Q-R

QCIF

This resolution is one quarter of CIF, with 144 lines and 176 pixels per line.

Quad

Utilizing digital video, this piece of equipment displays signals from four surveillance cameras on one monitor.

Range finder

This is a device that determines the required focal length and the resulting monitor image. While looking through it, the user can adjust the range finder to get the optimal image, with numbers on the range finder displaying the needed focal length.

Raster

A raster is a rectangular scan pattern of lines that the picture is created upon. It also refers to an active TV monitor that has no video information displayed.

Real Media

Real Networks developed an early multimedia protocol for video and audio (often streaming) called Real Media.

Real time video

Any picture having 24 or more frames per second appears continuous, or in real time.

Reed switch

This type of alarm activating device becomes active when contact is either opened or closed, as in a door or window being opened or closed. They are also capable of switcher activation to activate the relevant security camera.

Regulated power supply

A DC power supply with a minimal ripple factor is considered to be regulated.

Remote head surveillance camera

For surveillance situations where space is limited, this type of camera separates the CCD chip from the camera body by cable, considerably shrinking the overall camera size.

Remote monitoring

This allows an offsite user to monitor surveillance camera feeds, so a user can survey a site regardless of their location from it. The transfer of data from camera to user can be either over the Internet or the Ethernet, with IP cameras being suited to the task.

RF (Radio Frequency)

In order to be broadcast across a wireless network, video signals must be modulated into a RF signal.

RG-11

Having a thick centre core, this type of coaxial cable is used to transmit video signals of up to 550m.

RG-59

More commonly used than RG-11 for CCTV, this coaxial cable transmits video signals of up to 230m.

RGB (Red Green Blue)

These are the three primary colours of light. All other colours are derived from their mixture.

Ripple factor

Too little filtering in a DC power supply creates an amplitude variation called the ripple factor; with large amounts of it able to damage DC powered surveillance cameras.

ROI (Region of Interest)

Applied to the field of video surveillance, ROI stands for Region of Interest, meaning an area of the frame where motion is detected, in turn activating the surveillance camera.

Router

A router is a piece of equipment facilitating the exchange of packets throughout LAN or WAN networks. It moves packets across a predetermined path to their destination by storing and forwarding the packets, and then determining their optimal path along the network. A router is hardware based, but can also include software.

RS232 (or RS-232)

This is the communication standard that applies to PC serial communications. RS232 is commonly used as the mechanism for sending instructions that control PTZ security camera movement.

RTP (Real-time Transport Protocol)

RTP is a packet based communication protocol that adds timing and sequence information to each packet to allow the reassembly of packets to reproduce real time audio and video information. RTP is a transport used in IP audio and video environments

RTSP (Real Time Streaming Protocol)

This open standard for Internet streaming of audio and video is popular among DVR makers for remote viewing of live or stored security camera video over the Internet. RTSP controls the transmission of the data stream much the way a television remote controls the television. Like RTP, interoperability problems exist between different DVR systems.