Hence, the gamma value of 2.2 has become the golden standard of digital displays for proper calibration. And the exponent of 0.43 is approximately 2.33 and is quite close to gamma 2.2. This phenomenon was also found in Ebner and Fairchild’s study in 1998, where they used an exponent of 0.43 to convert linear intensity into lightness for neutrals to provide an optimal perceptual encoding of grays. Looking at the overall grays in the visual encoding row, the perceived differences between each gray patch are almost identical. And from 0.9 to 1.0 in linear intensity, the difference is not perceivable, whereas it is perceivable in visual encoding. Please note that between 0.0 and 0.1, there is a big visual gap in linear intensity whereas it is much less apparent between 0.0 and 0.1 in visual encoding. At the top row, visual encoding represents the intensity increase from black to white in a power-law fashion. At the bottom row, linear intensity represents the intensity increase from black to white in a linear fashion. And accuracy is enhanced by improving calibration images and revised user instructions. The overall display gamma is actually comprised of (i) the native monitor/LCD gamma and (ii) any gamma corrections applied within the display itself or by the video card. Settings are now independent for multiple monitors. Finally, in the fourth picture the display gamma over-compensates for the image gamma, resulting in an overall system gamma that curves downward (thereby darkening the image).
Support for OLED and high contrast displays.
The main reason that a power-law relationship exists between the output luminance and the input voltage or digital value is because the visual system does not operate in a linear way. Video production: Gamma 2.4, BT.1886 and Rec.709. Many of you may wonder why a standard gamma curve is defined as gamma 2.2.
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