Standards

How PHOTARCH aligns with — and differs from — existing imaging standards

The need for standardisation in cultural heritage imaging has long been recognised. Institutions such as the Library of Congress and the National Library of the Netherlands have published detailed technical guidelines to ensure the preservation quality, colour fidelity, and long-term accessibility of digital surrogates (FADGI, 2023; Metamorfoze, 2012).

PHOTARCH builds upon the foundation laid by these initiatives, while adapting their principles to the specific demands of archaeological artefact photography. Unlike flat document scanning or general digitisation workflows, photographing three-dimensional, textured, and context-rich objects in archaeology requires additional considerations: angle control, physical scale, lighting structure, and a consistent visual logic across entire collections.

FADGI and Metamorfoze: Foundational frameworks

The FADGI guidelines (Federal Agencies Digital Guidelines Initiative) outline a multi-star rating system that specifies measurable targets for resolution, noise, colour accuracy, and tonal response. Although these metrics were originally developed for scanning and reprographic capture, many of their technical expectations — such as use of ICC profiles, inclusion of colour targets, and control over tonal range — are directly applicable to photographic documentation (FADGI, 2023).

Metamorfoze, similarly, sets minimum image quality standards for digitisation projects in libraries and archives, with emphasis on lossless formats, proper lighting, and colour management workflows (Metamorfoze, 2012). Both standards provide invaluable baselines for understanding image quality, but neither was built specifically for artefacts or archaeological contexts.

Archaeological imaging: Specific needs

Archaeological artefacts are materially complex, often irregular, and typically require multi-angle documentation. They are also tightly linked to context — spatial, typological, and comparative — which places higher demands on metadata and repeatability. A single image of a ceramic sherd is not simply a visual object; it is part of a broader system of interpretation involving typology, chronology, and provenance.

PHOTARCH addresses these needs by extending existing image standards into a domain-specific method. It integrates lighting geometry and physical reference tools to allow direct comparison between objects from different collections, countries, and excavations. This supplements — rather than replaces — standards like FADGI and Metamorfoze.

Toward a machine-readable future

One of PHOTARCH’s key ambitions is to make archaeological photography machine-readable without sacrificing human interpretability. By structuring camera angles, embedding metadata, and ensuring visual consistency, the method supports not only comparison and education, but also AI-driven categorisation and automated analysis.

As cultural heritage data becomes increasingly digitised, the role of visual standards grows in both technical and ethical importance. A standardised photographic approach ensures not only preservation and accessibility — but also the ability to see, study, and share artefacts more clearly across generations.

References

  • FADGI (2023). Technical Guidelines for Digitizing Cultural Heritage Materials, 3rd ed. Library of Congress.
  • Metamorfoze (2012). Preservation Imaging Guidelines – Image Quality, Version 1.0. National Library of the Netherlands.