Axis 26031R3 User Manual

Also see for Axis 216FD: Installation guide Specifications Product guide User manual Installation guide

Axis 26031R3 User Manual Manual pdf 58 page image

58 AXIS 216FD - Glossary of TermsGlossary of TermsActiveX - A standard that enables software components tointeract with one another in a networked environment,regardless of the language(s) used to create them. Webbrowsers may come into contact with ActiveX controls,ActiveX documents, and ActiveX scripts. ActiveX controlsare often downloaded and installed automatically asrequired.AF (Autofocus) - A system by which the camera lensautomatically focuses on a selected part of the subject.Angle - The field of view, relative to a standard lens in a35mm still camera, expressed in degrees, e.g. 30°. Forpractical purposes, this is the area that a lens can cover,where the angle of view is determined by the focal length ofthe lens. A wide-angle lens has a short focal length andcovers a wider angle of view than standard or telephotolenses, which have longer focal lengths.ARP (Address Resolution Protocol) - This protocol is usedto associate an IP address to a hardware MAC address. Arequest is broadcast on the local network to discover theMAC address for an IP address.ARTPEC (Axis Real Time Picture Encoder) - This chip isused for image compression.ASIC (Application Specific Integrated Circuit) - A circuitdesigned for a specific application, as opposed to a generalpurpose circuit, such as a microprocessor.Aspect ratio - A ratio of width to height in images. Acommon aspect ratio used for television screens andcomputer 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 electricallycontrolled by the camera, to automatically regulate theamount of light allowed to enter.AVI (Audio Video Interleave) - A video format thatsupports simultaneous playback of audio and video.Bitmap - A bitmap is a data file representing a rectangulargrid of pixels. It defines a display space and color for eachpixel (or "bit") in the display space. This type of image isknown as a "raster graphic." GIF's and JPEG's are examplesof image file types that contain bitmaps.Because a bitmap uses this fixed raster method, it cannoteasily be rescaled without losing definition. Conversely, avector graphic image uses geometrical shapes to representthe image, and can thus be quickly rescaled.Bit rate - The bit rate (in kbit/s or Mbit/s) is often referredto as speed, but actually defines the number of bits/timeunit and not distance/time unit.Bluetooth - Bluetooth is an open standard for wirelesstransmission 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 eachother on a network, without having to enter IP addresses orconfigure DNS servers. Bonjour is a trademark of AppleComputer, Inc..Broadband - In network engineering terms, this describestransmission methods where two or more signals share thesame carrier. In more popular terminology, broadband istaken to mean high-speed data transmission.CCD (Charged Coupled Device) - This light-sensitive imagedevice used in many digital cameras is a large integratedcircuit that contains hundreds of thousands of photo-sites(pixels) that convert light energy into electronic signals. Itssize is measured diagonally and can be 1/4", 1/3", 1/2" or2/3".CGI (Common Gateway Interface) - A specification forcommunication between a web server and other (CGI)programs. For example, a HTML page that contains a formmight use a CGI program to process the form data once it issubmitted.CIF (Common Intermediate Format) - CIF refers to theanalog video resolutions 352x288 pixels (PAL) and 352x240pixels (NTSC). See also Resolution.Client/Server - Client/server describes the relationshipbetween two computer programs in which one program, theclient, makes a service request from another program, theserver, which fulfils the request. Typically, multiple clientprograms share the services of a common server program. Aweb browser is a client program that requests services (thesending of web pages or files) from a web server.CMOS (Complementary Metal Oxide Semiconductor) - ACMOS is a widely used type of semiconductor that uses bothnegative and positive circuits. Since only one of the circuittypes is on at any given time, CMOS chips require lesspower than chips using just one type of transistor. CMOSimage sensors also allow processing circuits to be includedon the same chip, an advantage not possible with CCDsensors, which are also much more expensive to produce.Codec - In communications engineering, a codec is usuallya coder/decoder. Codecs are used in integrated circuits orchips that convert e.g. analog video and audio signals into adigital format for transmission. The codec also convertsreceived digital signals back into analog format. A codecuses analog-to-digital conversion and digital-to-analogconversion in the same chip.Codec can also mean compression/decompression, in whichcase it is generally taken to mean an algorithm or computerprogram for reducing the size of large files and programs.Compression - See Image Compression.Contrast - Defines the degree of difference between thelightest and darkest parts of an image or video stream.DC-Iris - This special type of iris is electrically controlledby the camera, to automatically regulate the amount of light