Linear and Nonlinear Procedures for Flicker Reduction

Disturbances related to all TV standards (PAL, NTSC, SECAM) have, through necessity, long been considered acceptable properties of the systems. The main effects are large area flicker, edge flicker, and interline flicker. These defects are caused by a low number of lines, a too low field frequency, and the renunciation of vertical and temporal prefiltering in camera and postfiltering in display. At the camera end, alias components could be avoided by using a higher number of lines followed by vertical filtering. In time direction the problem could be solved with a higher field frequency and temporal filters. At the display end, harmonics are present in the form of line structure and flicker effects. These harmonics could be suppressed by a high definition monitor with double field frequency and two-dimensional filtering.