Painng: School of Athens - The Index · Painng: School of Athens, Raphael, 1510‐11, Plato and...
Transcript of Painng: School of Athens - The Index · Painng: School of Athens, Raphael, 1510‐11, Plato and...
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Pain%ng:SchoolofAthens,Raphael,1510‐11,PlatoandAristotlecentralfigures.
Itisclearthatscholarshipmethodologyhaschangedovertheages.ItshouldcomeasliAlesurprisethatinthisageoftechnologicaladvancesthatthenewgenera%onislookingtowardon‐linedigitaltoolstosupportandexpandtheirscholarship.AtNYUithasbecomeapparentthatthereisanincreasingrolefordigitalmigra%onofanalogmaterial(books,archivalmaterial,andmul%media)toaccessibledigitalformats.Aseduca%onbecomeslessaboutloca%ondigitallibrariesbecomeawayofsharingaknowledgebasewiththenextgenera%onofscholars.
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Veracity,context,andcomprehensivenessmaAerastheyalwayshaveinscholarship.Thetruth,thatisthelookandfeeloftheoriginal,needstobeguardedduetotheflexibilityofdigitalfiles.Alsoofconcernisthelongevityofdigitalfiles.Newdigitalsurrogatesmustbemadetowithstandthetestof%mesothataccesstothematerialcanbeongoing.Microfilmlasts500yearsifcorrectlymade.Adigitalfileneedstobecreatedtobesttechnicalbenchmarksandtointerna%onallyunderstoodstandardssothatittoocanlast.Standalonewebsitesareunlikelytolastlongandwillprovideonlytemporaryaccess.Createongoingaccessadigitalprojectneedstobecarefullyconsidered.
Ins%tu%onshavetodothebestthattheycanaboutsavingdigitalfilesthatwerecreatedbeforedigitalstandardswerefirmlyinplace.Insomecasestheselegacyfileswillneedtobenormalizedtocurrentstandardssothattheycanbepreserved.
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Justasyoucandriveacarwithoutunderstandingthemechanicsofaninternalcombus%onengine,youcanalsopar%cipateinguidingdigitalprojectspar%cularlyintermsofcuratorship,withoutknowinghowtocreateeachpartofadigitallibrary.Specialistswillbeneededtocompleteanydigitalproject.
Selec%ngthecontenttosaveisen%relywithintherealmofthesubjectspecialist.Howtosavethatmaterialneedstobeguidedbydigitallibrarytechnicalservicesandconformtostandards.Tocreateonlinecollec%onsacleardigitalcollec%onpolicymustexist.Tocon%nuetoaccessonlinecollec%onsanumberofdifferentkindsofmetadatawillbeneededincludingcleardiscovermechanisms,descrip%vemetadataandtechnicallywellformedfiles.
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Accessprojects,whileeasilylaunchedareunlikelytopersist.Whateveraccessiscreated,eitherviaFlickr,afindingaid,oraAachingtoanonlinecatalog,theremustbeanunderlyingpreserva%onfilethatisheldinarepositorywithsufficientmetadatafordiscoveryoverthelongterm.
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Thefollowingfindadiscussionaboutbasiccharacteris%csofimagefilesthatarecreatedforpreserva%on.Conserva%on,thefirstconcernforrarephysicalmaterialisparamount.Digi%za%onshouldnotdamagetheoriginalar%fact.Onlyonedigi%za%onofrarematerialsshouldbeplannedasawayofconservingtheoriginalforthefuture.Goodtechnicalcapturetakesnomore%methatpoorlowresolu%oncapture.Truepreserva%onimagingwillrequiregoodequipmentandsignificantplanningbutcanbeextremelyefficientoncesetupgiventhenewgenera%onofequipment.
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Accessed8/3/2012,hAp://brb.sdsc.edu/,fromSustainableEconomicsforaDigitalPlanet:EnsuringLong‐TermAccesstoDigitalInforma<on,pg19,finalreportoftheBlueRibbonTaskForceonSustainableDigitalPreserva%onandAccess.
Itisimportanttorememberthatdigitalfileswilllivebeyondtheiroriginaldigi%za%onneed(forexampleforcoursework)andcon%nuetobeusedbyscholarsindifferentwaysover%me.Sincethoseusescannotbepredicteddigi%za%onneedstobedonetoincludefutureneeds.Highresolu%onimageswithcorrectcolorinforma%onabouttheoriginalwillbekeytothisongoinguse.Validfilesthatcancon%nuetobeusedover%mearerequiredaswell.
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Itisespeciallyimportanttothescholarthatthedigitalcapturebeastruthfultotheoriginalaspossible.Thereshouldbenodigitalfixingofrips,cleanupofstains,enhancingtextorcolor.Sincescholarswillbeusingthismaterialtostudymanydifferentaspectsofthematerial,forexamplefadingofamanuscript,itisimportantnottousedigitaltoolstomanipulatethedigitalimage.
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AtNYULibrariesanumberofourmaterialsarear%stmade.Ofenthecreatorhasmanipulatedcolororotheraspectsoftheoriginal.Themigra%onspecialistwillrespecttheinten%onsofthear%st/creator.
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Fullcoloristhemostdesirabletechnicalspecifica%onforresearchers.Fullcolorfilesmaintainthelookandfeeloftheoriginalcontentandsubstrate(inthiscasepaper)andwillallowresearchestousetheseimagesasdigitalsurrogatesfortheoriginalmaterialsinmanycases.Grayscale,thoughfarlessusefulhasbeenusedbysomeforpreservinglegibilityofthecontent.Bi‐tonalcaptureisnearlyuselessandofenverydifficulttoread.
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hAp://afghanistandl.nyu.edu/
Thissiteisanexampleofapreserva%onprojectwithanaccesscomponent.Pleasenotetheamountofmetadatathattravelswiththeindividualbooksaswellasthepermanentcita%onforscholarlypublica%on.
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hAp://dlib.nyu.edu/rosie/
Thissite,similarly,isapreserva%onprojectwithanaccess“frontend”.
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Agreatdealofmetadataisneededtoiden%fyandunderstanddigitalprojects.Descrip%vemetadataisthedomainofthesubjectspecialist/cataloger.Inthissessionotherclassesofmetadatawillbediscussed,thoughtechnicalmetadatawillbeexploredmoredeeply.Expertsinmetadataissuesareneededtobuildatruedigitallibrary.Somemetadatawilllikelybeneededeveninaccessprojects.
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Followingfindabriefoutlineofbasicinforma%onneededtohavetodiscussdigitalimagingwithyourdigitallibraryorvendor.Aswithalltoolsgoodimagingcanonlybedonewithgoodequipment.
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Adigitalpictureisnotaphotograph.Itisbinaryinforma%onthatisinterpretedbyagraphicaluserinterface(GUI)thatisavailableonyourcomputer.WithouttheGUIdigitalphotographswouldbeunreadable.Thepixelisthebasicunitofdigitalimaginganditisrepresentedbyonecoloronly.
Alldigitalimagesare,attheircore,binaryinforma%on.
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Othercommonformatssuchasjpegs,pngs,jpeg2000arenotacceptableforpreserva%onworkastheyarelossy.Lossyfilescontaincompressionthatchangesthepixelswitheachsave.Followingseeanexampleofjpegcompression.
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Lossycompressiondamagesafileirreparably.Savingafileoverandoverwillexacerbatethis.
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Exampleofjpegcompressionerrors.
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Apar%cularlytrickypartofdigitalimagesistheirrela%onshiptothecolorofthesourceobject.Acolorspecialistshouldbeconsultedtomakesurethatyourequipmentischaracterizedandcalibratedandthatanappropriatecolorspaceisembeddeddirectlyintothedigitalimage.AtNYULibrariesweembedallimageswiththeinterna%onalcolorspaceCIERGBwhichisastandardheldbytheCommissionInterna%onaledeI’Éclairage.AdobeRGBisanotherofenusedcolorspaceforarchivalwork.Aboveisanexampleofonegenera%onoflossfromanunmanagedcolorfile.
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Badcolormanagementwillobscurethecoloroftheoriginalmakingitmuchlessusefulforresearchers.
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Colormanagementisascience.Thereisimportantmathema%calmappingthathappensindigitalimagesthatmustbemaintained.
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Mostreflec%vematerialcanbeimagedat400or600pixelsperinch.Moredetailedoriginalssuchasslides,glassnega%ves,transparenciesandotherswillneedamuchhigherresolu%on(ofenupto4000pixelsperinch)tocaptureallofthedetailfromanoriginalanalogsource.
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600ppiversus72ppi
Therearesomeotherimportanttechnicalcharacteris%cstoconsider.Imagingspecialistswillbeabletodiscussthesecharacteris%cswithyou.PleaseknowthatcleaningpicturesupinimagingsofwaresuchasAbodePhotoshopaferthefactresultsinbadlydamagedfiles.Correctfilesneedtobemadeatthe%meofcapture.
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Thisinforma%oniscreatedbythepeoplewhounderstandthematerialthebest,thesubjectspecialistorcataloger.
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Thistypeofmetadataisgenerallycreatedbydigitallibrariesorvendorswhoaremigra%nganalogmaterial(books,documents,mul%media)todigitalfiles.
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Digitalobjectstonothavetheintui%vestructuringofthesourcematerial.Mul%‐volumesets,foldoutpages,inserts,materialsrelatedtomul%media,etc.mustallbestructuredsothatthedigi%zedobjectcanbeunderstoodclearlybyresearchers.
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Thesetypesofspecializedmetadataarebesthandledbyexperts.Rightsmetadatahelpdigitallibrariescontrolitemsthathavenotclearedcopyright.
TopreservedigitalfilestheyneedtobeheldinanIT(Informa%onTechnology)structurethatpreservesthefilesandtheinforma%onaboutthefiles.Thisisaverycomplexfield.Followingfindanoverviewofinforma%onaboutrepositoryneeds.
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Valida%onistheprocessofevalua%ngadigitalobjecttodeterminewhetheritmeetsthestandardthatitpurportstomeet.Forexampleascannercanmakeanimagefilesuchas“object.%f”.ThisfilemayopeninAdobePhotoshopwhichisbuilttoopenanythingitcan,validornot.Thefilemayhoweverbefundamentallyflawedoroutofstandard.Over%mesuchinvalidfileswillbecomeillegible.jHove,hAp://hul.harvard.edu/jhove/,createdbyHarvardUniversityLibraries,willvalidateanimagefileandinformyouthatyourfileis“well‐formedandvalid”.Thisisacri%calstepincrea%ngpreserva%onimages.
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NYULibrariescurrentlyusesSHA‐256checksums.RunningchecksumsinaccordancewithgoodITprincipleswillguaranteethatyourfileshavenotchangedover%me.
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Fromthelongviewweneedtorememberthatpreserva%onisaboutsavingnotonlytheinforma%onobject,butalsoallthatsupportsit.Thisincludesacomplexhierarchyofinforma%onthathastobepreservedtoallowthedigitalfiletobeperceivabletotheresearcher.Toseetheimageofadigi%zedpagethescreenimagehastobecomprehended.Behindthatlieslayersofgraphicalinterfaces,metadatainstruc%ons,binaryinforma%onetc.Allhavetobepreservedandmanagedsothattheendresultishumanreadable.
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hAp://www.oclc.org/research/publica%ons/archive/2000/lavoie/
Apreserva%onrepositoryismuchmorethanabackedupcomputer.
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Thankyou.
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