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.
3D recording, documentation and management of cultural heritage by
Documentation of our cultural heritage is experiencing an explosion of innovation. New tools have appeared in recent decades including laser scanning, rapid prototyping, high dynamic range spherical and infrared imagery, drone photography, augmented and virtual reality and computer rendering in multiple dimensions. These give us visualisations and data that are at once interesting, intriguing and yet sometimes deceptive. This text provides an objective and integrated approach to the subject, bringing together the techniques of conservation with management, photographic methods, various modelling techniques and the use of unmanned aerial systems. This interdisciplinary approach addresses the need for knowledge about deploying advanced digital technologies and the materials and methods for the assessment, conservation, rehabilitation and maintenance of the sustainability of existing structures and designated historic buildings. Furthermore, this book actively provides the knowhow to facilitate the creation of heritage inventories, assessing risk, and addressing the need for sustainability.In so doing it becomes more feasible to mitigate the threats from inherent and external causes, not only for the built heritage but also for moveable objects and intangible heritage that suffer abandonment and negligence as well as looting and illegal trafficking. The book is written by a team of international experts based upon their practical experience and expertise. It therefore creates a unique book that encapsulates the knowledge of this discipline required by anyone working in this field.
Digital Techniques for Documenting and Preserving Cultural Heritage by 
Photogrammetric Applications for Cultural Heritage by
This guidance covers the practical application of photogrammetry in recording cultural heritage, with particular reference to structure from motion (SfM) techniques. Our audience for this document includes survey contractors, archaeological contractors, voluntary organisations and specialists. Photogrammetric image acquisition and processing, until recently requiring a considerable investment in hardware and software, are now possible at a fraction of their former cost. This has led to a huge increase in the use of photogrammetry in cultural heritage recording. The skills required to apply the techniques successfully and accurately are discussed, and background information on how various parts of the process work is provided so that better results can be achieved through better understanding. Photogrammetry is characterised by its versatility, and is applicable over a wide range of scales, from landscapes to small objects. The particular requirements needed at these different scales are outlined, and both imaging techniques and useful ancillary equipment are described. The different types of outputs are discussed, including their suitability for further interrogation using a range of established analytical techniques and the presentation options available. A range of case studies illustrates the application of photogrammetry across a variety of projects that broadly reflect the areas discussed in the text. This document is one of a number of Historic England technical advice documents on how to survey historic places.
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.
Visit our photogrammetry page to find out more about how this method can be used.
