XGA (Image resolution – Video graphics)
The initials ‘XGA’ mean “Extended Graphics Array”. This was a consumer market standard indicating 1024 x 768 pixels in a display screen (old cathode ray tube type originally). The format was introduced in 1990 by IBM (International Business Machines). It had a market presence until after the year 2000 by which time it had been superseded. The format size (1024×786 pixels) is still considered an important screen and presentation size for images and other display media.
The XGA format supported 65,000 colours and allowed up to 16 bit colour depth (known as ‘high colour’) giving the format a market advantage in screen design. The high number of colours available allowed for more realistic colour representations. The previous format, VGA – 800 x 600 pixels, and earlier had not been able to display more than 256 colours (or only 128), which had flat colour representations giving the display a cartoon-like appearance.
Video Graphics types and generations
VGA underwent eleven generations of improvement. It was superseded by the following…
XGA – Extended Graphics Array (Nine generations);
QXGA – Quad Extended Graphics Array (QEGA seven generations);
HXGA – Hyper Extended Graphics Array (HXGA six generations);
Current in 2012:
HD – High Definition (currently 7th generation in 2012)