CARRIER CHROMINANCE SIGNAL CONTOUR CORRECTION DEVICE

摘要

PROBLEM TO BE SOLVED: To simplify the processing, to make the processing stable and to reduce the cost by processing directly a carrier chrominance signal to as to correct the signal steeply, that is, a short rise and fall times of the edge part. SOLUTION: A 1st subtractor circuit 2 subtracts a delayed carrier chrominance signal input (j) from a carrier chrominance signal input (a) to obtain a primary differentiation signal (b). Then the signal is given to a 2nd delay circuit 3 and a minimum/maximum value circuit 4, from which a corrected first order differentiation signal (c). A 2nd subtractor circuit 6 subtracts the delayed correction first order differentiation signalλfrom the corrected first order differentiation signal (c) to produce a secondary differentiation signal (d). The corrected first order differentiation signal (c) is full-wave-rectified and a rectified first order differentiation signal (e) is outputted. The signal (d) or (e) which is smaller is selected and the selected signal is outputted as a corrected second order differentiation signal (f). A gain control circuit 10 multiplies a correction amount (m) with the corrected second order differentiation signal (f) to output a correction signal (g). The correction signal (g) is added to the delayed carrier chrominance signal (h) to obtain a carrier chrominance signal output (i) whose color contour is steeply corrected.