Originally Posted by DaleDe
1. If a color image is dark as shown on the screen I will increase the chroma a bit to bring out the contrast. For gray scale I may tweak it a bit for good contrast.
In order to preserve the 'color' of the image, I change the 'luminance', by doing 'gamma correction', when images are too dark so that the whites don't get washed out when the darks are lightened.
Gamma correction is also useful for the reverse: too light areas ramped down to acceptable levels.