Reducing line flicker in still picture, e.g. test card on TV receiver screen

摘要

The method is intended for still pictures represented by frames having a vertical frequency of 100 Hz, their status being transmitted as digital information in its lines. As the pictures are received, this information is evaluated and it is established whether the current picture is a test picture, a marked still picture or a normal television picture. A first control signal is generated in the latter case. If it is a test or still picture, a second control signal is generated. The signals control the read out from two memories (8,9); in the sequence AABB by the first control signal and in the sequence ABAB by the second control signal, where A and B are the respective half frames.