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Thera Frescoes

Benedict J. Brown

Princeton University

Benedict J. Brown COS 598c — Thera Frescoes

GeographyThera is a Greek island. The modern name is Santorini.

http://www.boutrostours.com/images/map-greece.gif

Benedict J. Brown COS 598c — Thera Frescoes

History

I Aegean civilization: before “ancient Greece”I Minoan age: c. 2000 BC – c. 1400 BC

I Named for King Minos of CreteI Centered on CreteI Bronze-age civilizationI Overseas trade with Cyprus, Egypt, Aegean IslandsI Pre-Indo-European: not Greek, alphabet undecipheredI Cycladic islands had distinct culture, infulenced by Crete and

Eastern civilizationsI Eventually conquered by Mycaeneans

I Sources:I Encyclopedia Brittancia: “Aegean Civilizations”I http://www.ancientgreece.com/history/history.htmI http://en.wikipedia.org/wiki/History of Greece

Benedict J. Brown COS 598c — Thera Frescoes

Eruption

Thera exploded about 1650 B.C.

http://www.mmtaylor.net/Holiday2000/Legends/Atlantis.html

Benedict J. Brown COS 598c — Thera Frescoes

Eruption

Most of island and civilization destroyed

http://www.mmtaylor.net/Holiday2000/Legends/Atlantis.html

Benedict J. Brown COS 598c — Thera Frescoes

Eruption

Explosion was bigger than Mt. St. Helens or Krakatoa

http://www.mmtaylor.net/Holiday2000/Legends/Atlantis.html

Benedict J. Brown COS 598c — Thera Frescoes

Eruption

Source of Atlantis legend?

http://www.mmtaylor.net/Holiday2000/Legends/Atlantis.html

Benedict J. Brown COS 598c — Thera Frescoes

Akrotiri

I Major excavation at AkrotiriI Well preserved by ash, like PompeiiI No bodies =⇒ time to evacuate island

Thera Foundation Thera Foundation

Benedict J. Brown COS 598c — Thera Frescoes

Wall Paintings

I The most important finds are wall paintings

Saffron Gatherers - Thera Foundation

Benedict J. Brown COS 598c — Thera Frescoes

Wall Paintings

I The most important finds are wall paintings

Spirals - David Dobkin

Benedict J. Brown COS 598c — Thera Frescoes

Wall Paintings

I The most important finds are wall paintings

Thera Foundation

Benedict J. Brown COS 598c — Thera Frescoes

Wall Paintings

I Shattered by eruption and earthquakes

Spirals - David Dobkin

Benedict J. Brown COS 598c — Thera Frescoes

FrescoPainting on plaster:I Basically invented by Minoans, used by Romans,

rediscovered during Italian Renaissance(http://en.wikipedia.org/wiki/Fresco)

I Buon frescoI Pigment is applied to wet plasterI Highly durableI Pigment must be applied very quickly

I A seccoI Paint (pigment with binder) is applied to dry plasterI Much less durableI Useful for touching up after plaster has dried

I Thera wall paintings are mostly buon fresco, with some asecco elements

Benedict J. Brown COS 598c — Thera Frescoes

Fragment Matching

I Archaeologists match based on edge fits (3-D)I PainstakingI Requires lots of handling of piecesI What about erosion?

I Many things we could matchI 2-D and 3-D edge profileI thicknessI paintingI plaster color/discolorationI proximity of findsI user annotationsI some of these have been explored some

Benedict J. Brown COS 598c — Thera Frescoes

Painting TechniquesI Curves painted using stencils to allow fast painting on wet

plasterI Use curve fitting to identify stencils (Papaodysseus et al.)I Stencils are Ellipses, hyperbolae and linear spirals

Papaodysseus et al.

Benedict J. Brown COS 598c — Thera Frescoes

Existing Matching WorkI 2-D Edge profileI Line widthsI Curve extension

Papaodysseus et al.

Benedict J. Brown COS 598c — Thera Frescoes

Existing Matching WorkI 2-D Edge profileI Line widthsI Curve extension

Fragoulis et al.

Benedict J. Brown COS 598c — Thera Frescoes

Existing Matching WorkI 2-D Edge profileI Line widthsI Curve extension

Papaodysseus et al.

Benedict J. Brown COS 598c — Thera Frescoes

Other Tasks for ComputerI Archiving (annotated database)I Technical analysis (e.g. curve fitting)I Color restorationI Inpainting missing areasI Efficient distribution of work

David Dobkin

Benedict J. Brown COS 598c — Thera Frescoes

Scanning SetupI Assume frescoed face is flat, scan with flatbed scannerI Scan back with 3-D scanner for thickness and registrationI Scan sides with 3-D scanner for matching

Turntable

Flatbed Scanner

Fragment

Fragment3−D

Scanner

3−DScanner

Benedict J. Brown COS 598c — Thera Frescoes

3-D ScannerI Off-the-shelf, NextEngine scanner

Benedict J. Brown COS 598c — Thera Frescoes

3-D ScannerI Off-the-shelf, NextEngine scanner

Benedict J. Brown COS 598c — Thera Frescoes

User Experience

I Archaeologist scans piece, and simultaneously entersinformation into db

I Virtual worktable for matching piecesI Ability to annotate pieces graphicallyI Distributed, multi-user, matching environment

Benedict J. Brown COS 598c — Thera Frescoes