Contrast compression circuits

Color television contrast compression apparatus for television cameras having a plurality of imaging tubes for producing a corresponding plurality of video signals and comprising:

• amplitude compression circuits for each of said plurality of video signals and each comprising
• gamma circuit means responsive to the corresponding said video signal for producing a corresponding compressed video signal,
• signal subtraction means for subtracting said corresponding video signal from said compressed video signal to produce a compression difference signal,
• signal multiplication means for multiplying said compression difference signal by a picture gamma control signal to produce a controlled difference signal, and
• signal adder means for additively combining said controlled difference signal back again with the corresponding said video signal to produce a second compressed video signal having controlled de-emphasis;
• picture gamma control means for providing a picture gamma control signal;
• and,
• means for connecting said picture gamma control means to said signal multiplication means for each of said compression circuits whereby contrast compression of said plurality of video signals is simultaneously and uniformly controlled by said picture gamma control signal.