The use of digital technologies has opened up access to the primary sources that are fundamental to humanities scholars. Whether this is through straightforward digital photography, audio capture of oral histories, or more advanced techniques that give access to three-dimensional objects and landscapes, the ability to understand sources in detail without needing access to original artefacts has enabled new research and democratised fields of study.
As these technologies develop, new methods have been developed of enhancing and displaying features of artefacts that have been otherwise hidden. 3D scanning and photogrammetry have allowed the analysis of object use, and enable us to print 3D surrogates that can be handled and explored. Techniques such as RTI allow the enhancement of surface structure, making worn and difficult inscriptions more readable. And methods such as multi-spectral imaging reveal new secrets such as the composition of pigments and inks, and the ability to isolate textual features.
Underlying this is a methodical and scientific approach to imaging that aims to preserve and protect the original sources, that is gathered under the umbrella of Digital Humanities. Many of these methods are new to humanities study, though they have been prevalent in other disciplines for some time. The application of digital methods to the study of human cultures, languages and arts remains an exciting field of development.
Digital media are increasingly popular in museum exhibitions, and a growing number of heritage institutions and museums are undertaking 3D digitisation of their collections to develop engaging displays for in-person audiences as well as online. Digitisation can also supplement traditional techniques for preserving and documenting physical cultural heritage, and enable investigations and research without the need for physical access.
One key benefit of digitising 3D objects is the possibility of sharing them online, opening accessibility to much wider audiences than was previously possible. For example:
There are a number of widely used techniques for creating 3-dimensional representations of objects. Each places emphasis on a different aspect of the representation, whether this is the visual effect, the accurate capture of colour or shape, the enhancement of certain features, or the creation of 3D surrogates through use of 3D printing.
Photogrammetry has developed from techniques of stereoscopy and structure from motion to become a general-purpose tool to capture and create objects and landscapes. It takes still images of a scene from viewpoints all around a given subject, and using the embedded metadata and other information in the images, recreates the structure and surface colour of the subject. It can produce highly accurate results if the process of taking images is carefully controlled.
Structured Light Scanning allows a more interactive process of creating a 3D surrogate. The scanner throws a pattern of light across an object, and uses sensors to read the reflected pattern, discerning the surface shape from this in real time. On some models of scanner, cameras capture colour information in addition, to create a wire frame model with an overlay or skin of texture and colour.
Laser Scanning provides a means to capture large structures, such as archaeological sites or buildings. The scanner is placed at appropriate locations around the site, and the structure of the scene is calculated from the time-of-flight of a laser beam cast around the scanner. Placement of the scanner is crucial, and usually multiple captured scenes are merged to create a full view of the site.
Reflectance Transformation Imaging is a method for extracting 3-dimensional surface data from a single viewpoint. By varying the lighting angles in a controlled manner, it creates a matrix of surface 'normals' that indicate the direction of reflected light from the surface. The result is an interactive image, where the light source can be moved digitally to provide an almost 3-dimensional view of the object. This representation of the surface can be enhanced mathematically to exaggerate the surface relief, and can produce views of marks, inscriptions and indentations on surfaces to assist in reading or for scientific understanding, e.g. butchery marks on bones or tool marks on bindings.