Video signal correction system

A video signal correction system for correcting the saturation of a color signal comprising:

• a luminance signal correction circuit for correcting the tone of an input luminance signal;
• an average picture level detection circuit for detecting the average picture level of the luminance signal;
• a coefficient calculation circuit for effecting corrective calculations on the basis of an output signal of the average picture level detection circuit;
• a first adder for adding an output signal of the luminance signal correction circuit and an output of the coefficient calculation circuit to each other;
• a delay circuit for delaying the luminance signal;
• a second adder for adding an output signal of the delay circuit and a constant to each other;
• a divider circuit for dividing an output signal of the first adder by an output signal of the second adder;
• and
• a multiplier circuit for controlling the amplitude of the input color carrier signal by an output signal of the divider circuit.

A video signal correction system for correcting the saturation of a color signal comprising:

• a luminance signal correction circuit for receiving a luminance signal and producing a corrected luminance signal, said luminance signal correction circuit correcting the tone of said luminance signal;
• an average picture level detection circuit for receiving said luminance signal and producing an average picture level signal at an output thereof;
• a coefficient calculation circuit coupled to the output of said average picture level detection circuit, said coefficient calculation circuit producing a corrected average picture level signal;
• a delay circuit for receiving said luminance signal and producing a delayed luminance signal at an output thereof;
• luminance signal limiting means coupled to the output of said delay circuit, said luminance signal limiting means producing a limited delayed luminance signal having a value above a predetermined level;
• an adder for receiving said corrected luminance signal and said corrected average picture level signal, said adder producing a corrected sum signal;
• a divider circuit coupled to said adder and said luminance signal limiting means for dividing said corrected sum signal by said limited delayed luminance signal, a color amplitude corrected signal being produced at an output of said divider circuit;
• and
• a multiplier circuit for receiving an input color carrier signal and being coupled to the output of said divider circuit, said color amplitude corrected signal controlling the amplitude of the input color carrier signal.