Digital Imaging for Cultural Heritage Preservation: Analysis, Restoration, and Reconstruction of Ancient Artworks (Digital Imaging and Computer Vision)

521 Pages·2011·12.99 MB·English

by  Filippo Stanco

ELECTRICAL ENGINEERING
Digital Imaging for Cultural
Heritage Preservation
Analysis, Restoration, and Reconstruction of Ancient Artworks
As scientists collaborate with historians and archaeologists to examine, preserve, and restore great works of art and
other valuable historic artifacts, they are pioneering an uncharted interdisciplinary field. Effective collaboration requires
a novel common language to ensure a successful interface between information technology professionals and experts
in the humanities.

Driven by this urgent need for communication, Digital Imaging for Cultural Heritage Preservation: Analysis,
Restoration, and Reconstruction of Ancient Artworks bridges the informational gap between the various
professional communities that must work together. As digital imaging becomes more cost-effective and easier to use,
this book makes it easier to implement and share new devices and techniques, many of which are still considered
experimental. Presenting developments in a way that can be understood by all involved, it addresses the most
prominent topics and applications of digital image processing, analysis, and computer graphics in the field of cultural
heritage preservation.
T O P I C S I N C L U D E
• Application of computer graphics and 3D • Use of spectral imaging and reproduction
modeling to restore artifacts, including books, • Digital reconstruction and mosaicing
photos, and videos • ARC 3D—a public online service that converts
• Digitization to measure, analyze, and provide 3D photos into 3D models
documentation of entire complex objects and • Analysis of classic works of art and the
large sites such as the Parthenon methods artists used to create them
• Reconstruction and visualization technologies • Discovery of patterns in eroded rock
to process sampled data • Copyright protection of digital images
Assuming basic prior knowledge of digital image processing and computer graphics fundamentals, each chapter
contains illustrations and figures that elucidate presented concepts in detail, as well as chapter summaries and a
bibliography for further reading. This collection of contributions from well-known experts encompasses key aspects of
the field and will help to propel these important techniques into the next century.
Filippo Stanco
K11154
Sebastiano Battiato
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Digital Imaging for Cultural
Heritage Preservation
Analysis, Restoration, and Reconstruction of Ancient Artworks
Digital Imaging and Computer Vision Series
Series Editor
Rastislav Lukac
Foveon, Inc./Sigma Corporation
San Jose, California, U.S.A.

Computational Photography: Methods and Applications, edited by Rastislav Lukac
Super-Resolution Imaging, edited by Peyman Milanfar
Digital Imaging for Cultural Heritage Preservation: Analysis, Restoration, and
Reconstruction of Ancient Artworks, by Filippo Stanco, Sebastiano Battiato, and Giovanni Gallo
Visual Cryptography and Secret Image Sharing by Stelvio Cimato and Ching-Nung Yang
Image Processing and Analysis with Graphs: Theory and Practice by Olivier Lezoray
and Leo Grady
Perceptual Digital Imaging: Methods and Applications by Rastislav Lukac
Image Restoration: Fundamentals and Advances by Bahadir Kursat Gunturk and Xin Li
Digital Imaging for Cultural
Heritage Preservation
Analysis, Restoration, and Reconstruction of Ancient Artworks
Filippo Stanco
Sebastiano Battiato
Giovanni Gallo
Boca Raton London New York
CRC Press is an imprint of the
Taylor & Francis Group, an informa business
CRC Press
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Contents
Preface vii
Editors xi
Contributors xiii
1 ExperiencingthePast:ComputerGraphicsinArchaeology 1
FilippoStanco,DavideTanasi
2 UsingDigital3DModelsforStudyandRestorationofCulturalHeritageArtifacts 37
MatteoDellepiane,MarcoCallieri,MassimilianoCorsini,RobertoScopigno
3 ProcessingSampled3DData:ReconstructionandVisualizationTechnologies 69
MarcoCallieri,MatteoDellepiane,PaoloCignoni,RobertoScopigno
4 ARC3D:APublicWebServiceThatTurnsPhotosinto3DModels 101
DavidTingdahl,MaartenVergauwen,LucVanGool
5 Accurate and Detailed Image-Based 3D Documentation of Large Sites and Complex
Objects 127
FabioRemondino
6 Digitizing the Parthenon: Estimating Surface Reflectance under Measured Natural
Illumination 159
PaulDebevec,ChrisTchou,AndrewGardner,TimHawkins,CharisPoullis,JessiStumpfel,
AndrewJones,NathanielYun,PerEinarsson,ThereseLundgren,MarcosFajardo,Philippe
Martinez
7 ApplicationsofSpectralImagingandReproductiontoCulturalHeritage 183
SimoneBianco,AlessandroColombo,FrancescaGasparini,RaimondoSchettini,SilviaZuffi
8 DidEarlyRenaissancePaintersTraceOpticallyProjectedImages?TheConclusionof
IndependentScientists,ArtHistorians,andArtists 215
DavidG.Stork,JacobCollins,MarcoDuarte,YasuoFuruichi,DaveKale,Ashutosh
Kulkarni,M.DirkRobinson,SaraJ.Schechner,ChristopherW.Tyler,NicholasC.Williams
9 AComputerAnalysisoftheMirrorinHansMemling’sVirginandChildandMaarten
vanNieuwenhove 243
SilvioSavarese,DavidG.Stork,AndreyDelPozo,RonSpronk
10 VirtualRestorationofAntiqueBooksandPhotographs 263
FilippoStanco,AlfredoRestrepoPalacios,GiovanniRamponi
v
vi
11 AdvancesinAutomatedRestorationofArchivedVideo 299
AnilKokaram,FrancoisPitie,DavidCorrigan,DomenicoVitulano,VittoriaBruni,
AndrewCrawford
12 ComputationalAnalysisofArchaeologicalCeramicVesselsandTheirFragments 323
AndrewR.Willis
13 DigitalReconstructionandMosaicingofCulturalArtifacts 353
EfthymiaTsamoura,NikosNikolaidis,IoannisPitas
14 AnalysisofAncientMosaicImagesforDedicatedApplications 385
LamiaBenyoussef,Ste´phaneDerrode
15 DigitalReproductionofAncientMosaics 409
SebastianoBattiato,GiovanniGallo,GiovanniPuglisi,GianpieroDiBlasi
16 PatternDiscoveryfromErodedRockArt 429
YangCai
17 CopyrightProtectionofDigitalImagesofCulturalHeritage 451
VitoCappellini,RobertoCaldelli,AndreaDelMastio,FrancescaUccheddu
Index 483
Preface
Paintings, frescoes, antique photographic prints, incunabula, old books, handwritten documents,
sculptures,ceramicfragments,andotherancientmanufactsconstitutetheelementsofanextremely
valuable and immense historical patrimony. The digitalization of these treasures opens up the
possibilityofusingimageprocessingandanalysisandcomputergraphicstechniquestopreservethis
heritageforfuturegenerationsandtoaugmentitwithaccesoryinformationorwithnewpossibilities
for its enjoyment and use. Digital imaging solutions can be used to generate virtually restored
versionsoftheoriginalartworkstobepresentedinonlinemuseumsand/orforfurtherdevelopment
ofhistoricalstudies;applicationofvariousfeatureextractionandimagedataanalysistechniquesare
usefulinaddressingproblemsofauthorshipandartworkstylecategorizationinthehistoryofthearts;
three-dimensionalreconstructionofancientartworksorentirearcheologicalsitesallowsthecreation
ofmultidimensionalmodelsthatincorporateinformationcomingfromexcavations,archaeological
know-how,andheterogeneoushistoricalsources.
Pioneerworksinthisareahavesprungupfromtheclose,buttoooftenoccasional,cooperation
ofscientistswithhistoriansandarchaeologists.Casestudiesinthesekindsofinterdisciplinaryworks
arenowabundant,yetthedifferentworldsofinformationtechnologyandartandhistoryhavenot
builtarobustcommonlanguage.Thisbookwishestorespondtothegrowingdemandofthisareato
bridgetheexistinggapbetweenthesedifferentscientificcommunities.Theurgencyofprovidinga
commonground,wheretechnologymaymeethumanities,comesfromtheforthcominggenerationof
imagingdevicesthatwillprovidebetterperformanceswithlowercosts,allowingthewideapplication
of techniques nowadays considered experimental. This book comes as one of a few dedicated
monographsdealingwithdigitalimagingmethodsforculturalheritagepreservation.Itisacollection
ofcontributionswhichcoverthemostprominenttopicsandapplicationsofdigitalimageprocessing,
analysis, and computer graphics in the field of cultural heritage preservation. In this contributed
volume,well-knownexpertspresentacollectionofrecentresultscoveringawiderangeoftopics
andrelatedapplicationssuchasdigitization,indexationofvisualdatabases,automaticreassembly
of ceramic fragments, restoration and analysis of the digital images of original artworks, digital
archaeologyusinglaserscanning,photogrammetryand3Dfrom2Dphotoapproaches,computer
graphics by means of simulation for ancient mosaics reproduction, and copyright protection of
artworkimagesusingdigitalwatermarking.
Thebooktriestocoverthemostimportantresearchandapplicationdirectionsintheareaof
digitalimaging-drivenculturalheritagepreservation;hence,itcanconstituteaninvaluablereference
onthesubjectforbothscholarsandpractitionersformanyyearstocome.
This text is aimed at graduate students and advanced undergraduates, as well as researchers
andpractitioners,comingfrombothindustryandacademia.Itassumesonlysomepriorknowledge
ofdigitalimageprocessingandcomputergraphicsfundamentals.Eachchapterprovidesthefun-
damentalsforthetopicsunderconsiderationandthedetaileddescriptionoftherelevantmethods
appliedinconcreteapplication.Casestudiesarealsoprovidedtodemonstratetheeffectivenessof
thesurveyedtechniques.Tomakethematerialmoreaccessible,eachchapterhasitsowntableof
contents,drawings,andphotographs,whichwillelucidatethepresentedconceptsindetail,chapter
summary,andbibliographyforfurtherreading.
Thebookopenswithtwocontributions(Chapters1,2)thatdiscussandreviewhowitispossible
withpresentdaytechnologiestorealizedigitalprojectsthatintegratethecollecteddatawithvirtual
vii
viii
reconstructions,takingintoaccountthespecialists’hypotheses.Bothchaptersillustrate,withplenty
ofexamplesofdifferentcomplexitiesandscales,howdifferentexpertiseconvergeintoanewwayof
thinking,presenting,archiving,culturalheritagesites,artifacts,andknowledge.
Acquisition and processing of 3D data are at the core of this new field of study. In order to
supportthewidespreaddiffusionandacceptanceofthesetechnologiesakeyfactoristheavailability
ofsoftwaretools.Chapter3islargelydedicatedtoreviewingthelaserscanningtechniquesavailable
andpresentingpropersoftwaretoolstomanage3Ddata.Tocompletetheoverviewofthe3D-data
acquisitionmethodologiesavailable,Chapter4illustratesstate-of-the-arttechniquesforimage-based
3D-data acquisitions, and demonstrates how this approach can be effectively and economically
adoptedasanalternativetolaserscanning.
Chapter 5 offers a methodological review of the steps that have to be performed in order to
obtainasuccessfulintegrationofinformationcomingfromarchivalsources,3Dscanning,aerial
photography,andotherimage-basedtechniquestodocumentawholehistoricalsite.Tobeaccepted
by the general public, images and animations must satisfy high aesthetic standards. The chapter
shows how it is possible to make use of advanced computer graphics techniques to enhance the
experienceofamonumentorartifact.Chapter6illustrateshowstartingwith3Ddataandaccurate
photometricmeasurements,itispossibletorecreateorsynthesizeatmosphericalandlightconditions
aroundtheParthenon,offeringtotheobserveraperceptiveexperiencethatwouldbeimpossiblewith
atraditionalvisittothesite.
Colors,indeed,areacriticalingredientinanydigitalizationprojectofculturalheritage.Multispec-
tralanalysisandmultispectralsynthesisarethemostadvancedapproachesingatheringcolorimetric
informationfromrealityandareessentialforafaithfulreproduction.Maturecomputationalmethods
are now available to support these operations, and Chapter 7 offers a complete review of them.
Computationalmethodsareaddressingnotonlytheissuesofpreservation,restoration,andpresen-
tationofartifacts;theyofferpowerfultoolstoinvestigateandconfutehistoricalhypothesesabout
art.Examplesofhowcomputerexperimentsandanalysismayhelptoassessordisproveideasin
arthistory,whenpairedwithmoretraditionalhistoricalcompetenceanddocumentalevidence,are
reportedinChapters8and9.
Theapplicationofcomputationalmethodstoculturalheritageisnotatallrestrictedto3D-data
collectionandanalysis.Severalissuesrelativetogenuinelybi-dimensionalartifacts,likebooksand
flatdocuments,ormorerecentlyarchivedvideo,havereceivedconsiderableattention.Algorithms
forautomaticrestorationofthisclassofartifactsarepresentedinChapters10and11.
Restoringartifactsfromtheirfragmentedremainsisoneofthemostchallengingtasksofarche-
ologists. Fragment sets are frequently too large to be processed in an efficient way by a human
expert.Alternativehypothesesabouttheiroriginallayouthavetobeexploredandtested,and,sadly,
fragments are rarely sufficient for a complete reconstruction of whole objects like, for example,
vessels.Asdigitalizationismademoreefficient,thepracticeofvirtualrestorationfromthe3Ddata
hasbeenthesubjectofmanypioneeringexperiments.Thechallengeofreassemblingavasefromthe
digitalshapesofitsfragmentsrequiresasoundorchestrationofgeometricdataprocessingandof
patternrecognition.Chapter12reportsonanupdatedanddetaileddescriptionofthestate-of-the-art
solutions available for this problem for the case of vessels and ceramics. Chapter 13 reports on
similareffortsrelativetootherfragmentedartifactslikefrescoes.
Specialtechniquesarerequiredinthecaseofmosaics.Theirdigitalizationforarchivalaswell
asforreconstructivepurposeshastotakeintoaccountthespecialstructureofthisartisticmedium.
Chapter14isdevotedtothepresentationofsomecasestudiesindigitalizingandvirtualrestoringof
mosaics.Thestate-of-the-arttechniquesofcomputer-generatedmosaicscomparedtomoretraditional
photosandpaintings,awell-investigatedprobleminnon-photorealisticcomputergraphicsrenderings,
iscoveredinChapter15.
Anotherinterestingcasestudyrelatedtorockgraffitirestorationandenhancementisreportedin
ix
Chapter16.Finally,Chapter17reviewsthewatermarkingsofdigitalimages,addressingthecrucial
problemsofcopyrightprotectionandcontrolleddistributionofauthoredmaterial.
FilippoStanco,SebastianoBattiato,GiovanniGallo