Milestone LPR 1.0 - Manual (Page 42)

Milestone XProtect
®
LPR 1.0 Administrator's Manual
www.milestonesys.com 42 Glossary
Glossary
A
Aperture: On a camera, aperture refers to the adjustable opening (a.k.a. iris) used for controlling the
amount of light coming through a lens. The aperture thus has a significant effect on the exposure of
images.
D
Dynamic range: A camera's dynamic range determines, among other things, its sensitivity in low- and
high-light conditions, how it reacts to changing light conditions, and how sensitive it is to infrared
lighting.
E
Event: A predefined incident occurring on the surveillance system; used by the surveillance system for
triggering actions. Depending on surveillance system configuration, events may be caused by input
from external sensors, by recognized motion, by data received from other applications, or manually
through user input. The occurrence of an event could, for example, be used for making a camera
record with a particular frame rate, for activating outputs, for sending e-mail alerts, or for a combination
thereof.
F
FPS: Frames Per Second, a measurement indicating the amount of information contained in video.
Each frame represents a still image, but when frames are displayed in succession the illusion of
motion is created. The higher the FPS, the smoother the motion will appear. Note, however, that a
high FPS may also lead to a large file size when video is saved.
Frame rate: A measurement indicating the amount of information contained in motion video. Typically
measured in FPS (Frames Per second).
G
Gain: Gain is basically the way in which a camera takes a picture of a scene and distributes light into
it.
I
Interlacing: Interlacing is a method determining how an image is refreshed when shown on a screen.
With interlacing, the image is refreshed by first scanning every other line in the image, then scanning
every opposite line, and so forth. This allows for a faster refresh rate because less information must be
processed during each scan. However, in some situations, interlacing may cause flickering, or the
changes in only half of the image's lines for each scan may be noticeable.
Iris: On a camera, iris refers to the adjustable opening (a.k.a. aperture) used for controlling the
amount of light coming through a lens. Iris thus has a significant effect on the exposure of images.
J
JPEG: An image compression method, also known as JPG or Joint Photographic Experts Group. The
method is a so-called lossy compression, meaning that some image detail will be lost during
compression. Images compressed this way have become generically known as JPGs or JPEGs.
JPG: An image compression method, also known as JPEG or Joint Photographic Experts Group. The
method is a so-called lossy compression, meaning that some image detail will be lost during
compression. Images compressed this way have become generically known as JPGs or JPEGs.
K