Web-sharing for a cultural heritage computer database of Central Sicilian monuments

Paintings, etchings and lithographs are a way of documenting and journeying into the past. One of the most important values of pictures, though often neglected, is that they are an inexhaustible source of knowledge both for architectural historians and for architect restorers. They contain a lot of important data and this information can be an extremely useful aid to understanding cultural heritage in urban and historic sites. The lithographic prints made by Grand Tour travellers (even allowing for the possible subjectivity of the artist’s interpretation), the guides, the albums and the collections of images especially created to increase the aesthetic and cultural values of private libraries, provide an iconographic description (and at the same time a catalogue) of an architectural heritage and landscape that are not always recognizable today. Photography later supplemented and developed this documentary role of paintings, although it did not completely overcome the constraints arising from the personal vision of the photographer. With the advent of social networks, the role of photography, once restricted by the local diffusion environment and limited by the heaviness of paper, crossed many of its borders. Tools for sharing photo albums like Flickr, Facebook, Picasa, etc., allowing people almost instantly to share photos taken anywhere in the world, fulfill an essential function of "reality” documentation. This "random” material is a public catalogue, easily accessible and continuously updated, even if still limited to the status of mere “image”. Nowadays, the new generation of laser scanners, ever smaller and lighter and equipped with integrated coaxial cameras, can deliver accurate measurements of architectural structures and their environment, in a very short time. These instruments can provide point clouds that are in reality 3D photographs, from which a wide range of information can be extracted and they can create 3D models to be published on the Web for cataloguing and archival purposes. In particular, the FARO SCENE 4.8, the latest version of the scan processing software for the FARO Laser Scanner, incorporates the specific one-click WebShare function. This application makes it possible to publish scanned data on the Internet, thus enabling everyone to share images, including metric, technical and material property information. Unlike photographs, which deliver only the image of the monument, the 3D model can be sliced in order to obtain cross-sections and plans; it can be examined and processed to give orthophotos; finally it can yield data which is useful for understanding the chemical and physical properties of the artifact. Unlike images, however, the model obtained from a point cloud is an incredible database, a kind of "solid" photograph which allows the material state of an architectural object to be “penetrated”. This paper aims to address the issue of the new frontier represented by laser scanning methodology and its usefulness in the field of documenting cultural goods, starting from the objectives (and showing the first results) of a wide-ranging project of Web-documentation of the cultural heritage of Central Sicily.