Image repetition frequency doubling system for TV circuit - uses symmetrical double median filter for interpolation between image points of input half frames to provide intermediate half frames

摘要

The system has intermediate output half frames obtained by interpolation of input image points (INP) inserted between input half frames. A symmetrical double median filter (MED1, MED2) uses overlying input image points (P1, P2; P3,P4) of the actual half frames and the vertically intermediate input image points (P3, P2) of the immediately adjacent half frames to interpolate image points (PiA, PiB) of progressive half frames. The image points of the output half frames between the input half frames are obtained from the mean of temporally adjacent input image points and interpolated image points. ADVANTAGE - Reduced line flicker or movement interference.