JPS6482879A - Adaptive type emphasis system - Google Patents

Abstract

PURPOSE:To obtain a higher emphasis gain in accordance with the contents of an image by performing an emphasis adapted to a signal level of a high frequency signal component selectively with respect to a signal component of intermediate and high frequencies in an image area in which a high frequency signal component of an image signal is small. CONSTITUTION:An image signal is supplied to low-pass filters 9, 10, a high frequency signal component is fetched as a difference of a through input image signal from a subtracter 11, and its high frequency signal component is supplied to an absolute value device 12, and also, supplied to a non-linear input image signal level detecting ROM 13. By an absolute value A of a high frequency component signal level from the absolute value device 12 and a genuine signal level B from the level detecting ROM 13, a non-linear processing use ROM 7 is brought to access, an emphasis signal component or a de-emphasis component is fetched at a stroke, supplied to an adder and a subtracter 5, 6, and an output image signal which has performed an emphasis or a de-emphasis is obtained. In this regard, as for the non-linear processing use ROM 7, the larger the absolute value input A of the high frequency component signal level is, and the smaller the genuine image signal level input B is, the more the output level increases.