digital video quality vision models and metrics

... Stefan. Digital video quality : vision models and metrics / Stefan Winkler. p. cm. Includes bibliographical references and index. ISBN 0-470-02404-6 1. Digital video. 2. Image processing Digital ... is necessary to build computational models of the HVS and integrate them in tools for perceptual quality assessment. Digital Video Quality - Vision Models and Metrics Stefan Winkler # 2005 John ... 1/f. 30 VISION Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com Digital Video Quality Vision Models and...

Ngày tải lên: 27/06/2014, 14:20

... to hybrid standards such as D2-MAC (analog video, digital sound) and delayed the introduction of 100 % digital video. However, the very rapid progress made in compression techniques and IC technology ... algorithms and modulation schemes, which are explained in Chapters 6 and 7. We will now examine the principles and various steps of video and audio compression which allow these bit-rates (and in ... standards for broadcasting digital pictures to the consumer, and the solutions chosen for the European DVB system (Digital Video Broadcasting) based on the international MPEG-2 compression standard. The...

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Ngày tải lên: 14/08/2014, 12:21

Ngày tải lên: 14/08/2014, 12:21

Ngày tải lên: 14/08/2014, 12:21

... LLC Sondhi, M.M. & Schroeter, J. “Speech Production Models and Their Digital Implementations” Digital Signal Processing Handbook Ed. Vijay K. Madisetti and Douglas B. Williams Boca Raton: CRC Press ... NasalCoupling Nasalsoundsareproducedbyopeningthevelumandtherebycouplingthenasalcavitytothevocal tract.Innasalconsonants,thevocaltractitselfisclosedatsomepointbetweenthevelumandthe lips,andalltheairflowisdivertedintothenostrils.Innasalvowelsthevocaltractremainsopen. (NasalvowelsarecommoninFrenchandseveralotherlanguages.Theyarenotnominallyphonemes ofEnglish.However,somenasalizationofvowelscommonlyoccursinEnglishspeech.) Intermsofchainmatrices,thenasalcouplingcanbehandledwithouttoomuchadditionaleffort. Asfarasitsacousticalpropertiesareconcerned,thenasalcavitycanbetreatedexactlylikethevocal tract,withtheaddedsimplificationthatitsshapemayberegardedasfixed.Thecommonassumption isthatthenostrilsaresymmetric,inwhichcasethecross-sectionalareasofthetwonostrilscanbe addedandthenosereplacedbyasingle,fixed,variable-areatube. Thedescriptionofthecomputationsiseasiertofollowwiththeaidoftheblockdiagramshown inFig.44.5.Fromaknowledgeoftheareafunctionsandlossesforthevocalandnasaltractsthree chainmatricesK gv ,K vt ,andK vn arefirstcomputed.Theserepresent,respectively,thematricesfrom glottistovelum,velumtotractclosure(orvelumtolips,incaseofanasalvowel),andvelumto nostrils. FromK vn withsomeassumedimpedanceterminationatthenostrils,theinputimpedanceof thenostrilsatthevelummaybecomputedasindicatedinEq.(44.16b).Similarly,K vt givesthe inputimpedanceatthevelum,ofthevocaltractlookingtowardthelips.Atthevelum,thesetwo impedancesarecombinedinparalleltogiveatotalimpedance,sayZ v .Withthisastermination,the velocitytovelocitytransferfunction,T gv ,fromglottistovelumcanbecomputedfromK gv asshown c  1999byCRCPressLLC FIGURE44.5:Chainmatricesforsynthesizingnasalsounds. inEq.(44.16b).Foragivenvolumevelocityattheglottis,U g ,thevolumevelocityatthevelumis U v =T gv U g ,andthepressureatthevelumisP v =Z v U v .OnceP v andU v areknown,thevolume velocityand/orpressureatthenostrilsandlipscanbecomputedbyinvertingthematricesK vn and K vt . 44.4 SourcesofExcitation Asmentionedearlier,speechsoundsmaybeclassifiedbytypeofexcitation:periodic,turbulent,or transient.Allofthesetypesofexcitationarecreatedbyconvertingthepotentialenergystoredinthe lungsduetoexcesspressureintosoundenergyintheaudiblefrequencyrangeof20Hzto20kHz. Thelungsofayoungadultmalemayhaveamaximumusablevolume(“vitalcapacity”)ofabout5 l.Whilereadingaloudthepressureinthelungsistypicallyintherangeof6to15cmofwater(6000 to15000Pa).Vocalcordvibrationscanbesustainedwithapressureaslowas.2cmofwater.Atthe otherextreme,apressureashighas195cmofwaterhasbeenrecordedforatrumpetplayer.Typical averageairflowfornormalspeechisabout0.1l/s.Itmaypeakashighas5l/sduringrapidinhalesin singing. Periodicexcitationoriginatesmainlyatthevibratingvocalfolds,turbulentexcitationoriginates primarilydownstreamofthenarrowestconstrictioninthevocaltract,andtransientexcitations occurwheneveracompleteclosureofthevocalpathwayissuddenlyreleased.Inthefollowing,we willexplorethesethreetypesofexcitationinsomedetail.Theinterestedreaderisreferredto[18] formoreinformation. 44.4.1 ... Synthesis Thevocaltractisapproximatedbyaconcatenationofabout20uniformsections.Thecross-sectional areasofthesesectionsiseitherspecifieddirectly,orcomputedfromaspecificationofarticulatory parametersasshowninFig.44.3.Thechainmatrixforeachsectioniscomputedatanadequate samplingrateinthefrequencydomaintoavoidtime-aliasingofthecorrespondingtimefunctions. (Computationofthechainmatricesrequiresaspecificationofthelossesalso.Severalmodelsexist whichassignthelossesintermsofthecross-sectionalarea[11,16]). Thechainmatricesfortheindividualsectionsarecombinedtoderivethematricesforvarious portionsofthetract,asappropriatefortheparticularspeechsoundbeingsynthesized.Forvoiced sounds,thematricesforthesectionsfromtheglottistothelipsaresequentiallymultipliedtogive thematrixfromtheglottistothelips.Fromthek 11 ,k 12 ,k 21 ,k 22 componentsofthismatrix,the transferfunction U out U in andtheinputimpedanceareobtainedasinEqs.(44.16a )and( 44.16b). KnowingtheradiationimpedanceZ R atthelipswecancomputethetransferfunctionforoutput pressure,H= U out U in Z R .TheinverseFFTofthetransferfunctionHandtheinputimpedanceZ in givethecorrespondingtimefunctionsh(n)andz in (n),respectively.Thesefunctionsarecomputed every20ms,andtheintermediatevaluesareobtainedbylinearinterpolation. Forthecurrenttimesamplinginstantn,thecurrentpressurep 1 (n)attheinputtothevocaltract isthencomputedbyconvolvingz in withthepastvaluesoftheglottalvolumevelocityu g .Withp 1 known,thepressuredifferenceP s −p 1 onthelefthandsideofEq.(44.22)isknown.Equation(44.18) isdiscretizedbyusingabackwarddifferenceforthetimederivative.Thus,anewvalueoftheglottal volumevelocityisderived.This,togetherwiththecurrentvaluesofthedisplacementsofthevocal folds,givesusnewvaluesforthedrivingforcesF 1 andF 2 forthecoupledoscillatorEqs.(44.24a) and( 44.24b).Thecoupledoscillatorequationsarealsodiscretizedbybackwarddifferencesfortime derivatives.Thus,thenewvaluesofthedrivingforcesgivenewvaluesforthedisplacementsofthe vocalfolds.Thenewvalueofvolumevelocityalsogivesanewvalueforp 1 ,andthecomputational cyclerepeats,togivesuccessivesamplesofp 1 ,u g ,andthevocalfolddisplacements. Theglottalvolumevelocityobtainedinthisway,isconvolvedwiththeimpulseresponseh(n)to producevoicedspeech. Ifthespeechsoundcallsforfrication,thechainmatrixofthetractisderivedastheproductoftwo matrices—fromtheglottistothenarrowestconstrictionandfromtheconstrictiontothelips,as discussedinthesectiononturbulentexcitation.Thisenablesustocomputethevolumevelocityat theconstriction,andthusintroduceanoisesourceonthebasisoftheReynoldsnumber. Finally,toproducenasalsounds,thechainmatrixforthenasaltractisalsocomputed,andthe outputatthenostrilscomputedasdiscussedinthesectiononchainmatrices.Ifthelipsareopen, theoutputfromthelipsisalsocomputedandaddedtotheoutputfromthenostrilstogivethetotal speechsignal.Detailsofthesynthesisproceduremaybefoundin[24]. References [1]Edwards,H.T.,AppliedPhonetics:TheSoundsofAmericanEnglish,SingularPublishing Group,SanDiego,1992,Chap.3. [2]Olive,J.P.,Greenwood,A.,andColeman,J., AcousticsofAmericanEnglishSpeech,Springer Verlag,NewYork,1993. [3]Fant,G., AcousticTheoryofSpeechProduction,MoutonBookCo.,Gravenhage,1960,Chap. 2.1,93-95. [4]Baer,T.,Gore,J.C.,Gracco,L.C.,andNye,P.W.,Analysisofvocaltractshapeanddimensions usingmagneticresonanceimaging:Vowels, J.Acoust.Soc.Am.,90(2),799-828,Aug1991. c  1999byCRCPressLLC 44 Speech Production Models and Their Digital...

Ngày tải lên: 22/01/2014, 12:20

... and Implications for Quality, David J. Ballard, Robert S. Hopkins III, and David Nicewander 43 4 Quality Improvement Systems, Theories, and Tools, Mike Stoecklein 63 Part II Organization and ... Strategy, and Tools provides a guide for quality improvement and a facilitator for dialog about quality. The chapters define quality in depth and put it into context for healthcare organizations and ... Improvement, the National Quality Forum, and the Agency for Healthcare Research and Quality has now clearly estab- lished the magnitude of the nation’s problems in healthcare quality and what needs to...

Ngày tải lên: 17/02/2014, 19:20

Ngày tải lên: 18/02/2014, 11:20

... with ROUGE/BE and Pyramid, DUC and TAC also asked human judges to score every candidate summary with regard to its content, readability, and overall re- sponsiveness. DUC and TAC defined linguistic quality ... be between 0 and 1. Math- ematically, TESLA takes as input the following: 1. The BNG of the model summary, X, and the BNG of the candidate summary, Y . The ith en- try in X is x i and has weight ... Computational Linguistics Combining Coherence Models and Machine Translation Evaluation Metrics for Summarization Evaluation Ziheng Lin † , Chang Liu ‡ , Hwee Tou Ng ‡ and Min-Yen Kan ‡ † SAP Research, SAP...

Ngày tải lên: 07/03/2014, 18:20

... camera area the video and audio signals are switched to the monitor and the guard sees and hears the activity in the scene and initiates a response. 1.4.2 Overt vs. Covert Video Most video installations ... computing power, solid-state and magnetic memory, digital processing, and wired and wireless video signal transmission (analog, digital over the Internet, etc.), the basic video system still requires ... analog /digital video mechanisms, and brackets are smaller in size and weight resulting in lower costs and providing more aesthetic installations. The small cameras and lenses satisfy covert video...

Ngày tải lên: 01/06/2014, 07:52

... parts to a Mini DV track: video, audio, subcode and ITI (Insert and Tracking Information). The video and audio are self-explanatory. The subcode holds timecode, date and time and track numbers. The ... second of DV video. 14 The Videomaker Guide to Digital Video and DVD Production Figure 3.1 4:1:1 Sampling—DV Encoding hardware samples each frame of video for luminance (brightness) and chrominance (color) ... Web videographer. Hitachi will soon introduce a DVD-RAM camcorder. This uses a removable DVD disc that stores ultra-high quality MPEG-2 video. Expect long recording times, high video quality and...

Ngày tải lên: 01/06/2014, 11:26

... local contrast enhancement algorithm for digital video cameras. EURASIP Journal on Image and Video Processing 2011 2011:6. Submit your manuscript to a journal and benefi t from: 7 Convenient online ... improve visual quality has gained increasing attention and becomes an active area in image and video processing researches [1,2]. This article addresses two common defects: LDR and poor contrast. Several ... contrast preservation) and Sigma 16, the proposed method with a = -1 (local contrast enhancement) and (g) Sigma 4, (h) Sigma 8, (i) Sigma 16. Tsai and Chou EURASIP Journal on Image and Video Processing...

Ngày tải lên: 20/06/2014, 22:20

... ranges from 40 to 80 for the mean of regional standard deviation and from 100 to 200 for the image mean. Tsai and Chou EURASIP Journal on Image and Video Processing 2011, 2011:6 http://jivp.eurasipjournals.com/content/2011/1/6 Page ... two parameters m min and m max set as (a) (m min , m max )= (100/255, 150/255), and (b) (m min , m max ) = (10/255, 250/255). Tsai and Chou EURASIP Journal on Image and Video Processing 2011, ... local contrast enhancement algorithm for digital video cameras. EURASIP Journal on Image and Video Processing 2011 2011:6. Submit your manuscript to a journal and benefi t from: 7 Convenient online...

Ngày tải lên: 21/06/2014, 00:20