Dispositive analysis and Tesserarum Sisciae Sylloge (TSS)


Case study nb. 1 Digitization of the commercial Roman lead tags of Siscia (AIUCD 2014): M. LAMÉ, F. PONCHIO, Ch. MANNARI.

This page presents the technologies used for the project Tesserarum Sisciae Sylloge and methodologically explained in the proposal AIUCD 2014.

We recommend first (or second, as you wish), to peruse, the methodological paper « Primary Sources of Information, Digitization Processes and Dispositive Analysis » [LINK] by Marion Lamé that describes the methodological framework (dispositive analysis) and the status of the art that requires this technical configuration and the poster LAMÉ, M. MANNARI, Ch. PONCHIO, F. 2014. Fonti in cerca di storici digitali: ridefinizione e mutamenti della fonte primaria. Una ricerca in informatica umanistica.  Poster presented at the AIUCD2014. Terzo convegno annuale, Bologna, 18-19 September 2014. http://eer.hypotheses.org/posters

This page describes the tools used for the digital humanities research dedicated to the dispositive analysis applied to primary sources of information.
We adopted well-established low-cost technologies. These integrates and apply the conclusion of pre-existing works (see bibliography).

From a digital humanities point of you, our intend is not to defend or, on the opposite, to discuss  “post-modernism” or to go beyond structuralism opening vivid debates. This is not the training of a digital humanist, but the one of philosophers, that might be digital humanists too or not. Our intend is to search and to find solutions for digital systems that inscriptions, of any period of time, deserve but also that any primary sources of information deserve or any objects of study of humanists deserve.

The last who spoke is not always the one who is right and that digital humanities are not only a question of fashion or the very last astonishing technology. This belief implies to take in consideration the great work done by both sides of the spectrum for decades: humanists and computer scientist. As we say in French “Dans les vieux pots, les bonnes soupes” (« In old pans, we cook the best meals » something close to « Experience always wins the day »).


  • wSystem = writing system
  • cSystem = context system (internal and external to the TBO)
  • tSystem = textual system
  • TBO = Text Bearing Object
  • DAP = Digital Autoptic Process.
  • g/t = graphico-textual relationship
  • c/t = contexto-textual relationship
  • g/c = graphico-contextual relationship

Tools with * are decribed below. The others are still on test.

Tools Used For Main Technologies Involved Linking Tool?
RTI Web viewer * Digital Autoptic Process (DAP) WebGL based No
MarkOut * Links wSystem with internal cSystem: written symbols and TBO. PHP + HTML5 + SVG + JPEG Yes


Tss viewer * Alternative viewer to RTI viewer, frame by frame. HTML5, JPEG, PHP No
Glyph Browser Links wSystem with tSystem. JPEG, Database technologies (PHP) Yes


Paper browser Used to centralize connections and access between systems and to enter into the economical statistics tool, that belongs to cSystem fed by the critical transcriptions, that belongs to tSystem. PHP, XML (EpiDoc TEI), HTML5 Yes


RTI Web Viewer

Webviewer RTI

The DAP for lead tags finds a faithful expression and representation thanks to RTI technologies. RTI techologies allow to mimic the pitch and yaw motion applied to the lead tag when somebody (a Roman dyer of the 2nd century AD or an epigrapher of the 21st century) attempts to read it.

History of those technologies.

They starts from Geographic Information Systems (GIS) based on layers. In the 1990′, online GIS viewers provide most of technological basis for online large image viewers and the annotation of their content. The evolution of browsers and HTML standards made possible such online GIS viewers.

The simplest strategy, used at the beginning, requires a server to assemble the visible layers, rescale the image to the final resolution and generate an image for the client to download and display. This strategy minimizes computational resources on the client and allows custom sophisticated image manipulation at the cost of increased latency and bandwidth.

A more recent solution split the large image into a pyramid (collection) or quadtree of small tiles, and leaves to the client to reassemble the final image, downloading only what is necessary and caching it for future display of the same region. The recent diffusion of the WebGL technology allows further processing of the image on the client. These were used to built up RTI Webviewer.

The software we use for the RTI Webviewer is based on this last approach and was developped by the Visual Computing Laboratory, CNR, Pisa.

TSS Viewer

We gave the name of the project to this alternative DAP.
The TSS viewer allows the user to individually access the 115 JPEG frames shoot to produce the RTI file. It inserts them in a friendly navigator that imitates the RTI viewer in a frame-by-frame manner, that is without interpolation. The user can choose which picture to annotate, according to the direction of the light, and download it in MarkOut. In addition, this tool is much less resource intensive than the RTI viewer and can be useful to users with limited connectivity or devices with limited capabilities (e.g.: lack of WebGl support or limited CPU power).


MarkOut is a linking tool. It allows the user to express the g/t relationship between the wSystem and the tSystem.

When moving the process of transcription from paper to computers, some tools provide the user with some means of annotating the image. Annotating an image can be the possibility to add simple rectangles around the (textual) spot of interest, or to draw over the image using a virtual pen, most commonly using a raster approach.

The key aspect classifying editors for annotation is the ‘tool’ given to the user to identify features on the image: three families of basic tools have been used so far.

  • A simple rectangle: easy to draw, process and visualize, has the main drawback of not being precise as it can be used to define a general region but not to define precisely the contours of a feature of a written signs or a written symbols. This becomes problematic in particular where those contours are not clear or damaged. Moreover, it  cannot take into consideration the decipherment process that is part of the transcription one.
    An example of such a system is “Tile” (Text Image Linking Environment) from Mith. This web-based tool assists the user in creating and editing 2D image-based electronic printed-like editions and digital archives of humanities texts.
    • Whenever the interpretation of the shape of a features plays an important role, alternative systems give the user a pencil-like tool to freely draw on a virtual canvas.
      While the user is given complete freedom in how to annotate the image, some disadvantages of this process emerge as the mouse is a poor tool for such a job, it requires repeated correction of mistakes by erasing and redrawing. Other minor problems with this approach consist in the inconvenience to processing: a very large number of small image, it might be difficult to convert into vector data which is required by a number of automated post-processing tools.
    • A third, approach is based on vector graphics and allows to create erase and curved lines through control points (handles). Initial creation of a line becomes slightly more complicated, but control points allows to precisely align a line and define its shape. The end result is a vector shape, not a raster image, with the additional advantages of resolution independence and compact encoding. All the shapes can be encoded in a single SVG document, carrying the necessary information to link each mark to the relevant database record. Sharing, viewing and modifying this document on the Web becomes easier (as it uses the same XML/CSS/Javascript technology of HTML), and exporting as well as sharing outside of the Web stays effortless.

Our approach is an hybrid of the second and third methods: the user is first given a pencil-like tool to draw the mark, his drawing is then converted to a vector shape of a line (a bezier curve) with handles that allows precise alignment and correction of eventual mistakes. The remainder of the pipeline follows the vector graphics approach. Each drawn symbol is associated to its relative Unicode code point, when inalterate, or any additional information following the TEI EpiDoc guidelines.

The operations performed with these editors can be usually automatized to a certain degree, using image processing techniques. In our case automatization proved infeasible: it is almost impossible to discern the letters using a single photo due to the characteristics of the material and of the incision, letter and symbols often are overlapping with older half erased marks.

Click on the image to a first prototype of the Markout tool

A future version of the MarkOut will be integrated with the WeBRTI VIewer to allow the user to cganbe the light direction while annotating the tag.

Glyph Browser

The written signs are letters and symbols and for the purpose of this Glyph Browser we use the Unicode terminology calling them characters. The different shapes that a character appears in the tags with, have been classified into a number of glyphs.

The glyph browser allows the user to easily retrieve all the occorrences of a glyph in the tags.


      • AMZ Archeological Museum of Zagreb and his curator, Dr. Ivan Radman
      • VCL-ISTI-CNR
      • Laboratorio di Cultura Digitale and its Director, Prof. Enrica Salvatori.
      • Prof. Perrine Kossmann
      • M.A. Alison Babeu
      • M.A. Eve Thomas-Richard
      • M.A. Chiara Mannari
      • Dr. Fabio Ciotti
      • Dr. Federico Ponchio
      • Dr. Angelo Mario Del Grosso
      • Dr. Marco Tarini
      • Dr. Francesca Tomasi
      • Marino Vazzana, for the brief presentation of amphora stamps databases.

Bibliographic suggestions on RTI technologies

Barbosa, João Garcia, João Luís Sobral, and Alberto José Proença. 2007. “Imaging Techniques to Simplify the Ptm Generation of a Bas-relief.” In The 8th International Symposium on Virtual Reality Archaeology and Cultural Heritage VAST2007, 28–31.

Cultural Heritage Imaging. 2014. “RTI Viewer.” http://culturalheritageimaging.org/What_We_Offer/Downloads/View/index.html.

Dellepiane, Matteo, Massimiliano Corsini, Marco Callieri, and Roberto Scopigno. 2006. “High Quality Ptm Acquisition: Reflection Transformation Imaging for Large Objects.” In The 7th International Symposium on Virtual Reality Archaeology and Cultural Heritage VAST2006, ed. M Ioannides, D Arnold, F Niccolucci, and K Mania, 179–186. Eurographics Association.

Earl, Graeme, Gareth Beale, Kirk Martinez, and Hembo Pagi. 2010. “Polynomial Texture Mapping and Related Imaging Technologies for the Recording, Analysis and Presentation of Archaeological Materials.” Archives XXXVIII (Figure 1): 218–223.

Earl, Graeme, Kirk Martinez, and Tom Malzbender. 2010. “Archaeological Applications of Polynomial Texture Mapping: Analysis, Conservation and Representation.” Journal of Archaeological Science 37 (8): 2040–2050.

Freeth, T, Y Bitsakis, X Moussas, J H Seiradakis, A Tselikas, H Mangou, M Zafeiropoulou, et al. 2006. “Decoding the Ancient Greek Astronomical Calculator Known as the Antikythera Mechanism.” Nature 444 (7119): 587–591.

Hammer, Øyvind, Stefan Bengtson, Tom Malzbender, and Dan Gelb. 2002. “Imaging Fossils Using Reflectance Transformation and Interactive Manipulation of Virtual Light Sources.” Paleontologia Electronica.

Mudge, Mark, Tom Malzbender, Alan Chalmers, Roberto Scopigno, James Davis, Oliver Wang, Prabath Gunawardane, et al. 2008. “Image-Based Empirical Information Acquisition , Scientific Reliability , and Long-Term Digital Preservation for the Natural Sciences and Cultural Heritage.” In Tutorial Eurographics 08. Eurographics.

Mudge, Mark, Tom Malzbender, Carla Schroer, and Marlin Lum. 2006. “New Reflection Transformation Imaging Methods for Rock Art and Multiple-Viewpoint Display.” In The 7th International Symposium on Virtual Reality Archaeology and Cultural Heritage VAST2006, ed. M Ioannides, D Arnold, F Niccolucci, and K Mania, 195–202. Citeseer.

Mudge, Mark, Jean-Pierre Voutaz, Carla Schroer, and Marlin Lum. 2005. “Reflection Transformation Imaging and Virtual Representations of Coins from the Hospice of the Grand St. Bernard.” In The 6th International Symposium on Virtual Reality Archaeology and Cultural Heritage VAST2005, ed. Mark Mudge, Nick Ryan, and Roberto Scopigno, Proceeding:29–39. Eurographics Association.

Padfield, Joseph, David Saunders, and Tom Malzbender. 2005. “Polynomial Texture Mapping: a New Tool for Examining the Surface of Paintings.” ICOM Committee for Conservation I: 504–510.

Willems, Geert, Frank Verbiest, Wim Moreau, Hendrik Hameeuw, Karel Van Lerberghe, and Luc Van Gool. 2005. “Easy and Cost-effective Cuneiform Digitizing.” In The 6th International Symposium on Virtual Reality Archaeology and Cultural Heritage VAST2005, ed. Mark Mudge, Nick Ryan, and Roberto Scopigno, 73–80. Eurographics Association.

Marion Lamé


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