CN109840874A - A kind of digital watermarking authentication method and device - Google Patents

Abstract

The invention discloses a kind of digital watermarking authentication method and devices, comprising: generates the carrier image of insertion watermark information image, comprising: according to watermark information image, generates digital hologram；Using initial carrier image as the amplitude of the input object light function of lens front focal plane, using digital hologram as the output object light function of back focal plane, foundation includes the constraining equation of initial carrier image, digital hologram, phase function, it is calculated using Fractional Fourier transform and solves the phase function for meeting constraining equation, according to the phase function for meeting constraining equation, the carrier image of insertion watermark information image is obtained；Further include the extraction password determined for extracting digital hologram, according to initial carrier image and extracts password, extract digital hologram, be based on digital hologram, rebuild watermark information image.The present invention provides a kind of digital watermarking authentication methods and device with good anti-print performance.

Description

A kind of digital watermarking authentication method and device

Technical field

The present invention relates to field of information security technology, a kind of digital watermarking authentication method and device are particularly related to.

Background technique

Digital watermark technology is to be directly embedded into watermark information in carrier information or secondary indication, does not influence carrier information Use value, be also not easy to be ascertained and modify again.Digital watermark technology is obtained in multi-media information security research field Important application.Currently, being embedded in the image-carrier information of watermark information after printing, scanning, there are watermark letters in print field The problem of breath is lost.In recent years, information optical holography is because it is with multidimensional, large capacity, high design freedom, high robust Property, difficult lancinating, natural concurrency, many advantages such as be difficult to crack, be applied to Information hiding and digital watermarking field It is with a wide range of applications.

Summary of the invention

In view of this, having good anti-it is an object of the invention to propose a kind of digital watermarking authentication method and device Print performance.

Based on above-mentioned purpose, the present invention provides a kind of digital watermarking authentication methods, comprising:

Generate the carrier image of insertion watermark information image, comprising:

According to the watermark information image, digital hologram is generated；

It is rear burnt with the digital hologram using initial carrier image as the amplitude of the input object light function of lens front focal plane The output object light function in face, establishes constraining equation:

|F^P{ f (x, y) exp [j φ (x, y)] } |=g (ξ, η)

Wherein, f (x, y) is initial carrier image, and g (ξ, η) is the digital hologram, and φ (x, y) is to be solved expires The phase function of the foot constraining equation, j are unit imaginary number；

It is calculated using Fractional Fourier transform and solves the phase function for meeting the constraining equation；

According to the phase function for meeting constraining equation, the carrier image of the insertion watermark information image is obtained I (x, y):

I (x, y)=f (x, y) exp [j φ (x, y)⁽ⁿ⁾]

Wherein, φ (x, y)⁽ⁿ⁾For the phase function for meeting the constraining equation.

Optionally, the method also includes:

Determine the extraction password for extracting the digital hologram, comprising:

Singular value decomposition is carried out to the phase function for meeting constraining equation, obtains singular value matrix D and two Unitary matrice U and V are based on symmetric encipherment algorithm, are encrypted, obtained at encryption to the singular value matrix D using symmetric key Result D` is managed, using D` as the extraction password.

Optionally, the method also includes:

According to the initial carrier image and password is extracted, extracts the digital hologram, comprising:

The extraction password is decrypted using the symmetric key based on the symmetric encipherment algorithm, generates the surprise Different value matrix D；

Using the singular value matrix D and two unitary matrice U and V, reconstruct obtains the phase for meeting constraining equation Bit function；

Using the initial carrier image and the phase function for meeting constraining equation, the digital hologram is calculated Scheme g (ξ, η):

G (ξ, η)=F^p{ f (x, y) exp [j φ (x, y)⁽ⁿ⁾]}

Optionally, the method also includes:

Based on the digital hologram, the watermark information image is rebuild,

Wherein, IFn indicates fresnel diffraction integration inverse transformation, and O (x, y) is the watermark information image reconstructed, O (ξ, η) For optical field distribution of the watermark information image on plane of vision, x, y are respectively coordinate of the O (x, y) in the pixel of object plane, ξ, η is respectively coordinate of the O (ξ, η) in the pixel of plane of vision, and z is the distance between object plane and plane of vision, and λ is the wave of light Long, k=2 π/λ is wave number.

Optionally, described calculated using Fractional Fourier transform solves the phase function for meeting the constraining equation Method, comprising:

It is the amplitude for inputting object light function with the initial carrier image, calculates intermediate output object light function Q⁽ⁿ⁾(ξ, η), Q⁽ⁿ⁾The amplitude of (ξ, η) is | Q⁽ⁿ⁾(ξ, η) |, the intermediate phase function of plane of vision is φ (ξ, η)⁽ⁿ⁾,

Q⁽ⁿ⁾(ξ, η)=| Q⁽ⁿ⁾((ξ, η) | exp [j φ (ξ, η)⁽ⁿ⁾]=F^PF (x, y)) exp [j φ (x, y)^(n-1)]} (8)

It is the amplitude for exporting object light function with the digital hologram, with the intermediate phase function phi of the plane of vision (ξ, η)⁽ⁿ⁾For phase function, inverse Fractional Fourier transform is carried out, the intermediate phase function phi (x, y) of object plane is obtained⁽ⁿ⁾,

T⁽ⁿ⁾(x, y)=| T⁽ⁿ⁾(x, y) | exp [j φ (x, y)⁽ⁿ⁾]=IF^P{ g (ξ, η) exp [j φ (ξ, η)⁽ⁿ⁾]} (9)

Calculate the amplitude of the intermediate output object light function | Q⁽ⁿ⁾(ξ, η) | the root-mean-square error with the digital hologram MSE:

Wherein, N_x、N_yRespectively digital hologram/initial carrier image the pixel in the direction x, y number, 1≤i≤ N_x, 1≤k≤N_y；

According to the root-mean-square error, judge whether the root-mean-square error is less than preset error threshold, if so, described Intermediate phase function phi (x, y)⁽ⁿ⁾Meet the constraining equation, if it is not, recalculating centre according to formula (8)-(10) Phase function, and judge whether the intermediate phase function meets the constraining equation.

The embodiment of the present invention also provides a kind of digital watermarking authentication device, comprising:

Image embedding module, for generating the carrier image of insertion watermark information image, described image insertion module includes:

Digital hologram generation module, for generating digital hologram according to the watermark information image；

Image synthesis module, for according to the digital hologram and initial carrier image, processing to generate the insertion water Print the carrier image of information image, comprising:

It is rear burnt with the digital hologram using initial carrier image as the amplitude of the input object light function of lens front focal plane The output object light function in face, establishes constraining equation:

|F^P{ f (x, y) exp [j φ (x, y)] } |=g (ξ, η)

Wherein, f (x, y) is initial carrier image, and g (ξ, η) is the digital hologram, and φ (x, y) is to be solved expires The phase function of the foot constraining equation, j are unit imaginary number；

It is calculated using Fractional Fourier transform and solves the phase function for meeting the constraining equation；

According to the phase function for meeting constraining equation, the carrier image of the insertion watermark information image is obtained I (x, y):

I (x, y)=f (x, y) exp [j φ (x, y)⁽ⁿ⁾]

Wherein, φ (x, y)⁽ⁿ⁾For the phase function for meeting the constraining equation.

Optionally, described device further include:

Password determining module: for determining the extraction password for extracting the digital hologram, comprising:

Singular value decomposition is carried out to the phase function for meeting constraining equation, obtains singular value matrix D and two Unitary matrice U and V are based on symmetric encipherment algorithm, are encrypted, obtained at encryption to the singular value matrix D using symmetric key Result D` is managed, using D` as the extraction password.

Optionally, described device further include:

Image zooming-out module, for extracting the digital hologram, wrapping according to the initial carrier image and extraction password It includes:

The extraction password is decrypted using the symmetric key based on the symmetric encipherment algorithm, generates the surprise Different value matrix D；

Using the singular value matrix D and two unitary matrice U and V, reconstruct obtains the phase for meeting constraining equation Bit function；

Using the initial carrier image and the phase function for meeting constraining equation, the digital hologram is calculated Scheme g (ξ, η):

G (ξ, η)=F^p{ f (x, y) exp [j φ (x, y)⁽ⁿ⁾]}

Optionally, described device further include:

Watermark reconstruction module, for rebuilding watermark information image based on the digital hologram extracted, comprising:

Wherein, IFn indicates fresnel diffraction integration inverse transformation, and O (x, y) is the watermark information image reconstructed, O (ξ, η) For optical field distribution of the watermark information image on plane of vision, x, y are respectively coordinate of the O (x, y) in the pixel of object plane, ξ, η is respectively coordinate of the O (ξ, η) in the pixel of plane of vision, and z is the distance between object plane and plane of vision, and λ is the wave of light Long, k=2 π/λ is wave number.

Optionally, described calculated using Fractional Fourier transform solves the phase function for meeting the constraining equation Method, comprising:

It is the amplitude for inputting object light function with the initial carrier image, calculates intermediate output object light function Q⁽ⁿ⁾(ξ, η), Q⁽ⁿ⁾The amplitude of (ξ, η) is | Q⁽ⁿ⁾(ξ, η) |, the intermediate phase function of plane of vision is φ (ξ, η)⁽ⁿ⁾,

Q⁽ⁿ⁾(ξ, η)=| Q⁽ⁿ⁾((ξ, η) | exp [j φ (ξ, η)⁽ⁿ⁾]=F^PF (x, y)) exp [j φ (x, y)^(n-1)]} (8)

It is the amplitude for exporting object light function with the digital hologram, with the intermediate phase function phi of the plane of vision (ξ, η)⁽ⁿ⁾For phase function, inverse Fractional Fourier transform is carried out, the intermediate phase function phi (x, y) of object plane is obtained⁽ⁿ⁾,

T⁽ⁿ⁾(x, y)=| T⁽ⁿ⁾(x, y) | exp [j φ (x, y)⁽ⁿ⁾]=IF^P{ g (ξ, η) exp [j φ (ξ, η)⁽ⁿ⁾]} (9)

Calculate the amplitude of the intermediate output object light function | Q⁽ⁿ⁾(ξ, η) | the root-mean-square error with the digital hologram MSE:

Wherein, N_x、N_yRespectively digital hologram/initial carrier image the pixel in the direction x, y number, 1≤i≤ N_x, 1≤k≤N_y；

According to the root-mean-square error, judge whether the root-mean-square error is less than preset error threshold, if so, described Intermediate phase function phi (x, y)⁽ⁿ⁾Meet the constraining equation, if it is not, recalculating centre according to formula (8)-(10) Phase function, and judge whether the intermediate phase function meets the constraining equation.

From the above it can be seen that digital watermarking authentication method provided by the invention and device, have the advantages that

1) method and device under this invention only has initial carrier image simultaneously and meets the phase letter of constraint condition Number information, can just recover watermark information image；Initial carrier image and phase function are based on due to rebuilding watermarking images information It realizes, it is unrelated with the insertion carrier image of watermark information image, thus, the carrier image of insertion watermark information image is by printing Scanning after duplicating, will not influence watermarking images information, so that the carrier image of insertion watermark information image has very strong resist Print characteristic；

2) method and device under this invention carries out processing to watermark information image using holographic watermark technology and generates number Hologram considerably increases and cracks difficulty, even if obtaining phase function and password in the item of no holographic production parameter and method Under part, it can not also rebuild and restore watermark information image；Meanwhile using symmetric encipherment algorithm (such as SM4 national secret algorithm) to phase letter Number is encrypted, and is realized the multi-enciphering to watermark information image, is further improved and crack difficulty；

3) method and device under this invention realizes the Information hiding including multimedia messages in carrier image and mentions It takes, greatly expands the scope of application, can guarantee the authenticity, diversity, non-reproduction of watermark information, realize watermark information Effective certification of the true and false.

Detailed description of the invention

In order to more clearly explain the embodiment of the invention or the technical proposal in the existing technology, to embodiment or will show below There is attached drawing needed in technical description to be briefly described, it should be apparent that, the accompanying drawings in the following description is only this Some embodiments of invention for those of ordinary skill in the art without creative efforts, can be with It obtains other drawings based on these drawings.

Fig. 1 is the method flow schematic diagram of the carrier image of the generation insertion watermark information image of the embodiment of the present invention；

Fig. 2 is the method flow schematic diagram of the reconstruction watermark information image of the embodiment of the present invention；

Fig. 3 is the apparatus structure schematic diagram of the carrier image of the generation insertion watermark information image of the embodiment of the present invention；

Fig. 4 is the apparatus structure schematic diagram of the reconstruction watermark information image of the embodiment of the present invention.

Specific embodiment

To make the objectives, technical solutions, and advantages of the present invention clearer, below in conjunction with specific embodiment, and reference Attached drawing, the present invention is described in more detail.

It should be noted that all statements for using " first " and " second " are for differentiation two in the embodiment of the present invention The non-equal entity of a same names or non-equal parameter, it is seen that " first " " second " only for the convenience of statement, does not answer It is interpreted as the restriction to the embodiment of the present invention, subsequent embodiment no longer illustrates this one by one.

Fig. 1 is the method flow schematic diagram of the carrier image of the generation insertion watermark information image of the embodiment of the present invention, such as Shown in figure, digital watermarking authentication method provided in an embodiment of the present invention, the carrier image including generating insertion watermark information image, Method includes:

S10: according to watermark information image, digital hologram is generated；

The digital hologram is the Object light wave with holographic plate record and refers to optical interferometric fringe pattern sample.By hiding watermark Information image obtains object light using fresnel diffraction integration transformation calculations as object light source and is distributed, then carries out calculating shape with reference light At digital hologram.

Fresnel diffraction integration transformation are as follows:

Wherein, Fn indicates fresnel diffraction integration, and O (x, y) and O (ξ, η) are respectively the light wave of object plane and plane of vision Distribution function；J is unit imaginary number, and x, y are respectively coordinate of object light (watermark information image) O (x, y) in object plane pixel, ξ, η is respectively coordinate (also referred to as spatial frequency domain coordinate) of the object light diffraction light O (ξ, η) in plane of vision pixel；Z be object plane with The distance between plane of vision；λ is the wavelength of light；K=2 π/λ is wave number.The diffraction field distribution of light wave is calculated using formula (1) (referred to as fresnel diffraction field).

Object light using fresnel diffraction integration transformation calculations watermark information image in plane of vision is distributed are as follows:

Wherein, O₀(x, y) is the amplitude of object light, ψ (x, y) be object light object plane phase function (if watermark information is Image then ψ (x, y)=0), O (ξ, η) is object light diffraction field distribution of the object light in plane of vision,It is flat in observation for object light The phase function in face.

It selects reference light (directional light) are as follows:

R (ξ, η)=R₀exp[2πjαξ] (3)

Wherein, R (ξ, η) is light distribution of the reference light in plane of vision, R₀For the amplitude of reference light, α is the biography of directional light Broadcast direction.

The object light of plane of vision is overlapped with reference light, obtains the intensity distribution of digital hologram are as follows:

H (ξ, η)=| R (ξ, η) |²+ | O (ξ, η) |²+R^*(ξ, η) O (ξ, η)+R (ξ, η) O^*(ξ, η) (4)

Wherein, R (ξ, η), O (ξ, η) are respectively the optical field distribution of object light O (x, y) and reference light in plane of vision, subscript * Expression takes conjugate complex number.

Record:

G (ξ, η) is real number, i.e. g (ξ, η)=| g (ξ, η) |, then g (ξ, η) is the light of object light and reference light in plane of vision (interference fringe) is distributed by force, referred to as digital hologram.

In the embodiment of the present invention, watermark information image is the image generated according to multimedia messages, and multimedia messages include Text, audio, image etc. are handled multimedia messages if multimedia messages are text or audio, are generated corresponding Watermark information image.

According to Fractional Fourier transform:

Wherein, x, y are respectively the coordinate of the pixel of image m (x, y), and M (ξ, η) is known as the dimension Fourier of m (x, y) Spectrum, ξ, η are respectively the spatial frequency domain coordinate (or coordinate of plane of vision pixel) of dimension Fourier spectrum M (ξ, η)；π is circle Frequency, φ=π p/2, p are the rank of fractional fourier transform.

Digital hologram is embedded in initial carrier image, generates the specific method of the carrier image of insertion watermark information image It is:

S11: being rear burnt with digital hologram using initial carrier image as the amplitude of the input object light function of lens front focal plane The output object light function in face, establishes following constraining equation:

|F^P{ f (x, y) exp [j φ (x, y)] } |=g (ξ, η) (7)

Wherein, f (x, y) be initial carrier image, g (ξ, η) be digital hologram, φ (x, y) be satisfaction to be solved about The phase function of beam condition.

S12: it is calculated using Fractional Fourier transform and solves the phase function φ (x, y) for meeting the constraint condition；

Detailed process is:

S120: being the amplitude for inputting object light function with initial carrier image f (x, y), calculates intermediate output object light function Q⁽ⁿ⁾ (ξ, η):

Q⁽ⁿ⁾(ξ, η)=| Q⁽ⁿ⁾((ξ, η) | exp [j φ (ξ, η)⁽ⁿ⁾]=F^PF (x, y)) exp [j φ (x, y)^(n-1)]} (8)

Wherein, n is the number of iterations.By the calculating of formula (8), intermediate output object light function Q is obtained⁽ⁿ⁾(ξ, η), vibration Width is | Q⁽ⁿ⁾(ξ, η) |, the intermediate phase function of corresponding plane of vision is φ (ξ, η)⁽ⁿ⁾。

When first time iteration, n=1 generates initial phase function phi (x, y) using two-dimensional random function⁽ⁿ⁾, obtain centre Export object light function Q⁽¹⁾(ξ, η).

It is the amplitude for exporting object light function, the intermediate phase being calculated with formula (8) with digital hologram g (ξ, η) Function phi (ξ, η)⁽ⁿ⁾For phase function, carries out inverse Fractional Fourier transform and calculates:

T⁽ⁿ⁾(x, y)=| T⁽ⁿ⁾(x, y) | exp [j φ (x, y)⁽ⁿ⁾]=IF^P{ g (ξ, η) exp [j φ (ξ, η)⁽ⁿ⁾]} (9)

Wherein, IF^PIt indicates dimension inverse Fourier transform, only need to take the p in formula (6)-p can pass through formula (9) Calculating, obtain object plane intermediate phase function be φ (x, y)⁽ⁿ⁾。

S121: the amplitude of intermediate output object light function is calculated | Q⁽ⁿ⁾(ξ, η) | with digital hologram | g (ξ, η) | root mean square Error MSE:

Wherein, N_x、N_yRespectively digital hologram/initial carrier image (the pixel number of two images is identical) is in x, y The number of the pixel in direction, 1≤i≤N_x, 1≤k≤N_y。

S122: according to the root-mean-square error being calculated, judge the intermediate phase function phi (x, y) being currently calculated⁽ⁿ⁾ Whether constraint condition is met, if meeting constraint condition, the intermediate phase function phi (x, y) that will currently be calculated⁽ⁿ⁾It is determined as The phase function of constraining equation shown in coincidence formula (7) executes step S1110-S1112, weight if not meeting constraint condition New calculate determines intermediate phase function, and judges whether it meets constraint condition.

In the embodiment of the present invention, if root-mean-square error MSE is less than the error threshold of setting, it is judged to currently being calculated Intermediate phase function phi (x, y)⁽ⁿ⁾Constraint condition shown in coincidence formula (7), the value of error threshold are 0.05.

S13: according to the phase function for meeting constraint condition, the carrier image of insertion watermark information image is obtained.

According to the determining phase function φ (x, y) for meeting constraining equation shown in formula (7)⁽ⁿ⁾, obtain being concealed with water Function I (x, y) before the complex wave of print information image are as follows:

I (x, y)=f (x, y) exp [j φ (x, y)⁽ⁿ⁾] (11)

Function I (x, y) is the carrier image for being embedded in watermark information image, insertion number before complex wave shown in formula (11) The carrier image I (x, y) of hologram contains all information of initial carrier image and digital hologram, and amplitude is original load Body image f (x, y), as shown in formula (12), the fractional Fourier transform of function I (x, y) is digital hologram g before complex wave (ξ, η):

|F^P{ f (x, y) exp [j φ (x, y)⁽ⁿ⁾] |=g (ξ, η) (12)

Fig. 2 is the method flow schematic diagram of the reconstruction watermark information image of the embodiment of the present invention, as shown, the present invention is real The digital watermarking authentication method of example offer is provided, including extracts watermarking images information, method includes:

S20: the extraction password for extracting digital hologram is determined；

Based on the phase function φ (x, y) for meeting constraint condition⁽ⁿ⁾, generate the extraction password for extracting digital hologram. It specifically includes:

The phase function φ (x, y) of constraint condition will be met⁽ⁿ⁾Singular value decomposition is carried out, singular value matrix D and two are obtained Unitary matrice U and V are based on symmetric encipherment algorithm, are encrypted using symmetric key to singular value matrix D, by encryption result D ` is as the extraction password for extracting digital hologram.

S21: according to initial carrier image and password is extracted, extracts digital hologram；

According to initial carrier image and password D` is extracted, the method for extracting digital hologram is:

S210: it is decrypted using symmetric key to password D` is extracted based on symmetric encipherment algorithm, generates singular value matrix D；

S211: it reconstructs to obtain phase function φ (x, y) using singular value matrix D and two unitary matrice U and V⁽ⁿ⁾；

S212: initial carrier image f (x, y) and phase function φ is utilized⁽ⁿ⁾(x, y) is calculated digital hologram g (ξ, η):

G (ξ, η)=F^p{ f (x, y) exp [j φ (x, y)⁽ⁿ⁾]}

S22: being based on digital hologram, rebuilds watermark information image.

Watermark information image is rebuild using holographic inverse transformation, specifically:

Reference light (referred to as reproduction light) is multiplied with digital hologram g (ξ, η), is obtained:

Wherein, It is normal It counts, in formula (15), if ignoringIt will not influence optical field distribution O (ξ, η) of the object light on plane of vision.O^*(ξ, η) be O (ξ, Conjugate image η) does fresnel diffraction integration inverse transformation, then obtains number if selecting original plane for diffraction (imaging) plane The reconstruction watermark information image O (x, y) of hologram；It should be understood that the R in formula (15)²(ξ, η) O^*The inverse transformation of (ξ, η) exists The fresnel diffraction integration of original plane generates a distribution close to uniform background field distribution, has substantially no effect on and rebuilds watermark letter The quality of image is ceased, thus, fresnel diffraction integration inverse transformation is made to O (ξ, η), is obtained:

Wherein, IFn indicates fresnel diffraction integration inverse transformation, and O (x, y) is the watermark information image reconstructed.Wherein, it selects The reference light for selecting different directions can be rebuild to obtain different watermarking images information, if selecting reference light for R^*(ξ, η) is then rebuild The watermark information image arrived is O^*(ξ, η)

Fig. 3 is the apparatus structure schematic diagram of the carrier image of the generation insertion watermark information image of the embodiment of the present invention.Such as Shown in figure, digital watermarking authentication device provided in an embodiment of the present invention, comprising:

Image embedding module, for generating the carrier image of insertion watermark information image；

Described image is embedded in module

Digital hologram generation module, for generating digital hologram according to watermark information image；

Object light using fresnel diffraction integration transformation calculations watermark information image in plane of vision is distributed are as follows:

Wherein, O₀(x, y) is the amplitude of object light, and ψ (x, y) is phase function of the object light in object plane, and O (ξ, η) is object light In the object light diffraction field distribution of plane of vision,For object light plane of vision phase function.

G (ξ, η) is real number, i.e. g (ξ, η)=| g (ξ, η) |, then g (ξ, η) is the light of object light and reference light in plane of vision (interference fringe) is distributed by force, referred to as digital hologram.

Image synthesis module, for according to digital hologram and initial carrier image, processing to generate insertion watermark information figure The carrier image of picture.

Using initial carrier image as the amplitude of the input object light function of lens front focal plane, using digital hologram as back focal plane Object light function is exported, following constraining equation is established:

|F^P{ f (x, y) exp [j φ (x, y)] } |=g (ξ, η) (7)

Wherein, f (x, y) is initial carrier image, and g (ξ, η) is digital hologram, and φ (x, y) is phase function to be asked.

According to step S1110-S1112, is calculated using Fractional Fourier transform and solve the phase for meeting above-mentioned constraint condition Bit function φ (x, y)；

According to the phase function for meeting constraint condition, the carrier image I (x, y) of insertion watermark information image is obtained:

I (x, y)=f (x, y) exp [j φ (x, y)⁽ⁿ⁾] (11)

The carrier image I (x, y) of insertion watermark information image contains the whole of initial carrier image and digital hologram Information, amplitude is initial carrier image f (x, y), as shown in formula (14), the fractional Fourier transform of carrier image I (x, y) As digital hologram g (ξ, η) contains all information of watermark information image in digital hologram,

|F^P{ f (x, y) exp [j φ (x, y)⁽ⁿ⁾] |=g (ξ, η) (12)

Fig. 4 is the apparatus structure schematic diagram of the reconstruction watermark information image of the embodiment of the present invention, as shown, the number Watermark authentication device further include:

Watermark extracting module, for extracting watermark information image.

The watermark extracting module includes:

Password determining module: for determining the extraction password for extracting digital hologram；

The phase function φ (x, y) of constraint condition will be met⁽ⁿ⁾Singular value decomposition is carried out, singular value matrix D and two are obtained Unitary matrice U and V are based on symmetric encipherment algorithm, are encrypted using symmetric key to singular value matrix D, by encryption result D ` is as the extraction password for extracting digital hologram.

Image zooming-out module, for extracting digital hologram according to initial carrier image and extraction password；

It is decrypted using symmetric key to password D` is extracted based on symmetric encipherment algorithm, generates singular value matrix D；It utilizes Singular value matrix D and two unitary matrice U and V reconstruct to obtain phase function φ (x, y)⁽ⁿ⁾；Using initial carrier image f (x, y) and Phase function φ⁽ⁿ⁾(x, y) is calculated digital hologram g (ξ, η):

G (ξ, η)=F^p{ f (x, y) exp [j φ (x, y)⁽ⁿ⁾]}

Watermark reconstruction module, for rebuilding watermark information image based on the digital hologram extracted.

Watermark information image is rebuild using holographic inverse transformation,

Wherein, IFn indicates fresnel diffraction integration inverse transformation, and O (x, y) is the watermark information image reconstructed.

The device of above-described embodiment for realizing method corresponding in previous embodiment there is corresponding method to implement The beneficial effect of example, details are not described herein.

It should be understood by those ordinary skilled in the art that: the discussion of any of the above embodiment is exemplary only, not It is intended to imply that the scope of the present disclosure (including claim) is limited to these examples；Under thinking of the invention, above embodiments Or can also be combined between the technical characteristic in different embodiments, step can be realized with random order, and be existed such as Many other variations of the upper different aspect of the invention, for simplicity, they are not provided in details.

In addition, to simplify explanation and discussing, and in order not to obscure the invention, it can in provided attached drawing It is connect with showing or can not show with the well known power ground of integrated circuit (IC) chip and other components.Furthermore, it is possible to Device is shown in block diagram form, to avoid obscuring the invention, and this has also contemplated following facts, i.e., about this The details of the embodiment of a little block diagram arrangements be height depend on will implementing platform of the invention (that is, these details should It is completely within the scope of the understanding of those skilled in the art).Elaborating that detail (for example, circuit) is of the invention to describe In the case where exemplary embodiment, it will be apparent to those skilled in the art that can be in these no details In the case where or implement the present invention in the case that these details change.Therefore, these descriptions should be considered as explanation Property rather than it is restrictive.

Although having been incorporated with specific embodiments of the present invention, invention has been described, according to retouching for front It states, many replacements of these embodiments, modifications and variations will be apparent for those of ordinary skills.Example Such as, discussed embodiment can be used in other memory architectures (for example, dynamic ram (DRAM)).

The embodiment of the present invention be intended to cover fall into all such replacements within the broad range of appended claims, Modifications and variations.Therefore, all within the spirits and principles of the present invention, any omission, modification, equivalent replacement, the improvement made Deng should all be included in the protection scope of the present invention.

Claims (10)

1. a kind of digital watermarking authentication method characterized by comprising

Generate the carrier image of insertion watermark information image, comprising:

According to the watermark information image, digital hologram is generated；

Using initial carrier image as the amplitude of the input object light function of lens front focal plane, using the digital hologram as back focal plane Object light function is exported, constraining equation is established:

|F^P{ f (x, y) exp [j φ (x, y)] } |=g (ξ, η)

Wherein, f (x, y) is initial carrier image, and g (ξ, η) is the digital hologram, and φ (x, y) meets institute for be solved The phase function of constraining equation is stated, j is unit imaginary number；

It is calculated using Fractional Fourier transform and solves the phase function for meeting the constraining equation；

According to the phase function for meeting constraining equation, obtain the insertion watermark information image carrier image I (x, Y):

I (x, y)=f (x, y) exp [j φ (x, y)⁽ⁿ⁾]

Wherein, φ (x, y)⁽ⁿ⁾For the phase function for meeting the constraining equation.

2. the method according to claim 1, wherein further include:

Determine the extraction password for extracting the digital hologram, comprising:

Singular value decomposition is carried out to the phase function for meeting constraining equation, obtains singular value matrix D and two tenth of the twelve Earthly Branches squares Battle array U and V, is based on symmetric encipherment algorithm, is encrypted using symmetric key to the singular value matrix D, obtain encryption knot Fruit D`, using D` as the extraction password.

3. according to the method described in claim 2, it is characterized by further comprising:

According to the initial carrier image and password is extracted, extracts the digital hologram, comprising:

The extraction password is decrypted using the symmetric key based on the symmetric encipherment algorithm, generates the singular value Matrix D；

Using the singular value matrix D and two unitary matrice U and V, reconstruct obtains the phase letter for meeting constraining equation Number；

Using the initial carrier image and the phase function for meeting constraining equation, the digital hologram g is calculated (ξ, η):

G (ξ, η)=F^p{ f (x, y) exp [j φ (x, y)⁽ⁿ⁾]}。

4. according to the method described in claim 3, it is characterized by further comprising:

Based on the digital hologram, the watermark information image is rebuild,

Wherein, IFn indicates fresnel diffraction integration inverse transformation, and O (x, y) is the watermark information image reconstructed, and O (ξ, η) is water Optical field distribution of the information image on plane of vision is printed, x, y are respectively coordinate of the O (x, y) in the pixel of object plane, and ξ, η divide Not Wei O (ξ, η) the pixel of plane of vision coordinate, z be the distance between object plane and plane of vision, λ for light wavelength, K=2 π/λ is wave number.

5. the method according to claim 1, wherein described calculated using Fractional Fourier transform solves satisfaction The method of the phase function of the constraining equation, comprising:

It is the amplitude for inputting object light function with the initial carrier image, calculates intermediate output object light function Q⁽ⁿ⁾(ξ, η), Q⁽ⁿ⁾ The amplitude of (ξ, η) is | Q⁽ⁿ⁾(ξ, η) |, the intermediate phase function of plane of vision is φ (ξ, η)⁽ⁿ⁾,

Q⁽ⁿ⁾(ξ, η)=| Q⁽ⁿ⁾((ξ, η) | exp [j φ (ξ, η)⁽ⁿ⁾]=F^PF (x, y)) exp [j φ (x, y)^(n-1)]} (8)

Be the amplitude for exporting object light function with the digital hologram, with the intermediate phase function phi of the plane of vision (ξ, η)⁽ⁿ⁾For phase function, inverse Fractional Fourier transform is carried out, the intermediate phase function phi (x, y) of object plane is obtained⁽ⁿ⁾,

T⁽ⁿ⁾(x, y)=| T⁽ⁿ⁾(x, y) | exp [j φ (x, y)⁽ⁿ⁾]=IF^P{ g (ξ, η) exp [j φ (ξ, η)⁽ⁿ⁾]} (9)

Calculate the amplitude of the intermediate output object light function | Q⁽ⁿ⁾(ξ, η) | the root-mean-square error MSE with the digital hologram:

Wherein, N_x、N_yRespectively number of the digital hologram/initial carrier image in the pixel in the direction x, y, 1≤i≤N_x, 1 ≤k≤N_y；

According to the root-mean-square error, judge whether the root-mean-square error is less than preset error threshold, if so, the centre Phase function φ (x, y)⁽ⁿ⁾Meet the constraining equation, if it is not, recalculating intermediate phase according to formula (8)-(10) Function, and judge whether the intermediate phase function meets the constraining equation.

6. a kind of digital watermarking authentication device characterized by comprising

Image embedding module, for generating the carrier image of insertion watermark information image, described image insertion module includes:

Digital hologram generation module, for generating digital hologram according to the watermark information image；

Image synthesis module, for according to the digital hologram and initial carrier image, processing to generate the insertion watermark letter Cease the carrier image of image, comprising:

Using initial carrier image as the amplitude of the input object light function of lens front focal plane, using the digital hologram as back focal plane Object light function is exported, constraining equation is established:

|F^P{ f (x, y) exp [j φ (x, y)] } |=g (ξ, η)

Wherein, f (x, y) is initial carrier image, and g (ξ, η) is the digital hologram, and φ (x, y) meets institute for be solved The phase function of constraining equation is stated, j is unit imaginary number；

It is calculated using Fractional Fourier transform and solves the phase function for meeting the constraining equation；

According to the phase function for meeting constraining equation, obtain the insertion watermark information image carrier image I (x, Y):

I (x, y)=f (x, y) exp [j φ (x, y)⁽ⁿ⁾]

Wherein, φ (x, y)⁽ⁿ⁾For the phase function for meeting the constraining equation.

7. device according to claim 6, which is characterized in that further include:

Password determining module: for determining the extraction password for extracting the digital hologram, comprising:

Singular value decomposition is carried out to the phase function for meeting constraining equation, obtains singular value matrix D and two tenth of the twelve Earthly Branches squares Battle array U and V, is based on symmetric encipherment algorithm, is encrypted using symmetric key to the singular value matrix D, obtain encryption knot Fruit D`, using D` as the extraction password.

8. device according to claim 7, which is characterized in that further include:

Image zooming-out module, for extracting the digital hologram according to the initial carrier image and extraction password, comprising:

The extraction password is decrypted using the symmetric key based on the symmetric encipherment algorithm, generates the singular value Matrix D；

Using the singular value matrix D and two unitary matrice U and V, reconstruct obtains the phase letter for meeting constraining equation Number；

Using the initial carrier image and the phase function for meeting constraining equation, the digital hologram g is calculated (ξ, η):

G (ξ, η)=F^p{ f (x, y) exp [j φ (x, y)⁽ⁿ⁾]}。

9. device according to claim 8, which is characterized in that further include:

Watermark reconstruction module, for rebuilding watermark information image based on the digital hologram extracted, comprising:

Wherein, IFn indicates fresnel diffraction integration inverse transformation, and O (x, y) is the watermark information image reconstructed, and O (ξ, η) is water Optical field distribution of the information image on plane of vision is printed, x, y are respectively coordinate of the O (x, y) in the pixel of object plane, and ξ, η divide Not Wei O (ξ, η) the pixel of plane of vision coordinate, z be the distance between object plane and plane of vision, λ for light wavelength, K=2 π/λ is wave number.

10. device according to claim 6, which is characterized in that

It is described that the method for solving the phase function for meeting the constraining equation, packet are calculated using Fractional Fourier transform It includes:

It is the amplitude for inputting object light function with the initial carrier image, calculates intermediate output object light function Q⁽ⁿ⁾(ξ, η), Q⁽ⁿ⁾ The amplitude of (ξ, η) is | Q⁽ⁿ⁾(ξ, η) |, the intermediate phase function of plane of vision is φ (ξ, η)⁽ⁿ⁾,

Q⁽ⁿ⁾(ξ, η)=| Q⁽ⁿ⁾((ξ, η) | exp [j φ (ξ, η)⁽ⁿ⁾]=F^PF (x, y)) exp [j φ (x, y)^(n-1)]} (8)

Be the amplitude for exporting object light function with the digital hologram, with the intermediate phase function phi of the plane of vision (ξ, η)⁽ⁿ⁾For phase function, inverse Fractional Fourier transform is carried out, the intermediate phase function phi (x, y) of object plane is obtained⁽ⁿ⁾,

T⁽ⁿ⁾(x, y)=| T⁽ⁿ⁾(x, y) | exp [j φ (x, y)⁽ⁿ⁾]=IF^P{ g (ξ, η) exp [j φ (ξ, η)⁽ⁿ⁾]} (9)

Calculate the amplitude of the intermediate output object light function | Q⁽ⁿ⁾(ξ, η) | the root-mean-square error MSE with the digital hologram:

Wherein, N_x、N_yRespectively number of the digital hologram/initial carrier image in the pixel in the direction x, y, 1≤i≤N_x, 1 ≤k≤N_y；

According to the root-mean-square error, judge whether the root-mean-square error is less than preset error threshold, if so, the centre Phase function φ (x, y)⁽ⁿ⁾Meet the constraining equation, if it is not, recalculating intermediate phase according to formula (8)-(10) Function, and judge whether the intermediate phase function meets the constraining equation.