Picture signal transmission system

A picture signal transmission system, comprising:

• first input terminal means for receiving a picture signal obtained by scanning a picture to be transmitted;
• second input terminal means for receiving timing pulses each indicating the start timing of said scanning of said picture;
• address counter means operatively coupled to said second input terminal means for successively assuming addresses of picture elements of said picture signal in response to said timing pulses;
• reference value memory means operatively coupled to said first input terminal means and said address counter for successively storing level information of an immediately prior one of said picture elements scanned;
• comparator means operatively coupled to said first input terminal means and said reference value memory means for comparing the level information of an instant picture element in said picture signal with said stored level information of prior stored picture elements of the picture being scanned to produce change information indicating whether or not the instant picture element changes against said stored level information;
• change information memory means operatively coupled to said comparator means and said address counter means for successively storing said change information of the picture elements;
• code generator means operatively coupled to said address counter means for generating a first signal train including start code units and synchronizing code units;
• level information memory means operatively coupled to said first input terminal means, said address counter means and said comparator means for successively storing level information of changed picture elements;
• combiner means operatively coupled to said address counter means, said code generator means, said change information memory means and said level information memory means for combining outputs of said code generator, said change information memory means and said level information memory means to produce an output signal train;
• and output terminal means operatively coupled to said combiner means for applying said output signal train to transmission medium.