JP4785393B2 - Image processing apparatus, image processing system, image processing method, and image processing program - Google Patents

Description

The present invention relates to an image processing apparatus, an image processing system, an image processing method, and an image processing program capable of easily verifying tampering of a printed material and easily verifying illegal copying of the printed material.

  Conventionally, when a latent image such as a character, symbol, or pattern is printed in a single color using offset printing or the like in a pattern consisting of halftone dots or lines on a printed material, the printed material may be counterfeit. A printing technique that can be discriminated at a glance is known (see Japanese Patent No. 2695523: “Printed Material Suitable for Copying Prevention”).

Conventionally, a technique for determining falsification of digital image data using a digital watermark is also known (see Japanese Patent Application Laid-Open No. 11-98344: “Illegal falsification determination method and apparatus for digital image using digital watermark”).
Japanese Patent No. 2695523 JP-A-11-98344

  However, with the technology of Japanese Patent No. 2695523, it can be determined at a glance that it is a copy, but it does not prevent forgery, and it cannot be verified when a part of the printed material is tampered. In the technique disclosed in Japanese Patent Laid-Open No. 11-98344, the target data is only digital image data, and it cannot be applied to printed matter.

An object of the present invention, a print of tampering easily be verified, and to provide an image processing apparatus which can be easily verified unauthorized copy of the printed matter, the image processing system, an image processing method and image processing program.

The image processing apparatus of the present invention is an image processing apparatus comprising means for superimposing a tampering verification ground pattern and an illegal copy verification ground pattern on a protection target image to be protected from tampering and unauthorized copying, and the illegal copy verification ground pattern crest, the dot size is not printed when printing by a predetermined copying means an image of the printed matter read by the predetermined image reading means, formed having the predetermined contour, the tampered verification background pattern, the A dot of a size to be printed when an image of a printed matter read by a predetermined image reading unit is printed by the predetermined copying unit is formed in a portion to be verified for tampering. The number of dots in the area is determined to be an even number or an odd number by a random number.

In the image processing apparatus of the present invention, the occupancy ratios of the dots of the illegal copy verification ground pattern and the tampering verification ground pattern are constant values or the same regardless of the location of the illegal copy verification ground pattern or the tampering verification ground pattern, respectively. A value close to a certain value can be set. As a result, even if the dot shape is different for each region, the densities can be matched by the arrangement density of the dots. Therefore, to look almost uniformly during printing, visually by that can not be able to identify like the string before copying.

An image processing system according to the present invention includes the above-described image processing apparatus, an image reading unit that reads an image displayed on a printed matter, and a falsification verification ground pattern included in the image read by the image reading unit. a revision verification means for verifying, characterized in that it has an image output apparatus, which includes a copy unit that prints at a predetermined resolution of the image read by the image reading means.

The image processing method of the present invention is an image processing method for executing a procedure for superimposing a tamper-proof copy-forgery-inhibited pattern and an illegal copy-checked copy-forgery-inhibited pattern on a protection target image to be protected from falsification and illegal copy, The copy-forgery-inhibited pattern is formed so as to have a predetermined outline by dots of a size that is not printed when an image of a printed matter read by a predetermined image reading unit is printed by a predetermined copying unit . When the image of the printed material read by the predetermined image reading unit is printed by the predetermined copying unit , dots of a size to be printed are formed in a portion to be verified for tampering, Each time, the number of dots in the area is set to an even number or an odd number by a random number.

In the image processing method of the present invention, the occupancy ratio of the dots of the illegal copy verification ground pattern and the tampering verification ground pattern is a constant value or the value regardless of the location of the unauthorized copy verification ground pattern or the tampering verification ground pattern, respectively. Ru can be set to a value close to a constant value.

The image processing program that can be executed by the computer of the present invention can execute the image processing method described above .

  According to the present invention, it is verified whether an image printed on a normal paper with a normal laser printer or an ink jet printer has been falsified and whether it is a copy without using a special material or ink. Can do. Therefore, it is possible to provide a printed matter that can verify falsification and copying at a very low cost.

  FIG. 1 is a configuration diagram of an image processing system of the present invention and an image processing apparatus of the present invention. In FIG. 1, an image processing system 100 includes an image processing device 1, an external device 2, and an image output device 3.

  The image processing apparatus 1 includes a falsification and illegal copy verification dot image generation unit 11, an image superimposing unit 12, and a printing unit 13.

  As described later, the falsification and illegal copy verification dot image generation unit 11 forms a falsification verification ground pattern and an illegal copy verification ground pattern in accordance with the protection target image. In the present invention, these local patterns are composed of a plurality of types of dots. Further, in this embodiment, for the sake of convenience of explanation, it is assumed that the tampering verification tint block and the illegal copy verification tint block are composed of two types of dots (large dots and small dots) having different sizes. In the present embodiment, small dots are dots that are not copied by the copying means 34 (“copier” of the present invention) described later of the image output apparatus 3, and large dots are dots that are copied by the copying means 34.

  The falsification and illegal copy verification dot image generation means 11 generates a falsification and illegal copy verification dot image corresponding to the protection target image GF0 shown in FIG.

  In the present embodiment, the falsification and illegal copy verification dot image includes an area composed of small dots formed regardless of the character arrangement of the protection target image GF0 (an area formed by the illegal copy verification ground pattern) and , And an area composed of other large dots (tamper verification background pattern area).

  The illegal copy verification copy-forgery-inhibited pattern area (area composed of small dots) has, for example, the outlines of characters and character strings such as “prohibited”, “copy prohibited”, and “VOID” or graphic outlines such as entry prohibition marks. Formed. These characters, character strings, or figures can be registered in the image processing apparatus 1 in advance, or can be acquired as setting information ST from the external apparatus 2 (for example, a computer) as shown in FIG.

  The alteration verification tint block area includes a portion to be verified for alteration. In the present embodiment, large dots are formed in the tamper-proof copy-forgery-inhibited pattern area in portions that do not belong to either the tamper-verification target portion or the illegal copy verification copy-forgery-inhibited pattern region. It is difficult for a person who intends to specify a part to be verified for falsification.

  The protection target image GF0 may be an image stored in advance in a predetermined memory in the image processing apparatus 1, or may be an image read from a scanner (not shown) provided in the external apparatus 2, for example. Alternatively, it may be an image read from a storage device (memory, magnetic recording medium, etc.) of the external device 2. Details of the falsification and illegal copy verification dot image generation processing by the falsification and illegal copy verification dot image generation means 11 will be described later.

  The image superimposing unit 12 can generate a superimposed image in which the falsification and illegal copy verification dot image generated by the falsification and illegal copy verification dot image generation unit 11 and the protection target image GF0 are superimposed.

  As the printing unit 13, a printer mechanism such as a laser printer, an ink jet printer, a thermal printer, a sublimation printer, or the like can be used. The superimposed image generated by the image superimposing unit 12 can be printed and output as a printed matter PD0.

  The external device 2 can be a computer as described above.

  The image output apparatus 3 includes an image reading unit 31, a tampering verification unit 32, a display unit 33, and a copying unit 34. The image reading unit 31 can read an image (verification target image) displayed on the verification target document PD1. The falsification verification unit 32 can verify the falsification by analyzing the falsification verification ground pattern included in the image read by the image reading unit 31. Details of the verification process by the falsification verification unit 32 will be described later.

  The display means 33 can display and output the verification result by the falsification verification means 32. The copying unit 34 can print the image read by the image reading unit 31 with a predetermined resolution.

  The operation of the image processing apparatus 1 will be described with reference to the flowchart of FIG.

  First, when there is an instruction to print a document (START), the image processing apparatus 1 prints the image displayed on the document (“print instruction document”) as an image that can verify tampering and illegal copying. Is determined (S101). When the instruction is not made ("NO" in S101), printing is performed without forming a background pattern (dot pattern) (S110). When the image is printed, that is, when the image related to the print instruction document is to be protected (“YES” in S101), outline data of a predetermined character string (“VOID” in this example) is generated for falsification verification. Define two areas, an area (area that is reproduced when copied) and an illegal copy verification area (area that is not reproduced when copied: the above character string part), and an illegal copy verification area. Temporarily stored in a predetermined storage unit as the binary data of small dots (S102). FIG. 3B shows a falsification verification area A1 and an illegal copy verification area A2. The illegal copy verification area A2 is filled with small dots.

  Next, as shown in FIG. 4, the entire image (protection target image) of the print instruction document is divided into rectangular areas (indicated by thick solid lines), and lattice points (indicated by intersections of thin solid lines) are defined inside. (S103). Then, one rectangular area is extracted from the divided rectangular areas (S104), one unprocessed grid point is extracted from the rectangular area (S105), and it is determined whether or not to generate a dot at the grid point (S105). S106).

  In this determination, if there is a character / graphic or illegal copy verification area at or around the grid point (in the case where a large dot overlaps the character / graphic, that is, the surrounding 4 If there is a character in the block), it is determined that no dot is to be generated (“YES” in S106), the process proceeds to S108, and there must be a character / graphic or illegal copy verification area at or around the grid point. If “NO” in S106, a large dot is assigned to the grid point (S107), and the process proceeds to S108. FIG. 5A shows a state in which dots are allocated in the rectangular area.

  In S108, it is determined whether or not processing has been completed for all lattice points in the rectangular area of interest. If processing has been completed, the processing returns to S105. Thereafter, the processing from S105 to S108 is repeated in the same manner, and when the processing is completed for all grid points of the rectangular region of interest (“YES” in S108), the number of dots in the rectangular region of interest is an even number. Or it adjusts so that it may become an odd number (S109). That is, an even odd number “1” or “0” is assigned to each rectangular area by a random number. Here, the number of dots in the rectangular area is an even number when “0” and an odd number when “1”. It is stipulated in.

  For example, even odd numbers “0”, “1”, “1”, “0”, “0” are assigned from the left in the rectangular area shown in FIG. Since the number of dots in the first, second, and fourth rectangular areas from the left is originally 14 (even), 13 (odd), and 8 (even), there is no need to adjust the number of dots for these areas. . On the other hand, since the number of dots in the third and fifth areas from the left is originally 10 (even) and 11 (odd), one dot is deleted and the number of dots is 9 (odd) and 10 (even). It is adjusted to.

  Next, it is determined whether or not the above adjustment processing has been performed for all rectangular areas. If there is an unprocessed rectangular area, the process returns to S103 and the processes of S103 to S108 are repeated (S110). When processing has been completed for all rectangular areas, the dots (large dots) adjusted for each rectangular area and the small dots embedded in the illegal copy verification area A2 representing the character string are superimposed on the document image as a background pattern ( (S111), the superimposed image is printed (S112), and the process is terminated. FIG. 6 shows the print result (printed material PD0) of the superimposed image. In FIG. 6, for the convenience of explanation, the dots in the alteration verification area A1 are shown without adjustment. In this case, the alteration verification tint block area includes a portion to be verified for alteration. In the present embodiment, large dots are formed in the tamper-proof copy-forgery-inhibited pattern area in portions that do not belong to either the tamper-verification target portion or the illegal copy verification copy-forgery-inhibited pattern region. It is difficult for a person who intends to specify a part to be verified for falsification.

  In the above example, the number of dots in the rectangular area is determined by only the alteration verification dots (large dots), but a plurality of small dots can be handled as one large dot. For example, when the area of a large dot is nine times that of a small dot, nine small dots can be handled as one large dot according to the area ratio. Also, one small dot can be handled in the same way as one large dot.

  The operation of the image output apparatus 3 will be described with reference to the flowchart of FIG. First, the verification target document PD1 is read by the scanner, and the verification target image is captured (S201). This verification target image may not have been tampered with or may have been tampered with.

  As in printing, the verification target image is divided into rectangular areas, one unprocessed rectangular area is taken out (S203), and a predetermined dot count counter is initialized to 0 (S204). Next, the dot number counter is initialized with 0 for the rectangular area of interest.

  Thereafter, one unprocessed grid point in the target rectangular area is extracted (S205), the presence or absence of a dot is determined (S206), and when it is determined that there is a dot, the counter is incremented by 1 ( S207). When this counter is incremented and when it is determined that there are no dots in S206, it is determined whether or not the processing of the intersections of all the grids in the rectangular area of interest has been completed. If not, the processing returns to S205. , S206 to S208 are repeated. As shown in the enlarged view of FIG. 8C, when a character and a large dot overlap (the overlapping portion is indicated by a symbol Q), the large dot is not counted by the counter.

  When the processing for all grid points is completed in S208, it is determined whether the even odd number of dots in the rectangular area matches the even odd number (random number “0” or “1”) at the time of printing ( S209) If they match (“YES” in S209), it is determined that there is no falsification for the rectangular area of interest (S210), and if they do not match (“NO” of S209), the rectangular area of interest is determined. It is determined that there has been tampering (S211).

For example, it is assumed that “1” of “¥ 1,000” in the printed matter PD0 in FIG. 6 has been altered to “4”.

  Then, it is determined whether or not the processing has been completed for all the rectangular areas (S212). If not, the processing is returned to S203, and the processing of S203 to 212 is repeated. If it is determined in S212 that the processing has been completed for all the rectangular areas, the verification result is displayed on the display means (display) as shown in FIG. 9 (S213), and the processing is terminated. In FIG. 9, a message indicating that alteration has occurred and a verification target document PD1 are displayed in a window.

  As shown in FIG. 8A, the number of dots in the “¥ 1,000” portion of the print PD0 that has not been tampered with is “14”, “13”, “9”, “8”, “10”. The even odd values are “0”, “1”, “1”, “0”, “0”. In contrast, the number of dots in the “¥ 4,000” portion of the verification target image is “14”, “12”, “9”, “8”, “10”, and the even odd number is “0”. , “0”, “1”, “0”, “0”. Therefore, in this case, as shown in FIG. 8B, it can be seen that the second rectangular area from the left has been tampered with.

  In the examples of FIGS. 8A and 8B, the case where the size of the rectangular area is larger than the size of the character has been described for convenience of explanation. However, the accuracy of tampering verification can be reduced by reducing the size of the rectangular area. Can be high. 10A and 10B, the size of the rectangular region is (1 and 4) times that in FIGS. 8A and 8B. FIG. 10A shows the upper and lower stages of the “1” portion of “¥ 1,000” of the printed material PD0 that has not been tampered with. In the upper stage, the number of dots is “12”, “15”, and the even odd number is “0” and “1”. In the lower row, the number of dots is “14” and “13”, and the even odd values are “0” and “1”. On the other hand, FIG. 10B shows the upper and lower stages of the “4” portion of “¥ 4,000” of the verification target document PD1 that has been tampered with. In the upper stage, the number of dots is “14”, “ 15 ”, the even odd values are“ 0 ”,“ 1 ”, and in the lower row, the dot numbers are“ 11 ”,“ 13 ”, and the even odd values are“ 1 ”,“ 1 ”. Therefore, since the even odd values of the lower part of the “1” portion of “¥ 1,000” of the printed matter PD0 and the lower portion of the “4” portion of “¥ 4,000” of the verification target document PD1 are different, the tampering has been performed. I understand that.

  FIG. 11A shows a copy result (copy printed matter PD2) by the copy means 34. FIG. FIG. 11B is a partially enlarged view of the copy printed matter PD2. In the example of FIG. 11A, the unauthorized copy verification area “VOID” of the verification target document PD1 (see FIG. 9) that has been tampered with is displayed in white. It should be noted that the verification target document (printed material PD0: see FIG. 6) that has not been tampered with is also displayed with the illegal copy verification area “VOID” blank when copied.

  FIG. 12 shows a flowchart in the case where a tampering verification area is defined only in a specific area as shown in FIG. The processes of S301 to S304 and S305 to S312 in the flowchart of FIG. 12 are the same as the processes of S101 to S104 and S105 to S112 of the flowchart shown in FIG. In FIG. 12, immediately after the processing of S304, it is determined whether or not the focused rectangular area is a falsification verification area (S304 ′). If it is not the falsification verification area, a predetermined type of dot is set at each grid point. Is assigned (S304 ″), and if it is a falsification verification area, the process proceeds to a process of extracting one unprocessed grid point (S305). In S304 ″, the size of the allocated dot may be the same size as the large dot allocated to the tampering verification area or is reproduced when copied by the copying unit 34 shown in FIG. If it is a size, it may be a size different from the large dot.

  In the process shown in FIG. 12, since the verification area is limited, it is possible to more efficiently verify whether or not tampering has occurred.

In the present invention, when the image to be protected GF0 is drawn with black or gray characters / figures on a white background, by making the colors easy to see such as magenta and cyan as a plurality of types of dots,
(1) It becomes easy to recognize characters and the like originally described in the protection target image GF0,
(2) The lower limit of the size of illegal duplication verification dots (small dots) can be reduced, and when duplicating and duplicating printed dots are copied by a copier, Even if the dot is relatively large, it can be erased,
(3) In the processing by the tampering verification means, it becomes easy to distinguish characters, figures, etc. originally drawn on the protection target image GF0 from dots, and high-precision counting by a counter can be performed.

1 is a configuration diagram of an image processing system of the present invention and an image apparatus of the present invention. 3 is a flowchart of FIG. 2 for explaining the operation of the image processing apparatus of FIG. (A) is a diagram showing a protection target image to be processed by the image processing apparatus of FIG. 1, and (B) is a diagram showing a falsification verification area and an illegal copy verification area. It is explanatory drawing which shows a mode that the whole protection object image was divided | segmented into the rectangular area, and the lattice point was defined inside. (A) is a figure which shows the state which allocated the dot in the rectangular area defined in the protection object image, (B) is a figure which shows the state which adjusted the number of dots allocated in (A) according to the even odd number value. is there. It is a figure which shows the printing result of a superimposition image. 2 is a flowchart illustrating an operation of the image output apparatus in FIG. 1. (A) is a diagram showing the number of dots and even odd values in a rectangular area of a printed material that has not been tampered with, (B) is a chart showing the number of dots and even odd values in a rectangular area of a verification target image, and (C) is an enlargement of the tampered area. FIG. It is a figure which shows a mode that the message which shows having been falsified, and the verification object document are displayed on the window. It is a figure which shows the case where the magnitude | size of a rectangular area is made small, (A) is a figure which shows the rectangular area before falsification, (B) is a figure which shows the rectangular area after falsification. (A) is a figure which shows the copy result by a copy means, (B) is the elements on larger scale of a copy printed matter. It is a flowchart in the case where a falsification verification area is defined only in a specific area. It is a figure which shows the verification object image in which the alteration verification area | region is defined only in the specific area | region.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image processing apparatus 2 External apparatus 3 Image output apparatus 11 Tampering and illegal copy verification dot image generation means 12 Image superimposing means 13 Printing means 31 Image reading means 32 Tampering verification means 33 Display means 34 Copying means 100 Image processing system GF0 Protection target Image PD0 Printed matter PD1 Document to be verified PD2 Copy printed matter

Claims (6)

An image processing apparatus comprising means for superimposing a falsification verification copy-forgery-inhibited pattern and an illegal copy verification copy-forgery-inhibited pattern on a protection target image to be protected from falsification and illegal copy,
The illegal copy verification copy-forgery-inhibited pattern is formed so as to have a predetermined outline by dots of a size that is not printed when an image of a printed matter read by a predetermined image reading unit is printed by a predetermined copying unit ,
As the tamper-proof copy-forgery-inhibited pattern, dots of a size to be printed when an image of a printed matter read by the predetermined image reading unit is printed by the predetermined copying unit are formed in a portion to be verified for tampering .
An image processing apparatus for determining whether the number of dots in an area is an even number or an odd number for each area of the tamper-proof copy-forgery-inhibited pattern.   The occupancy ratio of the dots of the illegal copy verification copy-forgery-inhibited pattern and the tamper-proof verification copy-forgery-inhibited pattern is a constant value or a value close to the constant value regardless of the location of the illegal copy verification copy-forgery-inhibited pattern or the falsification verification copy-forgery-inhibited pattern, respectively. The image processing apparatus according to claim 1. The image processing apparatus according to claim 1 or 2 , and
Image reading means for reading an image displayed on the printed matter;
A tamper verification unit that analyzes a tamper pattern for tampering included in an image read by the image reading unit to verify tampering; and a copying unit that prints the image read by the image reading unit at a predetermined resolution. Image output device,
An image processing system comprising: An image processing method for executing a procedure for superimposing a falsification verification copy-forgery-inhibited pattern and an illegal copy verification copy-forgery-inhibited pattern on a protection target image to be protected from falsification and illegal copy,
The illegal copy verification copy-forgery-inhibited pattern is formed so as to have a predetermined outline by dots of a size that is not printed when an image of a printed matter read by a predetermined image reading unit is printed by a predetermined copying unit ,
As the tamper-proof copy-forgery-inhibited pattern, dots of a size to be printed when an image of a printed matter read by the predetermined image reading unit is printed by the predetermined copying unit are formed in a portion to be verified for tampering .
An image processing method for determining whether the number of dots in an area is an even number or an odd number for each area of the tampering verification background pattern. The occupancy ratio of the dots of the illegal copy verification copy-forgery-inhibited pattern and the tamper-proof verification copy-forgery-inhibited pattern is a constant value or a value close to the fixed value, regardless of the location of the illegal copy verification copy-forgery-inhibited pattern or the falsification verification copy-forgery-inhibited pattern. The image processing method according to claim 4 . An image processing program for causing a computer to execute the image processing method according to claim 4 or 5 .