gamma correction : Java Glossary

Computer monitors don’t show shades of gray well. They tend to show them either too dark or too bleached out. (This same effect applies to colours too.) There are two ways of dealing with the problem. High end monitors have adjustable hardware to correct the problem. A software approach is to lighten dark parts of images and darken light parts of images to correct them so they will appear accurately on cheap monitors. That process, either by hardware or software is called gamma correction. Uncorrected images tend to allocate too many bits or too much bandwidth to extreme highlights that humans cannot differentiate and too few bits/bandwidth to shadow values that humans are sensitive too.