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A-to-D converter
Device that receives analog sound waveforms as an input and produces a digital audio stream, most frequently in Linear Pulse Code Modulation encoding.…
See Linear Pulse Code Modulation
A/D Converter
See A-to-D converter
Access file
See Derivative file
The degree to which the information correctly describes the object or process being measured. It can be thought of in terms of how close a reading or average of readings is to a true or target value. Accuracy is a different measure than precision.…
See Precision
Light perceived as having no hue, this includes the shades of neutral gray from white to black.…
An objective SFR-derived metric weighted by the Contrast Sensitivity Function (CSF) used to predict the subjective impression of sharpness.…
Adaptive thresholding
See Thresholding, adaptive
See Automatic Document Feeder
ADF scanner
See Sheetfed scanner
Administrative metadata
See Metadata, administrative
Adobe RGB
Adobe RGB is a Red-Green-Blue color space developed to display on computer monitors most of the colors of CMYK color printers. Adobe RGB specifies a D65 white point at a luminance of 160 cd/m2 and a gamma of 2.2. The Adobe RGB color space is significantly larger than the sRGB color space particularly in…
The Association for Information and Image Management (AIIM) was founded in 1943 as the National Microfilm Association and has evolved to serve the Enterprise Content Management Industry. AIIM’s Standards Program began developing standards in the early 1960s as a subcommittee of the American Library Association; today it is comprised of more than twenty committees…
A specific value assigned to a given metric to assess performance achievement. …
A sampling effect that leads to spatial frequencies being falsely interpreted as other spatial frequencies.…
See Also Distortion; Noise; Pixellation
An acronym for Analyzed Layout and Text Object, ALTO is an OCR output schema to store document layout and content information in XML format. ALTO is an extension schema to METS that was developed as a part of the METAe project. Sometimes referred to as METS/ALTO or METS/ALTO XML.…
Ambient light
Light existing in the environment that is not produced by the imaging system. Ambient light can be natural or artificial light. Ambient light is generally uncontrolled and can be highly variable, posing a possible risk to image quality. The level of ambient light should be minimized in relation to the level of light produced…
American Society for Quality
Analyzed Layout and Text Object
Represented by the symbol "Å," the angstrom is a unit of measure equal to 0.1 nanometer. The angstrom is a unit of measure commonly used in atomic measurements as well as the wavelengths of electromagnetic radiation.…
The American National Standards Institute (ANSI) is a private nonprofit organization that administers and coordinates the United States voluntary standards and conformity assessment system. Founded in 1918, it is the official U.S. representative to the world’s leading standards organizations, including the International Organization for Standardization (ISO), the International Electrotechnical Commission (IEC), and other regional…
Apochromatic lens
Lens designed to bring all colors into focus on the same plane. Film scanning lenses must be apochromatic and of a flat field design.…
See Also Flat fielding; Transmissive scanning
Application profile
Metadata set that consists of data elements drawn from different metadata schemas, which are combined, customized, and optimized for a particular local application or project.…
Archival master file
File that represents the best copy produced by a digitizing organization, with best defined as meeting the objectives of a particular project or program. In some cases, an archive may produce more than one archival master file. The terms used to name types of files vary within the digital library and digital archiving…
See Also Archival primary file; Production master file; Production primary file; Derivative file
Archival primary file
The term master carries with it a problematic social history for many in the cultural heritage, digital preservation and technology communities. In alignment with terminology changes in the wider software, technology and GLAM communities, FADGI states that the term primary is an acceptable substitute for master and the two convey the same intentions and meanings.…
See Also Archival master file; Production master file; Production primary file; Derivative file
Any orderly arrangement of individual sensor elements. In digital imaging, there are primarily three array types; two dimensional or area arrays, one dimensional or linear arrays, and tri-linear arrays consisting of three consecutive linear arrays of red, green, and blue sensitive sensor elements.…
See Also Bayer color filter array; Color filter array
Artifact (defect)
General term to describe a broad range of undesirable flaws or distortions in digital reproductions produced during capture or data processing. Some common forms of image artifacts include noise, chromatic aberration, blooming, interpolation, and imperfections created by compression, among others. In digital sound recordings, the effect of lossy compression is often cited as…
See Also Distortion; Compression, lossy; Noise; Moiré pattern
Artifactual value
See Informational and artifactual value
Aspect ratio
The relationship between the horizontal and vertical dimensions of an image. The horizontal dimension is normally listed first. For example, a 4-inch (vertical) by 6-inch (horizontal) print has an aspect ratio of 3:2.…
The American Society for Quality (ASQ) was formed in 1946 as the "American Society for Quality Control." With members in more than 120 countries, and its World Partner and Strategic Alliance international programs, it is the world\'s leading authority on quality. ASQ members use time-tested methods and processes to improve work in Education,…
Association for Information and Image Management
Automatic Document Feed Scanner
See Sheetfed scanner
Automatic Document Feeder
An attachment that can be added to many flatbed scanners to allow scanning batches of loose sheets in an unattended manner, often referred to as an ADF.…
See Sheetfed scanner