Projects – Digital Epigraphy and Archaeology

Shape-From-Shading 3D reconstruction On-Line Tool

angelbar — Tue, 15 Feb 2022 03:11:34 +0000

BERLIN, Germany
February 15, 2022

Our interdisciplinary team is happy to present today in Berlin’s Digital Classicist Seminar series the new on-line tool for 3D reconstruction of epigraphic squeezes using our shape-from-shading technique (MVA 2010). The new tool that replaces our older Digital Epigraphy Toolbox can be accessed in the following address:

https://www.digitalepigraphy.org/db/app/sfs

The new on-line tool utilizes cloud technology to store, process, and disseminate the results of the 3D reconstruction algorithm. It allows the users to upload pictures of a flat inscribed object (such as epigraphic squeeze, paper embossment, seal, inscriptions, casts of coins, and others), taken from the same perspective using 2 or 4 different lighting conditions.

The users then, can process the photos and produce the heightmap and normal map of the depicted surface.

A variety of sample projects is provided to help you familiarize yourself with the features and options of the software.

The software is open-source and the source code can be accessed within the application from the menu About > For Developers > Source Code

3D Scanning the Rosetta Stone

angelbar — Thu, 28 Jun 2018 15:49:09 +0000

Use 1-finger and 2-finger gestures to move, rotate, and zoom the 3D model of the Rosetta Stone below:

With the permission of the British Museum, an interdisciplinary team from the University of Florida and the University of Leipzig scanned the Rosetta Stone in June 2018 to generate a high-resolution 2D and 3D map of its inscribed surface. In our setup, we used a single DSLR camera (Nikon D3400), which was fixed on a tripod in front of the stone, and calibrated as follows: exposure time = 5 sec., ISO speed = ISO-100, F-stop = f/25, focal length = 135mm, and max aperture = 4.5. To reconstruct the tridimensional inscribed surface using the shape-from-shading method, we controlled the lighting of the stone using a handheld light wand (Ice Light) that served as a 15-inch long light source of 1600 lumen at 5600k color temperature.

We divided the artifact in 8 regions (4 rows and 2 columns), which were photographed individually at 6000 x 4000 pixel resolution. Each region was photographed in 4 different lighting directions (light from the left, top, right, bottom) by placing the light wand in the corresponding side of the region of interest. This quadri-directional lighting configuration allowed us to capture information related to the local orientation at each point of the surface through the differences of the light reflection observed in the corresponding four photographs. The entire scanning session, including opening the glass case of the artifact, setting up the equipment, digitizing the artifact, and putting everything in its original configuration before the opening of the museum took us 120 min.

During this time 32 photographs were taken in total (8 regions x 4 lighting conditions), which were then processed to compose high-resolution 2D and 3D representations of the surface with 0.08141mm sampling frequency, which is equivalent to 312 DPI resolution. The tridimensional details of the inscribed surface were captured in the depth map, which was computed by processing the four corresponding images of the same region of interest illuminated with four different lighting orientations using the method by A. Barmpoutis, E. Bozia, and R. Wagman published in the Journal of Machine Vision and Applications 21(6) in 2010. The depth map contains detailed three-dimensional information of the inscribed surface so that it can be visualized in 3D. The 3D reconstructed surface can be rendered as an interactive 3D model that can be manipulated by the user (move, scale, rotate) and can be inspected under different virtual lighting orientations and shading methods.

Finally, in addition to the 3D reconstruction of the inscribed surface, we used a hand-held laser scanner (Structure Sensor by Occipital) mounted on a tablet computer (iPad Air by Apple) in order to create a 3D model of the entire stone. Although the 3D model generated by this scanner can depict the overall shape of the entire artifact, it does not have enough resolution to capture the fine details of the inscribed surface. Therefore, the 3D reconstructed surface using shape-from-shading is complementary to the laser-scanned 3D model, as both of these forms can co-exist in order to depict different structural details of the artifact.

The result of this process is a high resolution 3D representation of the Rosetta Stone that is available on-line as an interactive web app and can be accessed through the project’s website.

In November 2019, the project was featured in German news outlets: https://www.mdr.de/wissen/stein-von-rosette-digital-leipzig-100.html

Digitization of inscriptions from the Aleshire collection

angelbar — Wed, 03 Jun 2015 16:34:57 +0000

GAINESVILLE, Fla.
June 3, 2015.

An interdisciplinary team from the Digital Epigraphy and Archaeology group at the University of Florida and the Aleshire Center for the Study of Greek Epigraphy at the University of California, Berkeley digitized in 3D squeezes (paper casts) of inscriptions from the Aleshire collection. The goal of this pilot project was to stretch the shape-from-shading (SFS) method¹ of the Digital Epigraphy Toolbox² to its limits by testing it to severely weathered inscriptions from Thebes and Sifnos.

SFS has been successfully used in the past by our group for 3D digitization of inscriptions from the Monumentum Ancyranum (in collaboration with Cornell University), seals and medals (in collaboration with the UK National Archives), paper embossments from Abraham Lincoln’s letters (in collaboration with the Library of Congress and Cornell University) and most recently inscriptions from Delphi, Thasos, and Delos (in collaboration with the University of Lyon 2 and the French School of Athens).

The question to be answered in this pilot project was: Can SFS assist epigraphists in reading severely weathered inscriptions by intensifying the inscribed symbols or even reveal new fragments?

To find the answer to this question, Prof. Nikolaos Papazarkadas and John Lanier (UC Berkeley) selected three sample squeezes with hard-to-read inscribed fragments and scanned them, using a regular flatbed scanner (Expression 10000XL by EPSON). Each fragment was scanned four times by rotating the squeeze 90 degrees each time, according to the SFS process¹. An example of the obtained results is shown in the figures below.

Figure 1. Left: One of the original scanned images of a squeeze from a severely weathered inscription. Right: The depthmap of the 3D reconstructed inscription that reveals several rows of inscribed characters.

Figure 2. Different visualizations of the depthmap from Fig.1(right) that intensify different details of the 3D reconstructed model. Left: Color inverted depthmap. Right: Histogram equalized depthmap.By comparing the original scanned image (Fig.1 left) with the depthmap of the 3D reconstructed inscription shown in the figures above, it is evident that the 3D digital model is significantly richer in information. According to Prof. Barmpoutis (University of Florida) “this is an exemplar case that demonstrates the capabilities of 3D digitized models compared to the original 2D images. It is truly remarkable how much more inscribed details can be seen in the depthmap computed by the SFS method, using just a conventional office paper scanner. When I first saw the scanned squeeze I was convinced that there was no inscription survived in this fragment, but when I saw the reconstruction results I could clearly recognize several letters despite the fact that I am not a professional epigraphist myself.”

Figure 3. Left: One of the original scanned images of a squeeze from a severely weathered inscription. Right: The 3D reconstructed depthmap computed by the SFS method from the Digital Epigraphy Toolbox.According to professional epigraphists from UC Berkeley who inspected the reconstructed data “the biggest difference is that it takes several hours in the museum in order to read what it can be read, while with the digitized squeeze it can be done conveniently at home”. They also noted that “the difference between SFS and RTI is obviously the cost” and “what was most impressive was the depthtmap, which is very useful and can be used for publication.”

Below you can find another example of an embedded 3D digitized squeeze from the Aleshire collection. Use your touch screen or mouse to interact with the exhibit. You can rotate, zoom, relight and view in full screen information about this inscription.

Figure 3 (touch/mouse interactive). The 3D reconstructed model of the Greek Column IG I3 475 from the Aleshire collection of squeezes at UC Berkeley.The results from this pilot project will be presented in detail by Prof. Eleni Bozia (University of Florida) and Prof. Nikolaos Papazarkadas (UC Berkeley) at the “Texte Messen – Messungen Interpretieren” Workshop organized by the Universität Freiburg, Germany on July 23-25, 2015. All 3D reconstructed models of the sample squeezes from this pilot study can be found at the following link: www.digitalepigraphy.org/legacy/collection/aleshire/

To learn more about how to use our open-access tools to digitize, analyze, and disseminate your own collection feel free to contact us or visit the web-site of the Digital Epigraphy and Archaeology project.

The DEA editorial team

References:

1. A. Barmpoutis, E. Bozia, R. S. Wagman, “A novel framework for 3D reconstruction and analysis of ancient inscriptions”, Journal of Machine Vision and Applications
2010, Vol. 21(6), pp. 989-998. PDF

2. Digital Epigraphy Toolbox, www.digitalepigraphy.org/legacy/toolbox.

Funded in part by the NEH grant HD-51214-11.

Digitization of Sculptures from the Museo Nazionale Romano

angelbar — Fri, 20 Feb 2015 16:04:26 +0000

GAINESVILLE, Fla.
February 20, 2015.

How can you search for a statue in a database without using any keywords or textual metadata?

The DEA group in collaboration with the museum of Palazzo Altemps in Rome, Italy¹ digitized in 3D statues from three of the collections housed in the museum: Boncompagni Ludovisi collection, Mattei collection, and Altemps collection. The digitization was performed using low-cost infrared depth sensors for iPad and XBOX by manually moving the sensor around the sculptures in order to capture their tridimensional form.

Picture from our digitization session in Palazzo Altemps. Each session lasted for about 180 seconds and captured several millions of polygons on the surface of each statue.This process produced a dataset of 3D digitized statues with 3D point accuracy in the range of millimeters. In addition, a skeleton fitting process calculated the location of 20 major joints in the body of each statue. The goal of this project was to use the skeletal information of the statues in order to study the pose variations of the statues, calculate affinities or differences between statues, and perform keyword-free database search.

This figure shows selected samples from our dataset of 3D digitized statues.Digital technologies have been adopted in various areas related to museum experience, digital preservation, as well as digitization and study of archaeological artifacts. Digital collections become even more useful educationally and scientifically when they provide tools for searching through the collection and analyzing, comparing, and studying their records. For example an image collection becomes powerful if it can be searched by content, technique, pattern, color, or even similarity with a sample image. The lack of keywords and generalizable annotation for such type of analysis generates the need for keyword-free feature-based analysis.

Visualization of the estimated skeletons of statues in our dataset shown from three different perspectives. Quantitative posture analysis can be applied to such dataset in order to assist scholars in studying the variations between sculptures from different cultures, eras, and schools.The DEA group has designed a framework in which each statue is represented in a feature space based on the skeletal geometry of the human body. A distance function is defined in the feature space and is employed in order to find statues with similarities in their pose. The search query in the presented framework is the body of the user, who can interact with the system and find which statues have poses similar to the user’s pose. The framework will be presented in the 17th International Confrence on Human-Computer Interaction to be held in Los Angeles, in August 2015.

Above you can find an example of an embedded 3D sculpture from the digitized collection. Use your mouse or touch pad to interact with the exhibit. You can rotate, zoom, relight and view in full screen information about this statue.This pilot project shows that the proposed framework² can be used for keyword-free feature-based retrieval of statues in mobile devices. It has the potential to be used as a scientific tool for assisting scholars in identifying statues with similar characteristics from a large repository of statues, but also as an interactive guide in museums. The future use of depth sensors in mobile devices will significantly support the creation of such repositories of 3D digitized artifacts, using limited resources (in terms of scanning time, computational effort, and cost) as well as their computer-assisted study as demonstrated in detail in the published article by Barmpoutis et al².

To learn more on how to use our open-access tools to digitize, analyze, and disseminate your own collection feel free to contact us or visit the web-site of the Digital Epigraphy and Archaeology project.

The DEA editorial team

References:

1. Museo Nazionale Romano di Palazzo Altemps, archeoroma.beniculturali.it/en/museums/national-roman-museum-palazzo-altemps.

2. A. Barmpoutis, E. Bozia, D. Fortuna, “Interactive 3D digitization, retrieval, and analysis of ancient sculptures, using infrared depth sensors for mobile devices “, 17th International Conference on Human-Computer Interaction, Los Angeles, August 2-7,
2015. PDF

Funded in part by the:
A. Rothman Fellowship in the Humanities from the Center for the Humanities and the Public Sphere at the University of Florida
B. and the Research Incentive Award from the College of the Arts at the University of Florida.

The images from our published article² are shown with permission from the Italian Ministry of heritage, cultural activities and tourism. Su concessione del Ministero dei beni e delle attività culturali e del turismo – Soprintendenza Speciale per il Colosseo, il Museo Nazionale Romano e l’area archeologica di Roma.

The E-STAMPAGES project

angelbar — Wed, 15 Oct 2014 16:57:22 +0000

GAINESVILLE, Fla.
October 15, 2014.

A collaborative team from Université Lyon 2, Maison de l’Orient et de la Méditerranée, the French School of Athens (École française d’Athènes), and the Digital Epigraphy and Archaeology group at the University of Florida have received a grant award from the French Ministry of Higher Education under the grant program BSN5 2014 ¹.This collaborative project titled “e-stampages” is lead by Prof. Michèle Brunet and is aiming to digitize and disseminate electronically the large collection of ektypa (estampages in French) of inscriptions from Delphi, Thasos, Delos, Crete, Aetolia, Chalcidice, Asia Minor, Boeotia, and Homole².

The awarded amount of €53,500 will cover the digitization costs of nearly 8000 casts of inscriptions and is expected to be completed by June 2016. The database that will be created will contain 2D and 3D digitized records of the entire collection as well as metadata entries regarding the original inscriptions.

During last summer, the team performed a series of pilot 3D digitization experiments at the University of Lyon in order to establish an efficient process that can be followed in such a large scale digitization project. In this pilot study selected paper casts of inscriptions were digitized using the shape-from-shading framework³ of the Digital Epigraphy Toolbox.

This photograph shows a visual comparison between a paper cast and the 3D digitized equivalent, shown on the computer monitor in the back. The picture was taken in June 2014 during our preliminary tests at the University of Lyon 2. Below you can interact with one of the preliminary 3D digitized models. Use touch gestures or mouse movements to interact with the e-stampage. You can rotate, zoom, relight and view in full screen information about this inscription.

A sample 3D digitized inscription from the collection of estampages at the University of Lyon 2. Touch your screen to interact with the 3D model using the Digital Epigraphy Toolbox.This important historical evidence can now be easily accessed and studied by scholars using this on-line viewer. One of the advantages of the Digital Epigraphy Toolbox viewer is that it can be easily embedded into websites or other databases by using the following HTML tag:

The above HTML tag corresponds to the sample inscription from the estampages collection at the University of Lyon 2. You can find the corresponding embed-tag of other exhibits within the information provided in their records in the Digital Epigraphy Toolbox⁴.

The DEA editorial team

References:

1. French Ministry of Higher Education grant program BSN5 2014. http://www.enseignementsup-recherche.gouv.fr/cid24149/dgesip.html

2. The E-STAMPAGES project public announcement http://www.efa.gr/index…

3. A. Barmpoutis, E. Bozia, R. S. Wagman, “A novel framework for 3D reconstruction and analysis of ancient inscriptions”, Journal of Machine Vision and Applications
2010, Vol. 21(6), pp. 989-998. PDF

4. Digital Epigraphy Toolbox, www.digitalepigraphy.org/legacy/toolbox.

The Digital Epigraphy Toolbox was funded in part by the NEH grant HD-51214-11.

Historical documents of Abraham Lincoln digitized in 3D

angelbar — Mon, 17 Feb 2014 16:50:32 +0000

GAINESVILLE, Fla.
February 17, 2014.

Have you wondered how ancient Greek and Latin inscriptions may relate to Abraham Lincoln?

Conservation experts, digital collection specialists, digital epigraphy scholars and computer scientists from the University of Florida, Cornell University and the Library of Congress have digitized in 3D historical documents of Abraham Lincoln. More specifically, the Cornell University’s copy of Abraham Lincoln’s Gettysburg Address has an embossed anaglyph on the top left of the front page of the document¹.
A similar embossment can also be found on a letter from T. D. Eliot to Abraham Lincoln dated on February 1, 1864, currently located in the manuscript division of the Library of Congress.

Embossments of Philp & Solomons, Washington D.C. stationary on a letter from T. D. Eliot to Abraham Lincoln (left) and the Conrell University’s copy of the Gettysburg Address (right).The study of various properties and characteristics of the paper from historical documents, including material properties and watermarks, may reveal significant information that can allow scholars to trace the history of the document as far as the stationary that provided the raw paper material. Michele Hamill, a Paper and Photograph Conservator at Cornell University, has studied in detail the Cornell University’s copy of Gettysburg address and traced the source of its paper to Philp & Solomons, Washington D.C. stationary^1,2.

Paper embossments can be effectively digitized and analyzed in 3D using the same tools that the Digital Epigraphy and Archaeology group has developed for reconstructing ancient Greek and Latin inscriptions³. “A paper embossment is no different than an epigraphic squeeze or ektypon, which is a paper cast of an inscription” according to Dr. Bozia, Associate Director of the Digital Epigraphy and Archaeology project.

Examples of two different 2D visualizations (heightmap and color heatmap) of the 3D reconstructed embossment of PHILPS & SOLOMONS using the Digital Epigraphy Toolbox⁴.The 3D digital collection that was created in this digitization project can be accessed on-line in this link through the interface of the Digital Epigraphy Toolbox⁴. These historical documents were digitized using bi-directional and quad-directional flatbed scanning³ performed by Rhea Garen from the Institute for Digital Collections, Cornell University, and Michelle A. Krowl from the Manuscript Division, Library of Congress.

Below you can find an example of an embedded 3D artifact from the digitized collection. Use touch gestures or mouse movements to interact with the exhibit. You can rotate, zoom, relight and view in full screen information about this embossment.

This important historical evidence can now be easily accessed and studied by scholars using this on-line viewer. One of the advantages of the Digital Epigraphy Toolbox viewer is that it can be easily embedded into websites or other databases by using the following HTML tag:

The above HTML tag corresponds to the PHILPS & SOLOMONS embossment from the letter of T. D. Eliot to Abraham Lincoln, Library of Congress. You can find the corresponding embed-tag of other exhibits within the information provided in their records in the Digital Epigraphy Toolbox⁴.

The DEA editorial team

References:

1. M. Hamill, Paper Matters: Preserving Cornell’s Gettysburg Address, blogs.cornell.edu/rememberinggettysburg.

2. Solomons Adolphus Simeon, www.jewishencyclopedia.com.

3. A. Barmpoutis, E. Bozia, R. S. Wagman, “A novel framework for 3D reconstruction and analysis of ancient inscriptions”, Journal of Machine Vision and Applications
2010, Vol. 21(6), pp. 989-998. PDF

4. Digital Epigraphy Toolbox, www.digitalepigraphy.org/toolbox.

Funded in part by the NEH grant HD-51214-11.

Important artifacts from The National Archives [UK] now digitized in 3D

angelbar — Thu, 23 Jan 2014 17:01:20 +0000

GAINESVILLE, Fla.
January 23, 2014.

A group of scholars and scientists from The National Archives [UK] and the University of Florida have successfully completed a joint 3D digitization project of important historical artifacts from the 13th-16th centuries. The 3D digital collection that was created in this pilot project includes seals and medals, as well as lace samples, and can be accessed on-line in this link through the interface of the Digital Epigraphy Toolbox¹.

Two examples of 3D digitized seals of Henry III King of England (left) and the coat of arms of Kiel (right).The artifacts were digitized in sub-millimeter accuracy using bi-directional flatbed scanning². This cost-effective technique reconstructs the tri-dimensional shape of the scanned objects using a regular flatbed office scanner.

“In this digitization project we experimented in digitizing materials with various reflectance properties. We were very happy to see that high quality 3D scans were acquired from a variety of materials such as paper, plaster and lace” according to Prof. Barmpoutis, who is the director of the Digital Epigraphy and Archeology project. Dr. Dinah Eastop and Rachel Farmer from The National Archives [UK] performed the bi-directional scanning of the artifacts, which were then processed and digitized in 3D by the Digital Epigraphy and Archaeology group (Drs. Bozia, Wagman, and Barmpoutis) at the University of Florida.

Below you can find an example of an embedded 3D artifact from the digitized collection of The National Archives [UK]. Use touch gestures or mouse movements to interact with the exhibit. You can rotate, zoom, relight and view in full screen information about this Great Seal of the Realm.

This important historical evidence can now be easily accessed and studied by scholars using this on-line viewer. One of the advantages of the Digital Epigraphy Toolbox viewer is that it can be easily embedded into websites or other databases by using the following HTML tag:

The above HTML tag corresponds to the Great Seal of the Realm from the collection of The National Archives [UK]. You can find the corresponding embed-tag of other exhibits within the information provided in their records in the Digital Epigraphy Toolbox¹.

The DEA editorial team

References:

1. Digital Epigraphy Toolbox, www.digitalepigraphy.org/legacy/toolbox.

2. A. Barmpoutis, E. Bozia, R. S. Wagman, “A novel framework for 3D reconstruction and analysis of ancient inscriptions”, Journal of Machine Vision and Applications
2010, Vol. 21(6), pp. 989-998. PDF

Funded in part by the NEH grant HD-51214-11.

Digital Epigraphy Toolbox

angelbar — Fri, 20 Dec 2013 15:49:09 +0000

DEA is an interdisciplinary project initiated by scientists from the Digital Worlds Institute and the Department of Classics at the University of Florida. The goal of the project is to develop new open-access scientific tools for the Humanities and apply concepts from digital and interactive media and computer science to Archaeology and Classics. In our web-site you can view our 3D collections and interact with our on-line exhibits, read about our recent results, find interactive demos of our projects, and learn more about our future research directions.

Bringing together Digital Media, Computer Science, and the Humanities.