The standard gamma value in a Windows environment is 2.2, but even though LCD monitors can be adjusted to a gamma value of 2.2, due to the individual tendencies of LCD monitors (or the LCD panels installed in them), it's hard to graph a smooth gamma curve of 2.2.
Traditionally, LCD panels have featured S-shaped gamma curves, with ups and downs here and there and curves that diverge by RGB colour. This often means that dark and light tones in particular often appear as tone jumps, colour deviations and colour breakdown when viewed by the user.
The job of the internal gamma correction feature is to allow for irregularities in the gamma curve to be corrected. To find out if a device has an internal gamma correction feature we need to take a look at the device specs where one figure is particularly useful which is its maximum number of colours. If the figure for the maximum number of colours is approximately 1,064,330,000 or 68 billion it can be considered to be compatible with internal gamma correction. Another figure to look for is the look-up table (LUT) value as 10- or 12-bit also show compatibility with internal gamma correction.
The internal gamma correction feature works by applying multi-gradation to colours and reallocating them.
While the input from a PC to an LCD monitor is in the form of colour information at eight bits per RGB colour, within the LCD monitor, multi-gradation is applied to increase this to 10 bits (approximately 1,064,330,000 colours) or 12 bits (approximately 68 billion colours). The optimal colour at eight bits per RGB colour (approximately 16.77 million colors) is identified by referring to the LUT and displayed on screen. This corrects irregularity in the gamma curve and deviations in each RGB colour.
For more information on look-up tables, take a look at this article: Look-Up Table (LUT) Importance
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