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Glossary of Technical Terms

The following is a glossary of scanning related technical terminology.


  • 8 bit grayscale contains 256 possible shades of gray.
  • 24 bit color contains a possible 16 million distinct colors. This method of scanning produces the largest file size.
  • 32 bit color contains a possible 16 million distinct colors as with 24 bit color and the other eight bits are used as a separate layer for representing levels of translucency in an object or image.
  • Bitmap provides a way to store a binary image, that is, an image in which each pixel is either black or white (or any two colors).
  • Color depth is the number of bits used to indicate the color of a single pixel in a bitmapped image. (See 8 bit grayscale, 24 bit color and 32 bit color above).
  • Crop refers to removing excess information that is surrounding an image of the original document but is not part of the image, like a white border.
  • Deskew is the ability of a scanner to detect that the item being scanned is not straight and to realign the scanned image to be straight.
  • DPI (dots per inch), the number of pixels per inch used in an image and determines the resolution of the image. See also resolution.
  • Duplex indicates two sided documents. A duplex scanner will scan both sides of a document at the same time.
  • Enhanced halftone is a conversion of a multitonal image to a bitonal image in such a way that the impression of a mulitonal image is retained.
  • Footprint represents the length and width dimensions of the scanner, indicating how much space is required for the device.
  • JPEG (jpg) stands for Joint Photographic Experts Group, the committee that created the JPEG standard. It defines how an image is compressed into a stream of bytes and decompressed back to an image.
  • Mbit/s (megabits per second) – the number of bits of data that are transferred per second. 1 megabit = 1,000,000 bits.
  • OCR (Optical Character Recognition) is electronic conversion of scanned images of handwritten, typewritten or printed text into machine-encoded text.
  • PDF (Portable Document Format) is an open file format created by Adobe in 1993 and is an accepted standard for digital file sharing.
  • Resolution is degree of fineness with which an image can be recorded or produced, often expressed as the number of pixels per unit of length (typically an inch).
  • Scan2Net® technology provides a code-free client via any web browser for all Image Access scanners. Scan2Net® frees the host PC from all image related and time critical tasks. Read more about this technology in the whitepaper on our website. http://www.imageaccess.de/?page=WhitePapersScan2NetDifference&lang=en
  • TIFF (Tagged Image File Format) is a storage format widely supported by image manipulation software applications.