CN102682418B - Method for embedding and extracting multiple zero watermarks of digital image - Google Patents
Method for embedding and extracting multiple zero watermarks of digital image Download PDFInfo
- Publication number
- CN102682418B CN102682418B CN201210144040.4A CN201210144040A CN102682418B CN 102682418 B CN102682418 B CN 102682418B CN 201210144040 A CN201210144040 A CN 201210144040A CN 102682418 B CN102682418 B CN 102682418B
- Authority
- CN
- China
- Prior art keywords
- watermark
- facs
- level digital
- digital watermark
- represent
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Editing Of Facsimile Originals (AREA)
- Image Processing (AREA)
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
Technical field
The present invention relates to a kind of zero digital watermark, especially relate to a kind of multiple zero watermark embedding and extracting method of digital picture.
Background technology
Digital watermarking, as a kind of technological means of effective solution Digital Media Works copyright protection and entitlement discriminating, is the study hotspot of Contemporary Digital media information security fields.Digital watermarking will be brought into play due effect, must possess two fundamentals of robustness and imperceptible.Watermark robustness, refers to that Digital Media is through after conventional digital signal processing or external attack, and the digital watermarking of embedding still has the aspect information such as copyright that good detectability still can reflect original figure media in other words.Watermark imperceptible, refers to that the embedding of digital watermarking can not have influence on the sense of hearing or the visual quality of original figure media, thereby can not affect the using value of original figure media.Obviously, traditional digital watermark technology, carry out certain modification by the spatial domain data to original figure media or coefficient in transform domain, certain characteristic information that comprises author or works is for example signed, copyright, sequence number, date or icon etc. are embedded in original figure media as digital watermarking, inevitably exist the contradiction between watermark robustness and watermark imperceptible: on the one hand, watermark robustness require in original figure media as much as possible embed digital watermark information with resist various conventional processing or have a mind to attack, and on the other hand, watermark imperceptible wishes that embed digital watermark information is as few as possible to avoid causing and the notable difference of original figure media, this is particularly important for some responsive digital pictures such as medical image and palmprint image etc., because the details pixel packets of this class digital picture has contained very important information, the distortion that in this class digital picture, the variation of any pixel causes all can affect the judgement to original digital image.
In recent years, the proposition of zero digital watermark had solved the contradiction between watermark robustness and the watermark imperceptible in traditional digital watermark technology well, became a new research branch in digital watermark technology.So-called zero digital watermark, construct a watermark keys by the unique characteristics of original figure media exactly, again to the to be embedded digital watermarking being of practical significance in conjunction with forming relevant zero watermark information post-registration to a kind of digital watermark technology in intellecture property watermark information database, it does not change to original figure media.Therefore, in zero digital watermark, the structure of zero watermark and registration process are exactly the digital watermark embed process on ordinary meaning, once register, original figure media are just considered to comprise real figure watermark and have possessed corresponding copyright protection ability.Because the real figure watermark in zero digital watermark is to be registered in intellecture property watermark information database, rather than be embedded in original figure media, also any problem that does not just exist original figure media quality to decline, just because of this characteristic, zero digital watermark well balance the contradiction between watermark robustness and the watermark imperceptible in traditional digital watermark technology.
At present, existing multiple zero watermarking project is suggested.2008, Zeng Fanjuan, Zhou Anmin have proposed a kind of digital picture zero watermarking project based on Contourlet conversion and svd on computer utility publication, first this scheme carries out Contourlet conversion to original image, be decomposed into the sub-band images of a series of multiple dimensioned, localization, directivity, select again low frequency sub-band to carry out piecemeal svd, construct zero watermark according to the unchangeability of the integer-bit size of first singular value in every decomposition.2009, the 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, first this scheme carries out scramble processing to watermarking images, then utilize low frequency subgraph after carrier image one-level wavelet decomposition and the watermarking images after scramble to obtain extracting matrix, carry out certain encryption that upsets to extracting matrix again, complete thus embedding and the extraction of zero watermark.2010, Bi Xiuli, He Chunxiang and Cheng Cheng have proposed a kind of zero watermarking project based on log-polar coordinate mapping and Lifting Wavelet on computer engineering and science publication, first this scheme carries out scramble by watermarking images, carrier image is carried out to convergent-divergent normalized, then carry out log-polar coordinate mapping, then carry out the lifting of one-level integer wavelet, after the low frequency subgraph after finally utilization is decomposed and scramble, watermarking images constructs zero watermark.2011, Wang Wujun has proposed zero watermarking project of a kind of multistage discrete cosine transform and svd on computing machine and digital engineering publication, first this scheme carries out multistage discrete cosine transform to the original image that will embed, extract low frequency subgraph and it is carried out to svd, secondly the watermarking images embedding is carried out to scramble, watermarking images after scramble is carried out to svd, finally the result after original image and twice svd of watermarking images is carried out to computing and produce zero watermark.
But zero watermarking project having proposed is at present the digital watermark technology that embeds and extract based on single zero watermark substantially, exist the limitation of function singleness.Embed multiple digital watermarkings to meet the needs of different application object owing to existing more in practical application in Digital Media works, such as width Digital Media works need to have two people or many people's signature with Shared Copyright after completing, or width Digital Media works are being issued, sell, the different phases such as use need to indicate that the different owners are (as creator, publisher, user etc.) use legal information, and for example the author of Digital Media works (or publisher) embeds for the robust watermarking of copyright authentication with for fragile watermark of content authentication etc. in works simultaneously.Therefore, consider from the application diversity of digital watermarking, the zero watermarking project research that embeds multiple digital watermarkings has more actual application value and wide application prospect.
Summary of the invention
Technical matters to be solved by this invention is to provide a kind of multiple zero watermark embedding and extracting method of digital picture, it has been realized and in original digital image, has embedded multiple zero watermarks, and multiple zero watermarks that embed have excellent robust performance, effectively guarantee that the quality of original digital image is unaffected simultaneously.
The present invention solves the problems of the technologies described above adopted technical scheme: a kind of multiple zero watermark embedding methods of digital picture, is characterized in that comprising the following steps:
1.-1, at multiple zero watermark built-in ends, the gray level image that the original digital image of supposing K to be embedded bi-level digital watermark is 8bit, and be designated as F, F={0≤f (m, n)≤255, 1≤m≤M, 1≤n≤N}, wherein, K >=2, M represents the vertical resolution of the original digital image F of K to be embedded bi-level digital watermark, N represents the lateral resolution of the original digital image F of K to be embedded bi-level digital watermark, M × N represents the resolution of the original digital image F of K to be embedded bi-level digital watermark, f (m, n) represent that in the original digital image F of K to be embedded bi-level digital watermark, coordinate position is (m, the pixel value of pixel n),
1. ,-2, at multiple zero watermark built-in ends, suppose that K to be embedded bi-level digital watermark is all bianry image, and be designated as W respectively
1, W
2..., W
k... W
k, 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) represent k bi-level digital watermark W to be embedded
kmiddle coordinate position is (i
k, j
k) the pixel value of pixel;
1.-3, the original digital image F of K to be embedded bi-level digital watermark is normalized, obtain the digital picture after normalized, be designated as F ', be (m by middle the digital picture F ' after normalized coordinate position, the pixel value of pixel n) is designated as f ' (m, n), f ' (m, n)=f (m, n)/255;
1.-4, F ' is carried out to L level two-dimensional discrete wavelet conversion, obtain a first small echo ll channel and multiple the first wavelet details subgraph, the first small echo ll channel is designated as to 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
represent to get the maximum integer that is less than himself, I
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 to two-dimension discrete cosine transform, obtain one with the first Two Dimension Discrete Cosine matrix of FA equal resolution, be designated as FAC, then FAC being carried out to Zig-Zag scanning arranges, obtain a first one-dimensional discrete cosine transform coefficient sequence, be designated as FACS, FACS={facs (x), 1≤x≤(M/2
l) × (N/2
l), wherein, facs (x) represents x discrete cosine transform coefficient in FACS, the 2nd discrete cosine transform coefficient in FACS starts to be discrete cosine transform ac coefficient;
1. ,-6, successively according to the resolution of each bi-level digital watermark to be embedded, from FACS, select respectively and meet the I imposing a condition
1× J
1, I
2× J
2..., I
k× J
k... and I
k× J
kindividual discrete cosine transform ac coefficient, forms 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 imposing a condition selecting from FACS
k× J
kthe k that individual discrete cosine transform ac coefficient forms a first one-dimensional discrete cosine transform ac coefficient sequence FACS
k, FACS
k={ facs
k(y), 1≤y≤I
k× J
k, then record FACS
1, FACS
2..., FACS
k... and FACS
kin the correspondence position information of various 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) represent FACS
kin y discrete cosine transform ac coefficient, impose a condition and be more than or equal to the difference threshold of setting for the absolute value of difference of two the discrete cosine transform ac coefficients of arbitrary neighborhood in the first one-dimensional discrete cosine transform ac coefficient sequence that makes to form;
1.-7, compare respectively FACS
1, FACS
2..., FACS
k... and FACS
kin the size of two discrete cosine transform ac coefficients of arbitrary neighborhood, and return to logical value 1 or 0 according to comparative result, for FACS
kin two discrete cosine transform ac coefficients of arbitrary neighborhood, it is designated as respectively to facs
kand facs (z)
k(z+1), judge facs
k(z) >facs
k(z+1) whether set up, if set up, return to logical value 1, otherwise, return to logical value 0, wherein, 1≤z≤I
k× J
k-1; Then compare FACS
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 to logical value 1 or 0 according to comparative result, for FACS
kin last discrete cosine transform ac coefficient and the 1st discrete cosine transform ac coefficient, if the former is large, return to logical value 1, otherwise, return to logical value 0; Again according to FACS
1, FACS
2..., FACS
k... and FACS
keach self-corresponding logical value of returning, builds 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 to a size by Row Column order arrangement mode
k× J
ktwo-dimensional matrix in, the first bi-level digital watermark keys using this two-dimensional matrix as k, is designated as WB
k;
1.-8, to K to be embedded bi-level digital watermark W
1, W
2..., W
k..., W
kcarry out respectively scramble processing, K the bi-level digital watermark obtaining after scramble is processed respectively correspondence is designated as WS
1, WS
2..., WS
k... and WS
k, then by 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), then by K zero watermark information WO
1, WO
2..., WO
k... and WO
kbe stored in the digital watermark information database of registration body, complete K bi-level digital watermark W
1, W
2..., W
k..., W
kembedding, wherein, WS
1represent W
1carry out the bi-level digital watermark obtaining after scramble processing, WS
2represent W
2carry out the bi-level digital watermark obtaining after scramble processing, WS
krepresent W
kcarry out the bi-level digital watermark obtaining after scramble processing, WS
krepresent W
kcarry out the bi-level digital watermark obtaining after scramble processing, WB
1represent the 1st the first bi-level digital watermark keys, WB
2represent the 2nd the first bi-level digital watermark keys, WB
krepresent K the first bi-level digital watermark keys, xor () is XOR function;
1.-9, at multiple zero watermark built-in ends, by the FACS of record
1, FACS
2..., FACS
k... and FACS
kin the positional information of various discrete cosine transform ac coefficient in FACS, a K zero 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 multiple zero watermark extracting ends.
FACS in described step 1.-6
1, FACS
2..., FACS
k... and FACS
kin the absolute value of difference of two discrete cosine transform ac coefficients of arbitrary neighborhood be more than or equal to respectively δ
1, δ
2..., δ
k... and δ
k, wherein, δ
1represent for FACS
1in two discrete cosine transform ac coefficients of arbitrary neighborhood difference absolute value set the 1st difference threshold, δ
2represent for FACS
2in two discrete cosine transform ac coefficients of arbitrary neighborhood difference absolute value set the 2nd difference threshold, δ
krepresent for FACS
kin two discrete cosine transform ac coefficients of arbitrary neighborhood difference absolute value set k difference threshold, δ
krepresent for FACS
kin two discrete cosine transform ac coefficients of arbitrary neighborhood difference absolute value set K difference threshold.
Multiple zero watermark extracting methods for digital picture, is characterized in that comprising the following steps:
2.-1, at multiple zero watermark extracting ends, the digital picture of K to be extracted bi-level digital watermark is designated as to TF, TF={0≤tf (m ', n ')≤255, 1≤m '≤M ', 1≤n '≤N ' }, wherein, K >=2, M ' represents the vertical resolution of the digital picture TF of K to be extracted bi-level digital watermark, N ' represents the lateral resolution of the digital picture TF of K to be extracted bi-level digital watermark, M ' × N ' represents the resolution of the digital picture TF of K to be extracted bi-level digital watermark, the resolution of the digital picture TF of K to be extracted bi-level digital watermark and the embedding of multiple zero watermark built-in ends have the resolution of digital picture of digital watermarking identical, tf (m ', n ') represent in the digital picture TF of K to be extracted bi-level digital watermark coordinate position for (m ', n ') the pixel value of pixel,
2. ,-2, at multiple zero watermark extracting ends, K to be extracted bi-level digital watermark is designated as respectively to W '
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
kresolution identical with the resolution of k bi-level digital watermark that multiple zero watermark built-in ends embed, w '
k(i '
k, j '
k) represent k bi-level digital watermark W ' to be extracted
kmiddle 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 is normalized, obtain the digital picture after normalized, be designated as TF ', by middle the digital picture TF ' after normalized coordinate position be (m ', n ') the pixel value of pixel be designated as tf ' (m ', n '), tf ' (m ', n ')=tf (m ', n ')/255;
2.-4, TF ' is carried out to L ' level two-dimensional discrete wavelet conversion, obtain a second small echo ll channel and multiple the second wavelet details subgraph, the second small echo ll channel is designated as to 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
represent to get the maximum integer that is less than himself, I
1' represent the 1st bi-level digital watermark W to be extracted
1' vertical resolution, J
1' represent the 1st bi-level digital watermark W to be extracted
1' lateral resolution, I
k' represent K bi-level digital watermark W ' to be extracted
kvertical resolution, J
k' represent K bi-level digital watermark W ' to be extracted
klateral resolution;
2.-5, TFA is carried out to two-dimension discrete cosine transform, obtain one with the second Two Dimension Discrete Cosine matrix of TFA equal resolution, be designated as TFAC, then TFAC being carried out to Zig-Zag scanning arranges, obtain a second one-dimensional discrete cosine transform coefficient sequence, be designated as TFACS, TFACS={tfacs (x '), 1≤x '≤(M '/2
l') × (N '/2
l'), wherein, tfacs (x ') represents the individual discrete cosine transform coefficient of x ' in TFACS, the 2nd discrete cosine transform coefficient in TFACS starts to be discrete cosine transform ac coefficient;
2.-6, according to the FACS of multiple zero watermark built-in end records
1, FACS
2..., FACS
k... and FACS
kin the correspondence position information of various discrete cosine transform ac coefficient in FACS, from TFACS, extract respectively the I of correspondence position
1' × J
1', I
2' × J
2' ..., I
k' × J
k' ... and I
k' × J
k' individual discrete cosine transform ac coefficient, forms 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 the FACS recording according to multiple zero watermark built-in ends
kin the correspondence position information of various 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
k' represent k bi-level digital watermark W ' to be extracted
kvertical resolution, J
k' represent k bi-level digital watermark W ' to be extracted
klateral resolution, tfacs
k(y ') represents TFACS
kin the individual discrete cosine transform ac coefficient of y ';
2.-7, compare respectively TFACS
1, TFACS
2..., TFACS
k... and TFACS
kin the size of two discrete cosine transform ac coefficients of arbitrary neighborhood, and return to logical value 1 or 0 according to comparative result, for TFACS
kin two discrete cosine transform ac coefficients of arbitrary neighborhood, it is designated as respectively to tfacs
k(z ') and tfacs
k(z '+1), judges tfacs
k(z ') >tfacs
kwhether set up (z '+1), if set up, returns to logical value 1, otherwise, return to logical value 0, wherein, 1≤z '≤I
k' × J
k'-1; Then compare TFACS
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 to logical value 1 or 0 according to comparative result, for TFACS
kin last discrete cosine transform ac coefficient and the 1st discrete cosine transform ac coefficient, if the former is large, return to logical value 1, otherwise, return to logical value 0; Again according to TFACS
1, TFACS
2..., TFACS
k... and TFACS
keach self-corresponding logical value of returning, builds 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 to a size by Row Column order arrangement mode
k' × J
k' two-dimensional matrix in, the second bi-level digital watermark keys using this two-dimensional matrix as k, is designated as TWB
k;
2.-8, by the K from multiple zero watermark built-in ends zero watermark information WO
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 the second bi-level digital watermark keys, TWB
2represent the 2nd the 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 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, obtains having K bi-level digital watermark of copyright authentication information, and correspondence is designated as respectively
with
2.-10, K bi-level digital watermark of copyright authentication information will be there is
with
respectively with multiple zero watermark built-in ends embed K bi-level digital watermark W
1, W
2..., W
k... and W
kcorrespondence is carried out similarity calculating one by one, and correspondence obtains K normalized correlation coefficient, then determines whether and extracts K the bi-level digital watermark W that multiple zero watermark built-in ends embed according to the size of K normalized correlation coefficient
1, W
2..., W
k... and W
k.
The detailed process of described step 2.-10 is:
Z1, K bi-level digital watermark of copyright authentication information will be there is
with
respectively with multiple zero watermark built-in ends embed K bi-level digital watermark W
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 the normalized correlation coefficient obtaining after similarity calculating, be designated as
Wherein, w
k(i
k, j
k) represent multiple zero watermark built-in ends embed k bi-level digital watermark W
kmiddle coordinate position is (i
k, j
k) the pixel value of pixel,
k the bi-level digital watermark W that multiple zero watermark built-in ends embed
kin the average of pixel value of all pixels,
represent to have k bi-level digital watermark of copyright authentication information
middle coordinate position is (i
k, j
k) the pixel value of pixel,
represent to have k bi-level digital watermark of copyright authentication information
in the average of pixel value of all pixels;
Z2, according to the size of K normalized correlation coefficient determine whether extract multiple zero watermark built-in ends embed K bi-level digital watermark W
1, W
2..., W
k... and W
k, for normalized correlation coefficient
if
value be 1, determine W
knondestructively extracted, if
value be more than or equal to δ
tand be less than 1, determine W
kextract successfully, if
value be less than δ
t, determine W
kextract unsuccessfully, wherein, δ
trepresent 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, when realizing multiple bi-level digital watermark of different objects, different purposes, embed, and do not interfere with each other between the multiple bi-level digital watermarks that embed, therefore more can meet the application diversity of digital watermarking, there is larger actual application value and wide application prospect.
2) than traditional digital watermark technology, embedding grammar of the present invention is not embedded into multiple reality bi-level digital watermarks in original digital image, but be registered in digital watermark information database, therefore not only realized the complete imperceptible of bi-level digital watermark embedding, and raw digital image data is not produced to any destruction, there is not any problem of image quality decrease, maintain original digital image information integrity, this is highly suitable for such as medical image of some responsive digital pictures, the copyright protection of the aspect such as palmprint image and military image.
3) embedding of the present invention and extracting method are to carry out in the compositum of two-dimensional discrete wavelet conversion (DWT) and two-dimension discrete cosine transform (DCT), take full advantage of both features, process multiple zero watermarks of attacking and embed and extract thereby realized the anti-normal image with excellent robust performance, well balance the contradiction between robustness and the imperceptible of digital watermarking.
Accompanying drawing explanation
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 embedding after a binary watermarking;
Fig. 2 b is the Lena digital picture embedding after two binary watermarkings;
Fig. 2 c is the Lena digital picture embedding after three binary watermarkings;
Fig. 2 d is the two-value signature watermark of extracting from Fig. 2 c;
Fig. 2 e is the two-value sequence number watermark of extracting from Fig. 2 c;
Fig. 2 f is the two-value icon watermark of extracting from Fig. 2 c;
Fig. 3 a adds the watermark Lena digital picture after 0.2 to the digital picture shown in Fig. 2 c by all pixel values;
Fig. 3 b adds the watermark Lena digital picture after 0.5 to the digital picture shown in Fig. 2 c by all pixel values;
Fig. 3 c subtracts the watermark Lena digital picture after 0.2 to the digital picture shown in Fig. 2 c by all pixel values;
Fig. 3 d subtracts the watermark Lena digital picture after 0.5 to the digital picture shown in Fig. 2 c by all pixel values;
Fig. 3 e is the two-value signature watermark of extracting from Fig. 3 a, Fig. 3 b and Fig. 3 c;
Fig. 3 f is the two-value sequence number watermark of extracting from Fig. 3 a, Fig. 3 b and Fig. 3 c;
Fig. 3 g is the two-value icon watermark of extracting from Fig. 3 a, Fig. 3 b and Fig. 3 c;
Fig. 4 a is through histogram equalization watermark Lena after treatment digital picture to the digital picture shown in Fig. 2 c;
Fig. 4 b is the two-value signature watermark of extracting from Fig. 4 a;
Fig. 4 c is the two-value sequence number watermark of extracting from Fig. 4 a;
Fig. 4 d is the two-value icon watermark of extracting from Fig. 4 a;
Fig. 5 a is the watermark Lena digital picture after [5 × 5] window medium filtering to the digital picture shown in Fig. 2 c;
Fig. 5 b is the watermark Lena digital picture after [11 × 11] window medium filtering to the digital picture shown in Fig. 2 c;
Fig. 5 c is the two-value signature watermark of extracting from Fig. 5 a;
Fig. 5 d is the two-value sequence number watermark of extracting from Fig. 5 a;
Fig. 5 e is the two-value icon watermark of extracting from Fig. 5 a;
Fig. 5 f is the two-value signature watermark of extracting from Fig. 5 b;
Fig. 5 g is the two-value sequence number watermark of extracting from Fig. 5 b;
Fig. 5 h is the two-value icon watermark of extracting from Fig. 5 b;
Fig. 6 a is the watermark Lena digital picture after the JPEG of 10% quality factor compression to the digital picture shown in Fig. 2 c;
Fig. 6 b is the watermark Lena digital picture after the JPEG of 4% quality factor compression to the digital picture shown in Fig. 2 c;
Fig. 6 c is the two-value signature watermark of extracting from Fig. 6 a;
Fig. 6 d is the two-value sequence number watermark of extracting from Fig. 6 a;
Fig. 6 e is the two-value icon watermark of extracting from Fig. 6 a;
Fig. 6 f is the two-value signature watermark of extracting from Fig. 6 b;
Fig. 6 g is the two-value sequence number watermark of extracting from Fig. 6 b;
Fig. 6 h is the two-value icon watermark of extracting from Fig. 6 b;
Fig. 7 a is to be that 0 variance is the watermark Lena digital picture after 0.02 Gaussian noise to the digital picture stack average shown in Fig. 2 c;
Fig. 7 b is to be that 0 variance is the watermark Lena digital picture after 0.05 Gaussian noise to the digital picture stack average shown in Fig. 2 c;
Fig. 7 c is the two-value signature watermark of extracting from Fig. 7 a;
Fig. 7 d is the two-value sequence number watermark of extracting from Fig. 7 a;
Fig. 7 e is the two-value icon watermark of extracting from Fig. 7 a;
Fig. 7 f is the two-value signature watermark of extracting from Fig. 7 b;
Fig. 7 g is the two-value sequence number watermark of extracting from Fig. 7 b;
Fig. 7 h is the two-value icon watermark of extracting from Fig. 7 b;
Fig. 8 a cuts the watermark Lena digital picture after 128 × 128 pixels of the upper left corner to the digital picture shown in Fig. 2 c;
Fig. 8 b cuts the watermark Lena digital picture after 256 × 256 pixels of the upper left corner to the digital picture shown in Fig. 2 c;
Fig. 8 c is the two-value signature watermark of extracting from Fig. 8 a;
Fig. 8 d is the two-value sequence number watermark of extracting from Fig. 8 a;
Fig. 8 e is the two-value icon watermark of extracting from Fig. 8 a;
Fig. 8 f is the two-value signature watermark of extracting from Fig. 8 b;
Fig. 8 g is the two-value sequence number watermark of extracting from Fig. 8 b;
Fig. 8 h is the two-value icon watermark of extracting from Fig. 8 b;
Fig. 9 a recovers the watermark Lena digital picture after former direction to the digital picture shown in Fig. 2 c again through counterclockwise rotating 5 degree;
Fig. 9 b recovers the watermark Lena digital picture after former direction to the digital picture shown in Fig. 2 c again through counterclockwise rotating 25 degree;
Fig. 9 c is the two-value signature watermark of extracting from Fig. 9 a;
Fig. 9 d is the two-value sequence number watermark of extracting from Fig. 9 a;
Fig. 9 e is the two-value icon watermark of extracting from Fig. 9 a;
Fig. 9 f is the two-value signature watermark of extracting from Fig. 9 b;
Fig. 9 g is the two-value sequence number watermark of extracting from Fig. 9 b;
Fig. 9 h is the two-value icon watermark of extracting from Fig. 9 b.
Embodiment
Below in conjunction with accompanying drawing, embodiment is described in further detail the present invention.
Multiple zero watermark embedding and extracting method of a kind of digital picture that the present invention proposes, watermark embeds and extracts is all to carry out in the compositum of wavelet transform and discrete cosine transform, takes full advantage of both excellent specific properties.The main process that multiple zero watermarks embed is: the wavelet transform that first original digital image is carried out suitable level, and the small echo ll channel obtaining is carried out to discrete cosine transform again, then according to the resolution of K bi-level digital watermark to be embedded, choose respectively the discrete cosine transform ac coefficient that absolute value that K group meets certain difference requires and form K discrete cosine transform ac coefficient sequence, finally construct the bi-level digital watermark keys of K robust according to discrete cosine transform ac coefficient magnitude relationship each other in each sequence, and carry out being saved in registration body after XOR and complete the embedding of K zero watermark with the K being of practical significance a bi-level digital watermark to be embedded, the main process of multiple zero watermark extracting is: by the digital picture of K to be extracted bi-level digital watermark is carried out to similar wavelet transform and discrete cosine transform processing procedure, in conjunction with K zero watermark information being kept in registration body, extract K relevant watermark to prove copyright or the entitlement to original digital image.
Multiple zero watermark embedding methods of a kind of digital picture of the present invention, it comprises the following steps:
1.-1, at multiple zero watermark built-in ends, the gray level image that the original digital image of supposing K to be embedded bi-level digital watermark is 8bit, and be designated as F, F={0≤f (m, n)≤255, 1≤m≤M, 1≤n≤N}, wherein, K >=2, M represents the vertical resolution of the original digital image F of K to be embedded bi-level digital watermark, N represents the lateral resolution of the original digital image F of K to be embedded bi-level digital watermark, M × N represents the resolution of the original digital image F of K to be embedded bi-level digital watermark, f (m, n) represent that in the original digital image F of K to be embedded bi-level digital watermark, coordinate position is (m, the pixel value of pixel n).
1. ,-2, at multiple zero watermark built-in ends, suppose that a K to be embedded digital watermarking is all bianry image, and be designated as W respectively
1, W
2..., W
k..., W
k, 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) represent 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, a K to be embedded digital watermarking can be selected has the bianry image such as the corresponding copyright information of practical significance or the author of entitlement information or owner's signature, mark, sequence number, date or company's icon.
1.-3, the original digital image F of K to be embedded bi-level digital watermark is normalized, obtain the digital picture after normalized, be designated as F ', be (m by middle the digital picture F ' after normalized coordinate position, the pixel value of pixel n) is designated as f ' (m, n), f ' (m, n)=f (m, n)/255.
1.-4, F ' is carried out to L level two-dimensional discrete wavelet conversion, obtain a first small echo ll channel and multiple the first wavelet details subgraph, the first small echo ll channel is designated as to 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
represent to get the maximum integer that is less than himself, 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 to two-dimension discrete cosine transform, obtain one with the first Two Dimension Discrete Cosine matrix of FA equal resolution, be designated as FAC, then FAC being carried out to Zig-Zag scanning arranges, obtain a first one-dimensional discrete cosine transform coefficient sequence, be designated as FACS, FACS={facs (x), 1≤x≤(M/2
l) × (N/2
l), wherein, facs (x) represents x discrete cosine transform coefficient in FACS, the 2nd discrete cosine transform coefficient in FACS starts to be discrete cosine transform ac coefficient.
1. ,-6, successively according to the resolution of each bi-level digital watermark to be embedded, from FACS, select respectively and meet the I imposing a condition
1× J
1, I
2× J
2..., I
k× J
k... and I
k× J
kindividual discrete cosine transform ac coefficient, forms 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 imposing a condition selecting from FACS
k× J
kthe k that individual discrete cosine transform ac coefficient forms a first one-dimensional discrete cosine transform ac coefficient sequence FACS
k, FACS
k={ facs
k(y), 1≤y≤I
k× J
k, then record FACS
1, FACS
2..., FACS
k... and FACS
kin the correspondence position information of various 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) represent FACS
kin y discrete cosine transform ac coefficient, impose a condition and be more than or equal to the difference threshold of setting for the absolute value of difference of two the discrete cosine transform ac coefficients of arbitrary neighborhood in the first one-dimensional discrete cosine transform ac coefficient sequence that makes to form.
At this, choosing of discrete cosine transform ac coefficient in each the first one-dimensional discrete cosine transform ac coefficient sequence 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 two discrete cosine transform ac coefficients of arbitrary neighborhood be more than or equal to respectively δ
1, δ
2..., δ
k... and δ
k, wherein, δ
1represent for FACS
1in two discrete cosine transform ac coefficients of arbitrary neighborhood difference absolute value set the 1st difference threshold, δ
2represent for FACS
2in two discrete cosine transform ac coefficients of arbitrary neighborhood difference absolute value set the 2nd difference threshold, δ
krepresent for FACS
kin two discrete cosine transform ac coefficients of arbitrary neighborhood difference absolute value set k difference threshold, δ
krepresent for FACS
kin two discrete cosine transform ac coefficients of arbitrary neighborhood difference absolute value set K difference threshold.With δ
kfor example, δ
ksetting principle be such, guaranteeing to choose I
k× J
kunder the prerequisite of individual discrete cosine transform ac coefficient, get maximal value, 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 respectively FACS
1, FACS
2..., FACS
k... and FACS
kin the size of two discrete cosine transform ac coefficients of arbitrary neighborhood, and return to logical value 1 or 0 according to comparative result, for FACS
kin two discrete cosine transform ac coefficients of arbitrary neighborhood, it is designated as respectively to facs
kand facs (z)
k(z+1), judge facs
k(z) >facs
k(z+1) whether set up, if set up, return to logical value 1, otherwise, return to logical value 0, wherein, 1≤z≤I
k× J
k-1; Then compare FACS
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 to logical value 1 or 0 according to comparative result, for FACS
kin last discrete cosine transform ac coefficient and the 1st discrete cosine transform ac coefficient, if the former is large, return to logical value 1, otherwise, return to logical value 0; Again according to FACS
1, FACS
2..., FACS
k... and FACS
keach self-corresponding logical value of returning, builds 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 to a size by Row Column order arrangement mode
k× J
ktwo-dimensional matrix in, the first bi-level digital watermark keys using this two-dimensional matrix as k, is designated as WB
k.
1.-8, to K to be embedded bi-level digital watermark W
1, W
2..., W
k..., W
kcarry out respectively scramble processing, K the bi-level digital watermark obtaining after scramble is processed respectively correspondence is designated as WS
1, WS
2..., WS
k... and WS
k, then by 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), then by K zero watermark information WO
1, WO
2..., WO
k... and WO
kbe stored in the digital watermark information database of registration body, complete K bi-level digital watermark W
1, W
2..., W
k..., W
kembedding, wherein, WS
1represent W
1carry out the bi-level digital watermark obtaining after scramble processing, WS
2represent W
2carry out the bi-level digital watermark obtaining after scramble processing, WS
krepresent W
kcarry out the bi-level digital watermark obtaining after scramble processing, WS
krepresent W
kcarry out the bi-level digital watermark obtaining after scramble processing, WB
1represent the 1st the first bi-level digital watermark keys, WB
2represent the 2nd the first bi-level digital watermark keys, WB
krepresent K the first bi-level digital watermark keys, xor () is XOR function.
At this, to K to be embedded bi-level digital watermark W
1, W
2..., W
k..., W
kcarry out respectively scramble processing, can effectively improve the security of zero watermark in registration body, can adopt conventional Arnold conversion in this scramble processing, also can adopt existing other ripe disorder methods.
1.-9, at multiple zero watermark built-in ends, by the FACS of record
1, FACS
2..., FACS
k... and FACS
kin the positional information of various discrete cosine transform ac coefficient in FACS, a K zero 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 multiple zero watermark extracting ends.
Multiple zero watermark extracting methods of a kind of digital picture of the present invention, it comprises the following steps:
2.-1, at multiple zero watermark extracting ends, the digital picture of K to be extracted bi-level digital watermark (being test pattern) is designated as to TF, TF={0≤tf (m ', n ')≤255, 1≤m '≤M ', 1≤n '≤N ' }, wherein, K >=2, M ' represents the vertical resolution of the digital picture TF of K to be extracted bi-level digital watermark, N ' represents the lateral resolution of the digital picture TF of K to be extracted bi-level digital watermark, M ' × N ' represents the resolution of the digital picture TF of K to be extracted bi-level digital watermark, the resolution of the digital picture TF of K to be extracted bi-level digital watermark and the embedding of multiple zero watermark built-in ends have the resolution of digital picture of digital watermarking identical, tf (m ', n ') represent in the digital picture TF of K to be extracted bi-level digital watermark coordinate position for (m ', n ') the pixel value of pixel.
2. ,-2, at multiple zero watermark extracting ends, K to be extracted bi-level digital watermark is designated as respectively to W '
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
kresolution identical with the resolution of k bi-level digital watermark that multiple zero watermark built-in ends embed, w '
k(i '
k, j '
k) represent k bi-level digital watermark W ' to be extracted
kmiddle 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 is normalized, obtain the digital picture after normalized, be designated as TF ', by middle the digital picture TF ' after normalized coordinate position be (m ', n ') the pixel value of pixel be designated as tf ' (m ', n '), tf ' (m ', n ')=tf (m ', n ')/255.
2.-4, TF ' is carried out to L ' level two-dimensional discrete wavelet conversion, obtain a second small echo ll channel and multiple the second wavelet details subgraph, the second small echo ll channel is designated as to 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
represent to get the maximum integer that is less than himself, this symbol is for rounding symbol, I downwards
1' represent the 1st bi-level digital watermark W ' to be extracted
1vertical resolution, J
1' represent the 1st bi-level digital watermark W ' to be extracted
1lateral resolution, I
k' represent K bi-level digital watermark W ' to be extracted
kvertical resolution, J
k' represent K bi-level digital watermark W ' to be extracted
klateral resolution.
2.-5, TFA is carried out to two-dimension discrete cosine transform, obtain one with the second Two Dimension Discrete Cosine matrix of TFA equal resolution, be designated as TFAC, then TFAC being carried out to Zig-Zag scanning arranges, obtain a second one-dimensional discrete cosine transform coefficient sequence, be designated as TFACS, TFACS={tfacs (x '), 1≤x '≤(M '/2
l') × (N '/2
l'), wherein, tfacs (x ') represents the individual discrete cosine transform coefficient of x ' in TFACS, the 2nd discrete cosine transform coefficient in TFACS starts to be discrete cosine transform ac coefficient.
2.-6, according to the FACS of multiple zero watermark built-in end records
1, FACS
2..., FACS
k... and FACS
kin the correspondence position information of various discrete cosine transform ac coefficient in FACS, from TFACS, extract respectively the I of correspondence position
1' × J
1', I
2' × J
2' ..., I
k' × J
k' ... and I
k' × J
k' individual discrete cosine transform ac coefficient, forms 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 the FACS recording according to multiple zero watermark built-in ends
kin the correspondence position information of various 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
k' represent k bi-level digital watermark W ' to be extracted
kvertical resolution, J
k' represent k bi-level digital watermark W ' to be extracted
klateral resolution, tfacs
k(y ') represents TFACS
kin the individual discrete cosine transform ac coefficient of y '.
2.-7, compare respectively TFACS
1, TFACS
2..., TFACS
k... and TFACS
kin the size of two discrete cosine transform ac coefficients of arbitrary neighborhood, and return to logical value 1 or 0 according to comparative result, for TFACS
kin two discrete cosine transform ac coefficients of arbitrary neighborhood, it is designated as respectively to tfacs
k(z ') and tfacs
k(z '+1), judges tfacs
k(z ') >tfacs
kwhether set up (z '+1), if set up, returns to logical value 1, otherwise, return to logical value 0, wherein, 1≤z '≤I
k' × J
k'-1; Then compare TFACS
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 to logical value 1 or 0 according to comparative result, for TFACS
kin last discrete cosine transform ac coefficient and the 1st discrete cosine transform ac coefficient, if the former is large, return to logical value 1, otherwise, return to logical value 0; Again according to TFACS
1, TFACS
2..., TFACS
k... and TFACS
keach self-corresponding logical value of returning, builds 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 to a size by Row Column order arrangement mode
k' × J
k' two-dimensional matrix in, the second bi-level digital watermark keys using this two-dimensional matrix as k, is designated as TWB
k.
2.-8, by the K from multiple zero watermark built-in ends zero watermark information WO
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 the second bi-level digital watermark keys, TWB
2represent the 2nd the 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 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, obtains having K bi-level digital watermark of copyright authentication information, and correspondence is designated as respectively
with
2.-10, K bi-level digital watermark of copyright authentication information will be there is
with
respectively with multiple zero watermark built-in ends embed K bi-level digital watermark W
1, W
2..., W
k... and W
kcorrespondence is carried out similarity calculating one by one, and correspondence obtains K normalized correlation coefficient, then determines whether and extracts K the bi-level digital watermark W that multiple zero watermark built-in ends embed according to the size of K normalized correlation coefficient
1, W
2..., W
k... and W
kand the robustness of K the bi-level digital watermark embedding.
In this specific embodiment, the detailed process of step 2.-10 is:
Z1, K bi-level digital watermark of copyright authentication information will be there is
with
respectively with multiple zero watermark built-in ends embed K bi-level digital watermark W
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 the normalized correlation coefficient obtaining after similarity calculating, be designated as
Wherein, w
k(i
k, j
k) represent multiple zero watermark built-in ends embed k bi-level digital watermark W
kmiddle coordinate position is (i
k, j
k) the pixel value of pixel,
represent k the bi-level digital watermark W that multiple zero watermark built-in ends embed
kin the average of pixel value of all pixels,
represent to have k bi-level digital watermark of copyright authentication information
middle coordinate position is (i
k, j
k) the pixel value of pixel,
represent to have k bi-level digital watermark of copyright authentication information
in the average of pixel value of all pixels.
Z2, according to the size of K normalized correlation coefficient determine whether extract multiple zero watermark built-in ends embed K bi-level digital watermark W
1, W
2..., W
k... and W
k, for normalized correlation coefficient
judgement
value whether be 1, if
value be 1, determine
with W
kin full accord, show W
knondestructively extracted, if this to be Lena digital picture after embed watermark be subject to certain processing or attack after extraction result, the bi-level digital watermark W of embedding be described
kthe ability with this processing of opposing or attack, has desirable robustness.If
value be not 1, judge again
value whether between δ
t-1, if
value between δ
t-1, the bi-level digital watermark that explanation extracts
bi-level digital watermark W with built-in end embedding
kthere is some difference, but have very large similarity between the two, at this moment can from extract result, recognize the bi-level digital watermark W of embedding
k, extract successfully.The value of related coefficient is larger, the bi-level digital watermark extracting
bi-level digital watermark W with built-in end embedding
kmore similar, more easily recognize the bi-level digital watermark W of embedding
k, extraction effect is better.If this to be Lena digital picture after embed watermark be subject to certain processing or attack after extraction result, the bi-level digital watermark W of embedding be described
kthe ability with this processing of more satisfactory opposing or attack, has good robustness.Wherein, δ
tfor watermark extracting thresholding, can value be generally 0.5.If
value not between δ
t-1, judge again
value whether be less than δ
t, if so, the bi-level digital watermark that explanation extracts
bi-level digital watermark W with built-in end embedding
kcorrelativity is very little, at this moment cannot from extract result, recognize the bi-level digital watermark W of embedding
k, extract unsuccessfully.
For multiple zero watermark embeddings of a kind of digital picture that the present invention proposes and feasibility and the validity of extracting method are described better, to embed three bi-level digital watermarks as example (K=3), carry out emulation by following experiment.
Experiment simulation carries out on Matlab7.5 platform, and the original digital image F of three bi-level digital watermarks to be embedded selects the Lena gray level image of 8bit, and resolution is 512 × 512, as shown in Figure 1a.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 as shown in Fig. 1 b, Fig. 1 c and Fig. 1 d.
Bi-level digital watermark is normalized original digital image F pixel before embedding, and then the digital picture F ' after normalized is carried out to 3 grades of two-dimensional discrete wavelet conversions.
The quality of the digital picture after embed digital watermark adopts Y-PSNR (PSNR) to pass judgment on,
Wherein, f (m, n) represent that in the original digital image of bi-level digital watermark to be embedded, coordinate position is (m, the pixel value of pixel n), f " (m; n) represent to embed the pixel value of the pixel that in the digital picture after bi-level digital watermark, coordinate position is (m, n), f
maxrepresent the max pixel value of original digital image.
The objective evaluation of digital watermarking testing result adopts normalized correlation coefficient (ρ):
1≤k≤K, wherein, w
k(i
k, j
k) represent k original bi-level digital watermark W
kmiddle coordinate position is (i
k, j
k) the pixel value of pixel,
represent k the bi-level digital watermark extracting
middle coordinate position is (i
k, j
k) the pixel value of pixel,
with
representative digit watermark W respectively
kwith
the average of pixel value of all pixels.Can determine whether how extract the bi-level digital watermark of embedding and the bi-level digital watermark robustness of embedding according to the size of normalized correlation coefficient ρ.
Fig. 2 a, Fig. 2 b and Fig. 2 c have provided respectively embedding two-value signature watermark W
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 Lena digital picture.From Fig. 2 a, Fig. 2 b and Fig. 2 c, can see, there is not any variation (PSNR → ∞ dB) in the Lena digital picture quality after embed watermark, consistent with original Lena digital picture, met the requirement of watermark imperceptible completely.Simultaneously visible, utilize multiple zero watermark embedding method of the present invention, the Lena digital picture quality after embed watermark can not become with the watermark number embedding, and therefore can embed easily and flexibly as required in actual applications multiple bi-level digital watermarks.Fig. 2 d, Fig. 2 e and Fig. 2 f are respectively three bi-level digital watermarks that extract from Fig. 2 c, in the time that the watermark Lena digital picture shown in Fig. 2 c is not processed by any attack, can completely nondestructively extract three bi-level digital watermarks of embedding, normalized correlation coefficient ρ is 1.
Watermark Lena digital picture is carried out to various attacks processing below, verify the robustness of multiple zero watermark embedding methods that the present invention proposes.
(1) brightness changes
Watermark Lena digital picture shown in Fig. 2 c is carried out to brightness regulation processing, add respectively 0.2,0.5 and subtract 0.2,0.5 computing by its all pixel values, correspondence obtains the watermark Lena digital picture as shown in Fig. 3 a, Fig. 3 b, Fig. 3 c and Fig. 3 d.After image pixel value plus-minus is processed, vision, there is obvious change 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 respectively 13.97dB, 6.02dB, 13.97dB and 6.02dB.Respectively the watermark Lena digital picture of Fig. 3 a, Fig. 3 b, Fig. 3 c and Fig. 3 d is carried out to watermark extracting, three bi-level digital watermarks that extract are respectively as shown in Fig. 3 e, Fig. 3 f and Fig. 3 g.Result demonstration, the watermark result of extracting from these 4 watermark Lena digital pictures is not only identical, and in full accord with three original bi-level digital watermarks.The impact visible, the digital watermarking embedding for the inventive method is not changed by luminance digital image completely, can correctly extract.
(2) histogram equalization
Watermark Lena digital picture shown in Fig. 2 c is carried out to histogram equalization processing, obtain the watermark Lena digital picture as shown in Fig. 4 a.Through histogram equalization processing, the pixel value of watermark Lena digital picture distributes obvious change has occurred, 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 extract from the watermark Lena digital picture of Fig. 4 a, from result, three bi-level digital watermarks that embed can be extracted very ideally, and normalized correlation coefficient ρ has reached respectively 0.990,0.991 and 0.997.
(3) medium filtering
Watermark Lena digital picture shown in Fig. 2 c is carried out to medium filtering processing, and filtering window size is respectively [5 × 5] and [11 × 11], and the watermark Lena digital picture obtaining after filtering is respectively as 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 extract from the watermark Lena digital picture of Fig. 5 a, and Fig. 5 f, Fig. 5 g and Fig. 5 h are respectively three bi-level digital watermarks that extract from the watermark Lena digital picture of Fig. 5 b.From watermark extracting result, for the medium filtering processing of [5 × 5] wicket, three bi-level digital watermarks that embed are not affected, there is desirable robustness, and for [11 × 11] the medium filtering processing of window greatly, can be seen 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 power, and normalized correlation coefficient ρ has reached respectively 0.964,0.991 and 0.997.
Table 1 has specifically provided watermark Lena digital picture and the watermark extracting result thereof after different windows size medium filtering, can be found out by table, and multiple zero watermark embedding methods that the present invention proposes have ideal anti-filtering processing power.
Watermark Lena digital picture quality after 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 to the processing of JPEG lossy compression method, and the compression quality factor is respectively 10% and 4%, and the watermark Lena digital picture obtaining is respectively as 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 extract from the watermark Lena digital picture of Fig. 6 a, and Fig. 6 f, Fig. 6 g and Fig. 6 h are respectively three bi-level digital watermarks that extract from the watermark Lena digital picture of Fig. 6 b.From watermark extracting result, the JPEG lossy compression method processing that is 10% for the compression quality factor, three bi-level digital watermarks that embed are not affected, there is desirable robustness, and the JPEG lossy compression method processing that is 4% for the compression quality factor, can be seen by Fig. 6 b, at this moment watermark Lena digital picture presents very significantly blocking artifact, there is serious degradation in visual quality, Y-PSNR PSNR is only 25.92dB, but three bi-level digital watermarks that embed still have very desirable anti-JPEG lossy compression method processing power, normalized correlation coefficient ρ has reached respectively 0.985, 0.997 and 1.0.
Table 2 has specifically provided watermark Lena digital picture quality and the watermark extracting result thereof under the different JPEG compression quality factors.As can be seen from Table 2, the inventive method has ideal anti-JPEG compression processing power, still can extract three embedded bi-level digital watermarks when the compression quality factor is decreased to 6% 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 shown in Fig. 2 c is carried out to noise, noise select 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 obtaining is respectively as 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 extract from the watermark Lena digital picture of Fig. 7 a, and Fig. 7 f, Fig. 7 g and Fig. 7 h are respectively three bi-level digital watermarks that extract from the watermark Lena digital picture of Fig. 7 b.From watermark extracting result, although watermark Lena digital picture is subject to Gauusian noise jammer, visual quality generation serious degradation, Y-PSNR PSNR is only 17.22dB and 13.67dB.But be that 0 variance is 0.02 Gauusian noise jammer for average, three bi-level digital watermarks that embed are not affected, there is desirable robustness, and be that 0 variance is 0.05 Gauusian noise jammer for average, three bi-level digital watermarks that embed still have very desirable anti-noise jamming ability, and normalized correlation coefficient ρ has reached respectively 0.980,0.994 and 1.0.
It is watermark Lena digital picture quality and the watermark extracting result thereof under 0 different variance Gauusian noise jammers that table 3 has specifically provided average.As can be seen from Table 3, the inventive method has ideal anti-noise jamming ability, the Gauusian noise jammer that is less than 0.03 for variance, and three bi-level digital watermarks of embedding can be extracted intactly.
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 to geometry cutting, start from the upper left corner to cut respectively 128 × 128 and 256 × 256 pixels, obtain the watermark Lena digital picture as shown in Fig. 8 a and Fig. 8 b.Fig. 8 c, Fig. 8 d and Fig. 8 e are respectively three bi-level digital watermarks that extract from the watermark Lena digital picture of Fig. 8 a, and Fig. 8 f, Fig. 8 g and Fig. 8 h are respectively three bi-level digital watermarks that extract from the watermark Lena digital picture of Fig. 8 b.From watermark extracting result, although watermark Lena digital picture is destroyed largely, Y-PSNR PSNR is only 17.29dB and 11.14dB, but the inventive method has goodish robustness for how much cuttings, three bi-level digital watermarks that embed still can be by intact extracting very, and normalized correlation coefficient ρ has reached respectively 0.973,0.972 and 0.981 and 0.874,0.883 and 0.899.
(7) how much rotations
Watermark Lena digital picture shown in Fig. 2 c is carried out to counter clockwise direction rotation, and angle is respectively 5 degree and 25 degree.In order to extract watermark, by the reverse rotation again of postrotational image, to recover former direction, the watermark Lena digital picture at this moment obtaining is respectively as shown in Fig. 9 a and Fig. 9 b, and its Y-PSNR PSNR is 19.10dB and 13.80dB.Fig. 9 c, Fig. 9 d and Fig. 9 e are respectively three bi-level digital watermarks that extract from the watermark Lena digital picture of Fig. 9 a, and Fig. 9 f, Fig. 9 g and Fig. 9 h are respectively three bi-level digital watermarks that extract from the watermark Lena digital picture of Fig. 9 b.From watermark extracting result, the inventive method also has reasonable robustness for how much rotation attacks, three bi-level digital watermarks that embed still can very clearly be extracted, and normalized correlation coefficient ρ has reached respectively 0.819,0.829 and 0.871 and 0.694,0.751 and 0.817.
Claims (4)
1. multiple zero watermark embedding methods for digital picture, is characterized in that comprising the following steps:
1.-1, at multiple zero watermark built-in ends, the gray level image that the original digital image of supposing K to be embedded bi-level digital watermark is 8bit, and be designated as F, F={0≤f (m, n)≤255, 1≤m≤M, 1≤n≤N}, wherein, K >=2, M represents the vertical resolution of the original digital image F of K to be embedded bi-level digital watermark, N represents the lateral resolution of the original digital image F of K to be embedded bi-level digital watermark, M × N represents the resolution of the original digital image F of K to be embedded bi-level digital watermark, f (m, n) represent that in the original digital image F of K to be embedded bi-level digital watermark, coordinate position is (m, the pixel value of pixel n),
1. ,-2, at multiple zero watermark built-in ends, suppose that K to be embedded bi-level digital watermark is all bianry image, and be designated as W respectively
1, W
2..., W
k..., W
k, 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) represent k bi-level digital watermark W to be embedded
kmiddle coordinate position is (i
k, j
k) the pixel value of pixel;
1.-3, the original digital image F of K to be embedded bi-level digital watermark is normalized, obtain the digital picture after normalized, be designated as F', be (m by coordinate position in the digital picture F' after normalized, the pixel value of pixel n) is designated as f'(m, n), f'(m, n)=f (m, n)/255;
1.-4, F' is carried out to L level two-dimensional discrete wavelet conversion, obtain a first small echo ll channel and multiple the first wavelet details subgraph, the first small echo ll channel is designated as to 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
represent to get the maximum integer that is less than himself, I
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 to two-dimension discrete cosine transform, obtain one with the first Two Dimension Discrete Cosine matrix of FA equal resolution, be designated as FAC, then FAC being carried out to Zig-Zag scanning arranges, obtain a first one-dimensional discrete cosine transform coefficient sequence, be designated as FACS, FACS={facs (x), 1≤x≤(M/2
l) × (N/2
l), wherein, facs (x) represents x discrete cosine transform coefficient in FACS, the 2nd discrete cosine transform coefficient in FACS starts to be discrete cosine transform ac coefficient;
1. ,-6, successively according to the resolution of each bi-level digital watermark to be embedded, from FACS, select respectively and meet the I imposing a condition
1× J
1, I
2× J
2..., I
k× J
k... and I
k× J
kindividual discrete cosine transform ac coefficient, forms 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 imposing a condition selecting from FACS
k× J
kthe k that individual discrete cosine transform ac coefficient forms a first one-dimensional discrete cosine transform ac coefficient sequence FACS
k, FACS
k={ facs
k(y), 1≤y≤I
k× J
k, then record FACS
1, FACS
2..., FACS
k... and FACS
kin the correspondence position information of various 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) represent FACS
kin y discrete cosine transform ac coefficient, impose a condition and be more than or equal to the difference threshold of setting for the absolute value of difference of two the discrete cosine transform ac coefficients of arbitrary neighborhood in the first one-dimensional discrete cosine transform ac coefficient sequence that makes to form;
1.-7, compare respectively FACS
1, FACS
2..., FACS
k... and FACS
kin the size of two discrete cosine transform ac coefficients of arbitrary neighborhood, and return to logical value 1 or 0 according to comparative result, for FACS
kin two discrete cosine transform ac coefficients of arbitrary neighborhood, it is designated as respectively to facs
kand facs (z)
k(z+1), judge facs
k(z) >facs
k(z+1) whether set up, if set up, return to logical value 1, otherwise, return to logical value 0, wherein, 1≤z≤I
k× J
k-1; Then compare FACS
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 to logical value 1 or 0 according to comparative result, for FACS
kin last discrete cosine transform ac coefficient and the 1st discrete cosine transform ac coefficient, if the former is large, return to logical value 1, otherwise, return to logical value 0; Again according to FACS
1, FACS
2..., FACS
k... and FACS
keach self-corresponding logical value of returning, builds 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 to a size by Row Column order arrangement mode
k× J
ktwo-dimensional matrix in, the first bi-level digital watermark keys using this two-dimensional matrix as k, is designated as WB
k;
1.-8, to K to be embedded bi-level digital watermark W
1, W
2..., W
k..., W
kcarry out respectively scramble processing, K the bi-level digital watermark obtaining after scramble is processed respectively correspondence is designated as WS
1, WS
2..., WS
k... and WS
k, then by 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), then by K zero watermark information WO
1, WO
2..., WO
k... and WO
kbe stored in the digital watermark information database of registration body, complete K bi-level digital watermark W
1, W
2..., W
k..., W
kembedding, wherein, WS
1represent W
1carry out the bi-level digital watermark obtaining after scramble processing, WS
2represent W
2carry out the bi-level digital watermark obtaining after scramble processing, WS
krepresent W
kcarry out the bi-level digital watermark obtaining after scramble processing, WS
krepresent W
kcarry out the bi-level digital watermark obtaining after scramble processing, WB
1represent the 1st the first bi-level digital watermark keys, WB
2represent the 2nd the first bi-level digital watermark keys, WB
krepresent K the first bi-level digital watermark keys, xor () is XOR function;
1.-9, at multiple zero watermark built-in ends, by the FACS of record
1, FACS
2..., FACS
k... and FACS
kin the positional information of various discrete cosine transform ac coefficient in FACS, a K zero 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 multiple zero watermark extracting ends.
2. multiple zero watermark embedding methods of a kind of digital picture according to claim 1, is characterized in that FACS in described step 1.-6
1, FACS
2..., FACS
k... and FACS
kin the absolute value of difference of two discrete cosine transform ac coefficients of arbitrary neighborhood be more than or equal to respectively δ
1, δ
2..., δ
k... and δ
k, wherein, δ
1represent for FACS
1in two discrete cosine transform ac coefficients of arbitrary neighborhood difference absolute value set the 1st difference threshold, δ
2represent for FACS
2in two discrete cosine transform ac coefficients of arbitrary neighborhood difference absolute value set the 2nd difference threshold, δ
krepresent for FACS
kin two discrete cosine transform ac coefficients of arbitrary neighborhood difference absolute value set k difference threshold, δ
krepresent for FACS
kin two discrete cosine transform ac coefficients of arbitrary neighborhood difference absolute value set K difference threshold.
3. multiple zero watermark extracting methods for the digital picture corresponding with multiple zero watermark embedding methods of digital picture claimed in claim 1, is characterized in that comprising the following steps:
2.-1, at multiple zero watermark extracting ends, the digital picture of K to be extracted bi-level digital watermark is designated as to TF, TF={0≤tf (m', n')≤255, 1≤m'≤M', 1≤n'≤N'}, wherein, K >=2, M' represents the vertical resolution of the digital picture TF of K to be extracted bi-level digital watermark, N' represents the lateral resolution of the digital picture TF of K to be extracted bi-level digital watermark, M' × N' represents the resolution of the digital picture TF of K to be extracted bi-level digital watermark, the resolution of the digital picture TF of K to be extracted bi-level digital watermark and the embedding of multiple zero watermark built-in ends have the resolution of digital picture of digital watermarking identical, tf (m', n') represent that in the digital picture TF of K to be extracted bi-level digital watermark, coordinate position is (m', the pixel value of pixel n'),
2. ,-2, at multiple zero watermark extracting ends, K to be extracted bi-level digital watermark is designated as respectively to W
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
k' lateral resolution, I'
k× J'
krepresent k bi-level digital watermark W to be extracted
k' resolution, k bi-level digital watermark W to be extracted
k' resolution identical with the resolution of k bi-level digital watermark that multiple zero watermark built-in ends embed, w'
k(i'
k, j'
k) represent k bi-level digital watermark W' to be extracted
kmiddle coordinate position is (i'
k, j'
k) the pixel value of pixel;
2.-3, the digital picture TF of K to be extracted bi-level digital watermark is normalized, obtain the digital picture after normalized, be designated as TF', be (m' by coordinate position in the digital picture TF' after normalized, 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 to L' level two-dimensional discrete wavelet conversion, obtain a second small echo ll channel and multiple the second wavelet details subgraph, the second small echo ll channel is designated as to 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
represent to get the maximum integer that is less than himself, I
1' represent the 1st bi-level digital watermark W to be extracted
1' vertical resolution, J
1' represent the 1st bi-level digital watermark W to be extracted
1' lateral resolution, I
k' represent K bi-level digital watermark W to be extracted
k' vertical resolution, J
k' represent K bi-level digital watermark W to be extracted
k' lateral resolution;
2.-5, TFA is carried out to two-dimension discrete cosine transform, obtain one with the second Two Dimension Discrete Cosine matrix of TFA equal resolution, be designated as TFAC, then TFAC being carried out to Zig-Zag scanning arranges, obtain a second one-dimensional discrete cosine transform coefficient sequence, be designated as TFACS, TFACS={tfacs (x'), 1≤x'≤(M'/2
l') × (N'/2
l'), wherein, tfacs (x') represents x' discrete cosine transform coefficient in TFACS, the 2nd discrete cosine transform coefficient in TFACS starts to be discrete cosine transform ac coefficient;
2.-6, according to the FACS of multiple zero watermark built-in end records
1, FACS
2..., FACS
k... and FACS
kin the correspondence position information of various discrete cosine transform ac coefficient in FACS, from TFACS, extract respectively the I of correspondence position
1' × J
1', I
2' × J
2' ..., I
k' × J
k' ... and I
k' × J
k' individual discrete cosine transform ac coefficient, forming K the second one-dimensional discrete cosine transform ac coefficient sequence, correspondence is designated as TFACS respectively
1, TFACS
2..., TFACS
k... and TFACS
k, for the FACS recording according to multiple zero watermark built-in ends
kin the correspondence position information of various discrete cosine transform ac coefficient in FACS, from TFACS, extract the I of correspondence position
k' × J
k' k the second one-dimensional discrete cosine transform ac coefficient sequence TFACS forming of individual discrete cosine transform ac coefficient
k, TFACS
k={ tfacs
k(y'), 1≤y'≤I
k' × J
k', wherein, I
k' represent k bi-level digital watermark W to be extracted
k' vertical resolution, J
k' represent k bi-level digital watermark W to be extracted
k' lateral resolution, tfacs
k(y') represent TFACS
kin y' discrete cosine transform ac coefficient;
2.-7, compare respectively TFACS
1, TFACS
2..., TFACS
k... and TFACS
kin the size of two discrete cosine transform ac coefficients of arbitrary neighborhood, and return to logical value 1 or 0 according to comparative result, for TFACS
kin two discrete cosine transform ac coefficients of arbitrary neighborhood, it is designated as respectively to tfacs
kand tfacs (z')
k(z'+1), judge tfacs
k(z') >tfacs
k(z'+1) whether set up, if set up, return to logical value 1, otherwise, return to logical value 0, wherein, 1≤z'≤I
k' × J
k'-1; Then compare TFACS
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 to logical value 1 or 0 according to comparative result, for TFACS
kin last discrete cosine transform ac coefficient and the 1st discrete cosine transform ac coefficient, if the former is large, return to logical value 1, otherwise, return to logical value 0; Again according to TFACS
1, TFACS
2..., TFACS
k... and TFACS
keach self-corresponding logical value of returning, builds 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 to a size by Row Column order arrangement mode
k' × J
k' two-dimensional matrix in, the second bi-level digital watermark keys using this two-dimensional matrix as k, is designated as TWB
k;
2.-8, by the K from multiple zero watermark built-in ends zero watermark information WO
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 the second bi-level digital watermark keys, TWB
2represent the 2nd the 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 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, obtains having K bi-level digital watermark of copyright authentication information, and correspondence is designated as W respectively
1 *, W
2 *..., W
k *... with
2.-10, K bi-level digital watermark W of copyright authentication information will be there is
1 *, W
2 *..., W
k *... with
respectively with multiple zero watermark built-in ends embed K bi-level digital watermark W
1, W
2..., W
k... and W
kcorrespondence is carried out similarity calculating one by one, and correspondence obtains K normalized correlation coefficient, then determines whether and extracts K the bi-level digital watermark W that multiple zero watermark built-in ends embed according to the size of K normalized correlation coefficient
1, W
2..., W
k... and W
k.
4. multiple zero watermark extracting methods of a kind of digital picture according to claim 3, is characterized in that the detailed process of described step 2.-10 is:
Z1, K bi-level digital watermark W of copyright authentication information will be there is
1 *, W
2 *..., W
k *... with
respectively with multiple zero watermark built-in ends embed K bi-level digital watermark W
1, W
2..., W
k... and W
kcorrespondence is carried out similarity calculating one by one, and correspondence obtains K normalized correlation coefficient, for by W
k *with W
kcarry out k the normalized correlation coefficient obtaining after similarity calculating, be designated as ρ (W
k, W
k *),
Wherein, w
k(i
k, j
k) represent multiple zero watermark built-in ends embed k bi-level digital watermark W
kmiddle coordinate position is (i
k, j
k) the pixel value of pixel,
represent k the bi-level digital watermark W that multiple zero watermark built-in ends embed
kin the average of pixel value of all pixels,
represent to have k bi-level digital watermark W of copyright authentication information
k *middle coordinate position is (i
k, j
k) the pixel value of pixel,
represent to have k bi-level digital watermark W of copyright authentication information
k *in the average of pixel value of all pixels;
Z2, according to the size of K normalized correlation coefficient determine whether extract multiple zero watermark built-in ends embed K bi-level digital watermark W
1, W
2..., W
k... and W
k, for normalized correlation coefficient ρ (W
k, W
k *), if ρ is (W
k, W
k *) value be 1, determine W
knondestructively extracted, if ρ is (W
k, W
k *) value be more than or equal to δ
tand be less than 1, determine W
kextract successfully, if ρ is (W
k, W
k *) value be less than δ
t, determine W
kextract unsuccessfully, wherein, δ
trepresent watermark extracting thresholding.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201210144040.4A CN102682418B (en) | 2012-05-11 | 2012-05-11 | Method for embedding and extracting multiple zero watermarks of digital image |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201210144040.4A CN102682418B (en) | 2012-05-11 | 2012-05-11 | Method for embedding and extracting multiple zero watermarks of digital image |
Publications (2)
Publication Number | Publication Date |
---|---|
CN102682418A CN102682418A (en) | 2012-09-19 |
CN102682418B true CN102682418B (en) | 2014-06-25 |
Family
ID=46814289
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN201210144040.4A Expired - Fee Related CN102682418B (en) | 2012-05-11 | 2012-05-11 | Method for embedding and extracting multiple zero watermarks of digital image |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN102682418B (en) |
Families Citing this family (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103198446B (en) * | 2013-04-02 | 2016-04-20 | 宁波大学 | A kind of digital watermark embedding for digital picture error concealing and extracting method |
CN105263024B (en) * | 2015-10-15 | 2018-06-29 | 宁波大学 | A kind of registration of HEVC video flowing zero watermarkings of anti-quantization transcoding and detection method |
CN106708449B (en) * | 2016-12-31 | 2019-12-17 | 金航数码科技有限责任公司 | negative color image watermark-based anti-copying method in monochrome printing |
CN107742272B (en) * | 2017-10-17 | 2021-01-08 | 大连理工大学 | Semi-fragile watermarking method based on image tampering positioning and recovery |
CN108648130B (en) * | 2018-04-04 | 2022-05-27 | 宁波大学 | Totally-blind digital watermarking method with copyright protection and tampering positioning functions |
CN108880805B (en) * | 2018-07-18 | 2020-06-30 | 北京理工大学 | Network key distribution method, device and system based on compression measurement fluctuation |
CN110570342B (en) * | 2019-07-01 | 2023-06-13 | 齐鲁工业大学 | Color medical image zero watermark construction method and system and color medical image zero watermark detection method and system |
CN114359012B (en) * | 2022-03-21 | 2022-06-14 | 中国民航大学 | Robust combined domain color image zero watermark embedding and extracting method |
CN115866271B (en) * | 2023-01-18 | 2023-05-02 | 北京锐马视讯科技有限公司 | Watermark multiplexing embedding method, system, equipment and storage medium |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101866478A (en) * | 2010-06-22 | 2010-10-20 | 北京大学 | Method for embedding and extracting watermark in digital image |
CN101908201A (en) * | 2010-06-28 | 2010-12-08 | 宁波大学 | Robust digital image adaptive zero-watermarking method |
-
2012
- 2012-05-11 CN CN201210144040.4A patent/CN102682418B/en not_active Expired - Fee Related
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101866478A (en) * | 2010-06-22 | 2010-10-20 | 北京大学 | Method for embedding and extracting watermark in digital image |
CN101908201A (en) * | 2010-06-28 | 2010-12-08 | 宁波大学 | Robust digital image adaptive zero-watermarking method |
Non-Patent Citations (3)
Title |
---|
周亚训,叶庆卫,徐铁峰.基于小波和余弦变换组合的图像水印方案.《电子学报》.2001,第29卷(第12期),第1693-1695页. * |
周亚训,金炜.一种小波和余弦变换组合域内鲁棒的自适应零水印算法.《光电工程》.2011,第38卷(第5期),第80-85页. * |
李京兵,黄席樾,周亚训.一种鲁棒的二值文本图像数字水印算法及仿真.《计算机工程》.2006,第32卷(第22期),第23-25页. * |
Also Published As
Publication number | Publication date |
---|---|
CN102682418A (en) | 2012-09-19 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN102682418B (en) | Method for embedding and extracting multiple zero watermarks of digital image | |
Mahto et al. | A survey of color image watermarking: State-of-the-art and research directions | |
CN101908201B (en) | Robust digital image adaptive zero-watermarking method | |
CN104616244B (en) | Image watermark insertion and extracting method based on BP neutral net compression domains | |
Kumar et al. | Image transformation technique using steganography methods using LWT technique | |
CN107292806A (en) | A kind of remote sensing image digital watermark embedding and extracting method based on quaternion wavelet | |
Liu et al. | Robust blind image watermarking based on chaotic mixtures | |
CN102024249A (en) | Digital image watermarking method based on visual perception characteristics | |
CN101719265B (en) | Digital image watermark embedding method and system thereof based on computer-generated hologram | |
Su et al. | A hybrid-Sudoku based fragile watermarking scheme for image tampering detection | |
CN105512999A (en) | Dual-transform color image holographic watermarking method | |
Fan et al. | A Robust Watermarking Technique Resistant JPEG Compression. | |
CN102930498B (en) | A kind of digital watermark embedding based on Lifting Wavelet and extracting method | |
Singh et al. | Fuzzy‐based secure exchange of digital data using watermarking in NSCT‐RDWT‐SVD domain | |
Su | Color image watermarking: algorithms and technologies | |
Kekre et al. | Hybrid watermarking of color images using DCT-Wavelet, DCT and SVD | |
Surekha et al. | Visual secret sharing based digital image watermarking | |
Dutta et al. | An efficient and secure digital image watermarking using features from iris image | |
Kekre et al. | Robust Watermarking Technique using Hybrid Wavelet Transform Generated from Kekre Transform and Discrete Cosine Transform | |
CN102708535B (en) | Zero-watermark insertion and extraction methods with multiple keys for digital images | |
Wang et al. | Review on digital image watermarking based on singular value decomposition | |
Moniruzzaman et al. | Robust RGB color image watermarking scheme based on DWT-SVD and chaotic system | |
Surekha et al. | Digital image ownership verification based on spatial correlation of colors | |
Mettripun et al. | Robust image watermarking based on luminance modification | |
Behravan et al. | Introducing a new method of image reconstruction against crop attack using sudoku watermarking algorithm |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
C06 | Publication | ||
PB01 | Publication | ||
C10 | Entry into substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
C14 | Grant of patent or utility model | ||
GR01 | Patent grant | ||
CF01 | Termination of patent right due to non-payment of annual fee | ||
CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20140625 Termination date: 20170511 |