CCTV Glossary K to O
- Luminance
- The brightness of a video signal
- LUX
- Used to specify how sensitive cameras are to light (measured in lumens/sq
metre).
e.g. a camera with a LUX Level of 0 can see in pitch black. The lower the
LUX Level the better the camera will see in the dark.
- Mega Pixel Resolution
- Mega Pixel resolution refers to video resolutions now achievable using IP Cameras. Unlike Analogue cameras, whose resolution is usually limited to around 752 x 582 (0.4 Mega Pixels), a Mega Pixel IP Camera can achieve far greater resolutions such as 1280 x 1024 (1.3 Mega Pixels) or 1600 x 1280 (2 Mega Pixels).
This increase in resolution produces far better image quality than a traditional analogue camera could ever achieve.
- Motion Detection
- Recording method for digital surveillance systems. When someone walks
in front of a camera, the pixels change and the DVR defines this as motion.
The surveillance system will then record these images to the hard disk.
This is a popular recording setup as every event recorded is actually
motion driven as opposed to a static image if the system was set to record
'round-the-clock'.
- MPEG
- Motion Picture Experts Group - a video compression technique for video
images
MPEG-4 has fast become the Digital CCTV standard recording compression
format.
MPEG-2 is used for DVD Recording quality.
- Multiplexer
- A Multi Screen CCTV device that allows input of 4, 9, 16 etc cameras
and provides a 'Mutli-Plexed' (or split screen) display of those cameras
- Noise
- Video Signal interference that usually appears as graininess or snow
on the picture.