In a lot of computer systems, images are encoded with a gamma of about 0.45 and decoded with a gamma of 2.2; a notable exception, until the absolution of Mac OS X 10.6 (Snow Leopard) in September 2009, were Macintosh computers: they acclimated 0.55 and 1.8 respectively. In any case, bifold abstracts in still angel files (as JPEG) are absolutely encoded (that is, they backpack gamma-encoded values, not beeline intensities), as are motion account files (such as MPEG). The arrangement can optionally added administer both cases, through blush management, if a bigger bout to the achievement accessory gamma is required.
The sRGB blush amplitude accepted acclimated with a lot of cameras, PCs, and printers does not use a simple power-law nonlinearity as above, but has a adaptation gamma amount abreast 2.2 over abundant of its range, as apparent in the artifice to the right. Below a aeroembolism amount of 0.04045 or a beeline acuteness of 0.00313, the ambit is beeline (encoded amount proportional to intensity), so γ = 1. The abject atramentous ambit abaft the red ambit is a accepted γ = 2.2 power-law curve, for comparison.
Output to CRT-based television receivers and monitors does not usually crave added gamma correction, back the accepted video signals that are transmitted or stored in angel files absorb gamma compression that provides a affable angel afterwards the gamma amplification of the CRT (it is not the exact inverse). For television signals, the absolute gamma ethics are authentic by the video standards (NTSC, PAL or SECAM), and are consistently anchored and able-bodied accepted values.
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