JPEG: Joint Photographic Experts Group
JPG/JFIF (Joint Photographic Experts Group/JPEG File Interchange Format) is a popular file format for storing raster image data. JFIF is the file format; JPG is the compression method JPG/JFIF is specified in the JPEG File Interchange Format and JPEG (ISO 10918). The Sustainability of Digital Formats site at the Library of Congress contains additional information about the JFIF file format as well as JPG compression encoding.
Currently, the Photographic Imaging, Microfilm and Textual Preservation Lab is using JPEG/JFIF (as well as TIFF) for most distribution files. JPEG files are well-suited for online access and use and are compressed for faster online transmission. JPEG files are created for use in NARA's Archival Research Catalog (ARC) as well as other internal databases, and for many reference requests.
NARA's JPEG/JFIF files are identified as PUID fmt/44 in the PRONOM database.
Although JPEG/JFIF is the formal full name of the file format (Joint Photographic Experts Group/JPEG File Interchange Format), the three character file name extension is JPG. We have used the three character file name here in keeping with he way the file format is most often expressed as a file name extension.
For more technical information about JPEG files, see the Technical White Paper.