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Illuminating the Herculaneum Papyri with New Digital Imaging Techniques
Dr. Kathryn E. Piquette Cologne Center for eHumanities, Universität zu Köln
Outline
• Theorising images
• Reflectance Transformation Imaging (RTI): What and why
• Herculaneum papyri
• Recovering writing from carbonised papyri: problems and possibilities
• Entangled relationships between writing and material ‘support’
• Future directions
• RTI: Increased reflexivity and rigour in the research process
!2
Theorising Cultural Heritage Images
• Documentation, illustration, preservation, unique perspectives, enhanced visualisation
• Move beyond notion of “images as resources”
• Situate image in reciprocal relationship:
!!
!!!
• Processes of visualising and seeing underpin empirical work, but often neglected (Melissa Terras 2006; Jon Wagner 2006)
• Critical awareness of image architecture (cf. Michael Shanks 2013)
• Creation, provision, consumption!3
• (Focus: artefacts and small-medium size surfaces)
Image
Information
Knowledge construction
Visualising & Seeing
Incised gneiss(?) vessel fragment, c.2800 BCE, Egypt, 1977.112.296, World Museum Liverpool (Piquette 2014,
in Dodson et al.)
Dr. Kathryn E. Piquette ([email protected])For analysis and downloadable RTI image file see Piquette 2014: https://www.academia.edu/4770946/Scribal_Practice_and_an_Early_Dynastic_Stone_Vessel_Inscription_Material_and_aesthetic_implications
Visual Perception, Environmental Conditions
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Light and Control • Fixity • Position • Angle • Intensity
Kat
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What is Reflectance Transformation Imaging (RTI)?
!7
Reflectance Transformation Imaging (RTI)
• Method of structured light photography
• Digital images taken of target object with camera in fixed position; illumination applied from different locations
• Multiple captures combined to produces interactive, relit record of surface
• Improved visualisation, archival record, preservation and conservation tool
• Legibility, physical structure • First algorithm for photo amalgamation developed by Tom Malzbender
et al. of HP labs in 2001: Polynomial Texture Mapping (PTM) Malzbender, T., Gelb, D. and Wolters, H. 2001. Polynomial Texture Maps. In Proceedings of the 28th Annual Conference on Computer Graphics and Interactive Techniques (SIGGRAPH 2001), 519–528.
Highlight Reflectance Transformation Imaging
• “H-RTI” • Fixed camera • Fixed target • Handheld light source • Reflective spheres • Measuring string • Optional computer
control • 36-48 exposures
Set-up in Ashmolean Museum, Oxford
Kat
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E. P
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RTI Capture Sequence
!9
RTI Fitting Process
x
RTIBuilder Version 2.0.2 (Mac, PC): http://culturalheritageimaging.org/
RTI Viewing
RTIViewer Version 1.1 (Mac, PC): http://culturalheritageimaging.org/
• Non-contact acquisition of data
• Clear representation of 3D shape
• Better discernment of surface detail than direct physical examination
• Visualisation through interactive viewing tools
• No data loss from shadows and specular highlights
• Higher resolution on the object surface than usually obtainable with 3D scanners
RTI Benefits
Happa J., Mudge, M., Debattista, K., Artusi, A., Gonçalves, A. and Chalmers, A. 2010. Illuminating the Past: State of the art. Virtual Reality 14(3): 155-182.
Bone comb from Nile Valley, World Museum, Liverpool, Piquette forthcoming
Kathryn E. Piquette
Cultural Heritage Applications
• Stone • e.g. rock art, inscriptions, lithics
• Mineral • Selenite curse tablet
• Metal • e.g. coins, implements, tablets • Magical curse on lead
• Wood • Wax on wooden tablet
• Clay • e.g. cuneiform tablets • Impressed sealing
• Skeletal & botanical remains • Textiles, parchment, paper, papyrus
!13
All above, Kathryn E. Piquette
Courtesy Trustees of the British Museum
Herculaneum Papyri• Vesuvius eruption 79 CE • Largest preserved library from ancient world
• c.1800 rolls • Epicurean philosophical treatises
http://www.bbc.co.uk/news/magazine-25106956
Carbonisation: Blessing & curse• Exposed to extreme heat but not consumed by fire,
charcoal-like appearance
• Preservative effect but reduces contrast between ink and papyrus, extremely fragile
!1.Herculaneum papyri: c.79 CE, c.1800 rolls 2. Petra papyri: 6th century CE, c.20 rolls
3. Egyptian Delta and Oxyrhynchus: Ptolemaic-Roman
Periods, c.300 documents
!15 http://www.bbc.co.uk/news/magazine-25106956 Kathryn E. Piquette
Unrolling the Papyri
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Kathryn E. Piquette
Kathryn E. Piquette
Methods for Writing* Recovery•Hand copying •Conventional photography •Multispectral imaging
• Infrared, visible, ultra violet • Infrared imaging: photography, reflectography, transmitted !
!17
http
://w
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* And other physical features
http://www.worldwidetelescope.org/Interact/Spectrum
Infrared photography: Pros and cons
• Vastly improved legibility but… • Light fixed, surface appears flattened • Holes vs. ink • Details obscured by self-shadowing • Difficult to discern layers • ‘Sottoposti', ‘sovrapposti’: reconstruction • Registration problems !18
Brigham Young University
Brigham Young University
Highlight Reflectance Transformation Imaging (H-RTI)
• Pilot tests
• February 2014: Visible H-RTI
• June 2014: Infrared H-RTI
• Cooperation between Universität zu Köln and the Biblioteca Nazionale di Napoli
!• Fixed camera
• Fixed target
• Handheld light source (IR LED)
• Reflective spheres
• Measuring string
• Computer control
• 48 exposures
UCLDH lens
Kathryn Piquette & H-RTI set-up in BNN, Naples
Photo: Gianluca del Mastro
P.Herc. 862, Cornice 1 Stitched
!20Brigham Young University
Infrared fixed light photograph, with “filter 7” (950 nm)
(IR photograph: Brigham Young University)
Infrared Reflectance Transformation Imaging (IR RTI), with 950nm filter
(RTI photograph: Kathryn E. Piquette)
Image Comparison: P.Herc. 862, Cr. 1, Pz. I
IR RTI Addresses Shortcomings of Previous Photography
• Increased contrast combined with clear representation of 3D shape
• Clear discernment of holes that can otherwise be confused with ink
• Distinguish layers with greater precision
• Count layers
• Discern sovrapposti, sottoposti
• Alleviate problem of self-shadowing
• Artificial enhancements
• Better understanding of written content in relation to physical structure
• More robust analysis and documentation of research process using RTIViewer annotation tools
!22
Kathryn E. Piquette
Brig
ham
You
ng U
nive
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y
RTI Tools for Supporting the Research Process
• Four aspects of work on the papyri
• Discovery, preservation, editing, interpretation
• Robust documentation
• Method of preservation
• Condition reporting/monitoring
• Systematic study
• Legibility
• Artefactuality
• Augments previous documentation methods
!23
Richard Janko
Both Kathryn E. Piquette
!24
• Process of seeing more systematic and rigorous • Bookmark viewing conditions + annotation • Reflexivity: Provokes new questions, raises new problems • Shareability of hypotheses, replicability of visual experience by
other researchers • High quality reproduction • Eventual citation of bookmarks in publication
Image: active, mediating, situated
• User interviews: benefit of emulating physical interaction with the artefact, 2D+ emphasises materiality, provokes multi-sensory engagement
RTIViewer:
Summing Up• RTI offers powerful visualisation tools for taking Herculaneum
papyri research forward (larger project now in planning stages) • Emulates physical interaction with the artefact • 2D+ emphasises materiality, provokes multi-sensory
engagement • Fosters critical making and use of images • Transparency and replicability of viewing experience &
conditions of interpretation
13 Both Kathryn E. Piquette
Acknowledgements
• Institut für Altertumskunde and Cologne Center for eHumanities, Universität zu Köln
• Academy of Sciences and Arts of Nordrhein-Westfalen in Duesseldorf
• KölnAlumni - Freunde und Förderer der Universität zu Köln e.V.
• Biblioteca Nazionale di Napoli
• Special thanks to Sofia Maresca, Gianluca Del Mastro, Michael McOskar, Richard Janko and BNN staff
• Lindsay MacDonald, Stuart Laidlaw, Eleni Kotoula and Antonino Cosentino
• UCL Centre for Digital Humanities
• UCL Institute of Archaeology
• Cultural Heritage Imaging (CHI): http://culturalheritageimaging.org/
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