CN102682418A - Method for embedding and extracting multiple zero watermarks of digital image - Google Patents

Abstract

The invention discloses a method for embedding and extracting multiple zero watermarks of a digital image. Multiple zero watermarks are embedded and extracted in a discrete wavelet transform and discrete cosine transform composite domain. The multiple zero watermarks are embedded by constructing a binary watermark secret key by using a coefficient in an original digital image composite domain and then carrying out XOR operation with multiple actual binary digital watermarks, and the multiple zero watermarks are extracted by constructing a binary watermark private key by using a coefficient in a to-be-tested digital image composite domain and combining with zero watermark information. The method has the advantages of excellent watermark robustness and capability of resisting conventional image processing attack; and meanwhile, the method for embedding has the advantages that a plurality of binary digital watermarks are registered in a copyright database without any changing an original digital image, therefore, the embedded binary digital watermarks are not completely detected, the contradiction between the robustness and the difficulty in detection of the digital watermarks is balanced, and multiple requirements of application of the digital watermarks are met.

Description

A kind of a plurality of zero watermark embedding and method for distilling of digital picture

Technical field

The present invention relates to a kind of zero digital watermark, especially relate to a kind of a plurality of zero watermark embedding and method for distilling of digital picture.

Background technology

Digital watermarking is the research focus of current digit media information security fields as effectively solving a kind of technological means that Digital Media Works copyright protection and entitlement are differentiated.Digital watermarking will be brought into play due effect, must possess two fundamentals of robustness and imperceptible.Watermark robustness is meant Digital Media after through conventional digital signal processing or external attack, and the digital watermarking of embedding still has the aspect information such as copyright that detectability preferably still can reflect the original figure medium in other words.The watermark imperceptible is meant that the embedding of digital watermarking can not have influence on the sense of hearing or the visual quality of original figure medium, thereby can influence the using value of original figure medium.Obviously; Traditional digital watermark technology; Promptly carry out certain modification through spatial domain data or coefficient in transform domain to the original figure medium; Certain characteristic information that will comprise author or works is for example signed, copyright sign, sequence number, date or icon etc. are embedded in the original figure medium as digital watermarking; Exist the contradiction between watermark robustness and the watermark imperceptible inevitably: on the one hand, watermark robustness requires in the original figure medium as much as possible embed digital watermark information to attack to resist various conventional processing or to have a mind to, and on the other hand; The watermark imperceptible hopes that then embed digital watermark information as few as possible is to avoid causing the notable difference with the original figure medium; For example medical image and palmprint image etc. are particularly important for some responsive digital pictures for this, because the details pixel of this type digital picture has comprised very important information, the distortion that variation caused of any pixel all can influence the judgement to original digital image in this type digital picture.

In recent years, the proposition of zero digital watermark had solved watermark robustness and the contradiction between the watermark imperceptible in traditional digital watermark technology well, became new research branch in the digital watermark technology.So-called zero digital watermark; Unique characteristics through the original figure medium constructs a watermark keys exactly; Combine to form a kind of digital watermark technology of relevant zero watermark information post-registration in the intellecture property watermark information database with the digital watermarking that is of practical significance to be embedded again, it does not change to the original figure medium.Therefore, in zero digital watermark, the structure and the registration process of zero watermark are exactly the digital watermark embed process on the ordinary meaning, in case registration is accomplished, the original figure medium have possessed corresponding copyright protection ability with regard to being considered to comprise the real figure watermark.Because the real figure watermark in zero digital watermark is to be registered in the intellecture property watermark information database; Rather than be embedded in the original figure medium; Also just there is not any problem of original figure media quality decline; Just because of this characteristic, zero digital watermark well balance watermark robustness and the contradiction between the watermark imperceptible in traditional digital watermark technology.

At present, existing multiple zero watermarking project is suggested.2008; Ceng Fanjuan, Zhou Anmin have proposed a kind of digital picture zero watermarking project based on Contourlet conversion and svd on the computer utility publication; This scheme is at first carried out the Contourlet conversion to original image; With its sub-band images that is decomposed into a series of multiple dimensioned, localization, directivity, select low frequency sub-band to carry out the piecemeal svd again, construct zero watermark according to the unchangeability of the integer-bit size of first singular value in the every decomposition.2009; People such as Zhao Jie, king's Xuan and He Bing have proposed a kind of zero watermarking project based on image scrambling and wavelet transformation on computer engineering and science publication; This scheme is at first carried out scramble to watermarking images and is handled; Utilize low frequency sub and the watermarking images behind the scramble after the carrier image one-level wavelet decomposition to obtain extracting matrix then, carry out certain encryption that upsets to extracting matrix again, accomplish the embedding and the extraction of zero watermark thus.2010; Bi Xiuli, He Chunxiang and Cheng Cheng have proposed a kind of zero watermarking project based on log-polar coordinate mapping and small echo lifting on computer engineering and science publication, this scheme is at first carried out scramble with watermarking images; Carrier image is carried out convergent-divergent normalization to be handled; Carry out log-polar coordinate mapping then, carry out the one-level integer wavelet again and promote, watermarking images constructs zero watermark behind low frequency sub after utilization is decomposed at last and the scramble.2011; Wang Wujun has proposed the zero watermarking project of a kind of multistage discrete cosine transform and svd on computing machine and digital engineering publication; This scheme is at first carried out multistage discrete cosine transform to the original image that will embed, and extracts low frequency sub and it is carried out svd, secondly the watermarking images that embeds is carried out scramble; Watermarking images behind the scramble is carried out svd, at last the result after original image and twice svd of watermarking images is carried out computing and produce zero watermark.

Yet the zero watermarking project that has proposed at present is based on the digital watermark technology that single zero watermark embeds and extracts basically, exists the limitation of function singleness.In the Digital Media works, embed a plurality of digital watermarkings to satisfy the needs of different application purpose owing to exist more in the practical application; The signature that needs two people or many people after accomplishing such as width of cloth Digital Media works is to share copyright; Perhaps a width of cloth Digital Media works need indicate the legal information that the different owners (like creator, publisher, user etc.) use in different phases such as issue, sale, uses, and and for example the author of Digital Media works (or publisher) embeds the robust watermarking that is used for copyright authentication simultaneously and is used for fragile watermark of content authentication or the like in works.Therefore, consider that the zero watermarking project research that embeds a plurality of digital watermarkings has more actual application value and wide application prospect from the application diversity of digital watermarking.

Summary of the invention

Technical matters to be solved by this invention provides a kind of a plurality of zero watermark embedding and method for distilling of digital picture; It has realized in original digital image, embedding a plurality of zero watermarks; And a plurality of zero watermarks that embed have excellent robust performance, have guaranteed that effectively the quality of original digital image is unaffected simultaneously.

The present invention solves the problems of the technologies described above the technical scheme that is adopted: a kind of a plurality of zero watermark embedding methods of digital picture is characterized in that may further comprise the steps:

1.-1, at a plurality of zero watermark built-in ends, the original digital image of supposing to wait to embed K bi-level digital watermark is the gray level image of 8bit, and is designated as F; F={0≤f (m, n)≤255,1≤m≤M; 1≤n≤N}, wherein, K>=2; M representes to wait to embed the vertical resolution of the original digital image F of K bi-level digital watermark, and N representes to wait to embed the lateral resolution of the original digital image F of K bi-level digital watermark, and M * N representes to wait to embed the resolution of the original digital image F of K bi-level digital watermark; F (m, n) expression waits to embed that coordinate position is (m, the pixel value of pixel n) among the original digital image F of K bi-level digital watermark;

1.-2, at a plurality of zero watermark built-in ends, suppose that K to be embedded a bi-level digital watermark is all bianry image, and be designated as W respectively ₁, W ₂..., W _k... W _K, then for k bi-level digital watermark W to be embedded _k, W _k={ w _k(i _k, j _k)=0 or 1,1≤i _k≤I _k, 1≤j _k≤J _k, wherein, 1≤k≤K, I _kRepresent k bi-level digital watermark W to be embedded _kVertical resolution, J _kRepresent k bi-level digital watermark W to be embedded _kLateral resolution, I _k* J _kRepresent k bi-level digital watermark W to be embedded _kResolution, w _k(i _k, j _k) expression k bi-level digital watermark W to be embedded _kMiddle coordinate position is (i _k, j _k) the pixel value of pixel;

1.-3, treat the original digital image F that embeds K bi-level digital watermark and carry out normalization and handle, obtain the digital picture after the normalization processing, be designated as F '; With the middle coordinate position of digital picture F ' after the normalization processing is (m; The pixel value of pixel n) be designated as f ' (m, n), f ' (m; N)=and f (m, n)/255;

1.-4, F ' is carried out L level two-dimensional discrete wavelet conversion, obtain one first small echo ll channel and a plurality of first small echo details subgraph, the first small echo ll channel is designated as FA, wherein, the resolution of FA is (M/2 ^L) * (N/2 ^L),

Min () is for getting minimum value function, and max () is for getting max function, symbol The maximum integer less than himself, I are got in expression ₁Represent the 1st bi-level digital watermark W to be embedded ₁Vertical resolution, J ₁Represent the 1st bi-level digital watermark W to be embedded ₁Lateral resolution, I _KRepresent K bi-level digital watermark W to be embedded _KVertical resolution, J _KRepresent K bi-level digital watermark W to be embedded _KLateral resolution;

1.-5, FA is carried out two-dimension discrete cosine transform; Obtain first a two-dimension discrete cosine transform matrix of coefficients with the FA equal resolution, be designated as FAC, then FAC is carried out Zig-Zag scanning and arrange; Obtain one first one-dimensional discrete cosine transform coefficient sequence; Be designated as FACS, FACS={facs (x), 1≤x≤(M/2 ^L) * (N/2 ^L), wherein, x discrete cosine transform coefficient among facs (x) the expression FACS, the 2nd discrete cosine transform coefficient among the FACS begins to be the discrete cosine transform ac coefficient;

The resolution of each bi-level digital watermark that basis is to be embedded 1.-6, successively selects from FACS respectively and satisfies the I that imposes a condition ₁* J ₁, I ₂* J ₂..., I _k* J _k... And I _K* J _KIndividual discrete cosine transform ac coefficient constitutes K the first one-dimensional discrete cosine transform ac coefficient sequence, and correspondence is designated as FACS respectively ₁, FACS ₂..., FACS _k... And FACS _K, for the satisfied I that imposes a condition that from FACS, selects _k* J _kThe k that individual discrete cosine transform ac coefficient constitutes first an one-dimensional discrete cosine transform ac coefficient sequence FACS _k, FACS _k={ facs _k(y), 1≤y≤I _k* J _k, write down FACS then ₁, FACS ₂..., FACS _k... And FACS _KIn the correspondence position information of each discrete cosine transform ac coefficient in FACS, wherein, I ₂Represent the 2nd bi-level digital watermark W to be embedded ₂Vertical resolution, J ₂Represent the 2nd bi-level digital watermark W to be embedded ₂Lateral resolution, facs _k(y) expression FACS _kIn y discrete cosine transform ac coefficient, imposing a condition is the absolute value of the difference of any adjacent two the discrete cosine transform ac coefficients in the first one-dimensional discrete cosine transform ac coefficient sequence that make the to constitute difference threshold more than or equal to setting;

1.-7, compare FACS respectively ₁, FACS ₂..., FACS _k... And FACS _KIn the size of any adjacent two discrete cosine transform ac coefficients, and return logical value 1 or 0, for FACS according to comparative result _kIn any adjacent two discrete cosine transform ac coefficients, it is designated as facs respectively _k(z) and facs _k(z+1), judge facs _k() > z; Facs _k(z+1) whether set up,, then return logical value 1 if set up, otherwise, return logical value 0, wherein, 1≤z≤I _k* J _k-1; Compare FACS then ₁, FACS ₂..., FACS _k... And FACS _KIn last discrete cosine transform ac coefficient and the size of the 1st discrete cosine transform ac coefficient, and return logical value 1 or 0, for FACS according to comparative result _kIn last discrete cosine transform ac coefficient and the 1st discrete cosine transform ac coefficient, if the former is big, then return logical value 1, otherwise, return logical value 0; Again according to FACS ₁, FACS ₂..., FACS _k... And FACS _KEach self-corresponding logical value of returning makes up the first bi-level digital watermark keys one to one, for FACS _kThe corresponding logical value of returning, it is I that the logical value of returning is stored in a size by Row Column series arrangement mode _k* J _kTwo-dimensional matrix in, this two-dimensional matrix as k the first bi-level digital watermark keys, is designated as WB _k

1.-8, treat K bi-level digital watermark W of embedding ₁, W ₂..., W _k..., W _KCarry out scramble respectively and handle, K the bi-level digital watermark that obtains after scramble is handled correspondence respectively is designated as WS ₁, WS ₂..., WS _k... And WS _K, then with WS ₁, WS ₂..., WS _k... And WS _KRespectively with K the first bi-level digital watermark keys WB ₁, WB ₂..., WB _k... And WB _KCorrespondence is carried out XOR and is obtained K zero watermark information one by one, and correspondence is designated as WO respectively ₁, WO ₂..., WO _k... And WO _K, WO ₁=xor (WS ₁, WB ₁), WO ₂=xor (WS ₂, WB ₂) ..., WO _k=xor (WS _k, WB _k) ..., WO _K=xor (WS _K, WB _K), again with K zero watermark information WO ₁, WO ₂..., WO _k... And WO _KBe stored in the digital watermark information database of registration body, accomplish K bi-level digital watermark W ₁, W ₂..., W _k..., W _KEmbedding, wherein, WS ₁Expression is to W ₁Carry out the bi-level digital watermark that obtains after scramble is handled, WS ₂Expression is to W ₂Carry out the bi-level digital watermark that obtains after scramble is handled, WS _kExpression is to W _kCarry out the bi-level digital watermark that obtains after scramble is handled, WS _KExpression is to W _KCarry out the bi-level digital watermark that obtains after scramble is handled, WB ₁Represent the 1st first bi-level digital watermark keys, WB ₂Represent the 2nd first bi-level digital watermark keys, WB _KRepresent K the first bi-level digital watermark keys, xor () is the XOR function;

1.-9, at a plurality of zero watermark built-in ends, with the FACS of record ₁, FACS ₂..., FACS _k... And FACS _KIn the positional information of each discrete cosine transform ac coefficient in FACS, K zero a watermark information WO ₁, WO ₂..., WO _k..., WO _KAnd K bi-level digital watermark W ₁, W ₂..., W _k..., W _KBe transferred to a plurality of zero watermark extracting ends.

Described step 1.-6 in FACS ₁, FACS ₂..., FACS _k... And FACS _KIn the absolute value of difference of any adjacent two discrete cosine transform ac coefficients respectively more than or equal to δ ₁, δ ₂..., δ _k... And δ _K, wherein, δ ₁Expression is to FACS ₁In the 1st difference threshold setting of the absolute value of difference of any adjacent two discrete cosine transform ac coefficients, δ ₂Expression is to FACS ₂In the 2nd difference threshold setting of the absolute value of difference of any adjacent two discrete cosine transform ac coefficients, δ _kExpression is to FACS _kIn k difference threshold setting of the absolute value of difference of any adjacent two discrete cosine transform ac coefficients, δ _KExpression is to FACS _KIn K difference threshold setting of the absolute value of difference of any adjacent two discrete cosine transform ac coefficients.

A kind of a plurality of zero watermark extracting methods of digital picture is characterized in that may further comprise the steps:

2.-1, at a plurality of zero watermark extracting ends, the digital picture of K to be extracted bi-level digital watermark is designated as TF, TF={0≤tf (m '; N ')≤and 255,1≤m '≤M ', 1≤n '≤N ' }; Wherein, K>=2, the vertical resolution of the digital picture TF of K to be extracted bi-level digital watermark of M ' expression; The lateral resolution of the digital picture TF of K to be extracted bi-level digital watermark of N ' expression; The resolution of the digital picture TF of M ' * K to be extracted bi-level digital watermark of N ' expression, the resolution of the digital picture TF of K to be extracted bi-level digital watermark and the embedding of a plurality of zero watermark built-in ends have the resolution of digital picture of digital watermarking identical, tf (m '; N ') coordinate position is the pixel value of the pixel of (m ', n ') among the digital picture TF of K to be extracted bi-level digital watermark of expression;

2.-2, at a plurality of zero watermark extracting ends, K to be extracted bi-level digital watermark is designated as W ' respectively ₁, W ' ₂..., W ' _k... And W ' _K, for k bi-level digital watermark W ' to be extracted _k, W ' _k=w ' _k(i ' _k, j ' _k)=0 or 1,1≤i ' _k≤I ' _k, 1≤j ' _k≤J ' _k, wherein, 1≤k≤K, I ' _kRepresent k bi-level digital watermark W ' to be extracted _kVertical resolution, J ' _kRepresent k bi-level digital watermark W ' to be extracted _kLateral resolution, I ' _k* J ' _kRepresent k bi-level digital watermark W ' to be extracted _kResolution, k bi-level digital watermark W ' to be extracted _kThe resolution of k bi-level digital watermark embedding of resolution and a plurality of zero watermark built-in ends identical, w ' _k(i ' _k, j ' _k) expression k bi-level digital watermark W ' to be extracted _kIn coordinate position be (i ' _k, j ' _k) the pixel value of pixel;

2.-3, the digital picture TF of K to be extracted bi-level digital watermark carried out normalization handle, obtain the digital picture after normalization is handled, be designated as TF '; With the middle coordinate position of digital picture TF ' after the normalization processing be (m '; The pixel value of pixel n ') is designated as tf ' (m ', n '), tf ' (m '; N ')=tf (m ', n ')/255;

2.-4, TF ' is carried out L ' level two-dimensional discrete wavelet conversion, obtain one second small echo ll channel and a plurality of second small echo details subgraph, the second small echo ll channel is designated as TFA, wherein, the resolution of TFA is (M '/2 ^L') * (N '/2 ^L'),

Min () is for getting minimum value function, and max () is for getting max function, symbol

The maximum integer less than himself, I are got in expression ₁The 1st the bi-level digital watermark W that ' expression is to be extracted ₁' vertical resolution, J ₁The 1st the bi-level digital watermark W that ' expression is to be extracted ₁' lateral resolution, I _KK the bi-level digital watermark W ' that ' expression is to be extracted _KVertical resolution, J _KK the bi-level digital watermark W ' that ' expression is to be extracted _KLateral resolution;

2.-5, TFA is carried out two-dimension discrete cosine transform; Obtain second a two-dimension discrete cosine transform matrix of coefficients with the TFA equal resolution, be designated as TFAC, then TFAC is carried out Zig-Zag scanning and arrange; Obtain one second one-dimensional discrete cosine transform coefficient sequence; Be designated as TFACS, TFACS={tfacs (x '), 1≤x '≤(M '/2 ^L') * (N '/2 ^L'), wherein, the individual discrete cosine transform coefficient of x ' among tfacs (x ') the expression TFACS, the 2nd discrete cosine transform coefficient among the TFACS begins to be the discrete cosine transform ac coefficient;

2.-6 the FACS that, writes down according to a plurality of zero watermark built-in ends ₁, FACS ₂..., FACS _k... And FACS _KIn the correspondence position information of each discrete cosine transform ac coefficient in FACS, from TFACS, extract the I of correspondence position respectively ₁' * J ₁', I ₂' * J ₂' ..., I _k' * J _k' ... And I _K' * J _K' individual discrete cosine transform ac coefficient constitutes K the second one-dimensional discrete cosine transform ac coefficient sequence, and correspondence is designated as TFACS respectively ₁, TFACS ₂..., TFACS _k... And TFACS _K, for FACS according to a plurality of zero watermark built-in end records _kIn the correspondence position information of each discrete cosine transform ac coefficient in FACS, from TFACS, extract the I of correspondence position _k' * J _kK the second one-dimensional discrete cosine transform ac coefficient sequence TFACS of ' individual discrete cosine transform ac coefficient formation _k, TFACS _k={ tfacs _k(y '), 1≤y '≤I _k' * J _k', wherein, I _kK the bi-level digital watermark W ' that ' expression is to be extracted _kVertical resolution, J _kK the bi-level digital watermark W ' that ' expression is to be extracted _kLateral resolution, tfacs _k(y ') representes TFACS _kIn the individual discrete cosine transform ac coefficient of y ';

2.-7, compare TFACS respectively ₁, TFACS ₂..., TFACS _k... And TFACS _KIn the size of any adjacent two discrete cosine transform ac coefficients, and return logical value 1 or 0, for TFACS according to comparative result _kIn any adjacent two discrete cosine transform ac coefficients, it is designated as tfacs respectively _k(z ') and tfacs _kTfacs is judged in (z '+1) _k(z ')>Tfacs _kWhether set up (z '+1), if set up, then returns logical value 1, otherwise, return logical value 0, wherein, 1≤z '≤I _k' * J _k'-1; Compare TFACS then ₁, TFACS ₂..., TFACS _k... And TFACS _KIn last discrete cosine transform ac coefficient and the size of the 1st discrete cosine transform ac coefficient, and return logical value 1 or 0, for TFACS according to comparative result _kIn last discrete cosine transform ac coefficient and the 1st discrete cosine transform ac coefficient, if the former is big, then return logical value 1, otherwise, return logical value 0; Again according to TFACS ₁, TFACS ₂..., TFACS _k... And TFACS _KEach self-corresponding logical value of returning makes up the second bi-level digital watermark keys one to one, for TFACS _kThe corresponding logical value of returning, it is I that the logical value of returning is stored in a size by Row Column series arrangement mode _k' * J _k' two-dimensional matrix in, this two-dimensional matrix as k the second bi-level digital watermark keys, is designated as TWB _k

2.-8, will be from K zero watermark information WO of a plurality of zero watermark built-in ends ₁, WO ₂..., WO _k... And WO _K, respectively with K the second bi-level digital watermark keys TWB ₁, TWB ₂..., TWB _k... And TWB _KCorrespondence is carried out XOR one by one, recovers to obtain K bi-level digital watermark, and correspondence is designated as TW respectively ₁, TW ₂..., TW _k... And TW _K, TW ₁=xor (WO ₁, TWB ₁), TW ₂=xor (WO ₂, TWB ₂) ..., TW _k=xor (WO _k, TWB _k) ..., TW _K=xor (WO _K, TWB _K), wherein, TWB ₁Represent the 1st second bi-level digital watermark keys, TWB ₂Represent the 2nd second bi-level digital watermark keys, TWB _kRepresent k the second bi-level digital watermark keys, TWB _KRepresent K the second bi-level digital watermark keys, xor () is the XOR function;

2.-9, respectively to K bi-level digital watermark TW ₁, TW ₂..., TW _k... And TW _KThe random processing that is inverted, K the bi-level digital watermark that obtains having copyright authentication information, correspondence is designated as respectively

With

K the bi-level digital watermark that 2.-10, will have copyright authentication information

With

K the bi-level digital watermark W that embeds with a plurality of zero watermark built-in ends respectively ₁, W ₂..., W _k... And W _KCorrespondence is carried out similarity calculating one by one, and correspondence obtains K normalized correlation coefficient, judges whether extract K the bi-level digital watermark W that a plurality of zero watermark built-in ends embed according to the size of K normalized correlation coefficient then ₁, W ₂..., W _k... And W _K

Described step detailed process 2.-10 is:

Z1, K the bi-level digital watermark that will have copyright authentication information

With K the bi-level digital watermark W that embeds with a plurality of zero watermark built-in ends respectively ₁, W ₂..., W _k... And W _KCorrespondence is carried out similarity calculating one by one, and correspondence obtains K normalized correlation coefficient, for inciting somebody to action

With W _kCarry out k normalized correlation coefficient obtaining after similarity is calculated, it is designated as

$\mathrm{\ρ}(W_k,W_k^{*})=\frac{\underset{i_k=1}{\overset{I_k}{\mathrm{\Σ}}}\underset{j_k=1}{\overset{J_k}{\mathrm{\Σ}}}((w_k(i_k,j_k)-\stackrel{\‾}{w_k})\×(w_k^{*}(i_k,j_k)-\stackrel{\‾}{w_k^{*}}))}{\sqrt{\underset{i_k=1}{\overset{I_k}{\mathrm{\Σ}}}\underset{j_k=1}{\overset{J_k}{\mathrm{\Σ}}}{(w_k(i_k,j_k)-\stackrel{\‾}{w_k})}^2\underset{i_k=1}{\overset{I_k}{\mathrm{\Σ}}}\underset{j_k=1}{\overset{J_k}{\mathrm{\Σ}}}{(w_k^{*}(i_k,j_k)-\stackrel{\‾}{w_k^{*}})}^2}},$ Wherein, w _k(i _k, j _k) k bi-level digital watermark W embedding of a plurality of zero watermark built-in ends of expression _kMiddle coordinate position is (i _k, j _k) the pixel value of pixel, K the bi-level digital watermark W that a plurality of zero watermark built-in ends embed _kIn the average of pixel value of all pixels,

K the bi-level digital watermark that expression has copyright authentication information

Middle coordinate position is (i _k, j _k) the pixel value of pixel,

K the bi-level digital watermark that expression has copyright authentication information

In the average of pixel value of all pixels;

Z2, judge whether extract K the bi-level digital watermark W that a plurality of zero watermark built-in ends embed according to the size of K normalized correlation coefficient ₁, W ₂..., W _k... And W _K, for normalized correlation coefficient

If

Value be 1, then confirm W _kNondestructively extracted, if

Value more than or equal to δ _TAnd, then confirm W less than 1 _kExtract successfully, if

Value less than δ _T, then confirm W _kExtract failure, wherein, δ _TExpression watermark extracting thresholding.

Compared with prior art, the invention has the advantages that:

1) than existing single zero digital watermark; Embedding grammar of the present invention can be according to the needs of practical application; Embed when realizing a plurality of bi-level digital watermark of various objectives, different purposes; And do not disturb mutually between a plurality of bi-level digital watermarks that embed, therefore more can satisfy the application diversity of digital watermarking, have bigger actual application value and wide application prospect.

2) than traditional digital watermark technology; Embedding grammar of the present invention is not embedded into a plurality of bi-level digital watermarks of reality in the original digital image; But it is registered in the digital watermark information database; Therefore not only realize the complete imperceptible of bi-level digital watermark that embeds, and raw digital image data has not been produced any destruction, do not had any problem of image quality decrease; Kept the original digital image information integrity, this is highly suitable for the for example copyright protection of aspects such as medical image, palmprint image and military image of some responsive digital pictures.

3) embedding of the present invention and method for distilling are in the compositum of two-dimensional discrete wavelet conversion (DWT) and two-dimension discrete cosine transform (DCT), to carry out; Both characteristics have been made full use of; Thereby a plurality of zero watermarks that realized having the anti-normal image processing attack of excellent robust performance embed and extract, well balance robustness and the contradiction between the imperceptible of digital watermarking.

Description of drawings

Fig. 1 a is original Lena digital picture;

Fig. 1 b is the watermark of original two-value signature;

Fig. 1 c is the watermark of original two-value sequence number;

Fig. 1 d is the watermark of original two-value icon;

Fig. 2 a is the Lena digital picture behind binary watermarking of embedding;

Fig. 2 b is the Lena digital picture behind two binary watermarkings of embedding;

Fig. 2 c is the Lena digital picture behind three binary watermarkings of embedding;

The two-value signature watermark of Fig. 2 d for from Fig. 2 c, extracting;

The two-value sequence number watermark of Fig. 2 e for from Fig. 2 c, extracting;

The two-value icon watermark of Fig. 2 f for from Fig. 2 c, extracting;

Fig. 3 a is for to add the watermark Lena digital picture after 0.2 to the digital picture shown in Fig. 2 c with all pixel values;

Fig. 3 b is for to add the watermark Lena digital picture after 0.5 to the digital picture shown in Fig. 2 c with all pixel values;

Fig. 3 c is for to subtract the watermark Lena digital picture after 0.2 to the digital picture shown in Fig. 2 c with all pixel values;

Fig. 3 d is for to subtract the watermark Lena digital picture after 0.5 to the digital picture shown in Fig. 2 c with all pixel values;

The two-value signature watermark of Fig. 3 e for from Fig. 3 a, Fig. 3 b and Fig. 3 c, extracting;

The two-value sequence number watermark of Fig. 3 f for from Fig. 3 a, Fig. 3 b and Fig. 3 c, extracting;

The two-value icon watermark of Fig. 3 g for from Fig. 3 a, Fig. 3 b and Fig. 3 c, extracting;

Fig. 4 a is to the watermark Lena digital picture of the digital picture shown in Fig. 2 c after histogram equalization is handled;

The two-value signature watermark of Fig. 4 b for from Fig. 4 a, extracting;

The two-value sequence number watermark of Fig. 4 c for from Fig. 4 a, extracting;

The two-value icon watermark of Fig. 4 d for from Fig. 4 a, extracting;

Fig. 5 a is to the watermark Lena digital picture of the digital picture shown in Fig. 2 c behind [5 * 5] window medium filtering;

Fig. 5 b is to the watermark Lena digital picture of the digital picture shown in Fig. 2 c behind [11 * 11] window medium filtering;

The two-value signature watermark of Fig. 5 c for from Fig. 5 a, extracting;

The two-value sequence number watermark of Fig. 5 d for from Fig. 5 a, extracting;

The two-value icon watermark of Fig. 5 e for from Fig. 5 a, extracting;

The two-value signature watermark of Fig. 5 f for from Fig. 5 b, extracting;

The two-value sequence number watermark of Fig. 5 g for from Fig. 5 b, extracting;

The two-value icon watermark of Fig. 5 h for from Fig. 5 b, extracting;

Fig. 6 a is to the watermark Lena digital picture of the digital picture shown in Fig. 2 c after the JPEG of 10% quality factor compression;

Fig. 6 b is to the watermark Lena digital picture of the digital picture shown in Fig. 2 c after the JPEG of 4% quality factor compression;

The two-value signature watermark of Fig. 6 c for from Fig. 6 a, extracting;

The two-value sequence number watermark of Fig. 6 d for from Fig. 6 a, extracting;

The two-value icon watermark of Fig. 6 e for from Fig. 6 a, extracting;

The two-value signature watermark of Fig. 6 f for from Fig. 6 b, extracting;

The two-value sequence number watermark of Fig. 6 g for from Fig. 6 b, extracting;

The two-value icon watermark of Fig. 6 h for from Fig. 6 b, extracting;

Fig. 7 a is for being that 0 variance is the watermark Lena digital picture after 0.02 Gaussian noise to the digital picture shown in Fig. 2 c stack average;

Fig. 7 b is for being that 0 variance is the watermark Lena digital picture after 0.05 Gaussian noise to the digital picture shown in Fig. 2 c stack average;

The two-value signature watermark of Fig. 7 c for from Fig. 7 a, extracting;

The two-value sequence number watermark of Fig. 7 d for from Fig. 7 a, extracting;

The two-value icon watermark of Fig. 7 e for from Fig. 7 a, extracting;

The two-value signature watermark of Fig. 7 f for from Fig. 7 b, extracting;

The two-value sequence number watermark of Fig. 7 g for from Fig. 7 b, extracting;

The two-value icon watermark of Fig. 7 h for from Fig. 7 b, extracting;

Fig. 8 a is for cutting the watermark Lena digital picture behind 128 * 128 pixels of the upper left corner to the digital picture shown in Fig. 2 c;

Fig. 8 b is for cutting the watermark Lena digital picture behind 256 * 256 pixels of the upper left corner to the digital picture shown in Fig. 2 c;

The two-value signature watermark of Fig. 8 c for from Fig. 8 a, extracting;

The two-value sequence number watermark of Fig. 8 d for from Fig. 8 a, extracting;

The two-value icon watermark of Fig. 8 e for from Fig. 8 a, extracting;

The two-value signature watermark of Fig. 8 f for from Fig. 8 b, extracting;

The two-value sequence number watermark of Fig. 8 g for from Fig. 8 b, extracting;

The two-value icon watermark of Fig. 8 h for from Fig. 8 b, extracting;

Fig. 9 a is for rotating the watermark Lena digital picture after 5 degree recover former direction again to the digital picture shown in Fig. 2 c through counter clockwise direction;

Fig. 9 b is for rotating the watermark Lena digital picture after 25 degree recover former direction again to the digital picture shown in Fig. 2 c through counter clockwise direction;

The two-value signature watermark of Fig. 9 c for from Fig. 9 a, extracting;

The two-value sequence number watermark of Fig. 9 d for from Fig. 9 a, extracting;

The two-value icon watermark of Fig. 9 e for from Fig. 9 a, extracting;

The two-value signature watermark of Fig. 9 f for from Fig. 9 b, extracting;

The two-value sequence number watermark of Fig. 9 g for from Fig. 9 b, extracting;

The two-value icon watermark of Fig. 9 h for from Fig. 9 b, extracting.

Embodiment

Embodiment describes in further detail the present invention below in conjunction with accompanying drawing.

The a plurality of zero watermark embedding and method for distilling of a kind of digital picture that the present invention proposes, watermark embeds and extracts all is in the compositum of wavelet transform and discrete cosine transform, to carry out, and has made full use of both excellent specific properties.The main process that a plurality of zero watermarks embed is: the wavelet transform that at first original digital image is carried out suitable level; And the small echo ll channel that obtains carried out discrete cosine transform again; The resolution of K the bi-level digital watermark that foundation is to be embedded then; Choose the discrete cosine transform ac coefficient that absolute value that K group satisfies certain difference requires respectively and constitute K discrete cosine transform ac coefficient sequence; Construct the bi-level digital watermark keys of K robust at last according to discrete cosine transform ac coefficient magnitude relationship each other in each sequence, and carry out being saved in the embedding that registration body accomplishes K zero watermark behind the XOR with the K that is of practical significance a bi-level digital watermark to be embedded; The main process of a plurality of zero watermark extracting is: through the digital picture of K to be extracted bi-level digital watermark is carried out similar wavelet transform and discrete cosine transform processing procedure; K zero watermark information in conjunction with being kept in the registration body extracts K relevant watermark with copyright or the entitlement of proof to original digital image.

A plurality of zero watermark embedding methods of a kind of digital picture of the present invention, it may further comprise the steps:

1.-1, at a plurality of zero watermark built-in ends, the original digital image of supposing to wait to embed K bi-level digital watermark is the gray level image of 8bit, and is designated as F; F={0≤f (m, n)≤255,1≤m≤M; 1≤n≤N}, wherein, K>=2; M representes to wait to embed the vertical resolution of the original digital image F of K bi-level digital watermark, and N representes to wait to embed the lateral resolution of the original digital image F of K bi-level digital watermark, and M * N representes to wait to embed the resolution of the original digital image F of K bi-level digital watermark; (m, n) expression waits to embed that coordinate position is (m, the pixel value of pixel n) among the original digital image F of K bi-level digital watermark to f.

1.-2, at a plurality of zero watermark built-in ends, suppose that K a to be embedded digital watermarking is all bianry image, and be designated as W respectively ₁, W ₂..., W _k..., W _K, then for k bi-level digital watermark W to be embedded _k, W _k={ w _k(i _k, j _k)=0 or 1,1≤i _k≤I _k, 1≤j _k≤J _k, wherein, 1≤k≤K, I _kRepresent k bi-level digital watermark W to be embedded _kVertical resolution, J _kRepresent k bi-level digital watermark W to be embedded _kLateral resolution, I _k* J _kRepresent k bi-level digital watermark W to be embedded _kResolution, w _k(i _k, j _k) expression k bi-level digital watermark W to be embedded _kMiddle coordinate position is (i _k, j _k) the pixel value of pixel.

In this specific embodiment, K a to be embedded digital watermarking can be selected the corresponding copyright information with practical significance or the author or the bianry images such as owner's signature, sign, sequence number, date or company's icon of entitlement information for use.

1.-3, treat the original digital image F that embeds K bi-level digital watermark and carry out normalization and handle, obtain the digital picture after the normalization processing, be designated as F '; With the middle coordinate position of digital picture F ' after the normalization processing is (m; The pixel value of pixel n) be designated as f ' (m, n), f ' (m; N)=and f (m, n)/255.

1.-4, F ' is carried out L level two-dimensional discrete wavelet conversion, obtain one first small echo ll channel and a plurality of first small echo details subgraph, the first small echo ll channel is designated as FA, wherein, the resolution of FA is (M/2 ^L) * (N/2 ^L),

Min () is for getting minimum value function, and max () is for getting max function, symbol The maximum integer less than himself is got in expression, and promptly this symbol is for rounding symbol, I downwards ₁Represent the 1st bi-level digital watermark W to be embedded ₁Vertical resolution, J ₁Represent the 1st bi-level digital watermark W to be embedded ₁Lateral resolution, I _KRepresent K bi-level digital watermark W to be embedded _KVertical resolution, J _KRepresent K bi-level digital watermark W to be embedded _KLateral resolution.

1.-5, FA is carried out two-dimension discrete cosine transform; Obtain first a two-dimension discrete cosine transform matrix of coefficients with the FA equal resolution, be designated as FAC, then FAC is carried out Zig-Zag scanning and arrange; Obtain one first one-dimensional discrete cosine transform coefficient sequence; Be designated as FACS, FACS={facs (x), 1≤x≤(M/2 ^L) * (N/2 ^L), wherein, x discrete cosine transform coefficient among facs (x) the expression FACS, the 2nd discrete cosine transform coefficient among the FACS begins to be the discrete cosine transform ac coefficient.

The resolution of each bi-level digital watermark that basis is to be embedded 1.-6, successively selects from FACS respectively and satisfies the I that imposes a condition ₁* J ₁, I ₂* J ₂..., I _k* J _k... And I _K* J _KIndividual discrete cosine transform ac coefficient constitutes K the first one-dimensional discrete cosine transform ac coefficient sequence, and correspondence is designated as FACS respectively ₁, FACS ₂..., FACS _k... And FACS _K, for the satisfied I that imposes a condition that from FACS, selects _k* J _kThe k that individual discrete cosine transform ac coefficient constitutes first an one-dimensional discrete cosine transform ac coefficient sequence FACS _k, FACS _k={ facs _k(y), 1≤y≤I _k* J _k, write down FACS then ₁, FACS ₂..., FACS _k... And FACS _KIn the correspondence position information of each discrete cosine transform ac coefficient in FACS, wherein, I ₂Represent the 2nd bi-level digital watermark W to be embedded ₂Vertical resolution, J ₂Represent the 2nd bi-level digital watermark W to be embedded ₂Lateral resolution, facs _k(y) expression FACS _kIn y discrete cosine transform ac coefficient, imposing a condition is the absolute value of the difference of any adjacent two the discrete cosine transform ac coefficients in the first one-dimensional discrete cosine transform ac coefficient sequence that make the to constitute difference threshold more than or equal to setting.

At this; Choosing of discrete cosine transform ac coefficient in each first one-dimensional discrete cosine transform ac coefficient sequence all is the 2nd discrete cosine transform coefficient (i.e. the 1st discrete cosine transform ac coefficient) since the first one-dimensional discrete cosine transform coefficient sequence FACS, and chooses and the K that forms the first one-dimensional discrete cosine transform ac coefficient sequence FACS ₁, FACS ₂..., FACS _k... And FACS _KIn the absolute value of difference of any adjacent two discrete cosine transform ac coefficients respectively more than or equal to δ ₁, δ ₂..., δ _k... And δ _K, wherein, δ ₁Expression is to FACS ₁In the 1st difference threshold setting of the absolute value of difference of any adjacent two discrete cosine transform ac coefficients, δ ₂Expression is to FACS ₂In the 2nd difference threshold setting of the absolute value of difference of any adjacent two discrete cosine transform ac coefficients, δ _kExpression is to FACS _kIn k difference threshold setting of the absolute value of difference of any adjacent two discrete cosine transform ac coefficients, δ _KExpression is to FACS _KIn K difference threshold setting of the absolute value of difference of any adjacent two discrete cosine transform ac coefficients.With δ _kBe example, δ _kSetting principle be such, guaranteeing to choose I _k* J _kGet maximal value under the prerequisite of individual discrete cosine transform ac coefficient, to improve the unchangeability of digital picture selected mutual magnitude relationship of these discrete cosine transform ac coefficients when under attack the processing.

1.-7, compare FACS respectively ₁, FACS ₂..., FACS _k... And FACS _KIn the size of any adjacent two discrete cosine transform ac coefficients, and return logical value 1 or 0, for FACS according to comparative result _kIn any adjacent two discrete cosine transform ac coefficients, it is designated as facs respectively _k(z) and facs _k(z+1), judge facs _k() > z; Facs _k(z+1) whether set up,, then return logical value 1 if set up, otherwise, return logical value 0, wherein, 1≤z≤I _k* J _k-1; Compare FACS then ₁, FACS ₂..., FACS _k... And FACS _KIn last discrete cosine transform ac coefficient and the size of the 1st discrete cosine transform ac coefficient, and return logical value 1 or 0, for FACS according to comparative result _kIn last discrete cosine transform ac coefficient and the 1st discrete cosine transform ac coefficient, if the former is big, then return logical value 1, otherwise, return logical value 0; Again according to FACS ₁, FACS ₂..., FACS _k... And FACS _KEach self-corresponding logical value of returning makes up the first bi-level digital watermark keys one to one, for FACS _kThe corresponding logical value of returning, it is I that the logical value of returning is stored in a size by Row Column series arrangement mode _k* J _kTwo-dimensional matrix in, this two-dimensional matrix as k the first bi-level digital watermark keys, is designated as WB _k

1.-8, treat K bi-level digital watermark W of embedding ₁, W ₂..., W _k..., W _KCarry out scramble respectively and handle, K the bi-level digital watermark that obtains after scramble is handled correspondence respectively is designated as WS ₁, WS ₂..., WS _k... And WS _K, then with WS ₁, WS ₂..., WS _k... And WS _KRespectively with K the first bi-level digital watermark keys WB ₁, WB ₂..., WB _k... And WB _KCorrespondence is carried out XOR and is obtained K zero watermark information one by one, and correspondence is designated as WO respectively ₁, WO ₂..., WO _k... And WO _K, WO ₁=xor (WS ₁, WB ₁), WO ₂=xor (WS ₂, WB ₂) ..., WO _k=xor (WS _k, WB _k) ..., WO _K=xor (WS _K, WB _K), again with K zero watermark information WO ₁, WO ₂..., WO _k... And WO _KBe stored in the digital watermark information database of registration body, accomplish K bi-level digital watermark W ₁, W ₂..., W _k..., W _KEmbedding, wherein, WS ₁Expression is to W ₁Carry out the bi-level digital watermark that obtains after scramble is handled, WS ₂Expression is to W ₂Carry out the bi-level digital watermark that obtains after scramble is handled, WS _kExpression is to W _kCarry out the bi-level digital watermark that obtains after scramble is handled, WS _KExpression is to W _KCarry out the bi-level digital watermark that obtains after scramble is handled, WB ₁Represent the 1st first bi-level digital watermark keys, WB ₂Represent the 2nd first bi-level digital watermark keys, WB _KRepresent K the first bi-level digital watermark keys, xor () is the XOR function.

At this, treat K bi-level digital watermark W of embedding ₁, W ₂..., W _k..., W _KCarry out scramble respectively and handle, can effectively improve zero security of watermark in registration body, handle at this scramble and can adopt conventional Arnold conversion, also can adopt existing other ripe disorder methods.

1.-9, at a plurality of zero watermark built-in ends, with the FACS of record ₁, FACS ₂..., FACS _k... And FACS _KIn the positional information of each discrete cosine transform ac coefficient in FACS, K zero a watermark information WO ₁, WO ₂..., WO _k..., WO _KAnd K bi-level digital watermark W ₁, W ₂..., W _k..., W _KBe transferred to a plurality of zero watermark extracting ends.

A plurality of zero watermark extracting methods of a kind of digital picture of the present invention, it may further comprise the steps:

2.-1, at a plurality of zero watermark extracting ends, the digital picture (being test pattern) of K to be extracted bi-level digital watermark is designated as TF, TF={0≤tf (m '; N ')≤and 255,1≤m '≤M ', 1≤n '≤N ' }; Wherein, K>=2, the vertical resolution of the digital picture TF of K to be extracted bi-level digital watermark of M ' expression; The lateral resolution of the digital picture TF of K to be extracted bi-level digital watermark of N ' expression; The resolution of the digital picture TF of M ' * K to be extracted bi-level digital watermark of N ' expression, the resolution of the digital picture TF of K to be extracted bi-level digital watermark and the embedding of a plurality of zero watermark built-in ends have the resolution of digital picture of digital watermarking identical, tf (m '; N ') coordinate position is the pixel value of the pixel of (m ', n ') among the digital picture TF of K to be extracted bi-level digital watermark of expression.

2.-2, at a plurality of zero watermark extracting ends, K to be extracted bi-level digital watermark is designated as W ' respectively ₁, W ' ₂..., W ' _k... And W ' _K, for k bi-level digital watermark W ' to be extracted _k, W ' _k=w ' _k(i ' _k, j ' _k)=0 or 1,1≤i ' _k≤I ' _k, 1≤j ' _k≤J ' _k, wherein, 1≤k≤K, I ' _kRepresent k bi-level digital watermark W ' to be extracted _kVertical resolution, J ' _kRepresent k bi-level digital watermark W ' to be extracted _kLateral resolution, I ' _k* J ' _kRepresent k bi-level digital watermark W ' to be extracted _kResolution, k bi-level digital watermark W ' to be extracted _kThe resolution of k bi-level digital watermark embedding of resolution and a plurality of zero watermark built-in ends identical, w ' _k(i ' _k, j ' _k) expression k bi-level digital watermark W ' to be extracted _kIn coordinate position be (i ' _k, j ' _k) the pixel value of pixel.

2.-3, the digital picture TF of K to be extracted bi-level digital watermark carried out normalization handle, obtain the digital picture after normalization is handled, be designated as TF '; With the middle coordinate position of digital picture TF ' after the normalization processing be (m '; The pixel value of pixel n ') is designated as tf ' (m ', n '), tf ' (m '; N ')=tf (m ', n ')/255.

2.-4, TF ' is carried out L ' level two-dimensional discrete wavelet conversion, obtain one second small echo ll channel and a plurality of second small echo details subgraph, the second small echo ll channel is designated as TFA, wherein, the resolution of TFA is (M '/2 ^L') * (N '/2 ^L'),

Min () is for getting minimum value function, and max () is for getting max function, symbol

The maximum integer less than himself is got in expression, and promptly this symbol is for rounding symbol, I downwards ₁The 1st the bi-level digital watermark W ' that ' expression is to be extracted ₁Vertical resolution, J ₁The 1st the bi-level digital watermark W ' that ' expression is to be extracted ₁Lateral resolution, I _KK the bi-level digital watermark W ' that ' expression is to be extracted _KVertical resolution, J _KK the bi-level digital watermark W ' that ' expression is to be extracted _KLateral resolution.

2.-5, TFA is carried out two-dimension discrete cosine transform; Obtain second a two-dimension discrete cosine transform matrix of coefficients with the TFA equal resolution, be designated as TFAC, then TFAC is carried out Zig-Zag scanning and arrange; Obtain one second one-dimensional discrete cosine transform coefficient sequence; Be designated as TFACS, TFACS={tfacs (x '), 1≤x '≤(M '/2 ^L') * (N '/2 ^L'), wherein, the individual discrete cosine transform coefficient of x ' among tfacs (x ') the expression TFACS, the 2nd discrete cosine transform coefficient among the TFACS begins to be the discrete cosine transform ac coefficient.

2.-6 the FACS that, writes down according to a plurality of zero watermark built-in ends ₁, FACS ₂..., FACS _k... And FACS _KIn the correspondence position information of each discrete cosine transform ac coefficient in FACS, from TFACS, extract the I of correspondence position respectively ₁' * J ₁', I ₂' * J ₂' ..., I _k' * J _k' ... And I _K' * J _K' individual discrete cosine transform ac coefficient constitutes K the second one-dimensional discrete cosine transform ac coefficient sequence, and correspondence is designated as TFACS respectively ₁, TFACS ₂..., TFACS _k... And TFACS _K, for FACS according to a plurality of zero watermark built-in end records _kIn the correspondence position information of each discrete cosine transform ac coefficient in FACS, from TFACS, extract the I of correspondence position _k' * J _kK the second one-dimensional discrete cosine transform ac coefficient sequence TFACS of ' individual discrete cosine transform ac coefficient formation _k, TFACS _k={ tfacs _k(y '), 1≤y '≤I _k' * J _k', wherein, I _kK the bi-level digital watermark W ' that ' expression is to be extracted _kVertical resolution, J _kK the bi-level digital watermark W ' that ' expression is to be extracted _kLateral resolution, tfacs _k(y ') representes TFACS _kIn the individual discrete cosine transform ac coefficient of y '.

2.-7, compare TFACS respectively ₁, TFACS ₂..., TFACS _k... And TFACS _KIn the size of any adjacent two discrete cosine transform ac coefficients, and return logical value 1 or 0, for TFACS according to comparative result _kIn any adjacent two discrete cosine transform ac coefficients, it is designated as tfacs respectively _k(z ') and tfacs _kTfacs is judged in (z '+1) _k(z ')>Tfacs _kWhether set up (z '+1), if set up, then returns logical value 1, otherwise, return logical value 0, wherein, 1≤z '≤I _k' * J _k'-1; Compare TFACS then ₁, TFACS ₂..., TFACS _k... And TFACS _KIn last discrete cosine transform ac coefficient and the size of the 1st discrete cosine transform ac coefficient, and return logical value 1 or 0, for TFACS according to comparative result _kIn last discrete cosine transform ac coefficient and the 1st discrete cosine transform ac coefficient, if the former is big, then return logical value 1, otherwise, return logical value 0; Again according to TFACS ₁, TFACS ₂..., TFACS _k... And TFACS _KEach self-corresponding logical value of returning makes up the second bi-level digital watermark keys one to one, for TFACS _kThe corresponding logical value of returning, it is I that the logical value of returning is stored in a size by Row Column series arrangement mode _k' * J _k' two-dimensional matrix in, this two-dimensional matrix as k the second bi-level digital watermark keys, is designated as TWB _k

2.-8, will be from K zero watermark information WO of a plurality of zero watermark built-in ends ₁, WO ₂..., WO _k... And WO _K, respectively with K the second bi-level digital watermark keys TWB ₁, TWB ₂..., TWB _k... And TWB _KCorrespondence is carried out XOR one by one, recovers to obtain K bi-level digital watermark, and correspondence is designated as TW respectively ₁, TW ₂..., TW _k... And TW _K, TW ₁=xor (WO ₁, TWB ₁), TW ₂=xor (WO ₂, TWB ₂) ..., TW _k=xor (WO _k, TWB _k) ..., TW _K=xor (WO _K, TWB _K), wherein, TWB ₁Represent the 1st second bi-level digital watermark keys, TWB ₂Represent the 2nd second bi-level digital watermark keys, TWB _kRepresent k the second bi-level digital watermark keys, TWB _KRepresent K the second bi-level digital watermark keys, xor () is the XOR function.

2.-9, respectively to K bi-level digital watermark TW ₁, TW ₂..., TW _k... And TW _KThe random processing that is inverted, K the bi-level digital watermark that obtains having copyright authentication information, correspondence is designated as respectively

With

K the bi-level digital watermark that 2.-10, will have copyright authentication information

With

K the bi-level digital watermark W that embeds with a plurality of zero watermark built-in ends respectively ₁, W ₂..., W _k... And W _KCorrespondence is carried out similarity calculating one by one, and correspondence obtains K normalized correlation coefficient, judges whether extract K the bi-level digital watermark W that a plurality of zero watermark built-in ends embed according to the size of K normalized correlation coefficient then ₁, W ₂..., W _k... And W _KAnd the robustness of K the bi-level digital watermark that embeds.

In this specific embodiment, step detailed process 2.-10 is:

Z1, K the bi-level digital watermark that will have copyright authentication information

With K the bi-level digital watermark W that embeds with a plurality of zero watermark built-in ends respectively ₁, W ₂..., W _k... And W _KCorrespondence is carried out similarity calculating one by one, and correspondence obtains K normalized correlation coefficient, for inciting somebody to action

With W _kCarry out k normalized correlation coefficient obtaining after similarity is calculated, it is designated as

$\mathrm{\ρ}(W_k,W_k^{*})=\frac{\underset{i_k=1}{\overset{I_k}{\mathrm{\Σ}}}\underset{j_k=1}{\overset{J_k}{\mathrm{\Σ}}}((w_k(i_k,j_k)-\stackrel{\‾}{w_k})\×(w_k^{*}(i_k,j_k)-\stackrel{\‾}{w_k^{*}}))}{\sqrt{\underset{i_k=1}{\overset{I_k}{\mathrm{\Σ}}}\underset{j_k=1}{\overset{J_k}{\mathrm{\Σ}}}{(w_k(i_k,j_k)-\stackrel{\‾}{w_k})}^2\underset{i_k=1}{\overset{I_k}{\mathrm{\Σ}}}\underset{j_k=1}{\overset{J_k}{\mathrm{\Σ}}}{(w_k^{*}(i_k,j_k)-\stackrel{\‾}{w_k^{*}})}^2}},$ Wherein, w _k(i _k, j _k) k bi-level digital watermark W embedding of a plurality of zero watermark built-in ends of expression _kMiddle coordinate position is (i _k, j _k) the pixel value of pixel,

Represent k the bi-level digital watermark W that a plurality of zero watermark built-in ends embed _kIn the average of pixel value of all pixels,

K the bi-level digital watermark that expression has copyright authentication information

Middle coordinate position is (i _k, j _k) the pixel value of pixel,

K the bi-level digital watermark that expression has copyright authentication information

In the average of pixel value of all pixels.

Z2, judge whether extract K the bi-level digital watermark W that a plurality of zero watermark built-in ends embed according to the size of K normalized correlation coefficient ₁, W ₂..., W _k... And W _K, for normalized correlation coefficient

Judge

Value whether be 1, if Value be 1, then confirm With W _kIn full accord, show W _kNondestructively extracted, if this to be Lena digital picture behind the embed watermark receive certain processing or attack after the extraction result, the bi-level digital watermark W of embedding be described _kHave the ability of this processing of opposing or attack, have desirable robustness.If

Value be not 1, then judge again

Value whether between δ _T-1, if

Value between δ _T-1, the bi-level digital watermark that extracts then is described

Bi-level digital watermark W with the built-in end embedding _kThere is some difference, but have very big similarity between the two, at this moment can from extract the result, recognize the bi-level digital watermark W of embedding _k, extract successfully.The value of related coefficient is big more, the bi-level digital watermark that extracts

Bi-level digital watermark W with the built-in end embedding _kSimilar more, recognize the bi-level digital watermark W of embedding more easily _k, extraction effect is good more.If this to be Lena digital picture behind the embed watermark receive certain processing or attack after the extraction result, the bi-level digital watermark W of embedding be described _kHave the ability of this processing of more satisfactory opposing or attack, have good robustness.Wherein, δ _TBe the watermark extracting thresholding, but general value is 0.5.If

Value not between δ _T-1, then judge again

Value whether less than δ _T, if the bi-level digital watermark that extracts then is described

Bi-level digital watermark W with the built-in end embedding _kCorrelativity is very little, at this moment can't from extract the result, recognize the bi-level digital watermark W of embedding _k, extract failure.

For a plurality of zero watermark embeddings that a kind of digital picture that the present invention proposes is described better and the feasibility and the validity of method for distilling, be example (K=3) to embed three bi-level digital watermarks, carry out emulation through following experiment.

Experiment simulation carries out on the Matlab7.5 platform, and the original digital image F that waits to embed three bi-level digital watermarks selects the Lena gray level image of 8bit for use, and resolution is 512 * 512, shown in Fig. 1 a.Three bi-level digital watermarks are respectively two-value signature watermark W ₁, two-value sequence number watermark W ₂With two-value icon watermark W ₃, resolution is respectively 28 * 50,16 * 64 and 25 * 32, respectively shown in Fig. 1 b, Fig. 1 c and Fig. 1 d.

Before the bi-level digital watermark embeds, original digital image F pixel is carried out normalization handle, the digital picture F ' after then normalization being handled carries out 3 grades of two-dimensional discrete wavelet conversions.

The quality of the digital picture behind the embed digital watermark adopts Y-PSNR (PSNR) to pass judgment on, $\mathrm{PSNR}=-10\×\log 10\left(\frac{\underset{m=1}{\overset{M}{\mathrm{\Σ}}}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{(f(m,n)-f^{\′\′}(m,n))}^2}{M\×N\×f_{\max }^2}\right),$ Wherein, (m, n) expression is waited to embed in the original digital image of bi-level digital watermark coordinate position for (" (m, n) expression embeds that coordinate position is (m, the pixel value of pixel n), f in the digital picture after the bi-level digital watermark for m, the pixel value of pixel n), f to f _MaxThe max pixel value of expression original digital image.

The objective evaluation of digital watermarking testing result adopts normalized correlation coefficient (ρ): $\mathrm{\ρ}(W_k,W_k^{*})=\frac{\underset{i_k=1}{\overset{I_k}{\mathrm{\Σ}}}\underset{j_k=1}{\overset{J_k}{\mathrm{\Σ}}}((w_k(i_k,j_k)-\stackrel{\‾}{w_k})\×(w_k^{*}(i_k,j_k)-\stackrel{\‾}{w_k^{*}}))}{\sqrt{\underset{i_k=1}{\overset{I_k}{\mathrm{\Σ}}}\underset{j_k=1}{\overset{J_k}{\mathrm{\Σ}}}{(w_k(i_k,j_k)-\stackrel{\‾}{w_k})}^2\underset{i_k=1}{\overset{I_k}{\mathrm{\Σ}}}\underset{j_k=1}{\overset{J_k}{\mathrm{\Σ}}}{(w_k^{*}(i_k,j_k)-\stackrel{\‾}{w_k^{*}})}^2}},$ 1≤k≤K, wherein, w _k(i _k, j _k) k original bi-level digital watermark W of expression _kMiddle coordinate position is (i _k, j _k) the pixel value of pixel,

K the bi-level digital watermark that expression extracts

Middle coordinate position is (i _k, j _k) the pixel value of pixel, With

Represent digital watermarking W respectively _kWith

The average of pixel value of all pixels.The bi-level digital watermark robustness that can judge the bi-level digital watermark that whether extracts embedding and embedding according to the size of normalized correlation coefficient ρ how.

Fig. 2 a, Fig. 2 b and Fig. 2 c have provided embedding two-value signature watermark W respectively ₁, embed two-value signature watermark W ₁With two-value sequence number watermark W ₂And embedding two-value signature watermark W ₁, two-value sequence number watermark W ₂With two-value icon watermark W ₃After the Lena digital picture.Can see that from Fig. 2 a, Fig. 2 b and Fig. 2 c any variation (PSNR → ∞ dB) does not take place the Lena digital picture quality behind the embed watermark, and is consistent with original Lena digital picture, satisfied the requirement of watermark imperceptible fully.Visible simultaneously, utilize a plurality of zero watermark embedding method of the present invention, the Lena digital picture quality behind the embed watermark can not become with the watermark number that embeds, and therefore in practical application, can embed a plurality of bi-level digital watermarks as required easily and flexibly.Fig. 2 d, Fig. 2 e and Fig. 2 f are respectively three bi-level digital watermarks that from Fig. 2 c, extract; When the watermark Lena digital picture shown in Fig. 2 c is not handled by any attack; Can fully nondestructively extract three bi-level digital watermarks of embedding, normalized correlation coefficient ρ is 1.

Carry out multiple attack in the face of watermark Lena digital picture down and handle, verify the robustness of a plurality of zero watermark embedding methods that the present invention proposes.

(1) brightness changes

Watermark Lena digital picture shown in Fig. 2 c is carried out brightness regulation handle, be about to its all pixel values and add 0.2,0.5 and subtract 0.2,0.5 computing respectively, correspondence obtains the watermark Lena digital picture shown in Fig. 3 a, Fig. 3 b, Fig. 3 c and Fig. 3 d.After the image pixel value plus-minus is handled; In view of vision; Obvious change has taken place in bright, the darkness of the watermark Lena digital picture shown in Fig. 3 a, Fig. 3 b, Fig. 3 c and Fig. 3 d, and Y-PSNR PSNR drops to 13.97dB, 6.02dB, 13.97dB and 6.02dB respectively.Respectively the watermark Lena digital picture of Fig. 3 a, Fig. 3 b, Fig. 3 c and Fig. 3 d is carried out watermark extracting, three bi-level digital watermarks that extract are respectively shown in Fig. 3 e, Fig. 3 f and Fig. 3 g.The result shows that the watermark result of from these 4 watermark Lena digital pictures, extracting is not only identical, and in full accord with three original bi-level digital watermarks.It is thus clear that the influence that the digital watermarking that embeds for the inventive method is not changed by luminance digital image fully can correctly extract.

(2) histogram equalization

Watermark Lena digital picture shown in Fig. 2 c is carried out histogram equalization handle, obtain the watermark Lena digital picture shown in Fig. 4 a.Handle through histogram equalization, the pixel value of watermark Lena digital picture distributes obvious change has taken place, and Y-PSNR PSNR drops to 19.56dB.Fig. 4 b, Fig. 4 c and Fig. 4 d are respectively three bi-level digital watermarks that from the watermark Lena digital picture of Fig. 4 a, extract; Can know by the result; Three bi-level digital watermarks that embed can both be extracted very ideally, and normalized correlation coefficient ρ has reached 0.990,0.991 and 0.997 respectively.

(3) medium filtering

Watermark Lena digital picture shown in Fig. 2 c is carried out medium filtering handle, the filtering window size is respectively [5 * 5] and [11 * 11], and the watermark Lena digital picture that obtains after the filtering is respectively shown in Fig. 5 a and Fig. 5 b.Fig. 5 c, Fig. 5 d and Fig. 5 e are respectively three bi-level digital watermarks that from the watermark Lena digital picture of Fig. 5 a, extract, and Fig. 5 f, Fig. 5 g and Fig. 5 h are respectively three bi-level digital watermarks that from the watermark Lena digital picture of Fig. 5 b, extract.Can know by the watermark extracting result; Medium filtering for [5 * 5] wicket is handled, and three bi-level digital watermarks of embedding are not affected, and have desirable robustness; And handle for the medium filtering of [11 * 11] big window; Can be seen that by Fig. 5 b at this moment the detailed information of watermark Lena digital picture is very fuzzy, Y-PSNR PSNR drops to 25.83dB; But three bi-level digital watermarks that embed have very desirable anti-Filtering Processing ability, and normalized correlation coefficient ρ has reached 0.964,0.991 and 0.997 respectively.

Table 1 has specifically provided watermark Lena digital picture and the watermark extracting result thereof behind different windows size medium filtering, can be found out by table, and a plurality of zero watermark embedding methods that the present invention proposes have very desirable anti-Filtering Processing ability.

Watermark Lena digital picture quality behind the table 1 different windows size medium filtering and extraction result

(4) JPEG lossy compression method

Watermark Lena digital picture shown in Fig. 2 c is carried out the JPEG lossy compression method handle, the compression quality factor is respectively 10% and 4%, and the watermark Lena digital picture that obtains is respectively shown in Fig. 6 a and Fig. 6 b.Fig. 6 c, Fig. 6 d and Fig. 6 e are respectively three bi-level digital watermarks that from the watermark Lena digital picture of Fig. 6 a, extract, and Fig. 6 f, Fig. 6 g and Fig. 6 h are respectively three bi-level digital watermarks that from the watermark Lena digital picture of Fig. 6 b, extract.Can be known by the watermark extracting result, be that 10% JPEG lossy compression method is handled for the compression quality factor, and three bi-level digital watermarks of embedding are not affected; Has desirable robustness; And be that 4% JPEG lossy compression method is handled for the compression quality factor, can see that by Fig. 6 b at this moment watermark Lena digital picture demonstrates very significantly blocking artifact; Serious degradation has taken place in visual quality; Y-PSNR PSNR is merely 25.92dB, but three bi-level digital watermarks that embed still have very desirable anti-JPEG lossy compression method processing power, and normalized correlation coefficient ρ has reached 0.985,0.997 and 1.0 respectively.

Table 2 has specifically provided watermark Lena digital picture quality and the watermark extracting result thereof under the different JPEG compression quality factors.Can find out that from table 2 the inventive method has very desirable anti-JPEG processed compressed ability, the compression quality factor is decreased at 6% o'clock and still can extracts three embedded bi-level digital watermarks zero defect.

Watermark Lena digital picture quality under the different JPEG compression quality of table 2 factor and extraction result

(5) stack Gaussian noise

Watermark Lena digital picture to shown in Fig. 2 c is carried out noise, noise select for use average be 0 variance be 0.02 and average be that 0 variance is two kinds of Gaussian noises of 0.05, the watermark Lena digital picture that obtains is respectively shown in Fig. 7 a and Fig. 7 b.Fig. 7 c, Fig. 7 d and Fig. 7 e are respectively three bi-level digital watermarks that from the watermark Lena digital picture of Fig. 7 a, extract, and Fig. 7 f, Fig. 7 g and Fig. 7 h are respectively three bi-level digital watermarks that from the watermark Lena digital picture of Fig. 7 b, extract.Can know by the watermark extracting result, disturb although watermark Lena digital picture receives Gaussian noise, visual quality generation serious degradation, Y-PSNR PSNR is merely 17.22dB and 13.67dB.But for average is that 0 variance is 0.02 Gaussian noise interference; Three bi-level digital watermarks that embed are not affected; Has desirable robustness; And be that 0 variance is that 0.05 Gaussian noise is disturbed for average, three bi-level digital watermarks of embedding still have very desirable antinoise interference performance, and normalized correlation coefficient ρ has reached 0.980,0.994 and 1.0 respectively.

It is watermark Lena digital picture quality and watermark extracting result thereof under 0 different variance Gaussian noises are disturbed that table 3 has specifically provided average.Can find out that from table 3 the inventive method has very desirable antinoise interference performance, disturb less than 0.03 Gaussian noise that three bi-level digital watermarks of embedding can both be extracted intactly for variance.

Watermark Lena digital picture quality under the different Gaussian noise intensity of table 3 and extraction result

(6) how much cuttings

Watermark Lena digital picture shown in Fig. 2 c is carried out the geometry cutting, begin to cut respectively 128 * 128 and 256 * 256 pixels, obtain the watermark Lena digital picture shown in Fig. 8 a and Fig. 8 b from the upper left corner.Fig. 8 c, Fig. 8 d and Fig. 8 e are respectively three bi-level digital watermarks that from the watermark Lena digital picture of Fig. 8 a, extract, and Fig. 8 f, Fig. 8 g and Fig. 8 h are respectively three bi-level digital watermarks that from the watermark Lena digital picture of Fig. 8 b, extract.Can know by the watermark extracting result; Although watermark Lena digital picture receives largely and destroying; Y-PSNR PSNR is merely 17.29dB and 11.14dB; But the inventive method has goodish robustness for how much cuttings, and three bi-level digital watermarks of embedding still can be by intact extracting very, and normalized correlation coefficient ρ has reached 0.973,0.972 and 0.981 and 0.874,0.883 and 0.899 respectively.

(7) how much rotations

Watermark Lena digital picture shown in Fig. 2 c is carried out the counter clockwise direction rotation, and angle is respectively 5 degree and 25 degree.In order to extract watermark, with the reverse rotation again of postrotational image, to recover former direction, shown in Fig. 9 a and Fig. 9 b, its Y-PSNR PSNR is 19.10dB and 13.80dB to the watermark Lena digital picture that at this moment obtains respectively.Fig. 9 c, Fig. 9 d and Fig. 9 e are respectively three bi-level digital watermarks that from the watermark Lena digital picture of Fig. 9 a, extract, and Fig. 9 f, Fig. 9 g and Fig. 9 h are respectively three bi-level digital watermarks that from the watermark Lena digital picture of Fig. 9 b, extract.Can know by the watermark extracting result; The inventive method is attacked for how much rotations also has reasonable robustness; Three bi-level digital watermarks that embed still can very clearly be extracted, and normalized correlation coefficient ρ has reached 0.819,0.829 and 0.871 and 0.694,0.751 and 0.817 respectively.

Claims (4)

1. a plurality of zero watermark embedding methods of a digital picture is characterized in that may further comprise the steps:

1.-1, at a plurality of zero watermark built-in ends, the original digital image of supposing to wait to embed K bi-level digital watermark is the gray level image of 8bit, and is designated as F; F={0≤f (m, n)≤255,1≤m≤M; 1≤n≤N}, wherein, K>=2; M representes to wait to embed the vertical resolution of the original digital image F of K bi-level digital watermark, and N representes to wait to embed the lateral resolution of the original digital image F of K bi-level digital watermark, and M * N representes to wait to embed the resolution of the original digital image F of K bi-level digital watermark; F (m, n) expression waits to embed that coordinate position is (m, the pixel value of pixel n) among the original digital image F of K bi-level digital watermark;

1.-2, at a plurality of zero watermark built-in ends, suppose that K to be embedded a bi-level digital watermark is all bianry image, and be designated as W respectively ₁, W ₂..., W _k..., W _K, then for k bi-level digital watermark W to be embedded _k, W _k={ w _k(i _k, j _k)=0 or 1,1≤i _k≤I _k, 1≤j _k≤Jk}, wherein, 1≤k≤K, I _kRepresent k bi-level digital watermark W to be embedded _kVertical resolution, J _kRepresent k bi-level digital watermark W to be embedded _kLateral resolution, I _k* J _kRepresent k bi-level digital watermark W to be embedded _kResolution, w _k(i _k, j _k) expression k bi-level digital watermark W to be embedded _kMiddle coordinate position is (i _k, j _k) the pixel value of pixel;

1.-3, treat the original digital image F that embeds K bi-level digital watermark and carry out normalization and handle, obtain the digital picture after the normalization processing, be designated as F '; With the middle coordinate position of digital picture F ' after the normalization processing is (m; The pixel value of pixel n) be designated as f ' (m, n), f ' (m; N)=and f (m, n)/255;

1.-4, F ' is carried out L level two-dimensional discrete wavelet conversion, obtain one first small echo ll channel and a plurality of first small echo details subgraph, the first small echo ll channel is designated as FA, wherein, the resolution of FA is (M/2 ^L) * (N/2 ^L),

Min () is for getting minimum value function, and max () is for getting max function, symbol

The maximum integer less than himself, I are got in expression ₁Represent the 1st bi-level digital watermark W to be embedded ₁Vertical resolution, J ₁Represent the 1st bi-level digital watermark W to be embedded ₁Lateral resolution, I _KRepresent K bi-level digital watermark W to be embedded _KVertical resolution, J _KRepresent K bi-level digital watermark W to be embedded _KLateral resolution;

1.-5, FA is carried out two-dimension discrete cosine transform; Obtain first a two-dimension discrete cosine transform matrix of coefficients with the FA equal resolution, be designated as FAC, then FAC is carried out Zig-Zag scanning and arrange; Obtain one first one-dimensional discrete cosine transform coefficient sequence; Be designated as FACS, FACS={facs (x), 1≤x≤(M/2 ^L) * (N/2 ^L), wherein, x discrete cosine transform coefficient among facs (x) the expression FACS, the 2nd discrete cosine transform coefficient among the FACS begins to be the discrete cosine transform ac coefficient;

The resolution of each bi-level digital watermark that basis is to be embedded 1.-6, successively selects from FACS respectively and satisfies the I that imposes a condition ₁* J ₁, I ₂* J ₂..., I _k* J _k... And I _K* J _KIndividual discrete cosine transform ac coefficient constitutes K the first one-dimensional discrete cosine transform ac coefficient sequence, and correspondence is designated as FACS respectively ₁, FACS ₂..., FACS _k... And FACS _K, for the satisfied I that imposes a condition that from FACS, selects _k* J _kThe k that individual discrete cosine transform ac coefficient constitutes first an one-dimensional discrete cosine transform ac coefficient sequence FACS _k, FACS _k={ facs _k(y), 1≤y≤I _k* J _k, write down FACS then ₁, FACS ₂..., FACS _k... And FACS _KIn the correspondence position information of each discrete cosine transform ac coefficient in FACS, wherein, I ₂Represent the 2nd bi-level digital watermark W to be embedded ₂Vertical resolution, J ₂Represent the 2nd bi-level digital watermark W to be embedded ₂Lateral resolution, facs _k(y) expression FACS _kIn y discrete cosine transform ac coefficient, imposing a condition is the absolute value of the difference of any adjacent two the discrete cosine transform ac coefficients in the first one-dimensional discrete cosine transform ac coefficient sequence that make the to constitute difference threshold more than or equal to setting;

1.-7, compare FACS respectively ₁, FACS ₂..., FACS _k... And FACS _KIn the size of any adjacent two discrete cosine transform ac coefficients, and return logical value 1 or 0, for FACS according to comparative result _kIn any adjacent two discrete cosine transform ac coefficients, it is designated as facs respectively _k(z) and facs _k(z+1), judge facs _k() > z; Facs _k(z+1) whether set up,, then return logical value 1 if set up, otherwise, return logical value 0, wherein, 1≤z≤I _k* J _k-1; Compare FACS then ₁, FACS ₂..., FACS _k... And FACS _KIn last discrete cosine transform ac coefficient and the size of the 1st discrete cosine transform ac coefficient, and return logical value 1 or 0, for FACS according to comparative result _kIn last discrete cosine transform ac coefficient and the 1st discrete cosine transform ac coefficient, if the former is big, then return logical value 1, otherwise, return logical value 0; Again according to FACS ₁, FACS ₂..., FACS _k... And FACS _KEach self-corresponding logical value of returning makes up the first bi-level digital watermark keys one to one, for FACS _kThe corresponding logical value of returning, it is I that the logical value of returning is stored in a size by Row Column series arrangement mode _k* J _kTwo-dimensional matrix in, this two-dimensional matrix as k the first bi-level digital watermark keys, is designated as WB _k

1.-8, treat K bi-level digital watermark W of embedding ₁, W ₂..., W _k..., W _KCarry out scramble respectively and handle, K the bi-level digital watermark that obtains after scramble is handled correspondence respectively is designated as WS ₁, WS ₂..., WS _k... And WS _K, then with WS ₁, WS ₂..., WS _k... And WS _KRespectively with K the first bi-level digital watermark keys WB ₁, WB ₂..., WB _k... And WB _KCorrespondence is carried out XOR and is obtained K zero watermark information one by one, and correspondence is designated as WO respectively ₁, WO ₂..., WO _k... And WO _K, WO ₁=xor (WS ₁, WB ₁), WO ₂=xor (WS ₂, WB ₂) ..., WO _k=xor (WS _k, WB _k) ..., WO _K=xor (WS _K, WB _K), again with K zero watermark information WO ₁, WO ₂..., WO _k... And WO _KBe stored in the digital watermark information database of registration body, accomplish K bi-level digital watermark W ₁, W ₂..., W _k..., W _KEmbedding, wherein, WS ₁Expression is to W ₁Carry out the bi-level digital watermark that obtains after scramble is handled, WS ₂Expression is to W ₂Carry out the bi-level digital watermark that obtains after scramble is handled, WS _kExpression is to W _kCarry out the bi-level digital watermark that obtains after scramble is handled, WS _KExpression is to W _KCarry out the bi-level digital watermark that obtains after scramble is handled, WB ₁Represent the 1st first bi-level digital watermark keys, WB ₂Represent the 2nd first bi-level digital watermark keys, WB _KRepresent K the first bi-level digital watermark keys, xor () is the XOR function;

1.-9, at a plurality of zero watermark built-in ends, with the FACS of record ₁, FACS ₂..., FACS _k... And FACS _KIn the positional information of each discrete cosine transform ac coefficient in FACS, K zero a watermark information WO ₁, WO ₂..., WO _k..., WO _KAnd K bi-level digital watermark W ₁, W ₂..., W _k..., W _KBe transferred to a plurality of zero watermark extracting ends.

2. a plurality of zero watermark embedding methods of a kind of digital picture according to claim 1 is characterized in that FACS during described step 1.-6 ₁, FACS ₂..., FACS _k... And FACS _KIn the absolute value of difference of any adjacent two discrete cosine transform ac coefficients respectively more than or equal to δ ₁, δ ₂..., δ _k... And δ _K, wherein, δ ₁Expression is to FACS ₁In the 1st difference threshold setting of the absolute value of difference of any adjacent two discrete cosine transform ac coefficients, δ ₂Expression is to FACS ₂In the 2nd difference threshold setting of the absolute value of difference of any adjacent two discrete cosine transform ac coefficients, δ _kExpression is to FACS _kIn k difference threshold setting of the absolute value of difference of any adjacent two discrete cosine transform ac coefficients, δ _KExpression is to FACS _KIn K difference threshold setting of the absolute value of difference of any adjacent two discrete cosine transform ac coefficients.

3. a plurality of zero watermark extracting methods of a digital picture is characterized in that may further comprise the steps:

2.-1, at a plurality of zero watermark extracting ends, the digital picture of K to be extracted bi-level digital watermark is designated as TF, TF={0≤tf (m '; N ')≤and 255,1≤m '≤M ', 1≤n '≤N ' }; Wherein, K>=2, the vertical resolution of the digital picture TF of K to be extracted bi-level digital watermark of M ' expression; The lateral resolution of the digital picture TF of K to be extracted bi-level digital watermark of N ' expression; The resolution of the digital picture TF of M ' * K to be extracted bi-level digital watermark of N ' expression, the resolution of the digital picture TF of K to be extracted bi-level digital watermark and the embedding of a plurality of zero watermark built-in ends have the resolution of digital picture of digital watermarking identical, tf (m '; N ') coordinate position is the pixel value of the pixel of (m ', n ') among the digital picture TF of K to be extracted bi-level digital watermark of expression;

2.-2, at a plurality of zero watermark extracting ends, K to be extracted bi-level digital watermark is designated as W ' respectively ₁, W ' ₂..., W ' _k... And W ' _K, for k bi-level digital watermark W ' to be extracted _k, W ' _k=w ' _k(i ' _k, j ' _k)=0 or 1,1≤i ' _k≤I ' _k, 1≤j ' _k≤J ' _k, wherein, 1≤k≤K, I ' _kRepresent k bi-level digital watermark W ' to be extracted _kVertical resolution, J ' _kRepresent k bi-level digital watermark W ' to be extracted _kLateral resolution, I ' _k* J ' _kRepresent k bi-level digital watermark W ' to be extracted _kResolution, k bi-level digital watermark W ' to be extracted _kThe resolution of k bi-level digital watermark embedding of resolution and a plurality of zero watermark built-in ends identical, w ' _k(i ' _k, j ' _k) expression k bi-level digital watermark W ' to be extracted _kIn coordinate position be (i ' _k, j ' _k) the pixel value of pixel;

2.-3, the digital picture TF of K to be extracted bi-level digital watermark carried out normalization handle, obtain the digital picture after normalization is handled, be designated as TF '; With the middle coordinate position of digital picture TF ' after the normalization processing be (m '; The pixel value of pixel n ') is designated as tf ' (m ', n '), tf ' (m '; N ')=tf (m ', n ')/255;

2.-4, TF ' is carried out L ' level two-dimensional discrete wavelet conversion, obtain one second small echo ll channel and a plurality of second small echo details subgraph, the second small echo ll channel is designated as TFA, wherein, the resolution of TFA is (M '/2 ^L') * (N '/2 ^L'),

Min () is for getting minimum value function, and max () is for getting max function, symbol

The maximum integer less than himself, I are got in expression ₁The 1st the bi-level digital watermark W ' that ' expression is to be extracted ₁Vertical resolution, J ₁The 1st the bi-level digital watermark W ' that ' expression is to be extracted ₁Lateral resolution, I _KK the bi-level digital watermark W ' that ' expression is to be extracted _KVertical resolution, J _KK the bi-level digital watermark W ' that ' expression is to be extracted _KLateral resolution;

2.-5, TFA is carried out two-dimension discrete cosine transform; Obtain second a two-dimension discrete cosine transform matrix of coefficients with the TFA equal resolution, be designated as TFAC, then TFAC is carried out Zig-Zag scanning and arrange; Obtain one second one-dimensional discrete cosine transform coefficient sequence; Be designated as TFACS, TFACS={tfacs (x '), 1≤x '≤(M '/2 ^L') * (N '/2 ^L'), wherein, the individual discrete cosine transform coefficient of x ' among tfacs (x ') the expression TFACS, the 2nd discrete cosine transform coefficient among the TFACS begins to be the discrete cosine transform ac coefficient;

2.-6 the FACS that, writes down according to a plurality of zero watermark built-in ends ₁, FACS ₂..., FACS _k... And FACS _KIn the correspondence position information of each discrete cosine transform ac coefficient in FACS, from TFACS, extract the I of correspondence position respectively ₁' * J ₁', I ₂' * J ₂' ..., I _k' * J _k' ... And I _K' * J _K' individual discrete cosine transform ac coefficient constitutes K the second one-dimensional discrete cosine transform ac coefficient sequence, and correspondence is designated as TFACS respectively ₁, TFACS ₂..., TFACS _k... And TFACS _K, for FACS according to a plurality of zero watermark built-in end records _kIn the correspondence position information of each discrete cosine transform ac coefficient in FACS, from TFACS, extract the I of correspondence position _k' * J _kK the second one-dimensional discrete cosine transform ac coefficient sequence TFACS of ' individual discrete cosine transform ac coefficient formation _k, TFACS _k={ tfacs _k(y '), 1≤y '≤I _k' * J _k', wherein, I _kK the bi-level digital watermark W ' that ' expression is to be extracted _kVertical resolution, J _kK the bi-level digital watermark W ' that ' expression is to be extracted _kLateral resolution, tfacs _k(y ') representes TFACS _kIn the individual discrete cosine transform ac coefficient of y ';

2.-7, compare TFACS respectively ₁, TFACS ₂..., TFACS _k... And TFACS _KIn the size of any adjacent two discrete cosine transform ac coefficients, and return logical value 1 or 0, for TFACS according to comparative result _kIn any adjacent two discrete cosine transform ac coefficients, it is designated as tfacs respectively _k(z ') and tfacs _kTfacs is judged in (z '+1) _k(z ')>Tfacs _kWhether set up (z '+1), if set up, then returns logical value 1, otherwise, return logical value 0, wherein, 1≤z '≤I _k' * J _k'-1; Compare TFACS then ₁, TFACS ₂..., TFACS _k... And TFACS _KIn last discrete cosine transform ac coefficient and the size of the 1st discrete cosine transform ac coefficient, and return logical value 1 or 0, for TFACS according to comparative result _kIn last discrete cosine transform ac coefficient and the 1st discrete cosine transform ac coefficient, if the former is big, then return logical value 1, otherwise, return logical value 0; Again according to TFACS ₁, TFACS ₂..., TFACS _k... And TFACS _KEach self-corresponding logical value of returning makes up the second bi-level digital watermark keys one to one, for TFACS _kThe corresponding logical value of returning, it is I that the logical value of returning is stored in a size by Row Column series arrangement mode _k' * J _k' two-dimensional matrix in, this two-dimensional matrix as k the second bi-level digital watermark keys, is designated as TWB _k

2.-8, will be from K zero watermark information WO of a plurality of zero watermark built-in ends ₁, WO ₂..., WO _k... And WO _K, respectively with K the second bi-level digital watermark keys TWB ₁, TWB ₂..., TWB _k... And TWB _KCorrespondence is carried out XOR one by one, recovers to obtain K bi-level digital watermark, and correspondence is designated as TW respectively ₁, TW ₂..., TW _k... And TW _K, TW ₁=xor (WO ₁, TWB ₁), TW ₂=xor (WO ₂, TWB ₂) ..., TW _k=xor (WO _k, TWB _k) ..., TW _K=xor (WO _K, TWB _K), wherein, TWB ₁Represent the 1st second bi-level digital watermark keys, TWB ₂Represent the 2nd second bi-level digital watermark keys, TWB _kRepresent k the second bi-level digital watermark keys, TWB _KRepresent K the second bi-level digital watermark keys, xor () is the XOR function;

2.-9, respectively to K bi-level digital watermark TW ₁, TW ₂..., TW _k... And TW _KThe random processing that is inverted, K the bi-level digital watermark that obtains having copyright authentication information, correspondence is designated as respectively

With

K the bi-level digital watermark that 2.-10, will have copyright authentication information

With

K the bi-level digital watermark W that embeds with a plurality of zero watermark built-in ends respectively ₁, W ₂..., W _k... And W _KCorrespondence is carried out similarity calculating one by one, and correspondence obtains K normalized correlation coefficient, judges whether extract K the bi-level digital watermark W that a plurality of zero watermark built-in ends embed according to the size of K normalized correlation coefficient then ₁, W ₂..., W _k... And W _K

4. a plurality of zero watermark extracting methods of a kind of digital picture according to claim 3 is characterized in that described step detailed process 2.-10 is:

Z1, K the bi-level digital watermark that will have copyright authentication information

With

K the bi-level digital watermark W that embeds with a plurality of zero watermark built-in ends respectively ₁, W ₂..., W _k... And W _KCorrespondence is carried out similarity calculating one by one, and correspondence obtains K normalized correlation coefficient, for inciting somebody to action Carry out k normalized correlation coefficient obtaining after similarity is calculated with Wk, it is designated as $\mathrm{\ρ}(W_k,W_k^{*})=\frac{\underset{i_k=1}{\overset{I_k}{\mathrm{\Σ}}}\underset{j_k=1}{\overset{J_k}{\mathrm{\Σ}}}((w_k(i_k,j_k)-\stackrel{\‾}{w_k})\×(w_k^{*}(i_k,j_k)-\stackrel{\‾}{w_k^{*}}))}{\sqrt{\underset{i_k=1}{\overset{I_k}{\mathrm{\Σ}}}\underset{j_k=1}{\overset{J_k}{\mathrm{\Σ}}}{(w_k(i_k,j_k)-\stackrel{\‾}{w_k})}^2\×\underset{i_k=1}{\overset{I_k}{\mathrm{\Σ}}}\underset{j_k=1}{\overset{J_k}{\mathrm{\Σ}}}{(w_k^{*}(i_k,j_k)-\stackrel{\‾}{w_k^{*}})}^2}},$ Wherein, w _k(i _k, j _k) k bi-level digital watermark W embedding of a plurality of zero watermark built-in ends of expression _kMiddle coordinate position is (i _k, j _k) the pixel value of pixel,

Represent k the bi-level digital watermark W that a plurality of zero watermark built-in ends embed _kIn the average of pixel value of all pixels,

K the bi-level digital watermark that expression has copyright authentication information

Middle coordinate position is (i _k, j _k) the pixel value of pixel,

K the bi-level digital watermark that expression has copyright authentication information

In the average of pixel value of all pixels;

Z2, judge whether extract K the bi-level digital watermark W that a plurality of zero watermark built-in ends embed according to the size of K normalized correlation coefficient ₁, W ₂..., W _k... And W _K, for normalized correlation coefficient

If

Value be 1, then confirm W _kNondestructively extracted, if

Value more than or equal to δ _TAnd, then confirm W less than 1 _kExtract successfully, if

Value less than δ _T, then confirm W _kExtract failure, wherein, δ _TExpression watermark extracting thresholding.

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