a) The exponent of that power law that is used to approximate the curve of output magnitude versus input magnitude over the region of interest.

b) Video - The power function of the electro gun in a CRT. It has become customary in video, as in photography, to extend the meaning and to use gamma as a synonym for the complete transfer function regardless of curve shape. Note: In the electronics system, increasing gamma decreases image contrast. c) Imaging Processing and Display – Nonlinear processing is useful in many television systems as a means of bandwidth limiting, and is normally applied at the camera. Given the predominance of CRT displays, the chosen exponent is related to that of the electron gun (typically 2.2 for systems with 525/59.94 scanning, 2.8 for systems with 625/50 scanning, and 2.22 for SMPTE 240M).