from an external scanner is input. . 5. The image processing apparatus according to claim 1, further comprising a concentric circle image determination mechanism and a magnetic detector for detecting the magnetism on the side of the original placed inside the platen cover. Image processing device. 6. The image processing apparatus according to claim 1, wherein the detection of the concentric circle image is performed a plurality of times by rotating the image by a predetermined angle.