The Archaeological Superintendency of Rome and the many institutions and scholars involved in studies and research concerning the monument, have felt the need to create a common information base in which to gather all documentation: present, future, art-historical, archaeological and conservation related.
A prototype of such a database was created during the initial phases of the project (September 2001 – April 2002), limited to the art-historical and conservation documentation in the pilot area of the south wall of the presbytery, including the apse.
An ortho-photomosaicTechnique for the production of planimetrically corrected photographs through scaling, tilting and relief distortion correction was created as a topographical base onto which all information concerning the wall paintings could be spatially referenced.
In order to cover the entire surface, an extensive photographic campaign was carried out: front view not-to-scale images were acquired in 6X6 cm format. Once a useful level of definition had been established, the images were scanned at the proper resolution, then scaled, spatially referenced and mosaicked on the basis of a detailed topographicalTechnique or method of graphically representing the physical features of a territorial region or surface on a map survey of the wall.
To cover the entire south wall of the presbytery (about 106 m2), 70 images and more than 3000 survey points were necessary. Of particular complexity was the coverage, as an ortho-photographic representation, of the curved surface of the semi-dome of the apse. In order to achieve this, the surface was “scanned”, through the use of a laser EDM Total Station, by measuring a total of about 2500 points. This allowed the creation of a 3D model onto which the ortho-images were projected.
The photomosaic of the pilot area was used by the conservators to digitally record topographical data generated by observations, through the use of CADComputer Aided Design software, during the preliminary condition survey. Data regarding the following subjects were recorded: superimposed layers of wall painting and/or historic plaster, execution techniques, condition, former restoration interventions, areas where instrumental measurements were carried out and/or samples for laboratory analysis were collected.
Once all data had been collected, samples were taken, analyses and diagnostics were carried out, all information was systematically organized, correlated through a relational database and connected to a GISGeographic Information System.
This allowed us to spatially refer and integrate such diverse data and types of information. It is planned to extend this database to all the wall surfaces of the church and atrium.
|Explorable photomosaic of the western wall of the Medical Saints Chapel|