Diller, Ramik & Wight
Contrast correction arrangements
 A contrast correction arrangement for a color television system detects the signal representative of the greatest brightness in a viewed scene, and multiplies the difference between the detected signal and a predetermined peak amplitude thereof by a control signal to produce a further signal which is variable in both sign and magnitude in dependence upon the departure of the detected signal from peak amplitude. A further multiplier multiplies the further signal with a normally provided composite color coded signal thereby to produce a video correction signal of sign varying in dependence upon the sign of the said further signal which is, in turn, mixed with the composite color coded signal to produce a resultant video signal of compressed, normal or expanded contrast range. 
The Marconi Company Limited
H H
H04N H04N
inventional inventional
Roger W.
Fenton