Bandwidth reduction of picture signals for transmission - uses first line of scanned picture as reference line and subsequent lines are derived from it

摘要

Picture signals are obtained by scanning in lines. X consecutive scanning lines (a-e) are used in a group, where X = M.1 + 1, with M and N being positive integers equal to or greater than two. Picture signals of the first line (a) in the group are used as estimated reference signals. Signals in the following lines (b-e) of the group are determined on ground of estimated signals based on preceding signals in the form of signals expressing coincidence or lack of coincidence. Estimated signals in the M lines are converted into a mode code in order to form N groups of mode coded signals.