gamma correction formula : .^(gamma) or .^(1/gamma)?

Question

I\'m looking for a simple gamma correction formula for grayscale images with values between 0 and 255.

Let\'s say that the gamma of my screen is 2.2 (it\'s an LCD screen

Answer 1

Both formulas are used, one to encode gamma, and one to decode gamma.

Gamma encoding is used to increase the quality of shadow values when an image is stored as integer intensity values, so to do gamma encoding you use the formula:

encoded = ((original / 255) ^ (1 / gamma)) * 255

Gamma decoding is used to restore the original values, so the formula for that is:

original = ((encoded / 255) ^ gamma) * 255

If the monitor does the gamma decoding, you would want to use the first formula to encode the image data.