JPH0512422A - Image processor - Google Patents

Abstract

PURPOSE:To prepare an original having a copy inhibit pattern and to inhibit the copy of the original having the copy inhibit pattern. CONSTITUTION:Read images are converted from three color image signals R, G and B to three color density signals C, M and Y by a luminance/density conversion part 102 of an image processing part 120. When the thin line pattern of the Y showing the 'copy inhibit original' overlapped in a sub operating direction at fixed intervals is inputted and the recording color of an output is Y, a pattern adding circuit 106 adds this thin line. When it is judged that there is the thin line part of the Y in the read image, a copy inhibit original judgement part 108 forcedly turns the image signal to '0' at the pattern adding circuit 106 regardless of the current recording color. Therefore, a white image, namely, white paper is outputted from a printer 107.

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 which forms an uncopyable image or prohibits copying of a specific original image.

[0002]

2. Description of the Related Art Conventionally, a document such as an official document or a secret document, which is prohibited from being copied, is provided with a stamp indicating that copying is prohibited or a display to that effect to prevent copying. In the present situation, no copying machine itself has a function of reading copy prohibition information on a document to make copying impossible.

[0003]

In the above-mentioned conventional copy inhibition method, even if a copy-prohibited seal is imprinted, copying is practically possible, and the copy-prohibited display makes the original manuscript difficult to see or displays. There is a risk that inadvertent copying will be possible even if you are conscious of. The present invention has been made in view of the above problems, and an object thereof is to provide an image processing apparatus capable of effectively prohibiting copying of a specific document.

[0004]

[Means for Solving the Problems] and

The present invention has the following structure as one means for solving the above problems. That is, according to the instruction input,
A means for adding image information having a specific pattern for designating copy prohibition of the original document to the image information of the document to be copied, and image information to which image information having the specific pattern for designating copy prohibition is added. First output means for outputting, detecting means for detecting the presence of image information having a specific pattern in the input image information of the original document, the image information having a specific pattern designating copy inhibition of the original document, and the detecting means. And a second output means for converting the input image information into a predetermined image and outputting it when a specific pattern designating prohibition of copy of the original is detected in the input image information.

[0007] Preferably, the specific pattern for instructing the copy prohibition is output by the first output means as an image having a density that is not visually readable and detectable by the detecting means. Also, preferably, the second output means is
When a specific pattern designating the copy inhibition of the original exists in the input image information at a predetermined ratio with respect to all the image information, it is output as a blank original.

More preferably, the second output means outputs, as a blank original, only an area in the input image information in which a specific pattern designating copy inhibition of the original exists. With the above-described structure, a copy-inhibited document having a copy-inhibited pattern whose density is invisible to human eyes is created, and a document having a copy-inhibited pattern is output as a white image.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. [Overall Configuration] FIG. 1 is a block diagram showing the overall configuration of a digital color copying machine (hereinafter referred to as a copying machine) according to an embodiment of the present invention. When copying is started in the copying machine shown in the figure, CCD (charge coupled device) 101 reads image signals of R, G, and B colors on the original,
Those signals are input to the image processing unit 120. In the brightness-density conversion unit 102 of the image processing unit 120, R, G, B
Image signals of three colors are C (cyan), M (magenta), Y
(Yellow) Converted to a three-color density signal. These C,
As for M and Y, an image signal of one color of the current recording color (for example, M, C, Y, K) is obtained by the processing in the masking / UCR circuit 103. Then, the obtained signal passes through the filtering 104 and the γ correction unit 105, and the pattern addition circuit 1
It is input to 06.

In this embodiment, the original is a "copy prohibited original".
A thin line of Y (yellow) is adopted as a pattern indicating that. That is, as shown in FIG. 2, the Y thin line (here, the width of 1 pixel) is thin enough to be indistinguishable by human eyes, but at a density that can be clearly detected by the CCD of the copying machine. They are overlapped at regular intervals (here, 10 pixel intervals) in the operation direction. The pattern adding circuit 106 of the copying machine includes an operation unit 11 as described later.
When the "copy prohibited document creation" signal is input from 0,
When the output recording color is Y, the thin line is added.

On the other hand, the three-color signals R, G, B read by the CCD 101 are also input to the copy-prohibited document determination section 108 at the same time, and it is determined whether the read image has the Y thin line portion, that is, the document. It is determined whether is prohibited from copying. When the copy-prohibited document determination unit 108 determines that the document is copy-prohibited, the pattern addition circuit 106 forcibly sets the image signal to 0 regardless of the current recording color. Therefore, if the "copy prohibited document" is copied by this copying machine, the printer 10
A blank sheet on which nothing is recorded is output from 7.

[Operation of Pattern Addition Circuit] FIG. 3 is a block diagram showing the configuration of the pattern addition circuit. In the figure, in the add-on address generation circuits 301 and 302,
Add-on address in main scanning direction and sub scanning direction,
That is, an address to which the copy prohibition pattern is added is generated. Since the add-on address generation circuits 301 and 302 have the same configuration, FIG. 3 shows only the configuration of the add-on address generation circuit 301.

In the add-on address generation circuit 301, the counter 303 counts the coordinate of the pixel in the main scanning direction, and the result is input to the comparators 304 and 305. The comparator 304 compares the coordinates in the main scanning direction with the start address again by the comparator 3
In 05, the coordinates in the main scanning direction are compared with the end address. The comparison result here is input to the flip-flop 306. Then, according to the Q output state of the flip-flop 306, the counter 307 adds an add-on address (st) in the main scanning direction for adding a copy prohibition pattern.
counting up (between art and end).

Similarly, the add-on address generation circuit 302 generates an add-on address in the sub-scanning direction. When the addition of the copy prohibition pattern is designated, the selector 308
Selects the address generated by the add-on address generation circuits 301 and 302. Further, in the RAM 309, information about a pattern to be added, here, a density of 10 (at 256 gradations), a thin line of 10 pixels at intervals, and the like are written in advance by the CPU 310.
Data is output according to the address selected in 08.

The add-on data signal output from the RAM 309 is compared with the image signal by the comparator 311,
The signal with the higher density level is selected by the selector 312 and becomes the output signal. That is, when the image signal is darker than the pattern to be added, the image signal is output as it is,
If the image signal has a lighter color, a pattern signal is output and added.

When the copy-prohibited document determination unit 108 described below determines that the image signal read by the copying machine has a "copy-prohibited pattern", the predetermined determination signal is a logical "1". Then, the result is input to the CPU 310. Then, the data in the RAM 309 is "00".
Can be rewritten as At the same time, the determination signal is also input to the AND gate 313, so that the add-on data from the RAM, that is, "0", is forced regardless of the density of the image signal.
0 ”is selected and output. As a result, the image signal to be output can be set to 0 (white image output) for the copy prohibited document.

[Copy Prohibition Original Judgment Section] FIG. 4 is a block diagram showing the structure of the copy prohibition original judgment section 108.
As shown in FIG.
Line drawing determination units 401 to 403 corresponding to G and B colors, a decoder 404, comparators 405 and 407, a counter 4
It is composed of 06.

The line drawing determination units 401 to 403 determine whether or not the image is a line drawing for each of the three color signals R, G, and B by the method described later, and only the line image determination unit 403 determines the line drawing, that is, B. When it is determined that only the signal is a line drawing, the output Y _{1 of the} decoder 404 becomes logical 1. This is a line drawing of Y added as a copy prohibition pattern,
This is a process for distinguishing a normal image, that is, a line drawing in which three color signals are mixed. In this way, the "yellow line" is detected.

At the same time, the B signal (which best represents yellow)
And a brightness level signal set to a constant value (here, 240 of 256 gradations, for example).
Compare with 05. Then, the logic 1 is output from the comparator 405 only when the level of the B signal is higher than the set value, that is, when the Y density is low. Further, the AND gate 408 calculates the logical product of the detection signal of the "yellow line" and the output of the comparator 405, and outputs the "light yellow line" signal.

The counter 406 counts the number of pixels for which the "light yellow line" signal is output for each recording color, and creates a cycle for every 16 lines. This counter 40
The output signal of No. 6 is compared with a designated threshold value, for example, the number of pixels of 16 lines × 1/12 by the comparator 407. When the “light yellow line” signal becomes larger than the threshold value, the “copy prohibition signal” is output. Is output.

Next, the principle of line drawing determination in the line drawing determination units 401 to 403 will be described. In the pixel group shown in FIG. 5, the luminance signal of the pixel of interest (pixel located at the center) is a,
When the luminance signals of the peripheral pixels are b to j as shown in the figure, first, of the three pixels adjacent vertically, horizontally, and diagonally, the image signals of the two pixels at both ends excluding the central pixel are added. That is,
A0 = b + c, A1 = d + e, A2 = f + g, A3 = h
Calculate + i. The larger this value, the greater the possibility that the images are continuous in that direction.

Next, the one having the maximum value among the four added values A0, A1, A2, and A3 obtained vertically, horizontally, and diagonally,
Take the difference from the one with the smallest value. If this value is small, it is determined that there is no difference in the directionality of the image and it is a "plane",
On the contrary, if this difference is large, it is considered that pixels are continuous in only one direction, that is, a line drawing exists in that direction. Then, by comparing this difference with the set threshold,
Obtain the "line drawing signal".

As described above, according to this embodiment,
By adding pattern information to the document image information that indicates copy prohibition and invisible display output, you can easily create a copy-prohibited document without damaging the original document and read the document image information When the copy prohibition pattern is detected, the original image can be displayed and output as a white image.

In the above-described embodiment, the copy inhibition document determination unit determines the line drawing for each recording color and outputs the white image. However, the copy inhibition signal is sent to the CPU to detect the copy inhibition pattern once. Then, it may be controlled to stop the subsequent sequence. Further, in the above-described embodiment, the full-color copy is described as an example. However, even in a monochrome copying machine, the Y toner is mounted, and the add-on pattern is added before scanning the actual image, whereby the copy prohibition pattern is added. You can create an original.

The present invention can be variously modified without departing from the spirit thereof. Therefore, modifications of the present invention will be described below. <Modification 1> A modification of the pattern adding circuit in the above embodiment will be described. FIG. 6 is a block diagram showing a modification of the pattern adding circuit. Here, the operation unit 110
Sends an add-on signal which is an instruction to add a copy prohibition pattern before the start of copying.

In the CCD 101, when reading a document, M
In order to obtain (magenta), C (cyan), Y (yellow), and K (black) color signals, the document is scanned four times in the order of M, C, Y, and K. That is, the R, G, and B color image signals read in the first scan are input to the image processing unit 120, where they are converted into M density signals, and then the printer 107.
Sent to. Thereafter, conversion into C, Y, and K density signals is performed in order to obtain a full-color image.

On the other hand, an image pattern (copy prohibition pattern) indicating that copying is impossible is previously stored in the RAM 152.
It is stored in the address corresponding to the address generated by the add-on address generator 155. Further, "0" is stored as data in the other addresses. Then, when generating the images of the first color (M) and the second color (C), the address for accessing the RAM 152 is switched by the selector 151 to that generated by the CPU 109, and the data “0” is read from the RAM 152. Occurs. That is, for M and C, the image signal of the document is output to the printer as it is.

At the time of generating the image of the third color (Y), the selector 108 switches the address signal to the RAM 152 to the address from the add-on address generator 155, and the RAM 152 generates add-on data which is a copy inhibition pattern. . Then, the OR gate 153 takes the logical sum of the image signal of the document from the image processing unit 120 and the add-on data, and outputs the result to the printer 107. Also for the fourth color (K), the image signal of the original is output to the printer as it is, as in M and C.
By doing so, the copy inhibition pattern can be easily added on without comparing the density of the image signal of the document with the additional pattern.

<Modification 2> In the above-described embodiment or modification 1, a copy prohibition pattern is added when copying a prepared document, and the pattern added is used as a copy-inhibited document. Therefore, since the original manuscript can still be copied, it is discarded.

Therefore, a case where the original document is stored in a storage device such as a floppy disk or a host computer will be described. That is, as shown in FIG. 7, when the add-on signal is output from the host computer 302 to the CPU 109, the address signal to the RAM 152 is generated by the selector 151 at the time of Y image generation, as in the first modification. The address is switched from the device 155. As a result, the copy prohibition pattern stored in the RAM 152 is added to the image input from the host computer 302 to the pattern adding circuit 106. By doing so, the copy prohibition pattern can be directly added at the time of image output, and the copy prohibition manuscript can be created without the need for a single copy operation.

<Modification 3> In the above embodiment, the image on the original is read for several lines from the start of reading, and it is determined that copying of the entire image is prohibited. Therefore,
In this modified example, a process in the case where a copy inhibition area and a copy permission area are present in one document will be described. Figure 8
FIG. 16 is a block diagram showing a configuration of a copy-prohibited document determination unit according to the third modification. In the figure, the same components as those of the copy-prohibited document determination unit shown in FIG. 4 are designated by the same reference numerals, and a detailed description thereof will be omitted here.

In the above embodiment, the area of 16 lines was searched when the copy prohibited document was judged. However, in this modified example, one line is divided into 256 pixels, and the threshold signal is 2.
It is set to about 56 pixels × 1/12 and it is determined whether or not the range is copy prohibited. That is, VCLK is 1
Input to the counter 601 via the / 16 frequency divider 603,
Counter output of counter 601 and its carrier output are D
The logical product is obtained with the output obtained by inputting to the F / F 602. Then, the signal obtained by the logical product is counted by the counter 4
By using it as a clear input of 06, the copy prohibition signal is reset every 256 pixels.

If it is determined that the section is not the copy prohibition section, the copy prohibition signal is not output, so that the normal copy operation is performed in that area. In this case, the image signal to be printed out is delayed by 256 pixels from the signal sent to the determination circuit for the copy-inhibited document.
As described above, according to this modification, when the copy prohibited area and the copy permitted area are mixed in one original, only the prohibited area can be output as a white image.

As described above, according to the above-described embodiment or the modification of the embodiment, a pattern for instructing the copy prohibition of the manuscript, which is displayed and output at a density that is unreadable by humans, is included in the image information. By adding it, a copy-protected document can be easily created without damaging the document. If there is a copy prohibition pattern in the read original image information,
By prohibiting copying by displaying and outputting a part or all of the original image as a white image.

In the above embodiment, the printer is not limited to a specific printer, and a laser beam printer, an ink jet printer, a thermal transfer printer, etc. may be used. The color of the copy prohibition pattern to be added is not limited to yellow, and may be another color that is inconspicuous to human eyes, such as yellow green, or another color that is inconspicuous to human eyes. The concentration may be about the same. If it is determined that the original should not be copied, for example, a black pattern is added on, a black solid image is formed, or the operation of the apparatus itself is stopped (for example,
Copying may be prohibited by turning off the power.

[0034]

As described above, according to the present invention,
This has the effect of effectively prohibiting copying of a specific document.

[Brief description of drawings]

FIG. 1 is a block diagram showing the overall configuration of a digital color copying machine according to an embodiment of the present invention,

FIG. 2 is an example of a pattern showing a copy-protected document,

FIG. 3 is a block diagram showing the configuration of a pattern adding circuit of the digital color copying machine according to the embodiment.

FIG. 4 is a block diagram showing a configuration of a copy-prohibited document determination unit of the digital color copying machine according to the embodiment.

FIG. 5 is a diagram for explaining the principle of line drawing determination in a line drawing determination unit;

FIG. 6 is a block diagram showing a modification of the pattern adding circuit;

FIG. 7 is a diagram for explaining a process of adding a pattern to a document image stored in a storage device or the like;

FIG. 8 is a block diagram showing a configuration of a modified example of a copy-prohibited document determination unit.

[Explanation of symbols]

101 CCD 102 brightness-density converter 103 printer 104 Filtering 105 γ converter 106 pattern addition circuit 107 Printer 108 Copy Prohibition Original Judgment Section 109 CPU 301, 302 add-on address generation circuit 303 counter 304,305 Comparator

Claims (5)

[Claims] 1. A means for adding image information having a specific pattern for designating copy prohibition of the document to be copied in accordance with an instruction input, and a specific pattern for designating copy prohibition. First output means for outputting image information to which image information is added, and detection of presence of image information having a specific pattern in the input image information of the original document for designating copy inhibition of the original document to be copied And a second output means for converting the input image information into a predetermined image and outputting the same when the detection means detects a specific pattern designating prohibition of copying of a document in the input image information. An image processing apparatus comprising: 2. A specific pattern for instructing copy prohibition is
The image processing apparatus according to claim 1, wherein the image is output by the first output unit as an image having a density that is visually unreadable and that can be detected by the detection unit. 3. The second output means outputs as a blank document when a specific pattern designating document copy inhibition is present in the input image information at a predetermined ratio with respect to all image information. The image processing device according to claim 1. 4. The second output means outputs, as a blank document, only an area in the input image information where a specific pattern designating copy inhibition of the document exists. Image processing device. 5. An image processing apparatus comprising: means for creating an original document subjected to a predetermined process for inhibiting copying; and means for inhibiting copying of the original document subjected to the predetermined process. .