Term of the Moment
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Redirected from: metainformation
Definition: metadata
Data that describes other data. For example, data dictionaries and repositories provide information about the data elements in a database (see data dictionary). Digital cameras store metadata in the image files that include the date the photo was taken along with camera settings (see EXIF). Digital music files contain metadata such as song title and artist name (see ID3 tag). Metadata are stored in an HTML page (Web page) to help search engines define the page properly, and most especially, make it rank higher in the results list (see meta tag).
A Glaring Lack of Metadata
Music CDs were initially designed without metadata, such as album name, song titles and artist names. When the CD format was created in the early 1980s, there was no thought given to such metadata even though a couple thousand bytes out of more than six hundred million on the disc could have easily been reserved for future use. Later on, when CDs were played on a computer, the metadata was retrieved by an Internet search based on the track length in minutes and seconds of each song. A somewhat circuitous approach. When metadata was finally added to the CD format, old players could not support it. See CDDB.
Metadata in the Snowden Debacle
After former CIA employee Edward Snowden leaked top-secret American surveillance programs to the press in 2013, metadata came front and center. It was revealed that the U.S. National Security Agency (NSA) had undertaken massive phone surveillance, and the controversy was about what was recorded: the actual voice conversations or only the metadata (call times and telephone numbers). Even if voice content is not recorded, the call metadata can be analyzed to determine who contacted suspected terrorists.
Metadata in an Image File
A Ton More
A Glaring Lack of Metadata
Music CDs were initially designed without metadata, such as album name, song titles and artist names. When the CD format was created in the early 1980s, there was no thought given to such metadata even though a couple thousand bytes out of more than six hundred million on the disc could have easily been reserved for future use. Later on, when CDs were played on a computer, the metadata was retrieved by an Internet search based on the track length in minutes and seconds of each song. A somewhat circuitous approach. When metadata was finally added to the CD format, old players could not support it. See CDDB.
Metadata in the Snowden Debacle
After former CIA employee Edward Snowden leaked top-secret American surveillance programs to the press in 2013, metadata came front and center. It was revealed that the U.S. National Security Agency (NSA) had undertaken massive phone surveillance, and the controversy was about what was recorded: the actual voice conversations or only the metadata (call times and telephone numbers). Even if voice content is not recorded, the call metadata can be analyzed to determine who contacted suspected terrorists.
A huge amount of metadata can be stored in an image file. The IPTC Core section (expanded below) is a metadata standard from the International Press Telecommunications Council for adding creation data.
An image file can be edited to include a huge amount of metadata to describe the file. DICOM stands for Digital Imaging and Communications in Medicine.