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.
This is a glossary of some of the technical terms referred to in this catalog.
Image Access has a full list of technical terms and their definitions on our
website.
See the full glossary at
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.
Glossary of Terms
23
Continued on next page —>
