Glossary » G

The sensitivity of an electronic sensor, such as a CCD or CMOS chip. Increasing the gain makes the chip more sensitive to light, but also increases the amount of random electronic noise on the image.

A correction factor applied to linearise the relationship between screen luminance and the electron gun voltage in a CRT. Also used in graphical software to correct the colour gamut to suit lighting conditions.

The range of colours that a graphics system is able to display.

Used to describe lost detail or image corruption caused by re-recording signals. Digital editing in a native format avoids generation loss.

The reduction of contrast in the screen image when ambient light is brighter than the light emitted by the monitor.

Group Of Pictures. The sequence of frame types used by MPEG2 compression. See MPEG.

GPRS or General Packet Radio Service is a faster way for data transfer across a mobile phone network. Rates can vary to over 100k/s depending on how the network is set up. Every transmitter on a mobile network can usually handle up to eight calls. However if the transmitter is only handling one or two calls, and another user wants to use the mobile phone to transfer data, then the other "spare call spaces" capacity on the transmitter can be used to transfer data. This is why users are not promised a transfer rate, but billed by the quantity of data. Depending on how many calls are being handled at the time you want to transfer data, will depend on the speed. Voice calls always have priority therefore the data rate can go up or down according to how many people are using the transmitter. Mobile networks now often use many transmitters within reach of the mobile phone itself, so that it will use spare capacity on several transmitters rather than just one. Multimedia messages including video (not live), pictures and sounds are transferred using GPRS. GPRS has been referred to as 2.5G technology relating to the fact that 3G will offer much higher transfer of data.

Graphics Processing Unit. The GPU is the processor on a graphics card that does the majority of the work. This term was first used by nVidia when the GeForce chipset was launched, due to the chips ability to be able to calculate geometry and take the load away from the CPU.

Applicable to aperture grille monitors, this is the distance (in mm) between two phosphor lines of the same colour. The smaller the distance, the smaller the grille pitch will be generally resulting in a sharper and finer picture. Sometimes called stripe pitch.