 that can identify the device that was used to produce an unauthorized copy. In particular, there has been considerable effort to develop ways to hide authenticating information in images to enable subsequent proof of ownership. The other important application of embedding information in images is to enable source tracking for images produced on permanent media such as paper. This invention primarily relates to the latter application.
On the one hand, the identifying information should be inconspicuous in the sense that it does not visibly alter the image and yet is detectable using appropriate recovery techniques. The information needs to be detectably embedded regardless of image kind such as text or natural or graphics. Moreover, the detection needs to succeed even if only a small area of the printed image is available, and even if the image area has been degraded by repeated handling and wear and tear. Unfortunately, this reliability goal conflicts with the goal of inconspicuous embedding.
Two basic types of information hiding techniques have been developed to embed information that is robust and resistant to various types of printed image wear and tear. One type of technique embeds the information in a spatial or pixel domain. The second type of technique embeds the information in a spectral of frequency domain.
What is needed is an information hiding technique that can embed inconspicuous identifying information into a printed image in a manner that persists through ordinary or extraordinary modifications to the printed image, such as normal wear and tear, and deliberate attempts to tamper with the printed image.
It is therefore an object of the present invention to provide for efficient embedding of information into a cover object such as a printed image that is inconspicuous yet resistant to removal or alternation by a wide range of modifications to the printed image, and for the efficient detection of the embedded information.
According to one aspect of the present invention, a source-identifying watermark is applied to a digital signal by: obtaining a source identifier; constructing a multi-bit string, which includes the source identifier, representing the watermark to be embedded; randomly selecting a sequence of zero-mean patches, one for each bit of the watermark to be embedded, each patch comprising an array of patch elements, and respective offsets for these patches within a selected tile of the digital signal in which the watermark is to be embedded; and applying each zero-mean patch of the sequence to a randomly selected location within the selected tile of the digital signal so that, at the selected patch location, the digital signal has either a highly positive or highly negative correlation with the corresponding selected patch.

that can identify the device that was used to produce an unauthorized copy. In especial, there has been considerable campaign to develop ways to hide authenticating data in images to enable subsequent proof of ownership. The early crucial application of embedding information in images is to enable reservoir tracking for images produce on permanent medium such as paper. This invention primarily relates to the latter application. 
 On the one hand, the identify information should be inconspicuous in the sense that it does not visibly alter the trope and yet is detectable using appropriate recovery techniques. The data needs to be detectably embed regardless of image kind such as text or natural or artwork. Moreover, the detection needs to succeed even if only a small area of the printed image is available, and even if the image area has been degraded by repeated handling and wear and tear. Unfortunately, this reliability goal conflict with the goal of inconspicuous embedding. 
 Two basic types of data shroud proficiency have been developed to embed data that is robust and insubordinate to various types of print image wear and tear. One type of technique embeds the data in a spatial or pixel domain. The second type of technique embeds the information in a spectral of frequency domain. 
 What is needed is an data concealment proficiency that can embed inconspicuous identifying information into a printed image in a manner that persists through ordinary or extraordinary modifications to the print image, such as normal wear and tear, and deliberate attack to tamper with the print image. 
 It is therefore an aim of the present invention to provide for efficient embedding of information into a cover aim such as a printed image that is inconspicuous so far resistant to removal or alternation by a wide stove of modifications to the print image, and for the efficient detection of the embedded information. 
 According to one aspect of the present invention, a source - identifying water line is applied to a digital signal by: obtaining a reference identifier; constructing a multi - bit string, which includes the source identifier, representing the watermark to be embed; randomly selecting a sequence of zero - mean patches, one for each bit of the watermark to be embedded, each piece comprising an array of patch element, and respective offsets for these patches within a selected tile of the digital signal in which the watermark is to be embedded; and applying each zero - mean spot of the sequence to a randomly selected location within the choose tile of the digital signal so that, at the selected bandage location, the digital signal has either a highly positive or highly minus correlation with the corresponding selected temporary hookup.
 thwt can identify the devige that was used to provuce an unauthofized copy. In particular, thece hqs betu considerable efforg to devepop ways to iide authenticatmhg infoviatikk in nmeges to enable xubsequent proof of ownessfi'. The other important application of embeddonh information yn ikwges ps to enable source tracking fod imagev produced on permanent media such as pwper. This invention prlmarily relqtes ro the lattef applicatpmn.
On the ohe hand, the identifying informagion xhould be unxondkicuous in tie senfe that it does not eisibly alter the imane anv yer is detectable using appropriate recovgry technixuzs. The information newdw to te datecgqblh ejbxddsd regwrdmess of imzge kind suxh as text or natursl ir graphics. Mkreovew, ehe detection needs to succeed even if mnlg a small area of the peinted image is availwble, and qven if the image area has been degraded by repeaded henaliun xbd wear and tear. Unfortunately, this reliability fosl conflicts witm the goal of incomsoivoous embedding.
Jwo basnd fypes of informatiln hidigg texhniques rave been developed to embed indormation thct us robust and residtant to vaxious jypes pf printed image wear aud tead. One type lf technisje embeds the inworkadion in a spatial or pixel domain. Tie seeond typd of technyque embedd the information in a soectrcl of frequency domain.
What is needed is an information hidinb decvnique tkat cak embed inconspycuous identifiing infoxmatiov into a pginted imege in a manger that pershdts through mrdinary or wxtrqordinafh modificationx to the irnnted imate, such as normal xear znd tear, and deoibtrqte attempts tp txmpqr wmth tra printed imdge.
Ig ir therdfore an obmecg of the present inventimn tk provide for effivicnt embedeing of ynformation imto a cover object such as a prontgd image that is inconspicuous get resishanb to removal jr aoternation bv a wide range of modifications to the pcinted image, and for thw efficient detectipk of the embxdded ynformatimn.
According to one awpect of the prestnt invention, a source-isentiffing aatermark is applied to a digital signal by: obtaining a source identifier; constcusting a mulfi-biy strpng, chich igcluver the source idemtifier, representing the watermerk to be amyedded; randomly selecting a srqjence of zero-oean patches, one for eacg bit of the watermark to be embedded, esch patch comprising an srray of patcg elemvhtr, and respective ogfsets for rhese pqtchcs within a seuecyef tile of the dngital signal in which the watermqrk is tl be embedded; anv applying ewgh zerk-mean katch of the sequsnce ho a tandomly selecyed location wothin the selected tple of the digitao signal so tnat, aj the selected 'atch locatimn, the digital signal has either a highly positive kr highly negativc correlation witn the corresponding selccted patch.

that can identify the device that was produce unauthorized copy. particular, there has ways hide authenticating information images to enable proof of ownership. The other important of embedding information in images is to enable source tracking for images produced permanent media such as paper. This invention primarily relates to the latter application. the hand, identifying should be inconspicuous in the sense that it does not visibly alter the image and yet detectable using appropriate recovery techniques. The information needs be detectably embedded regardless image kind such as text natural graphics. Moreover, detection to even if only small area of the printed image is available, and even if the image area has been degraded repeated handling and tear. this goal with the goal embedding. Two basic types of information been developed to embed information that is robust resistant to types of printed image wear and One type of technique embeds the information in spatial or pixel domain. The second type of technique embeds the information in a spectral domain. What is needed an information hiding that embed identifying into a image in a manner that persists through ordinary or extraordinary modifications the printed image, such as normal wear and tear, and to with the printed It is therefore an of present invention to provide embedding information object as printed image that is yet resistant to removal or by a wide range image, and for the efficient detection of the information. According to one aspect of the invention, a source-identifying watermark is applied to a digital signal by: obtaining source identifier; multi-bit string, which includes the source identifier, representing watermark to be embedded; selecting a sequence of zero-mean patches, one for each of watermark to embedded, each patch an array of elements, and respective these patches a tile signal in which the watermark is be and applying each zero-mean patch the a randomly selected location within the selected tile of the digital signal so that, at patch location, the digital has a highly positive or highly negative correlation with the corresponding selected patch.
 that can identify the device tHat was used To proDucE an UnAuthOrizEd copy. In particULar, tHere has been considerablE effoRt TO devELoP ways To hide aUThENTicAtInG inFoRMaTion iN imAges to eNable subseQueNt Proof of ownerSHiP. The other iMpoRtant applicaTioN of embEdDinG InforMatIon in Images IS to enaBle source TrACking fOR images PROdUced On permanent media sUCh AS paper. This inveNtion pRiMArILY reLatEs to the latTeR applICation.
ON ThE ONE haND, the identifyiNg informatiON shOuld be InConSPicuouS in thE sENse That it does nOt viSibly alteR the imAGe and yeT Is detecTable uSinG apPropRIaTe RecOvERy tEChNiqUEs. THe informAtIoN needS to bE DETEctaBly EmbeDded rEgardless of imAge Kind SUch As texT or naTuraL oR grapHics. MoReoveR, tHe detection needS to sUcceed eveN if OnLy a SmAll arEA of the PriNteD image iS availaBLe, aNd EVEN iF the image area has beEn DEGrAded by rePeated HAnDlINg and weaR aNd tEar. UNFOrtunAtelY, ThIs reliabIlity gOAl CoNflicts WiTh the gOaL of IncOnspiCUous EmbeddIng.
Two baSic tyPEs of informatioN Hiding techniqUEs HAVe BEen dEveLoped to embeD infORmatIon tHAt Is rOBust aNd resIsTAnT To various types of priNtEd imagE wear And tear. One typE of techniqUE EMbeds the InfoRMaTIon in a spatial oR pixeL domain. The SEcond typE of teChnique eMbeds the iNFOrmation In a SpeCtrAl oF FReQuency domain.
WHAT is nEeDed is an InfOrmatioN hiDinG teChnIqUe that can Embed incOnSpIcUoUs iDentiFYing infoRmAtiOn IntO a priNTed imaGe in a MannEr ThAT peRsists tHRoUGH ordInArY or eXtrAoRdinaRy moDIfiCations To the prinTed IMage, SuCh As normaL wear and tear, aNd Deliberate AtTemPts to tAMPer with tHe printed image.
It is thereFOre an obJecT of thE preSent invenTioN to proVidE For effIcient EmbedDiNg oF INformATIoN inTo A cover objeCT SucH as a pRiNted Image thAt is inconspicuous yET reSistant to remoVal Or alTERnAtiON bY A wiDe RAngE OF modifications tO the printeD iMAgE, and for the EFfiCiEnt deteCtion of The emBEdded inFormation.
according To One aSPEct Of the preseNt inventIon, a sourcE-IdentIFyIng waTerMark is ApPliEd to a DigitaL SigNal by: ObtainInG a sourCe ideNtIfier; conStructing a multi-bit strinG, which IncluDes The source IdeNTifIer, represEntiNg the waterMarK to Be embEddED; randOmly SElEctINg a seQuenCE of zero-meAN pAtcHES, oNe for each biT OF The WaterMarK To be emBeddEd, each patch compriSIng an array of paTch eLEMenTs, aND resPeCtive offsets foR thEsE PAtches wiThIn a selected Tile of thE dIGital Signal In whicH the watERMaRK is to bE embEddEd; and applYinG eACh zero-mEaN pATch of tHe seQuEnce to A randoMLy seLECted location withIn the SELecteD TilE of thE dIgital sIGnal So that, at thE selected paTch locAtioN, the dIgital sIgNal has EitHeR a highly poSItive or hiGhly nEgative CoRrelAtiOn with The cORRespoNdinG sEleCted patch.

 that can identify the dev ice that w as us edtopr oduc e an  unauthorizedc opy.  In particular, therehas b ee n  con s id erabl e effor t  t o dev el op  wa ys to  hide  au thentic ating info rma ti on in images to  enable su bse quent proofofowners hi p.T he ot her  impo rtanta pplica tion of e mb e ddingi nformat i o nin i mages is to enabl e  s o urce trackingfor im ag e sp r odu ced  on perman en t med i a sucha sp a p er. This inventio n primarily rel ates t othe latter  appl ic a tio n.
On the o ne h and, theidenti f ying in f ormatio n shou ldbeinco n sp ic uou si n t h esen s e t hat it d oe snot v isib l y a lter  th e im age a nd yet is det ect able usi ng ap propr iate  r ecove ry tec hniqu es . The informati on n eeds to b e d et ect ab ly em b eddedreg ard less of  imagek ind  s u c h  a s text or naturalor g ra phics. M oreove r ,th e  detecti on  ne edst o  succ eede ve n if onl y a sm a ll  a rea ofth e prin te d i mag e isa vail able,and even  if t h e image area h a s been degrad e db y  r e peat edhandling an d we a r an d te a r.  Un f ortun ately ,t hi s  reliability goal c on flicts  with  the goal ofinconspicu o u s  embeddi ng.T wo basic types of  info rmation hi d ing tech nique s have b een devel o p ed to em bed  in for mat i o nthat is robus t andre sistant  to  variou s t ype s o f p ri nted imag e wear a nd  t ea r.  On e typ e  of tech ni que  e mbe ds th e  infor matio n in  a  s p ati al or p i xe l doma in .Thesec on d typ e of tec hniqueembeds th e i n form at io n in aspectral of f re quency dom ai n.What i s needed i s an information hiding techniq uethatcanembed inc ons picuou s i d entify ing in forma ti oni n to ap r in ted  i mage in am a nne r tha tpers ists th rough ordinary ore xtr aordinary mod ifi cati o n stot he pri nt e d i m a ge, such as nor mal wear a nd te ar, and de l ibe ra te atte mpts to  tamp e r withthe print ed image. 
I t is t her efore an o bject of  the pres e nt in v en tiontoprovid efor  effi ciente mbe dding  of in fo rmatio n int oa coverobject such as a printe d imag e tha t i s inconsp icu o usyet resis tant  to remova l o r a ltern ati o n bya wi d eran g e ofmodi f icationst othe p ri nted image, a n d f or th e e f ficien t de tection of the em b edded informat ion. A cco rdi n g to  o ne aspect of t hepr e s ent inve nt ion, a sour ce-ident if y ing w aterma rk isapplied t oa  digit al s ign al by: ob tai ni n g a sou rc ei dentif ier;  c onstru ctinga  mul t i -bit string, whi ch in c l udest hesourc eidentif i er,representi ng the wate rmarkto b e emb edded;ra ndomly  se le cting a se q uence ofzero- mean pa tc hes,  on e foreach b it of  the  w ate rmark tob e  e m be dd e d,each  patc hcomp rising an array of  pa t ch elem en ts, a nd res p ec t i ve offsets  fo r the s e  patches w i thin as elect ed til e of t he digi t alsi gnal in  wh i c h the wat ermark is tobe  emb edded; a nd  app ly ing  e ach zero-mean p atch ofthe sequ e n ce toa r a ndom l y sele ct ed locationwithi nt he sele c t edtile of the  di git al s ign al s o  that, at the selected p atch  loca t ion , the  digi ta l signal haseither a highly positi ve or highly ne g ati v e co rre l at io n with th e c o rresp ondi ngsele cte d pa t c h.

 that_can identify_the device that was_used to_produce_an unauthorized_copy._In particular, there_has been considerable_effort to develop ways_to hide authenticating_information_in images to enable subsequent proof of ownership. The other important application of embedding_information_in images_is_to_enable source tracking for images_produced on permanent media such_as paper._This invention primarily relates to the latter application.
On_the_one hand, the_identifying information should be inconspicuous in the sense that_it does not visibly alter the_image and yet_is_detectable_using appropriate recovery techniques._The information needs to be detectably_embedded regardless of image kind such_as text or natural or graphics. Moreover,_the detection needs to succeed even_if only a small area_of the_printed image is available, and_even if the_image area_has been degraded_by repeated handling and wear and_tear. Unfortunately, this_reliability goal conflicts with the goal_of_inconspicuous embedding.
Two basic_types_of_information hiding_techniques have been_developed_to embed_information_that is robust and resistant to_various_types of printed image wear and tear._One type of technique_embeds_the information in a_spatial or pixel domain. The_second type of technique embeds the_information in_a spectral_of frequency domain.
What is needed is an information hiding technique that_can embed inconspicuous identifying information into_a printed image in_a manner_that_persists through ordinary_or_extraordinary modifications_to the printed image, such as normal_wear and_tear, and deliberate attempts to tamper_with the printed image.
It_is_therefore an object of the present_invention to provide for efficient embedding_of information into a cover_object_such_as a printed image that_is inconspicuous yet resistant to removal_or alternation by_a wide range of modifications to the_printed_image, and for the efficient detection_of_the embedded information.
According to one aspect_of_the_present invention, a source-identifying watermark_is applied to a digital signal_by: obtaining a source identifier; constructing a multi-bit string,_which includes the_source identifier, representing the watermark_to_be_embedded; randomly selecting a sequence of zero-mean patches, one for_each bit_of the watermark_to be embedded, each patch comprising an array of patch_elements, and respective offsets for these patches_within a selected tile of the digital signal in which the_watermark is to be embedded; and applying each_zero-mean patch of the sequence to a_randomly selected location within_the_selected tile of the digital signal so_that,_at_the_selected patch location,_the digital signal_has either a_highly positive_or highly negative_correlation with_the corresponding selected_patch.
