KR20030055189A - Apparatus and method for inserting and detecting hologram watermark - Google Patents

Abstract

PURPOSE: A hologram watermark insertion and detection method and a system for the same are provided to have an unrecognizable property, which can not be found in a conventional digital watermark technique, to enhance a security by using a proprietary encoding property, and to enhance a robustness to a data damage in a commercial IO system by using a redundancy component of a hologram. CONSTITUTION: The system comprises a data input device(115), a conversion key generator(120), the first data converter(125) a hologram data synthesizer(130), a watermark insertion module(135), the second data converter(140), a transmission module(145), and a controller(150). The data input device(115) enables a user to input a cover image and watermark data. The conversion key generator(120) generates and manages parameter values necessary for making a data conversion in inserting watermark data into the cover image by using a hologram principle. The first data converter(125) generates each Fresnel hologram watermark on a frequency plane by making a Fresnel transformation of each watermark data, and converts the cover image into the image existing on a frequency plane by making a fast Fourier transformation. The hologram data synthesizer(130) synthesizes each Fresnel hologram watermark into one Fresnel hologram watermark. The second data converter(140) converts the digital watermark cover image, which is made by inserting the synthesized hologram watermark into the converted cover image in the watermark insertion module(135), into the watermark cover image on a spatial plane. The controller(145) controls each component for generating the watermark cover image and outputting it to an external device.

Description

Holographic watermark insertion and detection method and apparatus therefor {APPARATUS AND METHOD FOR INSERTING AND DETECTING HOLOGRAM WATERMARK}

The present invention relates to a holographic watermark embedding and detection method and apparatus, and more particularly to a holographic watermark embedding and detection method and apparatus for facilitating the authenticity of copyright protection of digital contents and forgery of identification card. It is about.

With the recent popularization of the Internet, including personal computers, various kinds of useful information have been distributed, and the information has been produced in various digital contents, which enables unlimited duplication of information. The digital watermarking technology is a technology for preventing illegal copying and illegal distribution of information and protecting copyright and ownership of data distributors. Originally, the watermark originated from the process of making ancient papyrus (paper) .Today, in the manufacturing of paper money, printing is done when the paper is wet, dried, and printed on both sides. It can also be used to get this in. In other words, watermarking refers to any technical method of concealing and extracting a special form of watermark (ie, information) to protect a series of copyrighted works.

Digital watermarks for the protection of copyrighted works require invisible and large amounts of various information insertion techniques in order to be robust to attacks and forgeries from various illegal users. However, from this point of view, digital watermarks are not yet as secure as encryption technology, and most of them are still insufficient to apply to the entire copyright management technology because they are in a trade-off state of toughness, information quantity and quality. Is considered.

In addition, ID card forgery and alteration prevention technology has been used optical hologram, special printing technology and fingerprint recognition technology, but ID card forged for various crimes due to the rapid development of various elements and image processing technology such as computer, camera, printer, scanner and color copying machine This situation is being used.

In general, watermarking a document can be divided into two methods of changing the position of the text and changing the text. Also, a method of inserting a watermark to be visible can include a logo or a barcode.

There are two ways to change the position of the text: Line Shifting and Word Shifting, which are fixed control lines or fixed lines. This is a method of checking the presence or absence of a watermark based on a word group.

However, this method has a problem in that the amount of information that can be inserted into the watermark is reduced by moving the fixed point up and down or left and right, and the amount of information that can be inserted is further limited by excluding lines that do not meet the reference value. there was.

In addition, a method of changing the text may include inserting a watermark by applying masking for each block. However, since the document image is basically a binary image, a slight deformation becomes a factor to deepen the distortion of the text, and also has a problem that adversely affects the detection performance of the watermark.

Accordingly, an object of the present invention is to facilitate the copyright protection of digital contents and authenticity of forgery of ID card, and to establish a sound distribution order of digital works and to prevent various crimes caused by forgery of ID card. An insertion and detection method and a device thereof are provided.

Another object of the present invention is to provide a holographic watermark embedding and detection method and apparatus capable of inserting various types of data (text, logo, image, etc.) in a large amount invisibly.

Another object of the present invention is not only to have the non-cognitive, which was pointed out as a limitation in the existing digital watermarking technology, but also to enhance security by using the encryption characteristics of the hologram technology. And a detection method and apparatus therefor.

Another object of the present invention is to use a redundancy component of the hologram to be robust to various signal processing and information corruption, and to be applied to existing commercialized input / output systems, in parallel with non-replicable technologies such as digital optical memory technology. To provide a holographic watermark embedding and detection method and apparatus for developing a more robust information security product.

1 is a block diagram showing a schematic configuration of an apparatus for performing a method for generating hologram watermarking according to an embodiment of the present invention.

Figure 2 is a conceptual diagram showing a series of processes of the holographic watermarking generating method according to an embodiment of the present invention.

Figure 3 is a block diagram showing a schematic configuration of an apparatus for performing a holographic watermarking detection method according to an embodiment of the present invention.

4 is a diagram illustrating a watermark detection result of the holographic watermarking detection apparatus according to the application of any three-dimensional depth value according to an embodiment of the present invention.

5 is a diagram illustrating a watermark detection result of the holographic watermarking detection apparatus according to the application of any interference angle according to an embodiment of the present invention.

FIG. 6 is a diagram illustrating a method for determining whether forgery / modulation and duplication of an identification card using a holographic watermarking detecting apparatus according to an exemplary embodiment of the present invention. FIG.

7 is an exemplary diagram of a screen configuration of a software program for performing the hologram watermark embedding and detection method according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

110: hologram watermarking generating device 115: data input unit

120: conversion key generation unit 125: first data conversion unit

130: hologram data synthesizing unit 135: watermark inserting unit

140: second data converter 145: transmitter

150: watermark generation control unit 310: hologram watermarking detection device

320: conversion key management unit 330: hologram watermark extraction unit

335: watermark information extraction unit 340: data comparison unit

350: watermark detection control unit

In order to achieve the above objects, according to an aspect of the present invention, in a method for embedding watermark information into digital content or a user information medium, wherein the user information medium is a social security card, passport, ID card, driver's license, credit card And receiving at least one watermark information and a cover image, wherein the cover image is an insertion region of the watermark information included in the digital content or the user information medium. Fresnel transforming the plurality of watermark information to generate a synthesized Fresnel hologram watermark existing on one frequency plane, and fast-Fourier transform the cover image onto a frequency plane. Generating converted cover image data present in the synthesized Fresnel hologram; Generating a digital watermarking cover image in which a RAM watermark and the transform cover image are located on one frequency plane, and performing a Fast Fourier Transform of the digital watermarking cover image to be located on a space plane. Generating a watermarking cover image, wherein the watermarking cover image includes the composite Fresnel hologram watermark existing in the frequency domain in the cover image. Provided is a system, apparatus, and recording medium which enable the performance of the hologram watermark embedding method.

In the hologram watermark embedding method, the generating of the plurality of watermarks by Fresnel transforming the plurality of watermark information to generate a composite Fresnel hologram watermark existing on one frequency plane may include: Receiving a conversion key for converting each watermark information of the information into individual Fresnel hologram watermarks, and Fresnel transforming each watermark information to correspond to the respective watermark information Generating the individual Fresnel hologram watermarks reflected on the transformed key and present on the frequency plane, and placing the plurality of individual Fresnel hologram watermarks on one frequency plane. Converting to a mark.

The conversion key may include a three-dimensional depth value in the Fresnel region where the watermark information is to be restored, and an interference angle for converting the watermark information into the individual hologram watermark for converting the watermark information. The individual Fresnel hologram watermark may be restored to the watermark information only when the conversion key is input.

In the hologram watermark embedding method according to the present invention, when the individual Fresnel hologram watermark is converted, the watermark information and a reference wave are present on an off-axis.

According to a preferred embodiment of the present invention, there is provided a method of detecting watermark information embedded in a watermarking cover image included in the user information medium to check whether a user information medium is valid, wherein the user information is provided. The medium includes at least one of a resident registration card, a passport, an identification card, a driver's license, and a credit card, and the cover image is an insertion area of the watermark information included in the user information medium-receiving the watermarking cover image. And Fast Fourier Transform the watermarking cover image to generate a digital watermarking cover image existing on a frequency plane, wherein the digital watermarking cover image is on one frequency plane. Contains nested composite Fresnel hologram watermarks and transform cover image data Extracting the composite Fresnel hologram watermark from the digital watermarking cover image, wherein the composite Fresnel hologram watermark is displayed by superimposing a plurality of individual Fresnel hologram watermarks on one frequency plane. Detecting a predetermined conversion key corresponding to each individual Fresnel hologram watermark or receiving a conversion key from a user, in order to convert any individual Fresnel hologram watermark into watermark information; Converting the individual Fresnel hologram watermark corresponding to the conversion key into inverse Fresnel by using the detected or inputted conversion key, and converting the converted watermark information into watermark information on a space plane; Displaying on or transmitting to the operator system A holographic watermark information detection method is provided, and a system, apparatus, and a recording medium for enabling the execution of the holographic watermark information detection method are provided.

The method for detecting holographic watermark information according to the present invention includes the step of checking whether the watermarking cover image matches the one of the watermark information, and if it matches, displaying a valid inspection result on a display unit or transmitting the result to an operator system. And if it does not match, displaying an error message on the display or transmitting the error message to the operator system.

The conversion key may include at least one of a three-dimensional depth value in the Fresnel region where the watermark information is to be restored, and an interference angle for converting the watermark information into the individual hologram watermark for converting the watermark information. In addition, the watermark information may be restored to the watermark information only when the input or set conversion key is input or set when the watermark information is converted into the individual Fresnel hologram watermark.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the following description of the method for embedding and detecting a hologram watermark according to the present invention, the original data is referred to as a cover image as specific data (for example, text, a logo, an image, etc.) attached to digital content or an identification card. Insertion data as information of a user inserted invisibly to prevent forgery on an image is called watermark information, and as a result, a cover image into which watermark information is inserted is referred to as a watermarking cover image.

Before describing the method and apparatus for embedding and detecting a hologram watermark according to the present invention, the essential requirements of watermarking will be described.

First, non-cognition is required in which humans cannot perceive visually inserted information. That is, in the case of multimedia content, it is difficult for a human to visually distinguish the original data from the watermarked data. However, in the case of lossy compression such as JPEG or MPEG, the watermark inserted may be removed if only non-cognition is satisfied.

Second, the watermark must take into account the amount of information to be inserted. That is, about 300 to 400 bits of information may be inserted so that the embedded information may not be recognized depending on the environment requiring the watermark. Therefore, it must be designed to insert the maximum information that can be inserted while considering the non-cognition.

Third, it must have a low error probability. In other words, even if there is no intentional or unintentional damage and damage, the probability of failing to extract the watermark and the probability that the watermark does not exist should be very low.

Fourth, the watermark must be able to be extracted even after various losses. As such, the watermarking technology should be designed to be able to insert a lot of information into the original data while extracting the information inserted in various signal processing while having a non-cognizability to protect the copyright and ownership of the data distributor from illegal users. do.

1 is a block diagram illustrating a schematic configuration of an apparatus for performing a method of generating a hologram watermark according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the hologram watermarking generating device 110 according to the present invention includes a data input unit 115, a conversion key generation unit 120, a first data conversion unit 125, a hologram data synthesis unit 130, The watermark inserting unit 135, the second data converter 140, the transmitting unit 145, and the watermark generation control unit 150 are included.

The data input unit 115 is a means for performing a function of receiving a cover image, watermark information, and the like. A method of receiving a cover image or the like by the data input unit 115 may be combined with an input means such as a scanner to receive an image or the like from a corresponding device, or information already stored in a storage unit (not shown) (for example, , Images, texts, and the like).

The conversion key generation unit 120 performs a function of generating and managing parameter values required in the process of converting the watermark information into the cover image using the hologram principle. This parameter value may be determined not only by the hologram watermarking generating device 110 itself but also by a user who generates the hologram watermark. For example, when generating a digital hologram, two parameters may be required: a three-dimensional depth value of each watermark information (z) and an interference angle (θ) between a reference wave and an object wave according to a change in the incident position of the reference wave. Each watermark information has a different three-dimensional depth value z.

The first data converter 125 performs Fresnel Transform (FT) on each watermark information to insert one or more watermark information into the cover image. The first Fresnel hologram watermark (Fresnel) exists on the frequency plane. It generates a hologram watermark and performs a function of transforming the cover image into transform cover image data existing on the frequency plane by performing a Fast Fourier Transform (FFT).

The hologram data synthesizing unit 130 has Fresnel-converted by the first data converter 125 to convert the respective watermark information into individual Fresnel hologram watermarks on the frequency plane. Synthesizes the watermark information into a synthetic Fresnel hologram watermark. Even if a plurality of watermark information is mixed on one frequency plane, each hologram data (i.e., each converted watermark information) has its own independent conversion key (i.e., three-dimensional depth value z and / or interference angle). (θ)), and a corresponding conversion key must be inputted to extract desired watermark information. The Fresnel hologram watermark is applied to the present invention because the generation and restoration of the Fresnel transform is very sensitively determined depending on the distance value between the spatial plane and the frequency plane of the Fourier transform. The original information can only be obtained when restoring the same value as the 3D depth value used in the creation. Therefore, it is very difficult for an illegal user to recognize an accurate three-dimensional depth value in the Fresnel region continuously present between the spatial domain and the frequency plane. In addition, the hologram method applied to the present invention uses an off-axis hologram that prevents the reference wave and the watermark information from being on-axis. It gets harder to get.

The watermark inserting unit 135 transmits one or more watermark information (ie, synthetic Fresnel hologram watermarks) existing on one frequency plane by the hologram data synthesizing unit 130 to the first data converting unit 125. The digital watermarking cover image is inserted into the cover image data converted into cover image data existing on the frequency plane.

The second data converter 140 may perform a Fast Fourier Transform (FFT) or an Inverse Fourier Transform (FFT) on the digital watermarking cover image generated by the watermark inserting unit 135 on data existing on one frequency plane. (IFT) to convert a watermarked cover image (ie, a cover image in which a watermark is inserted on the frequency plane) existing in a spatial plane.

The transmission unit 145 transmits the watermarking cover image converted by the second data conversion unit 140 to an external medium (for example, an output device such as an ID card generating device, a copyright information insertion server, etc.). do.

The watermark generation control unit 145 generates a watermarking cover image by using the watermark information and the cover image specified by the hologram watermarking generating apparatus 110 according to the present invention, and the generated watermarking cover image is an external medium. The data input unit 115, the conversion key generation unit 120, the first data conversion unit 125, the hologram data synthesis unit 130, the watermark inserting unit 135, and the second data to be used through the The converter 140 and the transmitter 145 perform a function of controlling.

In addition, although not shown in FIG. 1, the hologram watermarking generating device 110 may further include a storage unit that stores watermark information, a cover image, an operation program of the holographic watermarking generating device 110, and the like.

In addition, although the hologram watermarking generating device 110 is illustrated as a specific device having a hardware configuration in FIG. 1, the hologram watermarking generating device 110 may be implemented in the form of a software program that performs the same function as described above. In addition, when implemented in the form of a software program, a user purchases a separate hologram watermarking generating device 110 by simply installing the corresponding software program on a user terminal (for example, a personal computer, a PDA, a mobile communication terminal, etc.). If you do not do the same effect can be expected.

Hereinafter, the principle of digital hologram generation will be briefly described.

First, the watermark information is a random phase mask It is modulated by and computed. The mark image modulated by the random phase mask generates a digital hologram by interfering with a reference wave for generating the digital hologram. In this case, the random phase mask plays a role in uniformly distributing the components of the mark image in the entire area of the digital hologram.

Watermarked information In this case, the randomly phase-modulated mark image may be represented by Equation 1 below.

And, the reference wave used for digital hologram generation In this case, the frequency conversion value of the watermark information is It can be represented by. Using this, a digital hologram is generated as in Equation 2 below.

2 is a conceptual diagram illustrating a series of processes of a method for generating hologram watermarking according to an exemplary embodiment of the present invention.

Referring to FIG. 2, the hologram watermarking generating apparatus 110 (which includes a user terminal in which a software program that performs the same function is installed. The same applies below) may include Fresnel conversion of watermark information designated by a user in areas 210 and 220. (FT: Fresnel Transform) to convert the Fresnel Hologram watermark in the form of Fresnel Hologram in the frequency plane.

However, the watermark information converted into the individual Fresnel hologram watermark through the region 210 is first watermark information having a three-dimensional depth value z1 of 'z = 98.5', and is represented as the individual Fresnel hologram watermark through the region 220. The converted watermark information is second watermark information having a three-dimensional depth value z2 of 'z = 100'. FIG. 2 is a view illustrating a case where two watermark information is inserted into a cover image for convenience and have different three-dimensional depth values, for example. However, the holographic watermarking generating apparatus 110 according to the present invention may have three respective three-dimensional depth values. Naturally, unlimited watermark information having a dimensional depth value may be simultaneously inserted into one cover image. The three-dimensional depth value z is a kind of distance value (e.g., a positional movement of the object itself) that can be extracted and reconstructed in a Fresnel region continuously existing between the spatial domain and the frequency plane. Distance value). For example, when there is an object A having a three-dimensional depth value z1 and an object B having a three-dimensional distance value z2, and z1> z2, an object wave and a reference wave are interfered with it. After recording the interference pattern on the film, the reference wave is reflected on the film, so that the object can be felt as if each object exists in the order of object B and object A over the film.

Subsequently, the hologram watermarking generating apparatus 110 uses the hologram data synthesizing unit 130 to generate watermark information for each individual Fresnel hologram watermark generated through the regions 210 and 220 in one frequency plane. In other words, it synthesizes the synthesized Fresnel hologram watermark.

In operation 240, the hologram watermarking generating apparatus 110 transforms the cover image into transform cover image data existing in the frequency plane by performing a Fast Fourier Transform (FFT).

Thereafter, the hologram watermarking generating apparatus 110 applies a weight alpha to the synthesized Fresnel hologram watermark synthesized from the watermark information existing in one frequency plane through the region 230 in the region 250 and then in one of the region 260. A digital watermarking cover image is generated using the transformed cover image data and the composite Fresnel hologram watermark on the frequency plane of.

The reason why the weight is applied to the synthetic Fresnel hologram watermark in the area 250 is to prevent the recognition of the watermark information from the human eye, and the synthetic Fresnel hologram watermark is expressed by Equations 3 and 4 below. Is converted.

In Equation 3 described above Denotes a synthetic Fresnel hologram watermark, Represents a Fourier transform value of the cover image. And Wow Is the maximum value and Represents the minimum value.

The above-described equations (3) and (4) can obtain a normalized value as shown in equation (5) below.

Using the values obtained in Equation 5, a cover image (that is, a watermarking cover image) in which a synthetic Fresnel hologram watermark is inserted can be obtained, and the overlapped intensities of the two images can be obtained. Can be expressed as in Equation 6 below.

In equation (6) Denotes a weight function for superimposing (ie, inserting) the synthetic Fresnel hologram watermark on the cover image, which is processed in two cases as shown in Equation 7 below.

Α in Equation 7 represents a constant representing the weight of the hologram element, Represents a constant overlap of the entire image, Denotes a weight depending on the brightness distribution of the content image.

In this case, the reconstructed image g (x, y) is represented by Equation 8 below by Fourier transform.

here, Is the image reconstructed from the Fresnel hologram watermark element (ie, the image corresponding to the watermark information), and q (x, y) is the cover image Fourier spectral distribution. Equation 8 is watermark information Implies that the Fourier spectrum of the cover image is reconstructed. Therefore, these two components must be divided in the space domain.

In general, the spectral distribution q (x, y) of the content image is a strong DC component and is concentrated in the low frequency region. Based on this fact, if spectrum q (x, y) is limitedly distributed within a certain low frequency region, If appears in a specific high frequency region, the two components of Equation 8 described above may be divided in the spatial domain, respectively. However, in order to satisfy this condition, the cover image must pass through the low frequency filter and be distributed in a specific low frequency region.

Referring back to FIG. 2, the hologram watermarking generating device 110 performs a Fast Fourier Transform (FFT) or an Inverse Fourier Transform (FFT) on the digital watermarking cover image generated by the region 260 to spatialize the spatial domain. The image is converted into a watermarked cover image (that is, a cover image in which a watermark is inserted) existing in the plane).

3 is a block diagram illustrating a schematic configuration of an apparatus for performing a hologram watermarking detection method according to an exemplary embodiment of the present invention.

Referring to FIG. 3, the hologram watermarking detecting apparatus 310 may include a data input unit 315, a conversion key manager 320, a data converter 325, a hologram watermark extractor 330, and a watermark information extractor ( 335, a data comparator 340, a transmitter 345, and a watermark detection controller 350.

The data input unit 315 performs a function of receiving watermark information in the watermarking cover image. For example, the data input unit 315 may correspond to a scanner or a data receiver. If the hologram watermarking detecting apparatus 310 according to the present invention detects the sameness between the watermark information inserted in the photograph attached to the employee's card or the like and the information on the employee's card's surface (for example, a picture, a name, a company number, etc.) If so, the data input unit 315 may be a scanner or the like that can receive photo image and text information or a data receiver that can receive the photo image and text information from a scanner or the like combined through a communication network. . Of course, the text information may be used by receiving user information corresponding to the photo image attached to the ID card from a separate database through a communication network without using the text information written on the ID card surface.

The conversion key management unit 320 manages the conversion key (for example, three-dimensional depth value (z), interference angle (θ), etc.) applied when generating an individual or composite Fresnel hologram watermark applied to generate a watermarking cover image. It performs the function.

Since the first data converter 325 includes not only the cover image but also the composite Fresnel hologram watermark that exists on the frequency plane, the composite Fresnel hologram watermark is present on the watermarked cover image input by the data input unit 315. A fast Fourier transform (FFT) is performed to extract the cover image into a digital watermarked cover image existing on the frequency plane.

The hologram watermark extractor 330 removes a portion corresponding to the original cover image from the digital watermarking cover image converted by the first data converter 125. As a result, only the synthesized Fresnel hologram watermark remains as a result of the function of the hologram watermark extractor 330. For example, a method of extracting a difference value between the two by using a fast Fourier transform of the original cover image may be applied. .

The watermark information extraction unit 335 extracts the watermark information by performing inverse Fresnel conversion on the synthetic Fresnel hologram watermark extracted by the conversion cover image data extraction unit 230. In order to extract desired watermark information in the inverse Fresnel transformation process, a parameter value provided by the conversion key management unit 320 (that is, a conversion key including a three-dimensional depth value z and an interference angle θ) is applied. . For example, first watermark information having a three-dimensional depth value z1 of 'z = 98.5' and a second watermark having a three-dimensional depth value z2 of 'z = 100' in the watermarking cover image. When the information is inserted, the 3D depth value z should be applied as '98 .5 'in order to extract the first watermark information.

The data comparison unit 340 performs a function of checking whether the data input by the data input unit 315 and the watermark information extracted by the watermark information extraction unit 335 match each other. For example, the sameness between the watermark information inserted in the photograph attached to the employee ID and the information on the surface of the employee ID (for example, display information such as a photograph, name, employee number) by the hologram watermark detection apparatus 310 according to the present invention. If the device detects whether or not, information (for example, name) on the surface of the employee card input by the data input unit 315 and watermark information (for example, name) extracted by the watermark information extraction unit 335 Will check if the matches.

The transmission unit 345 checks whether the display information (eg, information on the surface of the employee card) inspected by the watermark information extraction unit 335 matches the watermark information inserted in the watermarking cover image. It performs the function of transmitting to an external device (eg door control device, theft alarm device, administrator monitor, etc.).

The watermark detection control unit 350 may perform the operation according to the inspection result by checking whether the holographic watermarking detection device 310 according to the present invention matches the watermark information and the display information inserted in the watermarking cover image. Data input unit 315, conversion key management unit 320, data conversion unit 325, hologram watermark extraction unit 330, watermark information extraction unit 335, data comparison unit 340, transmission unit 345 performs a function of controlling.

In addition, although not shown in FIG. 3, the hologram watermarking detecting apparatus 310 may further include a storage unit that stores a conversion key, an operation program, and the like, and visually confirms the inspection result by the data comparison unit 340. It may further include a display unit to enable.

In addition, although the hologram watermarking detection device 310 is illustrated as a specific device having a hardware configuration in FIG. 3, the hologram watermarking detection device 310 may be implemented in the form of a software program that performs the same function as described above. In addition, when implemented in the form of a software program, a user purchases a separate hologram watermark detection apparatus 310 by simply installing the corresponding software program on a user terminal (for example, a personal computer, a PDA, a mobile communication terminal, etc.). If you do not do the same effect can be expected.

In addition, a hologram watermarking generating device 110 is shown in FIG. 1 and a hologram watermarking detection device 310 is shown in FIG. 3 separately, and it is also described as a separate device, but it is a single hologram including both functions. Naturally, it can be implemented by a watermarking device or a software program.

The hologram watermarking detection process applied to the present invention can be similarly applied to the inverse process of the hologram watermarking generation process described above with reference to FIG. 2, and thus a detailed description thereof will be omitted. Only a brief description will be given.

In principle, watermark information (for example, a watermark image, which will be described below as a watermark image) can be restored by multiplying the reference wave used when generating the digital hologram and frequency converting the digital hologram.

In general, the reconstructed watermark image may be represented by Equation 3 below.

Equation 3 means that two images corresponding to the watermark image are obtained symmetrically at the origin of the coordinates in the reconstruction plane. The center of each image is located at (a, b) and (-a, -b). And two elements a and b are reference waves Is given by

That is, when the reference wave and the watermark image exist on the coaxial axis, they are always restored in the middle, but in the off-axis case, the position of the watermark image to be restored is selected according to the relative position of the two pieces of information. (See FIG. 5).

This may be used as a key value for determining whether a new image is forged or not according to whether the detected image is positioned in the reconstructed plane. That is, since the reference wave and the watermark image exist off-axis, the interference angle θ between them can be applied as one conversion key.

In particular, when the watermark image is binary data, the watermark image may be represented by Equation 4 below.

4 is a diagram illustrating a watermark detection result of the holographic watermarking detection apparatus according to the application of any three-dimensional depth value according to an embodiment of the present invention.

FIG. 4 is a diagram illustrating watermark information detection results when an arbitrary three-dimensional distance value is applied to detect (restore) watermark information embedded (overlapped) in a watermarking cover image. For example, the three-dimensional distance value 'z = 100' is applied in the process of generating the individual Fresnel hologram watermark.

As shown in the screen 410, the watermark information is image information including the text 'LMH'. When the individual Fresnel hologram watermark is generated to have the three-dimensional distance value 'z = 100', the watermark information is displayed. As shown on screen 420, the human eye is converted into a hologram that is indistinguishable from the human eye.

In order to detect the watermark information, a three-dimensional value of 'z = 100' equal to the three-dimensional distance value specified in the process of generating the watermark information as an individual Fresnel hologram watermark as a conversion key in the hologram watermark detection apparatus 310 is used. The distance value must be entered (or set). In addition, when the same 3D distance value is input (or set) in the process of detecting watermark information, the form in which the corresponding watermark information is detected and displayed on the display unit is shown on the screen 430.

However, a three-dimensional distance value that is not equal to the three-dimensional distance value (ie, z = 100) input during the individual Fresnel hologram watermark generation process (for example, z = 99, z = 99.5, z = 100.5, etc.) When the watermark information is input in the process of detecting the watermark information, as shown on screens 440 to 460, only information of a form in which the watermark information cannot be identified is displayed on the display unit.

That is, the hologram watermarking detecting apparatus 310 (or the hologram watermarking apparatus) according to the present invention recovers watermark information only when the correct conversion key is input, and appears as information having no meaning for the other cases.

In addition, the setting interval of the three-dimensional depth value (z) can be specified as a fine value of 0.01 or less, and since there is no limitation on the settable three-dimensional depth value (z), the amount of watermark information that can be inserted into the cover image is also limited. It doesn't work.

5 is a diagram illustrating a watermark detection result of the holographic watermarking detection apparatus according to the application of any interference angle according to an embodiment of the present invention.

As described above, in the hologram watermarking generating apparatus 110 and the hologram watermarking detecting apparatus 310 according to the present invention, an interference angle θ may be further applied as a conversion key in addition to the three-dimensional depth value z.

This is a technique in which the holography technology records and records the amplitude and phase of information as an interference fringe. In the present invention, the reference wave and the watermark image exist off-axis, The interference angle θ can be applied with one conversion key

The Fresnel hologram watermark applied to the present invention is similar to a random key used as a watermark for simple authentication in watermarking technology, but has a difference in that a plurality of desired information such as text or an image can be extracted. Since the inserted Fresnel hologram watermark is inserted in the frequency domain in a random pattern, it is possible to increase the amount of information, intelligibility, and trade-off that can be inserted than a general watermarking technique. In other words, it is possible to insert a large amount of information without being aware of it. In addition, due to the redundancy that is inherent in holograms, it is also possible to extract robustly embedded information in various signal processing techniques.

In FIG. 5, the hologram watermarking detection apparatus 310 is configured to change the position of the reference wave when generating the individual Fresnel hologram watermark, so that the conversion key (that is, the interference angle) of each individual Fresnel hologram watermark is applied differently. The detection result when watermark information is detected by inputting an arbitrary conversion key is shown. However, the 3D depth value z input when detecting specific watermark information is the same as the 3D depth value z applied when generating the individual Fresnel hologram watermark.

As shown on screens 510 to 540 of FIG. 5, even if the three-dimensional depth values z are the same, when the interference angle θ is different, the display position of the detected watermark information is changed.

It is possible to have higher security by detecting only a specific area of the watermark information extracted using this point.

That is, only watermark information displayed in a specific block can be recognized as valid or only valid when specific information is displayed in a predetermined block. This is a method of specifying, as a block, a position at which the watermark information should naturally be displayed when applying a specific interference angle θ.

For example, since only the watermark information displayed on the screen 550 is displayed in a predetermined block among the various watermark information displayed on the screens 550 to 580, only the watermark information on the screen 550 can recognize valid watermark information.

That is, in the case of using the watermarking system using the non-axis hologram according to the present invention, in order to extract the inserted watermark information, the three-dimensional depth value (ie, the distance value of the Fresnel region) and the interference angle (ie, the position of the reference wave) Must match exactly.

FIG. 6 is a diagram illustrating a method of determining whether forgery / falsification and duplication of an identification card using a holographic watermarking detecting apparatus according to an exemplary embodiment of the present invention.

In FIG. 6, the ID card 610 is input from the hologram watermark detection apparatus 310 and inserted into the watermarking cover image and the information (eg, photo, name, number, etc.) recorded on the surface of the ID card 610. A method of checking whether or not the watermark information is consistent and providing the test result information is illustrated. Of course, the user information may be used by receiving user information corresponding to the photo image attached to the identification card 610 from a separate database without using text information written on the surface of the identification card 610.

Of course, the object capable of detecting the watermark information in the hologram watermark detection apparatus 310 is not limited to the identification card 610. In addition, the ID information is input through the data input unit 315 which performs a function such as a scanner, a card reader or a copying machine coupled to the hologram watermark detection apparatus 310, or receives the corresponding information from an external data input device through a communication network. Can be received. In addition, when the data input unit 315 is configured in the form of a card reader or the like, an insertion hole for inserting or reading the identification card may be provided in the hologram watermarking detecting device 310.

Referring to FIG. 6, the hologram watermarking detecting apparatus 310 scans photo and text information (eg, name, number, etc.) attached or displayed on the input ID card 610 and is inserted into the photo. Receives a composite Fresnel hologram watermark.

Thereafter, the hologram watermark detection apparatus 310 classifies the input synthetic fresnel hologram watermark into one or more individual Fresnel hologram watermarks, and the watermark information corresponding to each individual Fresnel hologram watermark (for example, a photograph). , Name, etc.)

Then, the extracted watermark information is compared with the photo and text information scanned from the ID card 610 to check whether the ID card 610 has been forged.

Referring to the test result window 620 displayed on the display unit of the hologram watermark detection apparatus 310 or the display device coupled to the hologram watermark detection apparatus 310 via a communication network, the test result window may include a scan image area 625, The extracted image area 630 and the extracted user information area 640 may be included.

The scanned image area 625 is an area in which the photo image scanned from the ID card 610 is displayed, and the extracted image area 630 is an area in which the photo image included in the detected watermark information is displayed, and the extracted user information area ( 640 is an area in which user (ie, identification card holder) information included in the detected watermark information is displayed. The extraction user information area 640 further includes a test result display area for checking whether the user information displayed in the extraction user information area 640 and the user information (ie, text information) scanned from the identification card 610 match. can do.

It can be seen that the extracted image 630b and the extracted image 630c of the extracted image region 630 do not coincide with the photographic image of the scan image region 625 among the inspection results illustrated in FIG. 6.

In addition, it can be seen that all of the corresponding user information is displayed as an error in the extracted user information area 640 corresponding to the extracted image 630c.

That is, in the case of the extracted image 630b, only the picture attached to the outer surface of the identification card is changed while retaining the watermark information already inserted using an arbitrary picture editing program. In this case, however, each photo image does not match, so the ID card is judged to be forged, and the result information "Access Denied" is obtained.

In addition, in the case of the extracted image 630c, no photographic image is displayed in the extracted image region 630, and only error information is displayed in the extracted user information region 640. Therefore, the existing image attached to the identification card 610 is displayed. This is the case when the image is removed and replaced with a new photo without the watermark information inserted. In this case, since all the information in the extracted image area 630 and the extracted user information area 640 do not match, it is determined that the ID card is forged, and thus the result information "Access Denied" is obtained.

7 is an exemplary diagram of a screen configuration of a software program for performing the hologram watermark insertion and detection method according to an embodiment of the present invention.

Referring to FIG. 7, a screen configuration 710 and a hologram watermark when a user program having a software program for executing the hologram watermark insertion and detection method is installed to execute the hologram watermark insertion method by executing the software program. The screen configuration 720 when the detection method is performed is illustrated.

Although there is no separate description on the execution method of the software program, it will be easily understood by those skilled in the art through the above description, and thus redundant description thereof will be omitted.

As described above, when the holographic watermarking insertion and detection method according to the present invention is used, higher encryption is possible due to the variety of encryption keys (that is, conversion keys), and pictures of users attached to identification cards or credit cards, etc. It is impossible to use illegally by others through comparison between the watermark information inserted into the picture.

Even if the other person's picture is replaced with his own picture, when restoring in the case of forgery, the corresponding card and the corresponding data can be received from the central server. It doesn't work.

If you do not know the applied 3D depth value (i.e., the reconstruction distance), the information hidden in the Fresnel region cannot be modulated, and the information in the Fresnel region can be predicted as information because it looks like diffused noise in space. none. In addition, the information concealed in the Fresnel region is not restored for the restoring distance outside the gap because the effective clearance of the restoring distance is very small.

In addition, as the amount of inserted information increases, data may be spread, and thus security may be enhanced.

Therefore, in the existing watermarking technology, the form of information that can be inserted into a still image with non-cognition is limited to simple text, a logo, etc., but the cover image is applied when the holographic watermarking insertion and detection method according to the present invention is applied. Since various information can be inserted at the same time without restriction of watermark information, it can be superior in terms of information security.

The present invention is not limited to the above embodiments, and many variations are possible by those skilled in the art within the spirit of the present invention.

As described above, according to the method and apparatus for inserting and detecting a hologram watermark according to the present invention, it is possible to easily determine the authenticity of copyright protection of digital contents and forgery of ID card, and to establish sound distribution order of digital work and forgery of ID card. Various crimes caused by this can be prevented.

In addition, the present invention can insert a large amount of various types of data (text, logo, image, etc.) into the original data invisibly.

In addition, the present invention not only has non-awareness, which has been pointed out as a limitation in the existing digital watermarking technology, but also enhances security by using the encryption characteristics of the hologram technology, thereby improving the forgery prevention level and security.

In addition, the present invention is robust to various signal processing and information corruption by using the redundancy component of the hologram, and is applicable to existing commercialized input / output systems, and more robust in parallel with non-replicable technologies such as digital optical memory technology. Develop information security products.

Claims (12)

A method of embedding watermark information in digital content or a user information medium, the method comprising: Receiving a plurality of watermark information and a cover image, wherein the cover image is an insertion area of the watermark information included in the digital content or the user information medium; Fresnel transforming the plurality of watermark information to generate a synthetic Fresnel hologram watermark existing on one frequency plane; Fast Fourier transforming the cover image to generate transform cover image data present on a frequency plane; Generating a digital watermarking cover image in which the composite Fresnel hologram watermark and the transform cover image are located on one frequency plane; Fast Fourier Transform the digital watermarking cover image to generate a watermarking cover image located on a spatial plane, wherein the watermarking cover image is present in the frequency domain in the cover image. Fresnel hologram watermark inserted Hologram watermark insertion method comprising a. The method of claim 1, Fresnel transforming the plurality of watermark information to generate a synthetic Fresnel hologram watermark existing on one frequency plane, Receiving a conversion key for converting each watermark information of the plurality of watermark information into individual Fresnel hologram watermarks; Fresnel transforming the respective watermark information to generate the individual Fresnel hologram watermark on the frequency plane reflecting the conversion key input corresponding to the respective watermark information. ; Placing the plurality of individual Fresnel hologram watermarks on a frequency plane and converting them into a composite Fresnel hologram watermark Hologram watermark insertion method comprising a. The method of claim 2, The conversion key includes a three-dimensional depth value in the Fresnel region where the watermark information is to be restored and an interference angle for converting the watermark information into the individual hologram watermarks for converting the watermark information. Hologram watermark insertion method characterized in that. The method according to claim 2 or 3, The individual Fresnel hologram watermark can be restored to the watermark information only when the conversion key is input. Hologram watermark insertion method characterized in that. The method of claim 2, When converted into the individual Fresnel hologram watermark, the watermark information and reference wave are off-axis. Hologram watermark insertion method characterized in that. A method for detecting watermark information embedded in a watermarking cover image included in the user information carrier to check whether a user information carrier is valid, wherein the cover image is the water contained in the user information carrier. Insertion area of mark information, Receiving the watermarking cover image; Fast Fourier Transform the watermarking cover image to generate a digital watermarking cover image residing on a frequency plane, wherein the digital watermarking cover image is superimposed on one frequency plane. Includes a Fresnel hologram watermark and transform cover image data; Extracting the composite Fresnel hologram watermark from the digital watermarking cover image, wherein the composite Fresnel hologram watermark is represented by a plurality of individual Fresnel hologram watermarks superimposed on one frequency plane; Detecting a predetermined conversion key corresponding to each individual Fresnel hologram watermark or receiving a conversion key from a user to convert any individual Fresnel hologram watermark into watermark information; Converting the individual Fresnel hologram watermark corresponding to the conversion key by inverse Fresnel by using the detected or input conversion key to convert it into watermark information on a space plane; Displaying the converted watermark information on a display unit or transmitting it to an operator system Hologram watermark information detection method comprising a. The method of claim 6, Checking whether the watermark cover image matches any one of the watermark information; If there is a match, displaying a valid test result on the display or transmitting to the operator system; If it does not match, display an error message on the display or send it to the operator system The holographic watermark information detection method further comprises. The method of claim 6, The conversion key includes at least one of a three-dimensional depth value in the Fresnel region where the watermark information is to be restored, and an interference angle for converting the watermark information into the individual hologram watermark for converting the watermark information, When the watermark information is converted into the individual Fresnel hologram watermark, the watermark information may be restored to the watermark information only when an input or set conversion key is input or set. Holographic watermark information detection method characterized in that. A holographic watermark embedding apparatus for embedding watermark information into digital content or user information medium, wherein the user information medium includes at least one of a social security card, a passport, an identification card, a driver's license, and a credit card; Means for receiving a plurality of watermark information and a cover image, wherein the cover image is an insertion area of the watermark information included in the digital content or the user information medium; Means for Fresnel transforming the plurality of watermark information to generate a composite Fresnel hologram watermark existing on one frequency plane; Means for fast Fourier transforming the cover image to generate transform cover image data residing on a frequency plane; Means for generating a digital watermarking cover image in which the composite Fresnel hologram watermark and the transform cover image are located on one frequency plane; Means for generating a watermarking cover image located on a spatial plane by fast Fourier transforming the digital watermarking cover image, wherein the watermarking cover image is present in the frequency domain in the cover image. Fresnel hologram watermark inserted Hologram watermark insertion apparatus comprising a. A holographic watermark detection apparatus for detecting watermark information embedded in a watermarking cover image included in the user information medium to check whether a user information medium is valid, wherein the cover image is stored in the user information medium. An embedding area of the watermark information included therein, Means for receiving the watermarking cover image; Means for fast Fourier transforming the watermarking cover image to produce a digital watermarking cover image residing on a frequency plane, wherein the digital watermarking cover image is superimposed on one frequency plane Includes a Fresnel hologram watermark and transform cover image data; Means for extracting the composite Fresnel hologram watermark from the digital watermarking cover image, wherein the composite Fresnel hologram watermark is represented by a plurality of individual Fresnel hologram watermarks superimposed on one frequency plane; Means for detecting a predetermined conversion key corresponding to each respective Fresnel hologram watermark to convert any individual Fresnel hologram watermark into watermark information; Means for inverse Fresnel converting the individual Fresnel hologram watermark corresponding to the conversion key into the watermark information on a space plane using the detected conversion key; Means for displaying the converted watermark information on a display unit or transmitting it to an operator system Holographic watermark information detection apparatus comprising a. In the recording medium which can be read by the user terminal, a program of instructions that can be executed by the user terminal is tangibly embodied to perform the hologram watermark embedding method. Receiving a plurality of watermark information and a cover image, wherein the cover image is an insertion area of the watermark information included in the digital content or the user information medium; Fresnel transforming the plurality of watermark information to generate a synthetic Fresnel hologram watermark existing on one frequency plane; Fast Fourier transforming the cover image to generate transform cover image data present on a frequency plane; Generating a digital watermarking cover image in which the composite Fresnel hologram watermark and the transform cover image are located on one frequency plane; Fast Fourier Transform the digital watermarking cover image to generate a watermarking cover image located on a spatial plane, wherein the watermarking cover image is present in the frequency domain in the cover image. Fresnel hologram watermark inserted Recording medium recording a program for executing the. In the recording medium which can be read by the user terminal, a program of instructions that can be executed by the user terminal is tangibly embodied to perform the hologram watermark embedding method. Receiving the watermarking cover image; Fast Fourier Transform the watermarking cover image to generate a digital watermarking cover image residing on a frequency plane, wherein the digital watermarking cover image is superimposed on one frequency plane. Includes a Fresnel hologram watermark and transform cover image data; Extracting the composite Fresnel hologram watermark from the digital watermarking cover image, wherein the composite Fresnel hologram watermark is represented by a plurality of individual Fresnel hologram watermarks superimposed on one frequency plane; Detecting a predetermined conversion key corresponding to each individual Fresnel hologram watermark or receiving a conversion key from a user to convert any individual Fresnel hologram watermark into watermark information; Converting the individual Fresnel hologram watermark corresponding to the conversion key by inverse Fresnel by using the detected or input conversion key to convert it into watermark information on a space plane; Displaying the converted watermark information on a display unit or transmitting it to an operator system Recording medium recording a program for executing the.