| 摘要 |
PURPOSE:To enhance S/N ratio also for an input image signal having no vertical correlation by subtracting an input image signal and a signal which is obtained by amplitude/limiting a difference signal of an input/output image signal of a delay circuit. CONSTITUTION:An image signal Sin from a terminal 5 is supplied respectively to a 1H delay circuit 6 and subtraction circuits 7 and 9. The subtraction circuit 7 subtracts a 1H delay image signal S1H from an input image signal Sin and outputs a difference signal Sn, on a limiter 8. The difference signal Sn, consists of an image signal component and a noise both having no vertical correlation. Next, an image signal without vertical correlation is eliminated from the limiter 8, and a noise component signal Sn consisting of a noise component is taken out. This signal Sn is attenuated to 1/2 in level by a subtraction circuit 9, and subtracted from the input image signal Sin. Thus the circuit for processing an image signal can heighten S/N ratio for the input image signal having no vertical correlation. |
