| 摘要 |
PURPOSE:To ensure the optimum contour emphasization, by forming horizontal and vertical contour signals from a signal equivalent to the green light of a wide band and a signal equivalent to the green light of a narrow band and then controlling the contour. CONSTITUTION:The output of an LPF11 shown by a code 25 has a narrow band, and a contour part of a picture is limited to a low level. Then the output of the LPF11 is subtracted from the output of a delay line 13 shown by a code 26 to obtain a signal GH in the form of a horizontal contour part signal of secondary differential type in the horizontal direction as shown by a code 27. A code 28 is equal to the green signal output of a gate circuit 6, and a code 29 is equal to a green signal of 1H delay which is delivered from a gate circuit 7. The outputs of these circuits 6 and 7 are added together to obtain a waveform of a code 30. Then the signal of the code 28 is subtracted from the signal 30 to obtain a signal of a vertical contour part shown by a code 31. Then the degree of contour control is adjusted by controllers 15 and 16 to obtain optimum emphasization for both horizontal and vertical contour parts. |
