Digital format standards

A wide variety of content creation standards exist covering photographs, images, text, moving image and sound. Standards also differ depending on whether the content is digitised or born digital. Many are proprietary, controlled by private or commercial interests, while others are not well supported. Sorting through which digital format standards to use can be challenging, as the choices made at the point of creation strongly determines its future usability.

We recommend digital format standards that follow these principles:

• Quality: A good format is lossless (retains all the information captured) and creates an accurate version that is flexible for future re-use.
• Interoperable: A good format can be used by different software and hardware platforms and migrated to different carriers over time.
• Widely supported: A good format follows a widely supported open or industry standard.
• Self-contained: A good format supports a unique identifier and the ability to embed metadata according to a standard metadata schema.

Continued usability in different environments and contexts is central to good practice, and all standards where possible should support this. We have identified some standards that we consider meet this test.

Download Good Practice Standards - Photographs and images

Resolution Calculators

Two helpful online calculators are available for calculating image resolution for digital scanning.  The first calculator, from Scantips.com, is designed for scanning of negatives, slides and prints of a variety of types and sizes.  The second calculator, from the University of Illinois Library, calculates the resolution you need for scanning text, based on the quality index used for micrographics scanning.

Scanning and Printing Resolution Calculator, Scantips.com

Image Quality Calculator for text and manuscripts, University of Illinois Library

New Zealand resources

We recommend the following New Zealand resources for more in-depth information:

Digitisation Guidelines Specifications for Imaging - Alexander Turnbull Library, National Library of New Zealand, October 2006

Digitisation Standard - Archives New Zealand Government Recordkeeping Group, January 2007

A Guide to Recording Oral History - New Zealand History Online

Overseas resources

We recommend the following international resources for more in-depth information:

A Framework of Guidance for Building Good Digital Collections 3rd Edition - National Information Standards Organization, December 2007

BCR's CDP Digital Imaging Best Practices Version 2.0 - Bibliographical Center for Research, June 2008

Digital capture and image creation: standards and equipment - National Library of Australia

Short Guidelines for Video Digitisation - Training for Audiovisual Preservation in Europe (TAPE)

DIY Bookscanner - a web community for DIY bookscanners and software

Still Images, Moving Images and Sound Advice - JISC Digital Media

Recommended reading

Saving Tape - The New Zealand Film Archive

The Digital Dilemma: Strategic Issues in Archiving and Accessing Digital Motion Picture Materials - The Academy of Motion Picture Arts and Sciences, 2007

The Safeguarding of the Audio Heritage: Ethics, Principles and Preservation Strategy - International Association of Sound and Audiovisual Archives, 2005

Sustainability of Digital Formats: Sustainability Factors - Library of Congress, March 2007

Do you have other suggestions for good practice resources or recommended reading? Leave a comment below with the details.