Image Acquisitionand Proces

Glossary 235
Resolution There are two types of resolution in digital images: spatial and
intensity. Spatial resolution is the number of pixels per unit of length
along the x and y axis, whereas intensity resolution is the number of
quantized brightness levels that a pixel can have.
RGB Red, green, blue. A triplet of numeric values used to describe a color.
ROI Region of interest. A speciÞcation structure that allows for the deÞnition
of arbitrarily shaped regions within a given image. A ROI is a placeholder
that remembers a location within an image. The ROI can encompass the
entire image. See also AOI.
Scan line See Raster.
Screen Coordinates Screen coordinates are those of the actual graphics display
controller, with its origin at the upper lefthand corner of the display. See
also Coordinates.
Segment A contiguous section of a raster line deÞned in physical coordinates
by the triplet of its left-most point and length (x, y, l).
Systems Integrator A service provider who can deliver a custom hardware and
software system, integrating various components from different manufacturers,
often writing custom software and fabricating custom hardware.
TGA TrueVision Corporation Þle format extension.
TIFF Tagged Image File Format extension.
Thumbnail A small copy of an image usually used to display many images on
the screen at once in a browser conÞguration.
Transform An algorithm that alters an image, often written as xform. See also
Point Transform, Neighborhood Transform and Geometric Transform.
Triplet Three numbers which when used together represent a single quantity or
location (e.g., RGB or x, y, z.)
Umbras Portions of a shadow that are neither totally light nor totally dark.
Video Signal A time varying signal where the amplitude of the signal is proportional
to the light sensed on a point in the image, and the elapsed time
identiÞes the location of the sensed point in an image.
Video Stream A sequence of still images that are transmitted and displayed in
synchronous order given the appearance of live motion.
WMF Microsoft Corporation Windows MetaFile Format Þle format extension.
WPG Word Perfect Corporation Þle format extension.