DIGITAL CORRECTION OF LINEAR APPROXIMATION OF GAMMA

摘要

A circuit for gamma correcting a video signal incorporates both linear approximation (16) as well as a look-up table (12'), in which the disadvantages of linear approximation, i.e., inaccurate representation of the gamma function, and of a gamma look-up table, i.e., low resolution at low grey levels, are minimized. The transfer function of the look-up table (12') is chosen such that the inaccuracies of the linear approximation are compensated.