Patent ID: 6795588
Filing Date: 2004-09-21
Classification: G06T,H04N

Abstract:
A noise detector comprising:a high-frequency component extraction circuit extracting a high-frequency component of an input image signal; a level detection circuit detecting the level of said high-frequency component extracted by said high-frequency component extraction circuit and outputting the result of detection as a level signal; and a noise detection circuit detecting a small-amplitude edge around a large-amplitude edge of said image signal as noise on the basis of said level signal detected by said level detection circuit, wherein said noise detection circuit includes: an extension circuit outputting an extended signal obtained by extending the peak of said level signal detected by said level detection circuit, a conversion circuit outputting a 1/n signal obtained by converting the level of said extended signal output from said extension circuit to 1/n times, and a small-amplitude detection circuit comparing said 1/n signal output from said conversion circuit with said level signal output from said level detection circuit for detecting said small-amplitude edge around said large-amplitude edge of said image signal, wherein n is an integer.