TW201417034A - Anti-counterfeiting watermark and manufacturing method therefor - Google Patents

Abstract

An anti-counterfeiting watermark and a manufacturing method therefor are provided. The manufacturing method includes steps of: providing an individual pattern; using a concentration calibration table to select the concentration of amplitude modulation (AM) dots of at least one pattern area and frequency modulation (FM) dots of at least one background area to control that the gray scale value of the FM dots is smaller that of the AM dots before being duplicated and that the gray scale value of the FM dots is greater than that of the AM dots after being duplicated, in order to determine parameter setting of digital halftone screening; and printing the individual pattern onto a surface of an original document according to the parameter setting of the digital halftone screening, so as to form a watermark with a function of reversing the individual pattern to a negative contrast after being duplicated.

Description

Anti-counterfeit watermark image and manufacturing method thereof

The invention relates to an anti-counterfeiting watermark image and a manufacturing method thereof, in particular to a digital halftoning method for making a watermark to make the original image reversed from positive image after copying or scanning output. It is a negative image to determine whether it is an unauthorized copy of the watermark image and its manufacturing method.

With the advancement of information technology, the diversity of information carriers and the technology of copying are also rapidly developing. For example, photocopiers, scanners, etc. have the function of copying files quickly and accurately, and because the devices are constantly updated, the people who are interested can be in the shortest In the absence of authorization, copies of books, documents and even artistic creations are made, and illegal counterfeiters can forge high-quality reproductions with these devices. However, these replicas can't make the average person distinguish the authenticity in the first time, which causes the confusion between the original and the replica, and finally the intellectual property rights are severely hit. Therefore, many anti-counterfeiting mechanisms have been developed, such as gravure printing, paper watermarking, Tiny words, window-type security lines, infrared inks, etc., however, these anti-counterfeiting materials are costly and require special equipment. Therefore, how to provide low-cost and new anti-counterfeiting technology without special equipment is gradually receiving attention.

Furthermore, the existing file shading image encryption technology using a small structure includes different network lines of different thicknesses, different size dots, and different A pattern or a small word to form a tiny printed structure. At present, there are several references that can be used as comprehensive reference for comparison of advantages and disadvantages: (1) visual invisibility of digital watermark hiding; (2) effect of digital watermarking after file shading is copied and reproduced; And (3), the convenience and diversity of watermark detection.

The above-mentioned micro-printing structure such as a dot, a network cable, a special pattern or a small word is used as a watermark anti-counterfeiting technology for a security document. This method does not require the use of special printed materials or methods, and can reduce the manufacturing cost. Using a micro-printing structure that is more detectable than the human eye vision system, digital watermarks and the like can be hidden in different sizes of dot structures, and the technique can be used to hide the printed matter of the message or the pattern, and the human eye cannot distinguish at normal reading distance. The difference in these fine structures. However, after the copiers sample the difference in the fine structure of the dots of different sizes, the originally hidden message or pattern emerges, which can be used as an anti-counterfeiting mechanism for preventing the use of a copying machine to make forged or unauthorized copies.

These watermarking techniques used on paper usually use text or graphics as hidden messages and appear after copying, thereby achieving the effect of declaring copyright. At the same time, the way to display image watermark after copying is mostly to present a text message such as "COPY" or "VOID" after copying the document, thereby declaring the copyright. At present, the physical watermarking is not used to achieve the black and white inversion of the image, and if the physical watermark is to achieve this effect, expensive ink materials, printed materials and complicated printing processes are required.

Therefore, it is necessary to provide an anti-counterfeit watermark image and a manufacturing method thereof to solve the problems of the conventional technology.

The main object of the present invention is to provide an anti-counterfeit watermark image and a manufacturing method thereof, which pre-select various image regions (frequency modulation dots) and backgrounds in a personalized image by using a frequency modulation dot and a amplitude modulation dot of a concentration matching guide. The concentration value of the area (amplitude modulation dot) and the design of the watermark image by digital halftone network technology, and then the output is printed on an original document, and the watermark image is visually visible on the original document, The frequency adjustment dot of the image area and the density value of the amplitude modulation dot of each background area have been pre-designed to make the scanning component of the photocopying machine have different copying and frequency modulation dot copying ability when the original document is copied or scanned, thereby making a photocopying The watermark image on the copied document is changed from a positive image to a negative image, so that the watermark image on the document can be judged as a positive or negative image to know whether an unknown document is an original or an unauthorized copy. . Thereby, the present invention can provide personalized declaration copyright protection functions on commercial documents such as security documents or Wenchuang added products, so as to deter the effect of unauthorized copying, and can be applied to design customized personal characteristics. commodity.

To achieve the above objective, an embodiment of the present invention provides an anti-counterfeit watermark image and a method for fabricating the same, including the steps of: providing a humanized image; and selecting at least one image in the personalized image by using a concentration correction guide table. The individual density of the frequency modulation network point of the area and the amplitude modulation network point of at least one background area, so that the gray level value of the frequency modulation network point is lower than the tone before copying The grayscale value of the dot network point, and after copying, the grayscale value of the frequency modulation dot is higher than the grayscale value of the amplitude modulation dot, thereby determining the parameter setting of the digital halftone network; and the halftone through the digital halftone The parameter setting prints the personalized image to the surface of an original document to form a watermark pattern having a black and white inversion effect after copying.

In an embodiment of the invention, in the step of selecting the concentration of the amplitude modulation dots and the frequency modulation dots, the amplitude modulation dot is formed using a dot matrix method, and the frequency modulation dot is formed using an error diffusion method.

In an embodiment of the present invention, the concentration correction guide includes a plurality of different concentration correction units, and each of the concentration correction units includes a frequency modulation dot area and an amplitude modulation network point. The area, and the FM network area is located at a central location of the AM screen area.

In an embodiment of the present invention, in the step of selecting the concentration of the amplitude modulation network point and the frequency modulation network point, taking the amplitude modulation network point AM 2/64 as an example, the value of the background area is used, and the frequency modulation network point FM 210- 223 is taken as an example to determine the value of the image area.

In an embodiment of the invention, the personalized image is a large, full body, half-length or pictorial image containing at least a facial or expression feature.

In an embodiment of the present invention, after the step of printing and outputting the watermark image, the method further comprises: copying or scanning the original document, so that the watermark image on one of the copied documents is copied from the positive image to the negative image. To show The copy file is shown as an unauthorized copy.

In an embodiment of the present invention, after the step of outputting the watermark image, the method further includes: providing a file to be recognized, and determining that the watermark image on the file to be recognized is a positive image or a negative image, if If the image is to be recognized, the file to be recognized is an original image; if it is a negative image, the file to be recognized is determined to be an unauthorized copy.

In another aspect, an embodiment of the present invention further provides an anti-counterfeit watermark image formed on a surface of an original document, the anti-forgery watermark image comprising: at least one image region, which is modulated by a frequency modulation (FM) network And the at least one background area is formed by an amplitude modulation (AM) network point, and the background area and the image area together form a shape of a humanized image; wherein the grayscale value of the FM network point and the amplitude modulation network point are set before copying The grayscale value of the frequency modulation network dot is lower than the grayscale value of the amplitude modulation network dot, and is used to cause the grayscale value of the frequency modulation network dot to be higher than the grayscale value of the amplitude modulation network dot, thereby forming a black and white inversion after copying. The watermark pattern that acts.

In an embodiment of the present invention, the amplitude modulation network point AM 2/64 is used as the value of the background area, and the frequency modulation network point FM 210-223 is used as the value of the image area.

In an embodiment of the invention, the personalized image is a large, full body, half-length or pictorial image containing at least a facial or expression feature.

The above and other objects, features and advantages of the present invention will become more <RTIgt; Furthermore, the directional terms mentioned in the present invention, such as upper, lower, top, bottom, front, rear, left, right, inner, outer, side, surrounding, central, horizontal, horizontal, vertical, longitudinal, axial, Radial, uppermost or lowermost, etc., only refer to the direction of the additional schema. Therefore, the directional terminology used is for the purpose of illustration and understanding of the invention.

The invention provides an anti-counterfeit watermark image and a manufacturing method thereof, which mainly design a personalized image on an original document by using a mixed dot digital floating watermarking technique of amplitude modulation (AM) dots and frequency modulation (FM) dots. And preliminarily performing special concentration matching of the FM network point of the at least one image area and the amplitude modulation network point of the at least one background area on the basis of a concentration correction guide, and printing the personalized image to the The original document becomes a watermark image, wherein the original document can cause the watermark image content of the copy to be black and white reversed after copying, thereby displaying copyright protection, thereby effectively deterring unauthorized copying and adding custom The creativity and fun of Huan Chuang products.

As shown in FIGS. 1A and 1B, in a preferred embodiment of the present invention, the method for manufacturing the anti-forgery watermark image mainly comprises the steps of: providing a humanized image 10; using a concentration correction guide 12 (eg The third embodiment shows that the FM network point FM of at least one image area 101 in the personalized image 10 and the amplitude modulation network point AM of at least one background area 102 are selected. The individual density is such that the gray level value of the FM frequency point FM before copying is lower than the gray level value of the AM screen point AM, and is used to cause the gray level value of the FM frequency point FM to be higher than the gray level of the AM modulation point AM after copying. a step value for determining a parameter setting of the digital halftone network; and printing the personalized image 10 to a surface of an original document 20 according to the parameter setting of the digital halftone network to form a black and white after copying The floating watermark pattern 21 is reversed (as shown in Fig. 8). The invention will be described in detail below with reference to Figures 1A through 9 in detail detailing the implementation of the above-described steps of the preferred embodiment and its principles.

Referring to FIGS. 1A and 1B, a method for manufacturing an anti-counterfeit watermark image according to a preferred embodiment of the present invention first provides a humanized image 10. In this step, the personalized image 10 is preferably a variety of headshots, full body photos, half-length photos or pictorial images (such as cartoonized facial expressions) including at least facial or expression features, but not Limited to this. The personalized image 10 can be used in subsequent steps to design a watermark for a customized document, such as integrating the watermark design of the personalized image 10 into a page within a notebook, but is not limited thereto. As shown in FIG. 1A, the personalized image 10 (original) includes at least one image area 101 and at least one background area 102. The image area 101 uses an FM network point FM, and the background area 102 uses an amplitude modulation network point AM. . As shown in FIG. 1B, the personalized image 10 (copy) also includes at least one image area 101 and at least one background area 102, but the image area 101 and the background area 102 are in the following manners using the present invention. It can be black-and-white reversed after copying after design. The design principle is explained as follows.

Referring to FIGS. 2-6, the method for manufacturing an anti-counterfeit watermark image according to a preferred embodiment of the present invention is followed by selecting a concentration correction guide 12 to select at least one image region 101 of the personalized image 10. The individual density of the FM network point FM and the amplitude modulation network point AM of the at least one background area 102 is such that the gray level value of the FM frequency point FM before copying is lower than the gray level value of the AM modulation point AM, and is used to cause the frequency modulation after copying. The grayscale value of the dot FM is higher than the grayscale value of the AM of the AM, thereby determining the parameter setting of the digital halftone network. In this step, the personalized image 10 is composed of a plurality of different density correcting units 11. Each of the concentration correcting units 11 includes a frequency modulation dot area 111 and an amplitude modulation dot area 112, and the frequency modulation dot area 111 is designed to be located at a center position of the amplitude modulation dot area 112. As shown in FIGS. 3 and 4, the density correction guide 12 (original/copy) is used to select the density of the FM dots FM of each image region 101 in the personalized image 10 and the amplitude modulation of each background region 102. The concentration of the dot AM is as follows. First, the AM AM, the FM FM, and the digital halftone over-the-network method are explained. Based on the tone limit of the printed output device, only the "ink" and "no ink" can be used. The step mode simulates the display of continuous tone images, and the human eye has the characteristic of blurring the integration of adjacent two-order dot, so that the original two-order image is observed at a certain distance, and it seems to have a continuous tone. . Therefore, it is not possible to directly express the continuous tone of the original pattern. In order to make the pattern of the printed output close to the tone of the original pattern, it is necessary to adopt a halftone network processing method, that is, a phase. The original grayscale image is represented by the same spacing but different dot sizes, or with dense dot dots of the same dot size but different pitches. The former is called amplitude modulation (AM) dot, and the latter is called frequency modulation (frequency modulation, FM) outlets.

The digital halftone screening method can be classified into ordered dithering and error diffusion. In this step, the ordered dithering is mainly used to form the amplitude modulation dot AM, and the error diffusion is mainly used to form the FM dot FM. The calculation principle of the dot matrix method is to compare the continuous adjustment of the original and the threshold matrix to determine the signal value of the individual pixel points generated as 1 or 0, and first divide the image into a number of the same size as the threshold matrix. Blocks, due to the different numerical arrangement of the threshold matrix, can produce different dot structure images. For digital printing equipment, dot matrix method is a way to guide how digital printing devices are inked. More specifically, the halftone processing is performed on the block image, and the threshold value is generated by first converting the original gray scale image g(i, j) into the critical value matrix through the formula (1). gradation number g '(i, j), where N ₁ and N ₂ threshold matrix representative of the length and width.

After obtaining the order number g'(i,j) of the threshold matrix, the equation (2) is compared with the threshold matrix t(m,n) to determine the signal value at which the pixel becomes 1 or 0:

For example, if the number of modulations in a block is 6, and the sub-block size in this area is 8×8 pixels, the digital printing output device will inject according to the value of the threshold value, and the result is Of the 64 sub-positions, 6 are filled with black ink.

On the other hand, Error Diffusion is proposed by Robert Floyd and Louis Steinberg. The error caused by the image in the two-stage process begins to spread from the error of the top left pixel to the adjacent but not yet second-ordered. At the pixel, other pixels that absorb errors and have not been second-ordered continue to perform two-order and error diffusion until the last pixel, and the algorithm can be expressed by equation (3), where X is the original pixel. The gray scale value, after being compared with the threshold value T, produces the last two order value b. The error diffusion mask is shown in equation (4).

In this step, when the invention is performed, the personalized image 10 of the original can be divided into two parts: (1) at least one image area 101 designed by FM FM FM and (2) with amplitude modulation dots. At least one background area 102 of the AM design, wherein all of the image area 101 and the background area 102 are finally designed to be integrated on a paper file, AM spot and FM The network mode of the dot FM is designed in the above manner.

As shown in FIGS. 3 and 4, this step uses a density correction guide 12 (original/copy) to determine the concentration of the FM dots FM of each image region 101 of the personalized pattern 10 and the amplitude modulation dots of the respective background regions 102. The concentration of AM, in order to achieve its special concentration matching so as to have the effect of black and white inversion after copying, it is necessary to design the concentration correction guide 12, which includes the dot microstructure of each concentration correcting unit 11 as shown in Fig. 2. After the image and the copy of the concentration correction guide 12 are imaged and analyzed, the amplitude modulation/frequency modulation dot density combination parameter with better black and white inversion effect is selected, and the scanning correction image of the original of the density correction guide 12 is selected. Gray scale value analysis is shown in Figure 3. In addition, the original of the density correction guide 12 becomes a copy after copying, and the black and white inversion effect analysis of the copy of the density correction guide 12 is performed as shown in FIG.

When the concentration correction guide 12 is used to determine the dot concentration of the watermark, the center grid FM dot area 111 is initially set with a grayscale value, and the value is between 210 and 233 for halftone over-networking, and the surrounding squares are adjusted. The area 112 is represented by the ratio of the dot area, and the value is 2/64 as an example for halftone over-networking. The analysis method is to extract the pixel position of the horizontal axis of each combination line as the reference of the concentration in the lead-out table. Finally, the concentration of each pixel in the density correction and distribution table 12 (the original of FIG. 3) of the watermark pattern 11 and the concentration correction guide 12 (the copy of the fourth drawing) are averaged, and then the concentration of the fifth figure is plotted. The linear regression analysis of the gray scale value of the corrected guide original image and the linear regression analysis of the gray scale value after the image of the density correction guide of FIG. 6 are shown in the fifth and sixth graphs, the vertical axis generation The table represents the range of grayscale values, and the horizontal axis represents the set value of the FM dot FM, where '○' represents the change after the FM concentration of the FM site is averaged, and '×' represents the AM concentration of the AM dot. After the change.

From the original of the concentration correction guide of Fig. 5, it can be found that the gray scale value of the FM network FM and the AM screen AM is balanced between [AM 2/64, FM 223~224], if AM 2/64 is used as the background. For the area, and FM 224~233 is the image area detail, the gray level value of the FM screen of the watermark image is higher than the AM point AM; otherwise, if the image area details are between FM 210~223, then The grayscale value of the FM frequency point of the watermark image is lower than the amplitude modulation dot AM, but in the copy of the concentration correction guide of FIG. 6, if the frequency of the FM point FM and the amplitude modulation dot AM are selected, the value is [AM. 2/64, FM 224~233], the grayscale value of the FM FM point after copying in the copy of the concentration correction guide is still higher than the AM position AM, but if the FM point FM and the AM point of the AM point are selected The value is [AM 2/64, FM 210~223], then the grayscale value of the FM dot FM after copying in the copy of the concentration correction guide table can be higher than the AM dot AM, which is the design of the watermark. The concentration range area that you want to set in the pattern, so that you can know the optimal concentration matching parameters of the two kinds of dots (AM 2/64, FM 210~223) In order to achieve the object of the copied image may be black and white reversed. However, according to the practical application, the optimal concentration matching parameter of the above two kinds of dots may not be limited thereto, and may be selected from other values, which are described first.

Please refer to FIGS. 7 to 9 for the anti-counterfeiting of the preferred embodiment of the present invention. The method for manufacturing the watermark image is to: print the personalized image 10 to the surface of an original document 20 according to the parameter setting of the digital halftone network to form a watermark that can be reversed in black and white after copying. Pattern 21. In this step, the digital halftone network is performed via the flowchart of FIG. 7, and the watermark pattern 21 can be outputted into an original document 20, such as a notebook, a book, an identity document, a certificate, or Other files with secure encryption requirements, etc. Furthermore, the equation of the flowchart of Fig. 7 is as shown in equation (5): M = (G∩W) ∪ (G' ∩ ~ W)... (5)

Where W is the mask X, G is the AM dot, ~W is the background area of the mask X, G' is the FM dot, M is the last image, ∩ denotes the intersection, and ∪ denotes the union.

In this step, the present invention can achieve automated print output production using software or firmware or other types used in digital printing equipment. Furthermore, the present invention mainly sets the concentration values of the two types of frequency points of the frequency modulation and the amplitude modulation according to the optimal parameters obtained in the concentration matching guide outputted by the previous step (ie, AM 2/64, FM 210 to 223). The personalized image 10 is printed and outputted to an original document 20, and the output thereof is that the watermark image 21 on the original document 20 is displayed as a positive image by the human eye under a normal normal light source (as shown in FIG. 8). However, after copying to a copy file 30 (for example, an inside page of a notebook) by a photocopier, the watermark image 31 then becomes a negative image of black and white (as shown in FIG. 9).

Through the above steps, the implementation can be completed to have a security The floating watermark image 21 is formed on the surface of an original document (ie, print) 20, as shown in FIGS. 1 and 2, the watermark image 21 includes: at least one image area 101, And the at least one background area 102 is composed of a plurality of amplitude modulation dots AM, and the background area 102 and the image area 101 together form a shape of the humanized image 10 (as shown in FIG. 1). The grayscale value of the FM network point FM and the amplitude modulation network point AM is set such that the grayscale value of the FM network point FM is lower than the grayscale value of the AM modulation point AM before copying, and can be used after copying to cause the FM frequency point FM. The grayscale value is higher than the grayscale value of the amplitude modulation dot AM, thereby forming the watermark pattern 21 having a black and white inversion effect after copying.

On the other hand, after the above-described step of printing the watermark image 21, if any person unauthorizedly copies or scans an original document 20 by using a photocopier or a scanner, one of the copied documents will be copied. There is only a watermark image 31 which is changed from a positive image to a negative image, whereby the anti-counterfeiting technique of the present invention can be used to display the copy file 30 as an unauthorized copy so as not to be mistaken for the original. Alternatively, after the step of printing the watermark image 21, if any person provides a file to be recognized, the watermark image on the file to be recognized may be determined to be a positive or negative image. The quick and easy judgment is an original or an unauthorized copy, and if the judgment result is a positive image, it is determined that the to-be-identified document is an original (as shown in FIG. 8); if it is a negative image, it is determined that the to-be-identified file is one. Unauthorized copy (as shown in Figure 9).

As mentioned above, compared to the conventional watermarking technology is text or pattern As a hidden message and appearing after copying to announce the copyright, the present invention according to Figs. 1 to 9 selects the personalized map by using the FM dot area 111 and the amplitude adjusting dot area 112 of each density correcting unit 11 of the density matching guide 12. The density values of 10 image areas 101 (frequency modulation dots) and background areas 102 (amplitude modulation dots), and the design of the watermark image 21 by digital halftone network technology, and then outputted to an original document 20, floating The watermark image 21 is visually visible on the original document 20, since the density values of the image areas 101 (frequency modulation dots) and the background area 102 (amplitude modulation dots) have been previously designed to be when the original document 20 is copied or scanned. Therefore, the scanning component of the photocopier can only obtain the opposite image in black and white, so that the watermark image 31 on the photocopyed copy file 30 is changed from a positive image to a negative image, so that the watermark image on the document can be determined. Image is positive or negative to know if an unknown document is an original or an unauthorized copy. Thereby, the present invention can provide personalized declaration copyright protection functions on commercial documents such as security documents or Wenchuang added products, so as to deter the effect of unauthorized copying, and can be applied to design customized personal characteristics. commodity.

The present invention has been disclosed in its preferred embodiments, and is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

10‧‧‧ Personalized images

101‧‧‧Image area

102‧‧‧Background area

11‧‧‧Concentration Correction Unit

111‧‧‧ FM site area

112‧‧‧Amplitude adjustment network area

12‧‧‧Concentration Correction Guide

20‧‧‧ original document

21‧‧‧Watermark image

30‧‧‧Copy documents

31‧‧‧Watermark image

AM‧‧‧Amplitude adjustment outlets

FM‧‧‧ FM network

G‧‧‧AM outlets

G’‧‧‧FM outlets

W‧‧‧Mask X

~W‧‧‧Mask X background area

M‧‧‧ final image

∩‧‧‧Intersection

Figure 1A: Personalized image manuscript of a preferred embodiment of the present invention schematic diagram.

Figure 1B is a schematic illustration of a personalized image copy of a preferred embodiment of the present invention.

Figure 2 is a schematic diagram showing the microstructure of the AM/FM dot in each concentration correction unit of the personalized image of the preferred embodiment of the present invention.

Figure 3 is a diagram showing the gray scale value analysis of the density correction guide original and the scan image of the preferred embodiment of the present invention.

Figure 4 is a diagram showing the gray scale value analysis of the scan image of the copy correction guide of the preferred embodiment of the present invention.

Fig. 5 is a linear regression analysis diagram of the gray scale value after the image of the density correction guide of the preferred embodiment of the present invention is taken (×: AM 2/64, ○: FM 210-233).

Fig. 6 is a graph showing the linear regression analysis of the gray scale value after the image of the density correction guide of the preferred embodiment of the present invention is taken (×: AM 2/64, ○: FM 210-233).

Figure 7 is a flow chart showing the digital halftone over-network of the preferred embodiment of the present invention.

Figure 8 is a schematic diagram of the watermarking design of the personalized image of the preferred embodiment of the present invention integrated into the inner page of the notebook (original).

Figure 9 is a schematic diagram of the watermarking design of the personalized image of the preferred embodiment of the present invention integrated into the inner page of the notebook (copy).

10‧‧‧ Personalized images

101‧‧‧Image area

102‧‧‧Background area

AM‧‧‧Amplitude adjustment outlets

FM‧‧‧ FM network

Claims (9)

A method for manufacturing an anti-counterfeit watermark image, comprising: providing a humanized image; selecting a frequency modulation network point of at least one image region of the personalized image and an amplitude modulation network point of at least one background region by using a concentration correction guide table; The concentration is such that the grayscale value of the FM dot is lower than the grayscale value of the AM dot before copying, and is used to cause the grayscale value of the FM dot to be higher than the grayscale value of the AM dot after copying, thereby determining Parameter setting of the digital halftone network; and printing the personalized image to the surface of an original document according to the parameter setting of the digital halftone network to form a watermark pattern having a black and white inversion effect after copying . The method for manufacturing an anti-counterfeit watermark image according to claim 1, wherein in the step of selecting the concentration of the amplitude modulation dots and the frequency modulation dots, the amplitude modulation dot is formed by using a dot matrix method, and error diffusion is used. The method forms a frequency modulation network. The method for manufacturing an anti-counterfeit watermark image according to claim 1, wherein the concentration correction guide comprises a plurality of different density correction units, and each of the concentration correction units includes a frequency modulation dot area and a The amplitude adjustment dot area is located at a central position of the amplitude modulation dot area. The method for manufacturing an anti-counterfeit watermark image according to claim 3, wherein in the step of selecting the concentration of the amplitude modulation dot and the frequency modulation dot, the AM dot AM 2/64 is the background region. The value is taken, and the FM network point FM 210-223 is used as the value of the image area. The method for manufacturing an anti-counterfeit watermark image according to claim 1, wherein after the step of printing the watermark image, the method further comprises: copying or scanning the original document to make a copy on one of the copied documents. The watermark image is changed from a positive image to a negative image to display the copy file as an unauthorized copy. The method for manufacturing an anti-counterfeit watermark image according to claim 1, wherein after the step of outputting the watermark image, the method further comprises: providing a file to be recognized, and determining a watermark on the file to be recognized. The image is a positive image or a negative image. If it is a positive image, it is determined that the to-be-identified document is an original; if it is a negative image, it is determined that the to-be-identified file is an unauthorized copy. An anti-counterfeit watermark image formed on a surface of an original document, the anti-forgery watermark image comprising: at least one image region, composed of frequency modulation (FM) dots; and at least one background region, by amplitude modulation ( AM), the background area and the image area together form a shape of a humanized image; wherein the gray level value of the FM network point and the amplitude modulation network point is set such that the gray level value of the FM network point is lower than the amplitude modulation before copying The grayscale value of the dot is used to cause the grayscale value of the FM dot to be higher than the grayscale value of the AM dot, thereby forming the watermark pattern having a black and white inversion effect after copying. An anti-counterfeiting watermark image as described in claim 7 of the patent application, wherein The amplitude modulation network point AM 2/64 is taken as the value of the background area, and the FM network point FM 210-223 is used as the value of the image area. The anti-counterfeiting watermark image as described in claim 7, wherein the personalized image is a large-headed, full-length, half-length or pictorial image including at least a facial or expression feature.