An IFrame is a complete image frame (known as an Intra Frame) in MPEG encoding that is coded without reference to other pictures. Compression is achieved by reducing spatial redundancy in the image, but not temporal redundancy.
This device is used to intensify low-level lighting conditions via light sensitive phosphor screens, and is specifically used to improve the performance of surveillance cameras in low light conditions.
The plane at right angles to the optical axis at the image point.
Measured in ohms, impedance describes the input and output characteristic of an electrical system. For the best signal quality, both input and output impedances should be equal, with CCTV systems having 75-ohm impedance throughout.
The light that falls directly on an object.
Index of refraction
This ratio measures the angle of incidence to the angle of refraction of light, with a denser medium bending more light and having a higher index of refraction.
These cameras are well suited for surveillance of low light areas or areas with no light at all. Infrared LEDs surround the lens and shine infrared light, illuminating the scene. They usually have a fixed focal length lens, and present b/w images during low light (though some offer color in the day and b/w at night).
This is an alarm that uses infrared light to detect nearby movement.
A light source working in the infrared frequency range is called an infrared illuminator.
Invisible to the human eye, this electromagnetic radiation has a wavelength of greater than 750 manometers.