Cultural Heritage Imaging


Behind the Scenes: Museum Photography at the Oriental Institute by marlinlum

Recently Anna R. Ressman, Head of Photography at the Oriental Institute Museum, University of Chicago, shared a compelling article with me, and now I’m sharing it with you.

Here is a link to the Oriental Institute newsletter (PDF), which contains the article entitled, “Behind the Scenes: Museum Photography at the Oriental Institute.

Anna describes the process in which five very different artifacts are documented, each with a unique challenge. And yes, you guessed it, one of those artifacts was documented using the RTI highlight method.

Documentation of the Egyptian stele “was photographed with a method of computational photography called Reflectance Transformation Imaging (RTI).”

Using RTI to photograph OIM E14655 with photo assistants K. Bryce Lowry and Austin M. Kramer

Using RTI to photograph OIM E14655 with photo assistants K. Bryce Lowry and Austin M. Kramer

OIM E14655, Egyptian Stele, Limestone, New Kingdom, Medinet Habu, Egypt. 36x26cm

OIM E14655, Egyptian Stele, Limestone, New Kingdom, Medinet Habu, Egypt. 36x26cm

Specular enhancement using RTI of Egyptian Stele OIM E14655

Specular enhancement using RTI of Egyptian Stele OIM E14655

Anna concludes the section on RTI with these insights: “RTI files can be created in such a manner that pixel data is analyzed to show specular information rather than color data, which can reveal more information about the surface of the object than color data alone (figs. 3–4). As you can see, the inscriptions on the stele are much clearer in the specular-enhancement PTM image (fig. 3), even though the studio photograph (fig. 4) was taken using a macro lens under controlled studio lighting. The former may not be as aesthetically pleasing as the latter, but it reveals much more information than would normally be seen — and that is just a single image out of a series of forty-five.”

Be sure to download the complete article and check out the rest of the newsletter as well.

Anna R. Ressman is Head of Photography at the Oriental Institute Museum, University of Chicago, USA. Anna is also a freelance photographer and a fine artist.

[Photos by Anna R. Ressman/Courtesy Oriental Institute Museum, University of Chicago]



Interview: James Coddington, Chief Conservator, Museum of Modern Art, New York by cwillen

CHI Executive Director Debra Dooley recently conducted an email interview with James (Jim) Coddington (JC), Chief Conservator at the Museum of Modern Art (MoMA) in New York. CHI is building a custom light array for MoMA’a Conservation Department to help with capturing reflectance transformation imaging (RTI) media of objects in the museum’s collection.

1. How long have you been at the MoMA?

JC: 23 years

2. As Chief Conservator at MoMA, are you constantly searching for new techniques to preserve and restore art?

JC: It is a necessity when conserving contemporary art in particular.

3. What are you doing to digitally document, analyze, and preserve the MoMA collection at present?

JC: We are using standard RGB imaging as well as multi-spectral imaging via a spectral estimation technique using a standard RGB camera with filters. We also maintain written digital documentation of treatments and other reporting.

4. Why have you decided to expand from what you are doing now into reflectance transformation imaging (RTI) techniques?

JC: The importance of 3D information in documenting works of art has been long recognized, mostly in the form of raking light photos. RTI gives us the means to collect substantially more 3D information in a standardized way that also provides data for scientific analysis of surface structure and topography.

4. Why did RTI interest you?

JC: I think mostly the demonstrated ease of use.

5. How will you use RTI?

JC: We will be using it initially to document texture on printed out photo papers but we expect to use it on many different types of objects in our collection.

6. A custom light array is being built for the MoMA. What objects will you capture first?

JC: See Answer #5.



Imaging Paper Squeezes With RTI at the Smithsonian by cwillen

By Guest Blogger E. Keats Webb

I mentioned briefly last month some of the objects that we have been using Reflectance Transformation Imaging (RTI) on here at the Smithsonian’s Museum Conservation Institute (MCI).  One project involved paper “squeezes,” paper pulp molds made from the surfaces of ancient monuments at archaeological sites.

In some cases these “squeezes” are primary resources containing rare intellectual and physical information from monuments that have deteriorated or sites that no longer exist.  Unfortunately, the fragility of the paper minimizes accessibility of these objects to researchers and scholars. This makes them great candidates for non-destructive documentation of the 3-D characteristics of their surfaces with the RTI method.

Senior Conservator, Melvin Wachowiak, and I worked with the conservators from a Smithsonian museum, imaging a couple of examples of paper squeezes to see what the RTI method might contribute in terms of preservation and research.

Since the squeezes are molds taken from stone inscriptions, the writing is reversed.  After the image acquisition we “flipped” the images using imaging software, and then processed the files so that the final RTI product could be a legible rectified document for researchers to study.

We found that the RTI method increases legibility through the combination of raking light features and the specular enhancement option while also creating a surrogate that can be more extensively “handled” by researchers and scholars. (See images below.)

We continue to use RTI on a daily basis and look forward to sharing more with you about how the method is helping the scientists and conservators within MCI and the Smithsonian for the research and preservation of the collections.

paper_normal_lite

Detail of Paper Squeeze with Normal Light Position

 

Paper with raking light

Detail of Paper Squeeze with Raking Light

 

Paper with specular enhancement

Detail of Paper Squeeze with Specular Enhancement



Visualizing the future at Arqueologica 2.0, Seville, Spain by Michael Ashley
June 23, 2009, 10:37 pm
Filed under: Conferences | Tags: ,

by Michael Ashley

arqueologica logo

I had the pleasure of being invited to a special congress in Seville this past week. Arqueologica 2.0 is the first international congress on archaeology and informatics held in Spain. The organizers managed to bring together over 200 participants from 17 countries representing over 100 organizations, to discuss and debate virtual archaeology and its role in archaeological practice. I found the congress to be inspirational, exceptionally well run, and mostly a whole lot of fun.

Participants included representatives from some of the most important organizations that work to document, understand, preserve and communicate cultural heritage around the world. In fact, the congress was a truly international gathering of professionals who are passionate about cultural history and memory.

So often, the discussions of computer graphics and archaeology focuses on the divide between technologists and practitioners of the discipline. I was impressed by the efforts of the congress program facilitators to get us to look beyond the fissure and to the mutual benefits of integrating visualization methods into archaeology.

Jane Crawford and Michael Ashley at the opening session at the site of Italica

Jane Crawford and Michael Ashley at the opening session at the site of Italica

Throughout the congress, many recommendations and suggestions have been forwarded. I mention a few here because they resonate well and I hope we would generally agree are essential to promote the broad adoption of digital technologies in service of archaeology.
Bernie Frischer suggested that future Arqueologica meetings might have workshops to leave behind practical training with participants.
Richard Beacham called for case studies or pilot projects where we can test ideas and refine procedures in the real world.
Graeme Earl and several others suggested that virtual archaeology methodologies are actually archaeological techniques that must be truly integrated and carried out in archaeological practice.

Throughout the congress, many recommendations and suggestions were forwarded. I mention a few here because they resonate well and I hope we would generally agree are essential to promote the broad adoption of digital technologies in service of archaeology.

Bernie Frischer suggested that future Arqueologica meetings might have workshops to leave behind practical training with participants.

Richard Beacham, co-author of the London Charter on visualization in cultural heritage, called for case studies or pilot projects where we can test ideas and refine procedures in the real world.

Graeme Earl and several others suggested that virtual archaeology methodologies are actually archaeological techniques that must be truly integrated and carried out in archaeological practice.

Mediterranea Project

Mediterranea Project

Many of us were kindly invited to listen to Alfredo Grande discuss the ambitious Mediterranea Project, which seeks to integrate the cultural heritage of the Mediterranean for research and public access and enjoyment. Core to the project is an attention to ‘big blocks’ that are essential to archaeological work practice – documentation and research, conservation and preservation, presentation and information.

One of the highlights of the scientific program was the uniquely organized quick fire plenary session that involved 23 of us lined up in the first row of the auditorium. From the stage, Víctor Manuel López-Menchero Bendicho gave us each <2min. to summarize our opinion on the state of virtual archaeology. This led to a lively debate with many more questions than answers, but there was general consensus that even now in 2009, we are only scratching the surface at the potential for digital archaeology.

Daniel Plentinckx in the spotlight during the rapid fire plenary

Daniel Plentinckx in the spotlight during the rapid fire plenary

Arqueologica 2.0 was the first of what the sponsor organization, the Society for Spanish Virtual Archaeology (SEAV) (also launched at the congress), hope will become an annual event. I hope so, not because the world needs another conference, but because the spirit and enthusiasm expressed by our new friends in Spain is what the world needs.

My favorite quote from the congress was made by a colleague, “It’s more important who you work with than what you work on.” I would work with Alfredo and Victor anytime. I am sure we can find some really important things to do in an enjoyable fashion.

Muchas gracias por todo, nuevos amigos!