Gamma correction is needed to adjust images in response to the properties of human vision, in order to produce true color. A red pixel with a value of 192 would be three quarters of the possible brightness with a red pixel with a value of 10 would be extremely dark. When applying this range to color (RGB) colors can be produced at various brightness levels, while not affecting the color hue. Due to the imbalance, gamma is used to ensure the input relationship matches the desktop output. If the image is processed and displayed on a desktop without gamma correction, it will then be perceived by the user as being washed out or too bright. Our eyes capture brightness in a disproportional way, for example, if a camera captures an image in an extremely bright setting, our eyes perceive the light as being only a fraction brighter. Our normal vision (not excessively dark or exceedingly bright conditions) is more sensitive to changes in dark tones and due to the capture process of an image, color can be misrepresented, as a result of the difference in how we perceive brightness and the luminance, from when the original image was captured. Pixels have values that range between 0 (black) to 255 (white) with various degrees of grey in between. In a more technical sense, it is the correction of brightness in an image’s color through color shading balance in a pixel‘s value. In current LCD monitors, Gamma can be thought of as the moderator of the relationship between the brightness of the data captured (input) and how that affects the total human eye perception of color (output) while viewing the display, in terms of color brightness. Gamma, previously in CRT and early LCD monitors, was directly linked to voltage and was an important factor in reproducing images accurately on displays. Hence, the gamma value of 2.2 has become the golden standard of digital displays for proper calibration.Accurate Gamma 2.2 And Pre-set 5 Gamma Settings
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. 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. Many of you may wonder why a standard gamma curve is defined as gamma 2.2.