Digital Heritage 2018 3rd International Congress & Expo
avatar for Photogrammetric imaging of a large-scale Diego Rivera fresco mural

Photogrammetric imaging of a large-scale Diego Rivera fresco mural

Booth Photogrammetric imaging
2325 3rd St, Suite 323, San Francisco, CA, 94107, USA
Photogrammetric imaging of a large-scale Diego Rivera fresco mural
by Carla Schroer, Mark Mudge and William Maynez

This demonstration will show high-resolution outputs and share our experience capturing the fine surface details of a 6.7 by 22.5 meter (~ 151 square meters) 1940 fresco by Diego Rivera.
The project had multiple motivations: to produce benchmark historic documentation of the current state of the mural; provide details of the mural’s surface for conservation and restoration planning; promote awareness and research of the mural iconography and the brushwork of the artist.
In 1940, Mexican artist Diego Rivera (1886-1957) painted a huge mural (22 feet x 74 feet), an inspiring vision of the unity of art, religion, history, politics, and technology in the Americas. Originally titled The Marriage of the Artistic Expression of the North and of the South on this Continent, it is commonly known as Pan American Unity. Rivera created the work during the 1940 season of the Golden Gate International Exposition (GGIE) at Treasure Island on the Bay in San Francisco, California. The mural was the centerpiece of a program called “Art In Action” that featured many artists creating their works while the public watched.
“My mural will picture the fusion between the great past of the Latin American lands, as it is deeply rooted in the soil, and the highly mechanical developments of the United States.” — Diego Rivera
Because the fresco surface is so subtle, a high-resolution (sub-millimeter) capture was required. Approximately 2200 overlapping 50MP images were collected following a rule-based, error minimization and software independent capture methodology.
Another key goal of the work was to acquire appropriate metadata about the imaging project to aide in data reuse and scholarship. We employed a novel metadata acquisition and management approach using software tools developed by Cultural Heritage Imaging in collaboration with the Centre for Cultural Informatics of the Foundation for Research and Technology Hellas in Heraklion Crete.
The methodology and tools are designed for digital representations that are built with computational photography technologies, and that are intended for use in interdisciplinary science and humanities scholarship. The software builds a “Digital Lab Notebook” and takes the form of a user-friendly toolkit, which makes it possible to document not only the algorithmic transformation of photographic data, but also the context in which the photographs were created. Current computational photography technologies are based on the algorithmic extraction of information from multiple photographs, generating new information not found in any single photo. This software’s new metadata and knowledge management methodology produces metadata-rich empirical digital data. In turn this managed metadata enhances the likelihood of the information’s sustainability.
The result is CIDOC Conceptual Reference Model (CRM) mapped Linked Open Data (LOD) describing the capture context and data validity. The tools use a natural language interface to collect relevant information about the subject, people, project, and equipment. The user needs no CRM or LOD experience to produce this rich metadata result.During the Expo, we will show registered 2D seven gigapixel othomosaic images and Digital Elevation Maps (DEMs) of the mural. Detail areas of the mural as 3D models will also be shown. We will also share our collected metadata and image validation information, and discuss details of the image capture and processing.