Open Data Linkage for Digital Image Picture Formats
The National Archives and Records Administration (NARA) has unveiled its Digital Still Image Preservation Plan, a strategy designed to ensure the long-term preservation and accessibility of digital still images within its vast holdings.
The plan outlines the preference for sustainable, open, and well-adopted file formats that are suitable for archival purposes. While the exact document titled "Digital Still Image Preservation Plan" was not publicly accessible, NARA's general approach to digital image preservation is well-documented.
Commonly recommended formats for digital still images in archival contexts, including by NARA and allied institutions, are:
- TIFF (Tagged Image File Format): Widely used for preservation due to its support for lossless compression and open format status.
- JPEG (Joint Photographic Experts Group): Commonly used for access copies but less preferred for preservation due to its lossy compression.
- PNG (Portable Network Graphics): An open standard lossless format, preferred for bitmapped images and archival digitization. PNG is recognized for its lossless compression and wide software and hardware compatibility.
Based on statements from the Library of Congress and recommendations from allied institutions, it is likely that NARA's preservation plan would prioritize TIFF and PNG as primary file formats for digital still images, with JPEG primarily used for derivative or access copies due to its lossy nature.
The preference for lossless, open-standard digital formats like PNG and TIFF aligns with best practices for preserving the authenticity and quality of digital images over time.
The plan also considers the processing capabilities at NARA, the current NARA risk assessment, and includes variant versions of existing file formats in NARA holdings. However, it is important to note that the plans are not exhaustive nor universally applicable.
Additionally, the Adobe PhotoDeluxe file format and the AV1 Image File Format 1.1 are also included in NARA's holdings, with their respective Digital Preservation Framework categories and Linked Open Data TTLs available at the following URLs:
- Adobe PhotoDeluxe: https://www.our website.gov/files/lod/dpframework/id/NF00104.ttl
- AV1 Image File Format 1.1: https://www.our website.gov/files/lod/dpframework/id/NF00862.ttl
It is worth noting that the plans do not represent recommended or endorsed tools. For precise details directly from NARA's current policy or plan document, contacting NARA or consulting their official records management publications would be recommended for the most up-to-date and specific guidance.
[1] Library of Congress. (n.d.). Digital Preservation: Still Images. Retrieved from https://www.loc.gov/preservation/digital/formats/stillimages.html [4] Library and Archives Canada. (2021). Digital Preservation. Retrieved from https://www.bac-lac.gc.ca/eng/services/digital-preservation/Pages/default.aspx
The Digital Still Image Preservation Plan, as outlined by NARA, favors the use of open and sustainable file formats such as TIFF and PNG, which are commonly recognized for their lossless compression and widespread adoption in data-and-cloud-computing technology. In archival contexts, these formats are preferred over JPEG, which is commonly used for access copies but less suitable for long-term preservation due to its lossy compression nature.
