Bodyline Products International 216FD-V - Manual (Page 62)

62 AXIS 216FD/FD-V/MFD/MFD-V - Glossary of Terms
Glossary of Terms
ActiveX - A standard that enables software components to
interact with one another in a networked environment,
regardless of the language(s) used to create them. Web
browsers may come into contact with ActiveX controls,
ActiveX documents, and ActiveX scripts. ActiveX controls
are often downloaded and installed automatically as
required.
AF (Autofocus) - A system by which the camera lens
automatically focuses on a selected part of the subject.
Angle - The field of view, relative to a standard lens in a
35mm still camera, expressed in degrees, e.g. 30°. For
practical purposes, this is the area that a lens can cover,
where the angle of view is determined by the focal length of
the lens. A wide-angle lens has a short focal length and
covers a wider angle of view than standard or telephoto
lenses, which have longer focal lengths.
ARP (Address Resolution Protocol) - This protocol is used
to associate an IP address to a hardware MAC address. A
request is broadcast on the local network to discover the
MAC address for an IP address.
ARTPEC (Axis Real Time Picture Encoder) - This chip is
used for image compression.
ASIC (Application Specific Integrated Circuit) - A circuit
designed for a specific application, as opposed to a general
purpose circuit, such as a microprocessor.
Aspect ratio - A ratio of width to height in images. A
common aspect ratio used for television screens and
computer monitors is 4:3. High-definition television (HDTV)
uses an aspect ratio of 9:16.
Autoiris (or DC-Iris) - This special type of iris is electrically
controlled by the camera, to automatically regulate the
amount of light allowed to enter.
AVI (Audio Video Interleave) - A video format that
supports simultaneous playback of audio and video.
Bitmap - A bitmap is a data file representing a rectangular
grid of pixels. It defines a display space and color for each
pixel (or "bit") in the display space. This type of image is
known as a "raster graphic." GIF's and JPEG's are examples
of image file types that contain bitmaps.
Because a bitmap uses this fixed raster method, it cannot
easily be rescaled without losing definition. Conversely, a
vector graphic image uses geometrical shapes to represent
the image, and can thus be quickly rescaled.
Bit rate - The bit rate (in kbit/s or Mbit/s) is often referred
to as speed, but actually defines the number of bits/time
unit and not distance/time unit.
Bluetooth - Bluetooth is an open standard for wireless
transmission of voice and data between mobile devices (PCs,
handheld computers, telephones and printers).
Bonjour - Also known as zero-configuration networking,
Bonjour enables devices to automatically discover each
other on a network, without having to enter IP addresses or
configure DNS servers. Bonjour is a trademark of Apple
Computer, Inc..
Broadband - In network engineering terms, this describes
transmission methods where two or more signals share the
same carrier. In more popular terminology, broadband is
taken to mean high-speed data transmission.
CCD (Charged Coupled Device) - This light-sensitive image
device used in many digital cameras is a large integrated
circuit that contains hundreds of thousands of photo-sites
(pixels) that convert light energy into electronic signals. Its
size is measured diagonally and can be 1/4", 1/3", 1/2" or
2/3".
CGI (Common Gateway Interface) - A specification for
communication between a web server and other (CGI)
programs. For example, a HTML page that contains a form
might use a CGI program to process the form data once it is
submitted.
CIF (Common Intermediate Format) - CIF refers to the
analog video resolutions 352x288 pixels (PAL) and 352x240
pixels (NTSC). See also Resolution.
Client/Server - Client/server describes the relationship
between two computer programs in which one program, the
client, makes a service request from another program, the
server, which fulfils the request. Typically, multiple client
programs share the services of a common server program. A
web browser is a client program that requests services (the
sending of web pages or files) from a web server.
CMOS (Complementary Metal Oxide Semiconductor) - A
CMOS is a widely used type of semiconductor that uses both
negative and positive circuits. Since only one of the circuit
types is on at any given time, CMOS chips require less
power than chips using just one type of transistor. CMOS
image sensors also allow processing circuits to be included
on the same chip, an advantage not possible with CCD
sensors, which are also much more expensive to produce.
Codec - In communications engineering, a codec is usually
a coder/decoder. Codecs are used in integrated circuits or
chips that convert e.g. analog video and audio signals into a
digital format for transmission. The codec also converts
received digital signals back into analog format. A codec
uses analog-to-digital conversion and digital-to-analog
conversion in the same chip.
Codec can also mean compression/decompression, in which
case it is generally taken to mean an algorithm or computer
program for reducing the size of large files and programs.
Compression - See Image Compression.
Contrast - Defines the degree of difference between the
lightest and darkest parts of an image or video stream.
DC-Iris - This special type of iris is electrically controlled
by the camera, to automatically regulate the amount of light