We have used the three character file name here in keeping with the way the file format is most often expressed as a file name extension.
FILE EXTENSION DEFINITION FULL
NARA's WAV files are identified as PUID fmt/141 and fmt/142 in the PRONOM database.Īlthough WAVE is the formal full name of the file format (Waveform Audio File Format), the three character file name extension is WAV. The Sustainability of Digital Formats site at the Library of Congress contains information about the WAV file format. Sampling frequency, bit-depth, and monophonic or stereo, for example, are important characteristics of audio files. A codec performs the encoding and decoding of the raw audio data while the data itself is stored in a specific audio file format, such as Broadcast WAV (.wav). For audio files, it is important to distinguish between a file format and a codec.
FILE EXTENSION DEFINITION PDF
NARA's PDF files version 1.4 and are identified as PUID fmt/18 in the PRONOM database.Ĭurrently, the Photographic Imaging, Microfilm and Textual Preservation Lab are using the PDF format for distribution purposes only.Īn audio recording produced from original analog or digital audio formats that has been encoded using linear Pulse Code Modulation (PCM). Additional information about the PDF format can be found at the Sustainability of Digital Formats site at the Library of Congress. There are several subtypes of PDF including PDF-A.
PDF (Portable Document Format) is a popular format for storing many types of data including raster images. NARA's TIFF files are identified as PUID fmt/353 in the PRONOM database.Īlthough TIFF is the formal full name of the file format (Tagged Image File Format), the three character file name extension is TIF. The TIFF file format is a stable, well-documented, widely adopted, uncompressed file format widely used for master files in the digital imaging community. Additional information about the TIFF file format can be found at the Sustainability of Digital Formats site at the Library of Congress.Ĭurrently, the Photographic Imaging, Microfilm and Textual Preservation Lab is using the TIFF file format for both preservation master and most reproduction master files. TIFF (Tagged Image File Format) is a popular format for storing raster image data and is specified in TIFF Revision 6.0 from Adobe Systems. 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. NARA's JPEG/JFIF files are identified as PUID fmt/44 in the PRONOM database.Īlthough 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. JPEG files are created for use in NARA's Online Catalog as well as other internal databases, and for many reference requests. JPEG files are well-suited for online access and use and are compressed for faster online transmission. 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.Ĭurrently, the Photographic Imaging, Microfilm and Textual Preservation Lab is using JPEG/JFIF (as well as TIFF) for most distribution files. JFIF is the file format JPG is the compression method JPG/JFIF is specified in the JPEG File Interchange Format and JPEG (ISO 10918). JPG/JFIF (Joint Photographic Experts Group/JPEG File Interchange Format) is a popular file format for storing raster image data. Raster images can be stored in a variety of data formats, such as TIFF (.tif). Bit-depth, spatial resolution, and color encoding, for example, are all important characteristics of still images. The term raster data is often contrasted with vector data, in which geometrical points, lines, curves, and shapes are based upon mathematical equations, thus creating an image without specific mapping of data to pixels. A still image is data in which a grid or raster of picture elements (pixels) has been mapped to represent a visual subject, e.g., the page of a book or a photograph. Digital file types describe the types and characteristics of the files produced from the digitization of original record materials at NARA, as well as the standard or most common data formats that the Digitization Services Branch uses to store digitized records.Ī type of digital object that is created from the digitization of still image (textual documents and photographs) originals.