Stephan Makowski Seal Digitisation with Reflectance Transformation Imaging (RTI) Making Sigillographic Material Accessible to Researchers – Digitising, Catalogues, Editions of Seals 13 October 2016, Provincial Archives, Opava – branch Olomouc

1. Seal Digitisation with
Reflectance Transformation Imaging (RTI)
Cologne Center for eHumanities | Stephan Makowski | 13.10.2016

2. Cologne Center for eHumanities | Stephan Makowski | 13.10.2016
Agenda
 Introduction RTI
 Technical Design
 Examples
 Byzantine Seals
 Other techniques (3D)
 Archival relevance
 Beyond Digitisation

3. Cologne Center for eHumanities | Stephan Makowski | 13.10.2016
 Introduction RTI
 Technical Design
 Examples
 Byzantine Seals
 Other techniques (3D)
 Archival relevance
 Beyond Digitisation

4. Cologne Center for eHumanities | Stephan Makowski | 13.10.2016
 Introduction RTI
 Technical Design
 Examples
 Byzantine Seals
 Other techniques (3D)
 Archival relevance
 Beyond Digitisation

5. Cologne Center for eHumanities | Stephan Makowski | 13.10.2016
Introduction
„Reflectance Transformation Imaging“ (RTI)
 Origins from HP Labs (2001)
 Technique based on „Polynomial Texture Mapping (PTM)“
 Currently developed by „Cultural Heritage Imaging“

6. Cologne Center for eHumanities | Stephan Makowski | 13.10.2016
Introduction
„Reflectance Transformation Imaging“ (RTI)
 Advantages:
 “H-RTI is a non-invasive and non-contact recording
method, and therefore protects the heritage
resource being recorded.”
 Cost effective
 transportable
Source: Sarah M. Duffy: Multi-light Imaging for Heritage
Applications, English Heritage, 2013, p.3.

7. Cologne Center for eHumanities | Stephan Makowski | 13.10.2016
Introduction
„Reflectance Transformation Imaging“ (RTI)
 Disadvantages:
– Quality relies on the captured images
– Max. size 2m Ødiameter
– Gives just information about surface; not underlying
materials
Source: Sarah M. Duffy: Multi-light Imaging for Heritage
Applications, English Heritage, 2013, p.3.

8. Cologne Center for eHumanities | Stephan Makowski | 13.10.2016
 Introduction RTI
 Technical Design
 Examples
 Byzantine Seals
 Other techniques (3D)
 Archival relevance
 Beyond Digitisation

9. Cologne Center for eHumanities | Stephan Makowski | 13.10.2016
 Introduction RTI
 Technical Design
 Examples
 Byzantine Seals
 Other techniques (3D)
 Archival relevance
 Beyond Digitisation

10. Cologne Center for eHumanities | Stephan Makowski | 13.10.2016
Source: Sarah M. Duffy: Multi-light Imaging for Heritage
Applications, English Heritage, 2013, p.4.

11. Cologne Center for eHumanities | Stephan Makowski | 13.10.2016
Source: Sarah M. Duffy: Multi-light Imaging for Heritage
Applications, English Heritage, 2013, p.6.
1) Camera
2) Souce of Light
3) Archival Material, etc
4) „Light Identifier“

12. Cologne Center for eHumanities | Stephan Makowski | 13.10.2016
Source: Sarah M. Duffy: Multi-light Imaging for Heritage
Applications, English Heritage, 2013, p.11.
Lightangle

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To Do
1)Get / Build Equipment
2)Make pictures (jpeg) from any desired
lightangles
3)Make RTI File (ptm) with RTI Builder (free
and online available)
4)View with RTI Viewer (Software or
webplugin; free and online availale)

14. Cologne Center for eHumanities | Stephan Makowski | 13.10.2016
 Introduction RTI
 Technical Design
 Examples
 Byzantine Seals
 Other techniques (3D)
 Archival relevance
 Beyond Digitisation

15. Cologne Center for eHumanities | Stephan Makowski | 13.10.2016
 Introduction RTI
 Technical Design
 Examples
 Byzantine Seals
 Other techniques (3D)
 Archival relevance
 Beyond Digitisation

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Souce: http://culturalheritageimaging.org/Technologies/RTI/

21. Cologne Center for eHumanities | Stephan Makowski | 13.10.2016
Souce: http://culturalheritageimaging.org/Technologies/RTI/

22. Cologne Center for eHumanities | Stephan Makowski | 13.10.2016
 Introduction RTI
 Technical Design
 Examples
 Byzantine Seals
 Other techniques (3D)
 Archival relevance
 Beyond Digitisation

23. Cologne Center for eHumanities | Stephan Makowski | 13.10.2016
 Introduction RTI
 Technical Design
 Examples
 Byzantine Seals
 Other techniques (3D)
 Archival relevance
 Beyond Digitisation

24. Cologne Center for eHumanities | Stephan Makowski | 13.10.2016
Other techniques
• 3D-Method:
 Advantage:
 reproduce seals with 3D-modells
 interactive modell (turnable)
 Disadvantage:
 Slower then RTI
 More expensive

25. Cologne Center for eHumanities | Stephan Makowski | 13.10.2016
Souce: © 2016, Steadpro

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https://sketchfab.com/models/5e96a37616854991873c0a453527e743
https://sketchfab.com/models/eabf12338dba42aea69b388eae80e305
Examples

27. Cologne Center for eHumanities | Stephan Makowski | 13.10.2016
 Introduction RTI
 Technical Design
 Examples
 Byzantine Seals
 Other techniques (3D)
 Archival relevance
 Beyond Digitisation

28. Cologne Center for eHumanities | Stephan Makowski | 13.10.2016
 Introduction RTI
 Technical Design
 Examples
 Byzantine Seals
 Other techniques (3D)
 Archival relevance
 Beyond Digitisation

29. Cologne Center for eHumanities | Stephan Makowski | 13.10.2016
Archival Relevance
 Preservation:
 Seals don‘t have to be shown to the
audience
 Making RTI-images doesn‘t harm the
seals (light, heat, etc.)
 Audience:
 Attract scientifics and others to work
with online available images

30. Cologne Center for eHumanities | Stephan Makowski | 13.10.2016
 Introduction RTI
 Technical Design
 Examples
 Byzantine Seals
 Other techniques (3D)
 Archival relevance
 Beyond Digitisation

31. Cologne Center for eHumanities | Stephan Makowski | 13.10.2016
 Introduction RTI
 Technical Design
 Examples
 Byzantine Seals
 Other techniques (3D)
 Archival relevance
 Beyond Digitisation

32. Cologne Center for eHumanities | Stephan Makowski | 13.10.2016
Beyond Digitisation
 Encoding of Seals in Digital Humanities
 Description of Seals
 Metadata
 Usable and Searchable for others!
 “SigiDoc” (derived from EpiDoc)

33. Cologne Center for eHumanities | Stephan Makowski | 13.10.2016
Thank you very much!
Stephan Makowski, MA
Stephan.makowski@uni-koeln.de
Phone: +49-221-470-4052
http://www.cceh.uni-koeln.de
Links:
http://culturalheritageimaging.org/Technologies/RTI/
Software:
http://culturalheritageimaging.org/What_We_Offer/Do
wnloads/