| Title of Invention | APPARATUS AND METHOD FOR WATERMARKING A DIGITAL IMAGE |
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| Abstract | The present invention relates to an apparatus for adding a watermark to a moving image as it is displayed comprises a watermark generator in which data representing a watermark is generated. The watermark contains at least one of location data and time data pertaining to the displaying of the moving image. The location and time data is protected by forward error encoding. The watermark also contains at least one of program data identifying the moving image and frame data unique in identifying each frame of the moving image. The program and time data is protected by scrambling. A watermark applicator applies the watermark data to image data representing substantially all of the moving image depending on a characteristic, such as amplitude, of the data. |
| Full Text | \PPi^.RVTUS AiND METHOD FOR WATERMARKING A DIGITAL IMAGE BACKGROWfD OF THE INVENTION I, Field of the Invention 1 The p;e;ic:ni invention relates i:o a method and apparatus for watermarking a ; igirai ^inag'^ T':)e invention may be usefully employed in the newly emerging field : f digiial ciiicnn. II. Destrijiiion of the Related Art In th: tn,ditional film induslrv, theatre operators receive reels of celluloid film from a smdi :• o: through a distributor fcr eventual pi:esen:adon in a theatre :uditoriiim. The reels of film include the feature program (a full-length motion :icture) and a plara ity of previews and other promouoaa! material, often vefeiTed to :^ trai[i:rs. Tliis approach is well established and is basec in technology going back :rouod one hviridred years. Recentl) an evolution has started m the film industry, with the industry : :iovini: fron) ce'luloid film to digitized image and audio programs. Many advarxed : ichnologiei. iire involved and together rJiose lechnologie.'i i\xc becoming biown as : igital ^inemi;.. It is planned that digital cinema will provide a system for delivering : JO length nictiion pictures, trailers, advertisements and other audio/visual progiiuns :c)mpiising iniaiies and sound at "cinema-quality" to theatres throughout the world . sing digital izc imology. Digital cinema will enable the motion picture cinema [ iduslry to conveit .gracefully from the century-old medium of 35mm film into the :igital/wire]f;:,s oon-munication era of today. This advanced tecnnology will benefit ill segments of Hie movie industry. The intention is that digital cinema will deliver motion pictures tha: have been :igitized, compiesscd and encrypted lo theatres using either physical media :istribution [such ^s D\T)-PLOMS) or electronic traiismissum methods, such as via ,iatellii:e muUic:].!;t methods. Authorized theatres will aLtomatically receive the dijjuizec progr.ur;3 and store them '"n hard disk storage while still encrypted and coiipressed. At t ach showing, the digitized informat.ci'! v/ill be retrieved via a local aji-a net^vork fror/i the hard disk storage, be decrypted, deco.Tipresscd and d:en di: played iisini; c neina-qualiry elecuonic projectors featunng high qualit> tiigiial s(».md. ' [digital :;it;eiria will encompass many advanced t^rcn no logics, including digital c(nipre;>^ion, tilccrjcnic secuhty methods, network architectjres and management, tr;Jr;Snij:5 5ion te.:i"nologics s.nd cost-effecuvc hardware, softv/are and integrated circuit dt;: iign. The tLThnologies necessary for a cost-effecdve, reliable and secure system art beinj; analyse 1 and developed. These technologies include new forms of image CO npre:>>ion, b:ic.iuse m08t standard cornpression technologies, such as MPEG- 2, are 0]) ::mized for television quality. Thus, aitifacts and other distortions associated with the I technology show up readily when the image is projected on a large screen. \^ lateverthe image compression method adopted, it vvill ailect the eventual quality ol tne projected image. wSpecial compression systems hai/e therefore been designed spt:dtlcally for d:-^atal cineme. applications to provide "'cineaia-quality' images at bit rat^s averaging; le^s than 40 Mbps. Using this technology a 2-hoar movie will require 01 y aboat 40 GB of storage, making n suitable for transpoiiation on such media as sc -called digital versatile disks (DVDs) or transmission or broadcast via a wireless liiK. V/hiie this has obvious advantages in terms of the distribution of movies, it bmgs w th It A own problems in that i n itself such transpori.ation and transmission is nc" secure. Encrypdon and conditional access methods are therefore also being developed witri th:^ aim of preventing piracy of movicxS. In addition to digital theft, i.e., the L'left of a ];ristine digital copy cf the content of the DVDs and/or transmitted del!a, theie is al;:c the problem of optical theft. Optical theft is the recording of the in ige and audio content of a movie as it is being projected onto the screen of a th.:2.ten SUMMARY OF THE INVEN1 ION While tliere is no sure way of prevcndng digital or optical theft, it is possible lo reduce the likelihood o); i: occurring by increasing the probability of the l>crpeirators of rie theft being caught. The invention addresses the above-dir.cussed j>r;oblems as;;:'ciated with digital cinema and is useful in overcoming or at least leduciiig the prcblena of digital and optica! theft. To this end the invention aims to |i]:-ovid{i a mtitaod and apparatus for inserting an imperceptible wateiTnark or '^digital lingerprint" into the image content. The watem'iark prefez-ably indrcates al least one o: the location, (late and dmeof showing of the movie, thereby enabhng the location (late and iira^- of the theft to be determined. Althoug]] the foregoing inti'oduction and folhjwing description concentrate on the inijertion of ;i watermark into an image as the movie is being shown (thereby i nablirg both optical and digital thefi ai: the tiieater to be tracked), it will be i pprccated i:y r. lose possessed of the appropriate skills that the same technique could t (juall)' well :ie Msed in a telecine when original film is converted into digital form (thereby enab.ing digital 2rA optical iheft outside the theater to be tracked^ The ^vate^Tla^k might fcr example identify :iny one or more of ihe location, date and time (Hf cieiiLion Qitiv^ digital version of the film, the tllm ov/ner's identity, or copyright if-fomntion. The technique is applicable to still images ^.s well as moving images. Acccrdiiig to one iispect of the invention, there is provided an apparatus for ippiyiiig data n;presenting a watennaxk to data representing an image, the apparatus i omprising: a sC'urce of location and time data; an error coding unit connected to receive the Iccaiion and time data for applying a forvvai"d eiTor correction algorithm to the sa:. foirn on a sigr^al ricdium, and for receiving an apparatus specific key; a decoding cu:uit rcspon.S'ivi:; to the apparatus specific key ioc decoding and decompressing the reunved sign:!:. ".(»recover the data reprei.enting an imag^ rhercfrom; a control circuit fci analyzing J1 least a component of tl^.e image data (o d;:iermjne an attribute thereof ar^l to cv.tput ;i 3i^:nal representative of the attribute; a imarfa'ng control unit, cc'inected lo rei;eive [he signal from rhj conrrol cn-cuir, the image data from the scurce ^nd the rv[i:erraark data from the? combiner, for addinj^ the watermark data to th: imag^ date, deijending on a charactcnstic of the attribate and a chai'acteristic of the image dcta; ar inverse DCT transfonn cu'cuit connected to receive the watermarked inLige dcta and t(' convert the same fro.rn data representing the image as DCT cc" rfficieals in transform'a:tion space to data representing i:he image in pixel space; a pi Mil processor connected to receive the data representing the image in pixel space for cciivertiitg the pi;;el data into a format suitable for display; and a projector connected to 'ixejv,^fo^:Jatlnd pixel data from the pixel processor for projecting the image re:ieseriied th'.Neky. i^ccordnig to another aspect of the invention there is provided an apparatus for af ])lying data representing a watermark to data representing an image, the apparatus cojnprisiig: meurs for supplying location and tin"^.e data; means for receivmg the lo;ation and time data, for applying error coding to the said location and time data, arid outputting e:n'c-r coded data therefrom.; spreading raeans connected to receive the er-Df coded data U>T applying a spreading function to the error coded data and oi-i{)utting spniH.d data therefrom; means lor generatmg and outputting data re :resenting a pse'ido-random code; means for combining the spread data and the pS: udo-randor: cede and outputting wate:-mark data representing a location and tim.e spc cific watennark; means for supplying image data represerting an image h en -.isfomiation 5;p3ce; m.eans for analyzing at least a component of the image data to detf rmin»i an attribute thereof and for outputting a signal representative of the atuibute; and marking means, connected to receive the signal representative of the iDibute, the imag': daia and the waiermaj'k data, for adding the wateraiark data to the miige da:a depiending on a ch^uracteristic of the attribute and a characteristic of the mage da a. Accoidir g to a further aspect of the invention there is provided a nnethod of ;i:piying dat.3 re H'esenting a watermark to data represenaiig an image, the method ;;:mpridng: 3up;:ilying location and ti:nc data; applying a forward error correction .;il;7oritF m to ilui said location and tim'^ data to produce error coded data; applying a ^reading fu:ict:.:>n to the error coded data to create spread data by repeating portions of the error ct^ded data a number of times; generating data representing a DES code; ocmbining x\\t ;;])read data and the DES code to create walennark data representing a location and tim:; specific watermark; receiving signals cortaining sa:d data /nprestnting an image as DCT coefficients in transfonn space, which data as received in an encoded ar d compresst^d form on a signal medium; receiving an apparatus li; pacific key; decoding and decompressing the received signals responsive to the ripparatus sp(?cir c key to recover the data representing an image therefrom, analyzing :.i; leas: a oom]K:nent of the image data to determine an attribute thereof and to create a :■ The inve'iticn also provides an apparatus for adding a watermark to a moving iinage £S it h displayed, the apparams comprising: a watermark generator in which d.ua repiesenting n watermark is generated containing first information peitdining to tli'i displaying of the moving image and protected by forward error encoding and second hfonraticn pertaining to the displaying of the moving image and protected by so '-imbJing; and [\ watemajii-k applica'.or for applying tne watermark data to image data re: }rcsen:ing suosiantially all of the moving image depending on a characteristic of the dua. The inv.iM.ion. furdier provides a >'atermarking sys^eiH for applying data re iresenung a rnoving image to prodat;e watermarked image data which is output to a d iplay device Ice display of :hc moving image represented thereby, in which system ir "onnation idcat::fying at least one of the system, the image and the displaying of the in age i:i convclutionally encoded and spread and infonnation identifying at least one o:' the system, rJu: image and the dispiayuig of the Image is encrypted so as to produce ti 0. watermark data which is applied ic substantially all data representing the moving ii: age with thti exception of data having a value below a determined level iri order to ii-nirniz-e the introduction of visible noiss and other artifacts into the image by the wntermark. BKJEF DESCRIFl ION OF THE DRAWINGS The above and further features of the invention a:re set forth with particularity ir the appende»:. c. aims and together with advantages thereof will become charer from Ci)r.siderition of the following detailed description of an exemplary embodiment of tb: invention given with reference to tlie accompanying dravv'ings, in which: figure I illustrates a block diagram of a drgita! cinema system; rigure 2 i? a block diagram of a compressor/encryptor circuit used iri the system of Figure 1] rigure 2> illustrates an auditonum module used in the system of Figure 1; Figure 4 IE a block diagram representing parts of an encryption/decr^'ption unit fc appl>ing watei'marks to image data; Figure ti is a block diagram representing a wateiraark unit of the eri:ryption/dei^rypl:ion unit of Figure 4; and Figure DET:VILi;i) DESCRIPTION OF AN EMBODIMENT OF THE INVENTION The Ibllovving description is intended to provide both an D\'ervievv' of a digital cineiTia system :::\ which the invention may be embodied and a detailed disclosure of 1 IS presently preferred embodiment itself. Systems ;;irriilai' to the system snown ^'erein ire described extensively in ot!:er applications; astngned to the assignee of this application, jxluding USSN 09/564,;.74, entitled, "Apparatus And Method For : ucoding And Slonige Of Digital Image And Audio Signals" and USSN 09/563,880, .^ntitlcc, 'Apparatus And Method For Decoding Digital Image And Audio Signals" hoth f^led Mr/ 3, 2000, the teachings of which are incorporated herein by reference. A di^;-.;.al cinema system 100 embodying the invention is illustrated in Figure 1 ::f the cccoinpanying drawings. The digjital cinema system 100 comprises :\vo main ; v/stem;: at Icji^si: one central facility or hub 102 and at least one presentatioa or rheaier ■; jbsystem 10-:|. The hub 102 and the theater subsystem 104 are of a similar design to \]m of pendia:^ US Patent Application Senal No. 09/075,152, filed on May 8, 1998, i;signed to t^c same assignee as the present invention, :he teachings of v;hich are iiicorpc-rated nerein by reference. Image and audio information are compressed and stored on a storage medium, aid dJstribut^I fronci the hub 102 to the r.heater subsystem 104. Generally, one theater ; jbsy5.tem 104 i*^ utilized for each theater or presentation location in a network of :;resentation iucations that is to re-ceive image or audio uitormation, and includes ; :!me C3ntralii:.ec equipment as well a:; certain equipment employed for each presentation auditorium. In the '::entral hub 102, a source generator lOS receives film material and :?=ner£.tes a cij^-.il version of the film. The digital information is compressed and K) icrypted by a compressor/encryptor (CE) 112, and stored on a storage medium by a hub storage device 116. A network rrianager 120 monitors and sends control information to t:.e source generator 108, the CE 112, and the hub storage diivice 116. -. condition^] access manager 124 provides specific electronic keying information !■; jch that only specific theaters are authorized to sho^v specific programs. In the i:heater subsystem 104, a theater manager 128 controls an auditorium module 132. Biisedon control infoimanon received from the auditorium module 132, a tieater storagii device 136 transfers compressed infoni.aticn stored on the storage TTifKJium to a f laybacK modjle 140. The playback module 140 receives the O) Tipres ;ed infonnation frcm the theater storage device 136, and prepares the CO npres >ed information to a predetermined seqaence, size and data rate. The phyback modire 140 outputs the compressed informaiion to a decoder 144, The di; :oder 144 inputs compressed inforraar;(;Ti from the playback mod ale 140 and p<: i decryption decompression and formatting outputs the information to a p ojectci sound mcdule projector plays on pumectci i.lie module phiys iiifonriutior. sysi:em both uii jcr control cf auditorium> In ope]*3ii'0n, the source generator 108 provides digitized electronic image aj '^or programs lo the system. Typically, the source gerierai:or 108 receives film in: terial and g::::ie::ates a magnetic tape containing digitized information or d;ita. The filiri is digitally scanned at a very high -evolution to create the digitized version of the m: tion picture or other prot;rara. Typically, a known 'te-cciae" process geniirates the imige in;'onnat]cn while W'ell-known digital audio conversion processing generates th: audi: portion of the program. The images being processed need not be provided frjra a fi.m, but can be single picture or still frame type images, or a series o:'frames or :)ictun;s, inc:juding those shown as motion pictures of varying length. These im iges cm be presented as a scries or set to create v^-hat are referred to as image pi: i^ami. In addition, other material s.m be provided such as visual cue tracks for si;,;Tt-impaired audiences, subtitling for fcreign language and/or hearing impmred au(l].ence;>, or rnultimedia time cue tracks. Similarly, s:inc;le or sets of sounds or re!::Tdin§;s are used to form desired audio programs. Altem£:tiV£:ly, a high definition digital camera or odier known digital image ger eration device or method may provide the digitized image information. The use of a d gital cameia. which directly produces the digitized im.age information, is ;js|:e;cially useful for live event capture for substantially iimnediate o: :or lcrDpc^raneoL::s distribution. Computer workstations or similar equipment ::an also 3e ised ro directly generate graphical images that ;ire to be distributed. Hie digiiial image infoimation oi- program is presented to the co'ipres^Dr/encryptor 112, v/hich compresses the digital signal usmg a preselected tjiown formji cr process, reducing the amount of di^ntal iaformat:on nece£;sary to [eprodnce the original image with very liigh quality. Preferably, an ABSDCT t:chniC;Ue is used to compress the image source. A suitabiC ABSDCT compression txhnjc ue is disposed m U.S. Pat. Ncs. 5,021,891, 5,107,345, and 5,^52,104, the [cachings of v/hich ;ire incorporated herein by reference. The aud:o information may : Iso be digitjJiy corapressad using su.ndard techniqucis and may be ri.nie synchronized \vith the compr;i:sed imaga mformauon. The compressed image and audio iifornution i;^ r:':en encrypted and^or :^crambJed jsing one or more secure electronic tiethcds. The n( t^^'ork manager 120 mcnitors the status of compres.sor/encryptor 112, nid directs tic compressed information from the compress Furtfier, maintaining the audio program r.epai'ate from the image program 'i Uowii for syichronizing multiple languages from audio program.s to the image program, vvi:;;.o:rt having to recreate tne image program for each language. Moreover, i-aintaining a separate audio progran:; allows for suppo:l: of multiple speaker ci:nfigurat>on> withotif requiring intericiaving ofr/iultiple audio tracks with the image P"]gran. In additio:! to the image program and the audio program, a sepiu*ate p ■ jmot.onal p:;ograiTu or prnrao progrDm, may be added to (he system. Typically, p' )mot onal rriatciial change^i at a greater frequency tliari the feature prograin. Use of a iepara's pronic program allows prorriotional material to be updated without re quidr j: new feature image programs. The promo prograra comprises iufon'nation sii:h as advcnising (slides, audio, motion or the like) and trailers shown m r'le theater. B:: cause of die high storage capacity of storage media such as DVDs and RlIDs, thousands of slides or pieces of advertising may be stored. The high storage volume allows for custoimzadon, ai> specific slides, advertiscracnts or trailers rnay be shown ai: !jpecific theaters to targeted customers. ^dthou£!;h Figure 1 illustrates the compressed infonnation in the storage device 1 L6 and physically transporting storage mediuni/media to the theater subsystem 104, it: hould be understood that the compressed informadon. or portions thereof, may be tr jfiSniiaed to die :heater storage device 136 using any of a n umber wireless or wired trmsmi-iiion methods. Transmi.ssion niethods mcludc satellite transmission, well-k]i:wn nmlti-dro:', Internet access nodes, dedicated telephone lines, or point-to-point fil;er opt.c networks. A. block diagram of ihe compressor/encryptor 112 is illustrated in Figure 2 of th: accompanyin,E; drawings. Similar to the source generator 108, the c( npressor/encryptor 112 may be part of the central hub 102 or located in a separate fa: ility. For example, the compressor/encryptor 112 may be located with the source gt;ierato' 108 i]i a film or television production studio. In addition, the compression prc'Cess for eith;!;r image or audio information or data may be implemented a> a VcMable -ate process. The compressor/encryptor 112 receives a digital image and audio infoiniation pi:vided by the source generator 108. The digital image and audio information may be stored in frame buffers (not shown) before further processing- The digita:! image 5i;:^n.al is Dassed to an image compressor 184. In a prefened embodiment, the image xtripressor 184 processes a digital image signal using the ABSDCT technique le:cnbec in the ahovementioned US. Fat. Nos. 5,021,891, 5.107,345, and 5452,104. fn the ABSDCT technique, the color input signal is generally in a YIQ format, ;'-.th Y being, ihe lutninance, or brigliriiess, component, and I and Q being the ;iromniance, 3r color, components. Other formats suci as the YL'V, YCbQ, or RGB ')miats may also be used. EJecause or the low spatial sensitivity cf rhe eye to color, lis ABSDCT technique sub-sampler; he color (1 and Q) components by a factor of 'vo in i^ach of the horizonta, and veirxal directions. Accordingly, foar liiroinancc i;:mpcnent.s cjul two chrominance components are used to represent each spatial ::.'gment of ijiiaj^e input. The ABS E)CT Technique nlso supports a format called l:4-:4 where iu nonsamplmg of chrominance component takes place. Pixels in each i::mpcnent aie represented digitally in up to 10 bits Imcar or log scale. Each of the luminance and chrominance components is passed to a block ]iterle3ver. Generally, a 16x16 block is presented to the block interleaver, which orders the image samples within the ]6x 16 blocks to produce blocks and composite :; jb-biocks of data for discrete cosine trc.nsform (DCT) analysis. TheDCT operator is :ne me:hod ol converting a :ime-sa.mplcd signal to a frequency representation of the ume signal. By converting to a freciency representation, che DCT techniques have :een shewn '.o allov/ for very high levels of compression, as quantizers can be designed to tab:: advantage of the frequency distribution characteristics of an image. -icfera3ly, on;; 16x16 DCT is applied to a first ordering, four 8x8 DCTs are applied . t) a second curdering, 16 4x4 DCTs iitt applied to a third ordering, and 64 2x2 DCTs •}cz applied to a fouith ordering. The T'CT operation reduces the spatial redundancy inherent in the image :; ::urce. After tiM?. DCT is performed, most of the image signal energy tend;; to be c:ncen:rated in a few DCT coefficients. For the L6xl6 block and each sub-block, the transfc^rmed coefficierrs are ;ina]yzed to determine the number of bits required to encode the block or sub-block. Then, the block '^r the combination of sub-blocks, which requires the least number of :its to encode, is, chosen to represent the image segment. F'or example, two 8x8 sub-:locks, six 4x:4 sub-blocks, and eight 2x2 sub-blocks may be chosen to represent the mage segment. The chosen block or combination of sub-blocks is then properly arranged in i:rder. The DCF coefficient values may then undergo further processing such as, but r:(»i: limued to, iTcquency weighting, quantizaiion, and coding (such as variable length ceding) using known techniques, in preparation for traniiraission. The compresr.ed linage s:gnal ;> then provided to at least one image encn-ptor 188, The d.i^itai: audio i^ignal is generally passed to an a-idio compressor 192. f leferatly, tlie audio compressor 192 processes rnulti-channel audio uiforrriation u^ing a ;taud;Lrd digital audio compression algorithm. The compressed audio signal is ptovidcil to al least one audio encryptor 196. Altemadvely. tlie audio information nn' be ransterTcd and utilized in an inconiprcssed, but still digital, format. The ir^agt; encryptor 188 and the audio encryptor 196 encrypts the c:tnprc^sed iinag:; and audio signals, respectively, using any of a number of known ecryplion techniques. The image and audio signals may oc encrypted using the same cr different techniques. In a preferred embodiment, an encryption technique, which c:mpri52S real-time digital sequence scrambling of both image and audio p^:grarrming, :s used. At the tillage and audio encryptors 188 and 196, the programming material is p':cesscd by ] sc-ambler/encryptor circuit that uses time-varying electronic keying ij: brmaiion (typit;airy changed several times per second). The scrambled program iiTormaiion an then be stored or transmitted, such as over the air in a wireless Jink, \^ ;thout being decipherable to anyone who does not possess the associated electronic ki^Ning iatbnr.aticn used to scramble the program material or digital data. F.ncry])(icn. generally involves digital sequence scrambling or direct encryption o" ihe ccmpresse:l signal. The words "encryption" and "scrambling'* are used ir t;rcha:igeably and are understood to mean any means of processing digital datii si reams Df various sources using any of a number of ci.7ptographic techniques to sc Mnibjc, cov^r, or directly encrypt said digital streaais using sequences generated u; ng secret d...=;il:£.] values ('keys") in such a way that it :.s very difficult to recover the 01* ginal data sequence without knowledge of the secret key values. Elach ir.a]2e or audio program may use specific electronic keying inf^imation vvi;..ch is provided, encrypted by presentation-locadon or theater-specific electronic k;iying :uforma;.ion, to theaters or presentation locations acthorized to show that specific orograin. The conditional access manager (CAM) 124 handles this function. T::e: encrypted j>rogram key needed by the auditorium to decrypt the stored iiifonr.ation :o transmitted., or athervvi;je delivered, to the authorized theaters prior to ot.iyback of rhe program. Note that the .uored program infonuation may potcncialiy .):: trar..;;niitted, {:.a,ys or week:> before tlie authorized showing period begins, and that he eno 'ypteiJ iir.agc or audio prograir. key may be transnrjUeci or deavered just before 'lie authorized payback period begins. The encrypted program key may also be lansfeired u^i.ng a low dala rate link, or a transportable storage element such as a .v.agnetic or o-Mi::al media disk, a smart card, or other devices having erasable iicmor/ elernr*r.i:,5. The encrypted progrdin key may also be provided in suoh a way as contiol th Each theater subsystem 104 that receives an encrypted program key decrypts ih]S val je us rg its auditorium specific key, and stores this decrypted program key in it mcmc»ry device or other secured memory. When the program is to be played back, the thcc.ter or .c:ation specific and progiam specific keying infonuation is used, ])-eferably with a symmetric algoritfim, that was used kn tiie encryptor 112 in p -opanng the. cr.t:ry|)ted sij^al to now descramble/decrypi: program information in ic.'ii-tur.e. Retuniir,^; now to Figure 2, in addition to scrrLmbling, the image encryptor 188 may adl a "wateimark" or "fingerprint" which is usually digital in nature, to the ur.agc prograraming. This involves rhe msertion of £. location specific and^or time y^Qcifk visui] identifier into the progi*arn sequence. That is, the watermark is instructed to indicate the authorized locarion and time for presentation, for more t;' Yiciently tracking i;he source of illicit copying when necessary. The watermark may bi programni:'d to appear at frequent, but pseudo-random periods in the playback p-Qcess and wDuJd not be visible to ths viewing audience. The waremiark is perceptaally unnoticeable during presentation of decompressed image or audio irformj.tion at v/hat is predenned as a normal rate of transfer. However, the '^ atermark is detectable when the image or audio information is presented at a rate : ■ibstantially different from that non^ial rate, such as at a slower "non-real-time" or ;;iill frame p!a.yba.ck rate. U an unauthorized copy of a program is recovered, the d gital wateri:;:ark infonnadon can be read by auiiioride^:>, and the theacer from which lii cop> was iii2cte can be determined. Such a waterrna]:k technique may also be a:plied or ustc to identify i:hc audio pros;raais. The corapres.sed and encrypted intage and audio signals are both presented to a nultipie\er 200. At the multiplexer 200. the image and audio information is ni jltiploxed toj:;ether along vvith time synchronization information to allow ;hc image a • d auc.io-stre.;3n"..ed information to be played back in a time aligned manner at the th :ater subsys.tem 104. The multiplexed signal is then processed b\ a program p-cketiz^r 204, which packetizes the data to form the program stream. By p:cketi::ing the data, or fonnjng *'data blocLs," the program stream may be monitored d. ring d^compres^sion at Cae theater subs /stem 104 (see Figure 1) for errors in n: izmviii the :locks during decompression. Requests may be made by the theater ni inager 128 of the theater subsystem 104 to acquire data blocks exhibiting eirors. Accordingly, if ecrors exist, only small poitions of the program need to be replaced, ii .lead cf an ertje program. Requests of small blocks of acta may be handled over a V, ired or wireless link. This provides for mcrcased reliability and efficiency. .f-\ltem3.tiv::ly. the image and audio portions of a program are treated avS sv. jarate and cistinct programs. Thus, instead of using the n:.uidplexer 200 t^ n iltiplex the image and audio signals, the image signals are separately pacJietized. In t^is way the iinagr. prograiri may be ti*ansported exclusive of the audio program, and vice versa. As :5uch. the image and audio programs are assembled into combined program.? onl)' at playback time. This ;illows for different audio programs to be coiibiniid with ijDage programs for various reasons, such as varying languages, providin,? pos"-release updates orprogiam changes, to fit v/iihin local conomunity st3ndarcli;, and so forth. This ability to flexibly assign audio different multi-track p! ograiru: to irr.age programs is very useful for minimizing costs in altering programs aJi^ady ii distribution, and in addressing the larger multi-cultural markets now a' I liable to the film industry. The compi-essors 184 and 192, the encryptors 188 and 196, the mul'iplexer 21^), and the program packetizer 204 may be implemented by a cc:npres-£.ion/eni:r]/ption module (CEM) controller 208, a software-controlled pr: cesser progriunmed to perform the functions described lierein. That is, they can be ccnngured as generalized function haicware including a variety of programmable i iectronic dc vi(:(;s or computers that operate under softvvare or firmware program c onlrcil. They rray alternatively be :rnplemented using scaie other technology, such :?, thro Jgh ai ASIC or through one or more circuit card assemblies, i.e., constructed 11. specialized hardvi/are. The image and audio progra:r si ream is sent lo i.he hub storage device 116. "';"ie CEM ccmtj'ollej: 208 is primanly responsible for controlling and moniloring the ;tvtire compic;>sor/encryptor 112. T^^t CEM controller 208 may be implemented by [ rogrcjnmins a ;,'eneral-purj)ose hard'vv;:J'e device or computer to perform the required fj notions, or by using specialized hardware. Network control is provided to CEM :ontrcller2(]S from the network manager 120 (Figure 2) over a hub internal network, :S described herein. The (TtiM controller 208 communicates with the compressors 184 and 192, Ihe enoryptors 188 and :i9'5, the multip]ext:r 200, and tlie packetlzer 204 . e-ing a biowr: digital interface and controls the oper^ition of these elements. The ;"EM controller 208 may also control and monitor the storage module 116, and the : ata transfer between these devices. The 5for3.ge device 116 is preteribly constructed as one or more RilDs, DVDs risks o: other high capacity storage mediunv'media, which in general is of similar :esigri as the theater storage device 116 in theater subsystem 104. However, those skilled m the ixi will recognize that in some applications other media m.ay be used icludLig bu: \o: lirciited to DVDs (Digital Versatile Disks) or so-called JBODs C'Just 3 Bunc.i Of Drives"). The storage device 116 receives rhe compressed and encrypted iiage. audio, and control data from the program packetizer 204 during the compression phase. Operation of the storage device 116 i.s managed by the CEM i:ontroler208 Figure 3 of the accompanying diawings illustrates operation of the auditorium - lodule 132 Jibing one or raore RHDs (removable hard dri^ves) 308. For speed, i:apacit/, and convenience reasons, it may be desirable to use more than one RHD :!08a tc 308n. V/'hen reading data sequentially, some RHDi have a '^prefetching" :^ mature that arrtiinpares a following read command based upon a recent history of cc-nninands. This prefetching feature is useful in that the time required to read :; jquentia] information off the disk is reduced. Flowe ver, the time needed to read non-,:i :quential information off the disk may be increased if the RHD receives a command til it is u lexpectcd. In such a case, the prefetching feature of the RHD may cause the r;i idoiTi access r:u;mory of i:hc RliD to be fuJ!. thus requiring more time to access the ill brraa icn requested. Accordingly, t.aving more than one RIID is beneficial in that a f cquertial sLrearn of data, such as an image program, j::iay be read faster. Funher, a-::essing a seco;:d set of information t.^n a separate Rffl> disk, such as audio p ':)grarr;s, tra: j:irs.. control information, or advertising, is advantageous in that a'.::essing such information on a single RHD is more tirr^c consuming. T^hus, cotnprcissed information is read from one or more RHDs 308 into a b jffer 284. Tiie FDFO-RAM buffer 284 in the phiyback module 140 receives the pi:rtions of ccmpiressed information from, the storage device 136 at a predetermined nie. The FH'ORAM buffer 284 is of a sufficient capacity i,uch that the decoder 144, a::ij. subsequently the projector 148, is not overloaded or uncer-loadcd with ir;]brmation. Preferably, the FIFO-RAM buffer 284 has a c£.pacily of about 100 to 2'VJ Mli Use ol' the FIFO-^RiXM buffer 284 is a practical necessity because tiiere may b'.; a sevijral second delay when switching from one diive lo another. The portions of compressed information is output from the FIFO-RAM buffer into a network .nicrface 2S8, which provides the compressed information to the dt:';oder 144. Frtsferably, the network interface 288 is a l:ibcr channel ai-bitrated loop (I* I--AL.; inteif-icc. Altemadvely, although not specifically illusu'ated, a switch no -.work controiied by the theater manager 128 receives the output data from the pii yback module 140 and directs the data to a given d(icodsr 144. Use of the switch ne. work allow:; programs on any given playback module 140 to be transferred to any gi^en de::oder 144. V/hen a piogram is to be viewed, the program information is reprieved from thi storage device 136 and transferred :o the auditorium module 132 via the theater rtic nager 128. The. decoder 144 decrypts the data received from the storage :rojcctor J48- The audio infomaatior is also decompressed and provided to the Uiditonum's Jx-und system 152 for playback with the irnag;:^ program. The (lecc'der 144 vnll now be described in grocih^r detail by further reference to " igure 3. Th^^ decoder 144 processes a compressed/ertcr^'pted program to be visually ;:rojec:(!d on:o a screen or surface anc audibly presented using the sound system 152. 1 he dec:oder 144 compnses a controlling CPU (central processing unit) 312, which ::'ntroI;; the decoder. Alternatively, lie decoder may be controlJec via the theater manager 12^-. The decoder further compnses at least ont depacketi/er 316, a buffer .!14, an irna^^e dccr^^ptor/decompressor 320, and an audio decryptor/decompressor .!24. T le buffer may temporarily store information for the depackctizer 316. All of ihe ab The drp.acketizer2'16 identifits and separates the individual controi, image, nd aucio packers that arrive from the playback modale 140, the CPU 312 and/or the heatei manager 12?!. Control packets, may be sent to the theater manager 128 while he image and audio packets are sent to "Jie image and audio iacryption/dscompression systems 320 and 324, respectively. Read and write aerations tend to occur in bursts. Therefore, the buffer 314 is used to stream data 1 iioothly from the depacketizer 316 to the projection equipment. The theater manager 128 configures, manages the security of, operates, and uonitO]-s the Ueater subsystem 104. This includes the external interfaces, iimage aDd lidio decryption/decompression modales 320 and 324, along with projectc^r 148 and he sound system module 152, Controi information cones from the playback module i 40, tho CPU 312, the theater manager system 128, a remote control port, or a local : )ntro'. input, such tis a control panel on the outside of the auditorium modal? 132 ijusin^. or ch^issis. The decoder CPL 312 may also manage the electronic keys . ;signe j to ecich auditorium module 132. Pre-selected elecrronic cryptographic keys . ;signe3 to auditorium module 132 are used in conjunclicn with the electronic cryptographic key information that is embedded in the imags and audio data to de crypi the inuig:: and audio information before tae decompression process. Picferatly, th:: CPU 312 uset a standard microprocessor running snibedded in the S':ftwait of e;^:h auditorium module 1.32, as a basic funct^^nal or control clement. In addition, the CPU 312 is preferably configured to work or communicate C'^rtain iifontaiicn vdth theater manai^er 128 to maintain a history of presentations c: cumng in eacli auditorium, Information regarding thiii presentation history is then a i ailable for transfer to the hub 102 using the return Imk, or through a transportable ru:diuni at preselected times. ^^c imi:;ge decryptor/decomprcssor 320 takes the image data stream f:^om d:packe:izer*!JCs performs decryption, adds a watennark and reassembles the original image for presentation on the screen. The output of this oix^ration generally provides suiadard analog RGE» signals to digital cinema projector 148. Typically, decryption a ^d decompression are performed in real-time, allowing for real-time playback of the p.'jgraraming material. The image decryptor/decompressor 320 decry]:)ts and decomxpresses the image d3ta stream to re^/ersc the operation performed by the image compressor 184 and the irr.age eiicryptor 188 of the hub 102. Each auditoriumi m.odule 132 may process and d. 5play a different: program from other auditorium modules ;132 in the same theater sut'System ,104 or one or more auditorium modules 132 may process and display the sa lie progi-am simultaneously. Optionally, the same program may be displayed on n. iltipliJ projectors, the multiple projectors being delayed iii time relative to each oi:ier. The decry]:tion process uses previously provided unii:-specific and program-spxific ilectrcnic cryptographic key information in conjunction with the electronic k;;ys embecded in the data stream to dtjciypt the image information. Each theater su :systeii 10^1 is provided with the necessar>' cryptographic key information for all programs authorised EG be shown on each auditorium module 132. .^. multi-le/el cryptographic key manager is used to authorize specific p:ic:5entaiion s]/5.terns for display of specific prognmis. This multi-level key manager ty]>:.caily unlize;> eleclxonic key values which are specific to each authorized tlieater iTii.nager 128, i;he specific image and/or audio program, and^or a time varying cryptographic kc;y sequence within the image and/or audio program. An '^auditorium i pecific" electronic key, typically 56 biLs or longer, is programmed into each cuditc>:ium module 132. This progra'TimJns may be inip!':^mented using several techniques V) transfer ;.nd pi.-cseat tf^e Ley information for use. For example, Lae return link disc\issed above inay be ur>ecl hxough a link to transfer tne cryptographic infoimation from the c ondiuional access manager 124. Alternatively, smart card technology such a.s smart ( ard 328, pr^: programmed Hash meniory cards, and other known portable storage devices nmy !)e used. For example, the smart card 32S may be designed so that cliis value, once loaded in':o '.he card, cannot be read from the smart caj'd memoiy. Physical and electronic security measuies are used to prevent tampering with this key infe-nTiation and to detect attempted tampering or compromise. The key is jtored in such a way that it can be erased in the event of detected tampering attempts. '^'he smart caid circuitry includes a microprocessor core including a software irnplerienta'..on of an enci^ption algorithm, typically Data Encryption Standard (DES) The snuxl card can input values provided to it, encrypt (or decrypt) these ^aluejj using the on-card DES algorithm and the pre-stored auditorium specific key. end output t-.c r-'-suit. Altc^niatively, the smart card 32fi' may be used simply to transfer enc]'yp:::d electronic keying infarmation to circuitry in the theater subsystem ; 04 whicJi v/ould perform the processing of this key info:rmation for use by the image ;jid an die decryption processes. Image: |:'i*ogram daca streams undergo dynamic image decompression using an inverse ABSDCT algorithm or other image decompression process symmetric to the iraage compression used in the central hub compressor/encryptor 112. If image c ompressiotL is based on the ABSDCT ;dgorithm the decompression process includes ^';iriab]e length decoding, inverse frequency weighting, inverse quantization, inverse cjiferenti;il cjuad-tree traniiformation, K)CT, and DCT block combiner deinterleaving. ■^he processing elements used for decompression may be implemented in dedicated speciaJized hardware configured for this function such as an ASIC or one or more :ircui;: card a.^isemb.ies. Alternatively, the decompression processing elements may be implementeti a^; standard elements or generalized hardv^are including a variety of d ^ital sgnal processors or programm^^bb electronic device:; or computers Liat o;:erate under :\\c coiUrol of special furiction software or fimvvare programning. MLltipjc ASIC; n:iay be implenjenied to process the image iaformaiion in parallel to support iigh linage data rates. Dig'tal vv c.:ermarks are applied to the image daa before die image is output for display by the projector. The watermarks are applied by the image d;i:ryptcr/dec:nr.pressor 320 before the data is output to the projector 14S for display of the image that it represents. Meferrirg now to Figure A of th-^ accompanying drawings, relevant paits of the d rjryptcr/deciivnpressor 3W for applyiiis a watermark to ihe image are- shown therein. T' e dccrypLor/decom.prcssor 320 comprises a compressed data interface (CDI) 401, wtj.ch receives the depacke-ised, compressed and encrypted data from tiie d*i:ackeiiser 316 (see Figure 3). Data lerds to be moved around and processed in bursts, a id so iJie received data is stored m a random access store 402, which is pirJerab^y an >1'DRA!^ device or simikx, until it is needed. The data input to the S.I^RAJ^'] store 41)2 corresponds to compressed and encrypted versions of the image di a. The stoie 402, i:herefore> need not be very large (relatively spealdng) to be able to store data c jiresponding to a large number of image frajncs. From time to time, the data is tciken from the store 402 by the CDI 401 and on .put ic a decryption circuit 403 wher^ it is decrypted using a DES (Data Encryption Standard) key The DES key is specific to the encryption performed at the central fa: ility 102 (si;e Figure 1) and, therefore, enables the incoming data to be decrypted. Ti= data may cJsc be compressed before li is transmitred from the central facility, uE^ing lossless techniques including Huffman or run-length encoding and/or lossy te':hniqui*.s including block quantization in which the value of the data in a block is di s ided by a power of 2 (i.e, 2 or 4 or 8. etc). The decryptor/decompressor 320 thus cc:nprises a decoripressor, e.g., an inverse quantization block (Huffraan/IQB) deicompnjssor 404 that decompresJies the decrypted data. The decompressed data from the HuffmaaTQB decompressor 404 represents the image data in the DCT Iciiiain. S;nce iic system already comprses the necessary hardware and software to ifl'ict DCT ooPApi'ctssion techniques, specifically the above-mentioned ABSDCF ■.;:mpression technicue, to compress data, the same is uued '-:o embed a watei-mark into i!ie picture m th,^? DCT doaain, Othej- transfomuitioris could, of course, be used but ■; iica t:ie hardvvitrc i^ already there in the s-ysteni this offers the most cost-effective 'i)luncri. Data [o\n the decompressor 404 is, theti-^fore, inpur to a v.'atermai'k processor 1D5 vvh:re a Vv^aiermark is applied in a manner that will he desciibed in greater detail h:rein below. Tlie cata from the watem^ark processor 405 ,s then input to an inverse OCT i;';msfoniiirig circuit 406 where ihe data is conveited from the DCT domain into nage ciaia iri the piJvel domain. rhi thus produced pixel data is input to a frame buffer interface 407 and aisociaied SIJRAM store 408. The frame buffer intetface 407 and associated store 40'8 ser/es as a buffer m which the pixel data is held for reconstruction in a suitable "ormat "or diiiphr/ of the image by a pixel image processor 409. The SDRAM store IC'8 may be c»f a similar stze to that of the SDRAM store 402 associated with the .; impressed d£:ta interface 401. However, since the data input to the frame buffer interface 407 represents the image in the pixel comain, data for only a comparatively ; iiall nimbe.r of image frames can be stored in rhe SDRAM store 408. This is not a liroblem because the purpose of the frame buffer interface 407 is simply to reorder the data from ihe inverse DCT circuit and present it for refoiinatting by the pixel image f.rocessDr 409 at the display rate. The decompressed image data goes through digital to analog conversion, and ilvs ana:og sij^nals ai*e output to projector 148 for display of the image represented by \]K image da:a-. The projector 148 presents the electronic representation of a program i:n a scieen. The high quality projector is based on advanced technology, such as iquid crystal liiiht valve (LCLV) methods for processing optical or image .iformi.tion. The projector 148 receives an image signal from image ■iecryptor/decornpressor 320, typically in standard Red-Green-Blue (F:GB) video :; jpial fDimat. Alternatively, a digital interface may be used to convey the 'lecompresised digital image data to the projector 148 obviiaung the need for the 'Ugital-'.o-imalog process. Information transfer for control end monitoring of the ,:rojeci(>r 14S' is typically provided over a digital serial interface from the controller Fii;iuc: f of the accompanying drawings shou'S tie v/atermai'k processor 405 in <. de the watennark proccsi:or405 is a configurable coefficient modulator if which r store v identification information and decisions are ade o i :t:t to mark how heavily.> rhs \y:(t;;rmark processor 405 embecs an impercepLible projector identification c The Wt:te3'jiiark processor 405 t^mpioys a DES en gins? that is keyed to the pu>graiii key. This serves three purpose^;. Firstly, the watermark pattern cannot be predicted t»ecaa;;e the sequence is tied to a non-linear noise generator. Secondly, the v' 3term:irk is specific to the individual program and ensures the pirate cannot tamper v/ lii it, despiie having compromised another program or being aware of the v ueniiark technique. Thirdly, the watermark is imperceptible because it is masked in a loise-ike rarccm sequence, i.e., the code generated by the DES engine. ]t ks a.ssunjed that a video pirate v/ill know that the movie material he is sioiiling will contain a watermark of seme origin. He may not be able to perceive it or sijip it f'om tic; image, but he may be able to alter it using some or all of the followirg tne::;ods. BEiic manipulations such as resolution scaling and cropping occur when the p ;:grara is rei:orded onto a video camera or similar device. The digital cinema d ;;play format c;:.i^ be as large as 2560 x 1088; most consumer equipment is limited to a laaxirrum of 800 x 600 pixels (SVHS). This implies a resolution scaling operadon an:, possibly ai JO a cropping operation. The video pirate may decide to capture the en:ire \^':dth of the image (letterbox format) or a fraction of i: (pan and scan). C'ompex manipulations such as inter-frame averaging occur when two video fruaes .Tom the liame scene are used tC' average out the areas that have been 'vatemaike::. One form of this inter-frame averaging wculd occur when the charge-( oupl^d cevice (CCD) hi a video camera converts the 24 or 30 fps of the projector into its inteiiml refresh ra':e. Ano':her complex manipulation attack can occur when the same program s equerce is cipv.urcd from different projectors with different watermark identification c odes. Thie sets of frames can be compared to idenbfy which portions of a frame are marked and avcuage those out. A vaiiaiion on this scheme, collusion, uses two copies ur the jKogriirn The watermark processor 405 also comprises a DBS engine 432. The DES ;;ngine 432 generates DES codes entii'ely independently c>f the DES codes used by the ,;iES decryption unit 403 (see Figure 4), The DES key used by the DES decryption unit 403 pertains to the encryption and decryption of ih^ data from the central facility f see Fi.gure I) whereas the DES key generated by the DBS engine 432 is specific to i)ie theater ajid/cr the projector I which the movie is displayed. 7ho JDES mgim 432 is used to generate a pseudo-random noise (?l^) s::querK:^ for '^jnbedding the watermark data into the movie bits. A program key is loaded f^ora register 424 intc the DES engine 432 at the stait of the program, and used tJrDughour thf- p-ogram. At :he beginnirg of e:ich frame, the initia! vector is loaded V,' th the current iTarre number. The DES engine 432 is configured in output feedback niide. la this mimner, a long-period PN sequence is geriera:ed that is unique for e .ery fvanae cf every prograii,i. The th JS generated long PN sequence is outpat to an e /vn aniplJude control block 434 identifies the level at which each DCT ci:efficient is marked. Amplitude control is accomplished by determining the n I ignitu.je of ciich DCT coefficient and using the magnhucki of the DCT coefficients to index data in n look-up tabic. The niajjnitude of the coefficient is determined as \oi2 of -he absol.ite coefficient value. The DCT transfoim domain has the advantage tl; It watermarks are adaptable because the strength of the watermark depends on the ir cnsity value*, o! the DCT coefficients of the original image. The witermcirk is n: ide strong in the DCT coefficients with large intensity values and is attenuated in aio;as vviih small DCT values. Although amy color component may be used. Figure 5 illustrates only DCT coefficients for the luminance (Y) component of the image arc input to the amplitude control block 434 (and indeed to the watermark processor 405). In this embodiment, the DCT ccef:i;ients relating to the color different components (CR and CB) of the ir::age bypass the watermark processor 405 entirely. This is because the color dnference corooiients (CR and CB) by themselves cannot be used to produce a ixit:aningful im&ge but the luminance (Y) component may be used to create a black-art j-white version of the image. Processing the DCT coefficients for the Y coiiponcnt reduces processing overheads. In another embodiment, the CR aid/or Cs cu iiponents a;"e input to the watermark processor. The amplii.ude coniiol block 434 produces an ;unplitude value that is passed to a narking control block 436. The marking control block 43i$ controls the actual selection of th^ components to mark. Ii decides which DCT coefficients are marked ard in wliat types of sub-bJocks. Any block size (16x16, 8x8, 4x4, 2x2) may be marked, whether the block ii; deemed perceptually significant or not. In an :irnbociiment, both perceptually significant and other blocks are marked. In another ■iaboc.iment, peiceplually significant blocks are not jnarked. The marking control l.iiock 436 concerts the wareiinark value from the XOR combiner 433 into a negative vduc ['{) if .he watermark bit is a zero (0) and into a posjtive value (-t-1) if the '^'aterriark b.x is a one (1). The marking conrrol block 43'^ also decides whether or not the watennaik data will actually be incorporated into the DCT coefficients for the luminance cotaponent. To this end the marking control block examines the value of I lie coc Ticient and/or the amplitude value from the amplitude control block together vMth ot^ier information (including block size) peitaining to the DCT coefficients. illenerally, waiermai-king h not applied l;o coefficients whose log2 value is zero since ilus may intrcnkce a noise into the image. Such noise would probably be visible in I lie image and ii; therefore unacceptable. When watermarking is to be applied the i:ositi\t; (H-1) or negative (-1) value is added to the luminance (Y) data. The data output from the martmg controi block 436 are input to an adder 438 '/Mere they ace added to the DCT coei'ficients for the luminance componen: of the i.nage. In this v/ay, the watermark data is applied to the image data while still in the OCT domair. Apart from the DC components, all DCT coefficients are considered as ■ .:andid^.te& fc»: tlie application of watermark data. The data is applied depending on among other uings ^.he amplitude of a coefficient. The application of watermarking tt2X Thos^ posse:5sed of the appropnate skills will appreciate from the foregoing : lat the watermark is constructed to indicate the authorized locadon and time for ::esentation, for more efficiently tracing the source of illicit copying whe:a " ecessiiry. The watermark may appear at frequent, but deterministic periods in the :layb^.ck prcce.sj; and is not visible to the viewing audience. The watermark is :erceptQally unnoticeable during presentation of decompressed image or audio ifonriaiion at v/hat is predefined as a normal rate of transfer. However, the V .Uennark mrj be detectable, although not perceptible, when the image or audio ill 'orma'.ion i:; pKisented at a rate substantially different I'rom that normal ra-.e, such as a. a slov/er "rcn-real-time" or stjli frame playback rate. If an unauthorized copy of a P':grarr is recovered, the digital watennark infoimaiion CK be read by authorities, a:id the heater fn:>m which the copy was made can be determined. ^.."he waterma::ked DCT data thus produced by the watermarking pro*;:cssor 405 n- input LO the inverse DCT unit 406 where it is converted into pixel data as has ai] tiady 3een explained herein with reference to Figure 4. Tius, the di;:ryptca'/cecompressor320 serves to decrypt the incoming data, decomptess it, apply a n-aternark, corivert the data from tht DCT domain t;o the pixel domain and Hiconstract the pixels into a suitable format: for display of the image by the projector 118. The audio decryptor/cecompressor 324 shown m Figure 3 operates in a similai-Hi inner on thtt mdio data, although it does not apply data representing a vvalcmiark or fir geip.T: nt to the audio signal. Of course such a watermark technique may lilso be a]):lied or used to identify the audio piogi-anis, if desired. The audio d.::ryptcr/ceco'.Tipressor 324 takes the audio data stream from the dopacketi;:er 316, pi i'forms decryption, and reassembles the original audio for presentation on a theater's speakers or audio sound system 152. The output of this operation provides stEiidard line Jev^jl audio signals to the sound system 152. S imilar to the image decryptor/decompressor 320, the audio dc:ryptcr/dec:>;:rpressor32^i reverses the operation perfcrrned by the audio c(i iipres5or 192 and the audio encryptor 196 of the hub 102. Using electronic keys fr: m the cryptcgraphic smart card 32S in conjunction with the electronic keys eif bedde.d in !ha data stream, the decr>ptor 324 decrypts the audio information. The decrypted audio data is tlien decompre.ssed. ^LUdio decompression is perfonned with an algorithm symmetric to that used at he central hub 102 for audio compression. Multiple audio channels, if present, are dtoompres&ed. The number of audio channels is dependent on the muld-phonic sc und system di^sjgn of die particular auditorium, or present£.tion system. Additional atdio channels may be transmitted from the central hub 102 for enhanced audio [)r:'gram]ning fur pur|>oses such as multi-language audio tracks and audio cues for nght irapair^i audiences. The system may aiso provide aaditional data tracks i vTichronized t:) the image programs for purposes such a^; rnu'tinedia special effects (racks, suDtitlmg, and special visual cue tracks for hearing' impaired audiences. As discussed earlier, audio and data tracks iray be :irae synchronized to the iraage DrograiTts^ or may be presented as.ynchronously v/itiiout direct time synchronization. Image programs may consist of single frames (i.e., still images"), a sequence of sui;2le frame still images, or motion image sequences of short or long (lurarion. If neci.:;ssary, the aadio channels are provided lo ar, audio delay element, which ir.serts a delay as needed !:o synchronize the audio with the appropriate image frame, liach c:iannel then goes through a digital to analog conversion to provide what are Ijiown as 'line lever' outputs to sour.d system 152. That is, the appropriate analog level or format sigrals are generated from the digital data to drive the appropriate sound system. The line level audio outputs typically u.se standard XLR or AES/EBU c onnectois iound in most theater sou id systems. Rcfenrng back to Figure 3, the decoder chassis 14^ includes a fiber channel interface .28ii, the depacketizer 316, the decoder controller or CPU 312, the image (lecryp:or/deccrapressor 320, the audio decryptor/decompressor 324, and the c r>pto S'^curity inter, ocks may be used to prevent operation of ':he decoder 144 when it is not correctly instcilecl to the projector 148. The sc*und system 152 presents the audio portion of a program on the theater's speakers. Preferably, the sound system 152 receives up to 12 channels of standard f(j mat audio signals, either in digital or analog format, from, the audio d.ijryptcr/dccoirpressor 324. /Utema;ively, the playback mo-iule 140 and the decoder 144 may be integrated ino a S'.ngle playback-decoder unit 132. Combining the playback module 140 and the di;::oder raoduje 148 results in cost and access time savings in that only a single CPU (-:/>2 or 312) is needed to serve the functions of both the playback module 140 and the di.;:oder 144. Combination ox the playback module 140 ard the decoder 144 also does n-Jt requ.re the ij;::e of a fiber channel interface 388. [f muln/ple viewing locations are desired, information on any storage device 136 is cc»nfigured to Ixansfer compressed information of a single image program to d.;Jferert audilcriums with preselected programmable offsets or delays in time relative to each cither. Tficse preselected programmable offsets cxt made substantially equal to ;^,ero cr very umall when a single image program is to be presented to selected nr;ultiple auditodums substantially simultaneously. At other times, these offsets can be- set anywhere from a few minutes to several hours, depending on the storage ccnfigurition and capacity, in order to provide very flexible presentation scheduling. Tins allcws a theater complex to better address market demands for presentation c^'^nts such as first run films. The theater manager 128 is illustrated in greater detail in Figure 6 of the accompanying; 'i'awings. Turning now to Figure 6, the tneater manager 128 provides 0]»iraticfual control and monitoring of the entire presentation or theater subsj^stem KH, or cne or more auditorium modules 132 within a theater complex. The theater ir.Enager 128 may also use a program control means or mechanism for creating piogram SQts from, one or more received individual image and audio programs, which II: scheduled for presentatian on an auditorium system dunng an authorized interval. The thciiter manager 128 comphses a theater manager processor 336 and may DIvjonaJly contiun at least one modem 340, or other device that interfaces with a •eum lirk, for i-ending messages back to cenn-al hub 102. The theater manager 128 :nay include a visual display element such as a monitor and a user interface device ;aich ai; a keybo;\rd, which may reside ia a theater complex manager's office, ticket booth, or any orter suitable location that is convenient for theater operations. The t.eater manager processor ii6 is generally a litandard commercial or business jzrade computer, J'he theater manager procesiior 336 communicates with the netwcik manager 120 and condition^.! a-cess manager 124 (see Figure 1). Preferably, ihe modem 340 is used to communicate with the central hub 102. The modem 340 is ;;ener;illy a ttancard phone Hne modem, that resides m or is connected to the ■}roce:>.ior, and connects to a standarc two-wire telephone line to communicate back to he certral huo 102. Altematively, c;)mmunications betv/een the theater manager )roce:> jor 336 and the central hub 102 may be sent using other low data rate i;i^mmimioation!; methods such as Internet, private or public data netv/orking, vireless, or satellite comrQunication syii':ems. For these alternatives, the modem 340 s configured to provide the appropriate interface structure. Tlie -.heater manager 128 allows each auditorium m,oduIe 132 to communicate vith each storage device 136. A theater management module interface may include a )uffer memory such that information bursts may be transferred at high data rates from 'he theater s:orage device 136 using the theater manager interface 126 and processed r. slow er rate:> by other elements of the auditorium module 132. Infomialion comnmnicated betvv'een the theater manager 128 and the network nanagir 120 a::id/o:r the conditional access manager 124 include requests for ctransmission c)f portions of information received by the theater subsystem 104 that ijxhibiling uncorrectable bit errors, monitor and contro.^ i:nformation, operations eports and alatras, and ciyptographi: keying inform.ation. Messages communicated nay bt; cryptojp'apliically protected to provide eavesdropping type security and/or /erificition c.nd authentication. The ::!e;a.ter manager 128 may bs configured to provide fully automatic ^peraiion of nii presentation system, including control of the playback/display, iecunty, and network management functions. The theater manager 128 may also ^rovid'^ control of peripheral theater functions such as ticket reservations and sales, concession operations, and environmental control. Alternatively, manual intervention nay be used, to supplement control of some of the theater operations. The theater :i)ianagcr 128 rnuy also interface with certain existing conirol automation systems in ■he theater conplex for control or adjustment of ihes:i functions. The system to be -lied \y:\\ dejM^nd on the available technology and the needs of the panicular theater, iii wouid be Known. Throngli either control of theater manager 128 or the network n-ianagcr 120, ihe inve-ntion reneraily supports simultaneous playback and dispiay of recorded frograriminj^ -m multiple display projectors. Furthermore, under control of theater manager 128 jr the network manager 120> authorization of a program for playback uiultiplo times can often bt; done even though theater siibsystem 104 only reeds to icceive the pr-jgr^mming once. Security management may control the period of time ;. -id/or the number of playbacks that are allowed for each program. Throii.^;h automated control of the theater manager 128 by the network Kianagement nicdule 112, a means is provided for automatically storing, and ]»resent:ng programs. In addition, iheie is the abihty to concrol certain preselected ii itwork opera:ions from a location remote from the central facility using a control t'crnerii. For example, a television or film studio could automate and control the (! stributioTi cf films or other presentations from a centre! ;.o::alion, such as a studio C' Tree, and mr^e almost in'imediatc changes to preseniationii to account for rapid clianges in market demand, or reaction to presentations, or for other reason I iderstood ir the art. The th::a(:cr subsystem 104 may be connected with the auditorium module 132 i;;;mg a theater interface network (not shown). The theater interface network csi:eru(s) 132 of the theater subsystem 104. The theater interface network 126 may be implemented using any of a number of standard local area network atchitectures which exhibit adequate data transfer rates, connectivity, and reliabihty SI ch as arbitrated loop, switched, or hub-oriented networks. lEach storage device 136, as shown in Figure 1, provides for local storage of t:ia proErarnn:u.ng material that it is authorized to playback and display. The storage s ystem may b;:' centralized at each theater system. In this case the theater storage (li^vice 136 ullovvs the theater subsystem 104 to create presenrarion events tr: one or more auditoiiuir-S and maybe shared across several audiiionums m one time. D^peiiding upon capacity, the theater storage device 136 may store several j)rogra;7is at 3 lime. The cheater storcige device 136 :Tiay be connected usir:g a local txea network in such a way chat any program may be piayed back and presented on ;;ny au';hcri2:ed presentation system (i.e., projector). Also, the same program may be 5 imullaneously played back on two or raore presentauon systen-s. Having thus described the invendon by reference to a preferred embodiment it ii to be well ixderstood chat the embodiment in question is exemplary only and that irodilioations and variations such as ml] occur to those possessed of appropriate 1 j"iowk:dg.e and skills may be made without departure from the spirit and scope of the invention as set forth in the appended c::aims and equivalents thereof. What w- claim as our invention is; CLAIMS: '.. An apparatus for applying dat^i represeating a watermark to data r^presertirg m iraage, the apparatus comprising: a source of location and time data; an errc>r coding unit connected to receive the kxation and tirT]e data for aiplyini; a fC'rAc.rd error correction algorithm to the saic location and time data and ctiputimg en'or coded data tfierefrom; £ code spreading unit coupled to receive the e:rror coded data for spreading the e::or coded d^tii to create spread data by repeatedly outj:)utting portions of the error c:ded data a :iui::iber of times therefrom; •c DES code generator for generating and outputting data representing a DES C':de; £ coiT.biner for combining the spread data and the DES code and outputting V uennark data [(^presenting a location and time specific v/atermark; a receiver for receiving signals containing said data representing an image as EOT cocfficjenis in transform space, which data is received in an encoded and compressed form on a signal medium, and for receiving art apparatus specific key; a dccoc ing circuit responsive :o the app;iratus specific key for decoding and di*:ompres!iing i:ne received signals to recover the data representing an image therefrom; a comriD] circuit fcr analyzing at least a component of the imai^e data to d.j:ennine an altribute thereof and to output a signal representaive of the attribute; a marking control unit, coupled to receive the signal from the control circuit, tl:it' image data from the source and the watermark data from the combiner, for addmg the watermark data to the image data depending on a chcLracieristic of the attribute and a .'haracteristio of the image data; a:i invi:;ise DCT transform circiit connected to receive :he watennarked image d;. a and to convsirt the same from data representing the image as DCT coefficients in tr;nsformation space to data, representing the image in pixel space; a pixel processor connected to rxeive the data representing the image in pixel space far convening the pixel data into a format suitable for display; and a prcjcctor connected to receive formatted piNcl data from the pixel processor "Or pr(j_ecting the image represented thereby. 2. An apparatus as claimed in claim 1, fuither compnsing a source of :rograin ke> aula and a source of frame index data unique".y identifying each frame in J moving inuige. and wherein the DBS code generator is connected to the source to 'iceive the frame index data therefrom and to generate a DES code depending on the ::,:inic index data and the program key data. 3. -\n apparalns as claimed in claim 1, fuither comprising a source of MOgrarn key data and a source of frame index data uniquely identifying a rredetenninficl number of frames m a moving image, and wherein the DES code K;ner2.tor is connected to the source ^o receive the frame index data therefrom and to ^enerae a DES code depending on the frame index data and the program Icey daia. 4. iKn apparatus as clairred in claim 2, wherein the combiner comprises .3n exclusive-iDR (XOR) gate for combining the spread data and the DE^ code on a :it-by-'bit basis according to an XOR function. 5. An appara'-us as claimed in claim 4, wherein the control circuit is i:onnec:ed tC' receive data representing the luminance component of the image, and is i:onfigired :o (determine as said attribute an amplitude value of the luminance component as the logo of the value of the luminance component. 6. An gipparatus as claimed in claim 5, wherein the marking control unit i arranged to generate as a generated value from the watermark data a positive or -egative vaJ jc^ and to add the generated value to the ijnage data depending on the log2 ':f the \i\lut of the luminance component being greater than a predetermined ireshold. 'L An apparatus for applying data representing a watermark to data ri:prescr;tirig '-m ::iiage, the apparatus conprising: inean:> for supplying location 2^x10 time data; mein:i for receiving the locaricn and time data, for applying error coding to the S;id ioc.ition aid time data, £nd outpa'ting error coded da^a therefrom; spreadini? means coapled to receive the eaor eroded data for applying a s .readir g lur.cticm to the error coded data and outputting spread data therefrom; mean:; 'or generating and outpntting data representing a pseudo-random code; means for combinirg the sp^rcad data and the pseudo-random code and OL.tputti:ig wa::5nuark data representing a location and time specific watermaj*k; mean;; for supplying image data representing an image in transfoimation s|:s.ce; means for analyzing at least a component of tl;c image data to determine an a libure there::!" and for outputting a signal representative of" the attribute; aad inaj-kini^ means, coupled to receive the signal representative of the attribute, ihi iinc.ge datE; ;iad the watermark data, for adding the v^ateimark data to the image dua depending on a characteristic of the attiibute and a characteristic of the image dUa. 5.. An apparatus as claimed in claJn) 7, v/hercin the means for generating an:! outputtirg data representing a pseudo-random code is configured to apply a fo ^vard error correction algorithm to the location and time data. 9. An apparatus as claimed in claim 7, wherein the spreading means is configured to apply the spreading function depending on a spreading factor. 10. An apparatus as claimed in claim 7, wherein the spreading means is coifigursd to ap]}ly a spreading function in vvhich bits in the error coded data are rc;]»eated a nujnber of times 11- AT: apparatus as claimed in claim 7, wherein the means for generating ai.'i outputting da:a representing a pseudo-random code comprises a DES engine. 12. An apparatus as claiiu'd in claim II, fuither compmsing means for upplying profi^ram key cata and wherein the DES engine is connected to the means or sL.])pIyiTU|, io receive the program key data therefroir, and to generate a pseudo- ■andon code depending on the progrim key data. 13. An apparatus as claimed in claim II, further comprising means for ;upplying f]':3n:j„^. index data uniquely ideniifying each frame in a moving image, and vherein the DES engine is connected to the means for supplymg frame index data to •eceive the iTame index data therefrom and to generate a pseudo-random code depending en tre frame index data. 14. An apparatus as claim.ed in claim II, fiuther comprising means for iupplying frame index data uniquely identifying a prede:ermined number of frames in ii mo\ing image., and wherein the DES engine is connected to the means for supplying iiarne ndex data to receive the frame index data therefrom and to generate a pseudo- : cindoci cod^ depending on the frame index data. 15. An appai'atus as claimed in claim 12, fuither comprising means for supplying frame index data uniquely identifying each frame in a moving image, and ^vherein the D2S engine is connecteil to the means for Siupplying frame index data to leceive: the frame index data therefrom and to generate a pseudo-ni-ndora code depenciing en the frame index data and the program key data. 16. An apparatus as claimed in claim 7, wherein the combining means comprises an exclusive-OR (XOR) gate for combining the spread data and the pseudc-rancom code on a bit-by-bit basis according to an XOR function. 17. An apparai:u:> as claimed in claim 7, wherein the means for analyzing at least a component of the image dala is connected to receive data representing the luminance component of :he image. IS. An apparatus as claimed ii claim "7, wherdm the means for analyzing at lei.st a corapjiient of the image dat:i is connected to receive data reprssenang a ch^omin.mce j:orr>poncnt of the image. 19. An apparatus as claimed in claim '^, wherein !he means for analyzing at icEst a com|X)neat of the image data is configured to delenidiie an amplitude value as thi attribute. 20. An apparaDis as ciairacd in claim 19, wherein the amplitude is dt: enni ned as th';: Ioc;2 of a value of the component of the image data. 21- An apparatus as claimed in claim 7, wherein the marking means is arrnnged to generate as a generated value from the vvatermark data a positive or nc:native value and tc add the generated value to the image data depending on the said ch.iracteiistic of the attribute. 21. An apparatus as claimed in claim 2L wherein the means for analyzing at east a cc»mp;5r)ent of the image data is configured to determine an amplitude value as the aitribu:e and the characteristic is the amplitude vaJue bemg greater than a piideterroiried threshold. 23. An apparatus as claimed in claim 22, wherem the amplitude is delsrmin'^d as t]i 24. A:.\ apparatus as claimed in claim 7, further comprising: re cans for receiving signals containing said data representing an image in an in:oded and compressed fon:} on a sigiial medium, and for receiving an apparatus 5p'.'cific key; deccdiiig jneajis responsive to the apparatus specific key for decoding and ■ie:ompreiss!ng the received signals to recover the data representing an image iht-'efrorri. 25- An apparatus as claimed in claim 24, wherein the signals are conveyed on the med un'i as data packets and the means for receiving signals comprises data interface nnieanri for receiving the data packets. 26. An apparaiius as claimed in claim 24, wherein the means for receiving Mgnals is aiumjzed to receive the apparatus specific key ifirough a medium different than the raedinn; from which the encoded and compressed data signals ai-e received. 27. ,A.n apparam;? as clamied in claim 24, vv'hcrein the signals are encoded using DES encryption and the decoding circuit compn;>e=; a DES decryption engine. 2&. An apparatus as claimed in claim 24, wherein the signals are c ompressed us:i\g a lossless compresi^ion technique. 29. An apparams as claimed in claim 28, wherein the lossless compression technk ue cunrxises run-length encoding. 30. An apparatus as claimed in claim 24, wherein the signals are c ompn^ssed using a lossy compressicn technique. 31. An apparatus as claimed in claim 30, wherein the lossy compression t;chnic[ue comprises block quantization. 32. An apparatus as claimed in claim 24, further comprijing inverse transfi^rannji means circuit coupled to receive the wateimarked image data and to convert the ;5ame from data representing the image in transformation space to data IS presenting the image in pixel space. 33. An apparatus as claimed in claim 32, further composing pixel ['roceiJ:jing iricai^s coupled to receive the data representing the image in pixel space for c onverting the pixel data mto a fonnat suitable for display by a projector. ?4. A.n apparatus as claimed in claim 33, farther comprising an interface n.r^ms for bulft^ring data from the inverse [ransformmg means for the pixel processing n'ttans. 35. An apparali:.s as claimed in claim 33, fuither comprising displaying nru;ans couple:! to receive formatted pi^el data from the pixel processor for displaying th(- image lep/c-SiMUedby the pixel data. 36. A method of applying data representing a watermark to data represeni-ing an image, the method comprising: supplying location and time data; UDplybig a forward error correction algorithm to the said location and time d;. a to produce error coded data; applying-; a spreading function to the error coded data to create spread data by rcE eating; portions of the enor coded data a number of times; g'ineratiajz dav.a representing aDES code; combinin]^ the spread data and the DES code to create watermark data re:resenting a location and time specific watermark; re:ceiving signals containing said data represe:ating an image as DCT coefficients in transform space, which data is received in an encoded and compressed form on a signal nied:ium; receiving cji apparatus specific Jcey; d adding "he watermaik data to the image data depending on a characteristic of i:h(:' attribute ard a characteristic of the image data; ccfnvenirij;; the watennarked image data from data representing the image as DCT coefficients in transformation space to data representing the image in pixel sp:i:e; ccnverting the pixel data into a format suitable for display; and proje;cti"g the image represented by the formatted pixel data. 37. A method 'is claimed in claim 36, further comprising: :-;upplying program key data; supplyiag frame index data uniquely identifying each frame in a moving image; and generating the DBS code depending on the (xame index data and the program key daia. 3&- A method as claimed ;n claim 36, further comprising: supplying program key data; supplying frame mdcx data un:quely identifying a predetermined number of )rame;5 in a jnoving image; and generating the DES code depending on the frame index data and the program ]:ey da'.a. 39. A method as claimed in claim 37, further comprising combining the ; pread data dnt. the DES code on a bit-by-bit basis according to an XOR function. 40. A method as claimed in claim 39, further comprising: receivir.g data representing the luminance ccm]X)ncnt of the image; and deternijning as said attiibute an amplitude value of the luminance component a:> the ]og2 C'f thf; value of the luniinaace component. 4i. A method as claimed in claim 40, fuither comprising: generit:.ng as a generated value from the v/acermiark data a positive or negative valu°.; iind adding Ihe generated value :o the image data depending on the ]og3 of the -'alue of the luminance component being greater than a predetermined threshold. 42. A method of applying data represerrting a waterm^^xk to data representmi; an image, the method compnsing: supplyinjj location and time data; applying error coding to the said location and time data to produce error coded delta; ippiying a spreading function to :he error coded data to produce spread data; gencratin!.^ data representing a pseudo-random code; combinii]'}; the spread data and the pseuda-randoro code io produce watermark dbta represeniing a l(x;ation and time specific watermark; supplying image data represeniing an image in transformation space; £naly5:;[n:;; at least a componeit of the image da':a to determine i.n auiibute til jreof to produce a signal representative of the attribute; ard adding the waterm^irk data to ^he image data depending on a chai'acteristic of th ^ attribute and a characteristic of the image data. A3. A me:thod as claimed in claim 42, farther comprising applying a fo-^varc cnor coirection algorithm to tiie location and time da!a. 44, A method as claimed in claim 42, funher comprising applying the spreading fun:i:ion depending on a spn^admg factor. 45. A method as claimed in claim 42, furt'ner comprising applying a sp-eading i'urcticn in which bits in the error coded data are repeated a number of ti: ics. 46- A method as claimed in claim 45, whe;:e:'n the pseudo-random code ginerator is generated by way of a DES engine. 47. A method as claimed in claim 46, fuither comprising receiving program key datL and generating a pseudo-random code depending on the program ko / data. 43. A method as claimed m cLiim 46, further comprising: ;jupply;.ng; frame index data uniquely identifying each frame in a moving image; and ^^enereiing a pseudo-random c^d^ depending on the frame index dar.a. 49. A method as claimed in claim 46, further compns:ng: suppiyin,r, frame irdex data uniquely identifying a predetermined number of ticmes in a mcvirig image; and general ing a pseudo-random code depending on the frame index data. 50. A method as claimed m claim 47, further comprising: .';upplymg frame index data uniquely identifying each frame in a moving image, and generating a pseudo-random code depending on the frame index data and the I'ograirt key data. ;>1. A method as claimed in claim 47, further comprising: supplying fninie index data uniquely identifying a predeteranned number of ft ames in a irtc-vrng image, and generitii:g a pseudo-random code depending on the frame index data and the prograui key datx.. !)2. A method as claimed in claim 42, furtlier comprising combining the s,]iread data and :he pseud:>-random coce on a bit-by-bit basis according ■;o an XOR finctior. ;)3. A method as claimed in claim 42, further comprising supplying data ripreser ting ihe himinance component of the image. !;4. A method £.s claimed :in claim 42, further comprising determining an 2iir.plitude value as the attribute of the image. .55. A method as claimed in claim 54, wherein the amplitude is detennined i:! the k»g2 of a value of the component of the image data. 36. A method as claimed in claim 42, further compnsmg: jjeneraling as a generated valu^; from the watenna::k data a positive or negative \;due; and adding; i;l::e generated value tc* the image data depending on the said cliiracttristic of i:he attribute. ;>7. A method as claimed in claim 56, further comprising is determining an cjnplitude valje as the attribute, and wherein the characteristic is the amplitude value bcnng gieater v\m a predetermined threshold. !)8. A method as claimed in claim 57, wherein the amplitude is determined ae the l:g2 ot n value of the component of the image data. 59- A method a;; claimed in claim 42, further comprising: receiving! signals containing said data representing an image in an encoded and c: mpressed foira on a signal medium; riiceivin^ an apparatus specific key; and responcjng to the apparatus specific key by deco-Jing and decompressing the ri::ceived signals to recover the data representing an image therefrom. 60. A me±od as claimed in claim 59, where:.n tlie signals are conveyed on tlii medium as data packets. 11. A meiiiod as c]aimed ir claim 59, wherein the apparatus specific key is r{:>:eived via a n"iedium different than the medium from which the encoded and compressed dy.1:a signals arc received. 62. A method as claimed in claim 59, wherein the signals are encoded Uiing DfiS encryption. 63. A method as claimed in claim 59, wherein the signals are compressed U'oing a losskiis compression technique. 64. i\ method as claimed in claim 63, wherein the lossless compression lechnicue ccmprise.^ run length encoding. 65. A method as claimed in claim 59, wherein the signals are compressed I.sing a lossy compression technique. 66. A method as claimed m claim 65, wherein the lossy c:ompression technique compiises block quantization. 67. A method as claimed in claim 59, further comprising converting the \/atennarkecl image data from data n^presencing the image in transformation space to Lata representing the image in pixel space. 6S. A. method as claimed in claim 67, further comprismg convening the {ixel data in\o a format suitable for display by a projector. 69. A method as claimed in claim 68, farther comprising displaymg the image ieprcsen';ed by the pixel data. 70. An apparatus for adding a watermiirk to a moving im^ge as it is ::ispla/'^d, the apparatus comprising: a wa;en:nark generator in which data representing a watermark is generated :ontaining f.rst information pertaining to the displayimg of the moving image and :ioteci:(;d by forwiurd error encoding and second info:nnation pertaining to the ::isplay-ng of the moving image and protected by scrambling; and a wat<:jr::aark applicator for applying the watermark data to image substantially all of moving depending on a characteristic> 71. Ari apparatus as claimed in claim 70, wherein the watermark generator k connected vj receive a; least one of location data and time data as said first ir. 'ormation pertaining to the displaying of the image. 72. A:' apparatus as claimeil in claim 70, wherein the watermark generator is; :onnected t:> receive at least one of program data identifying the moving image and flime data unique in identifying eacb frame of the moving image as said second inbrmation pertaining to the displaying of the image. 73. Ari apparatus as claimed in claim 70, wherein the watermark generator is connected to r:;::eive at least one of program data identifying the moving image and fnmt dc.ta uri^qu^ in identifying a predetermined number of frames of the moving ir:age as said second information pertainmg to the displaymg of the image. 74. An apparatuis as claimed in claim 72, wherein the watermark generator is connected to receive at least one of location data £.nd time data as said first inlormation pt^ttiiining to the displaying cf the image. 75. An apparatus as claimed in claim 70, wherein the watermark generator comprises an 'Siror correcting circuit for receiving said ilrst informadon pertaining to the: displaying cf the image and applying said forward error encoding. 76. An apparatus as claime '^8. An apparatus as claimed in claim 70, wherein the watermark applicator comprises an adder for adding the watemnarlc data to the image data. "'9. A vvarermarking system for applying data representing a moving image i: prodtce waten'narked image data which is output to a display device for display of I'e mo\in applied to substantially all data representing ':he moving image with the ej.cepticn of datt: having c. value below a detennincd level in order to minimize the introduction o: visible noise and other artifacts into the image by the wateanark. An apparatus for applying data representing a watermark to data representing an image substantially as herein above described with reference to the accompanying drawings. A method of applying data representing a watermark to data representing an image substantially as herein above described with reference to the accompanying drawings. |
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| Patent Number | 227955 | ||||||||||||
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| Indian Patent Application Number | 1988/CHENP/2003 | ||||||||||||
| PG Journal Number | 10/2009 | ||||||||||||
| Publication Date | 06-Mar-2009 | ||||||||||||
| Grant Date | 27-Jan-2009 | ||||||||||||
| Date of Filing | 12-Dec-2003 | ||||||||||||
| Name of Patentee | QUALCOMM INCORPORATED | ||||||||||||
| Applicant Address | 5775 MOREHOUSE DRIVE, SAN DIEGO, CALIFORNIA 92121-1714, | ||||||||||||
Inventors:
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| PCT International Classification Number | G06T1/00 | ||||||||||||
| PCT International Application Number | PCT/US02/18960 | ||||||||||||
| PCT International Filing date | 2002-06-13 | ||||||||||||
PCT Conventions:
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