Noise reduction apparatus of frame recursive type

摘要

Disclosed is a noise reduction apparatus of a frame recursive type which can reduce occurrence of an afterimage phenomenon such as blurring or trailing of contours of motion images even when the difference between image frames is small. In the noise reduction apparatus, a frame recursive type filter generates a differential image signal representing a difference between a current input image signal and a delayed image signal obtained by delaying the input image signal by at least one frame period, reduces noise in the differential image signal thereby to generate a feedback image signal, and adds the feedback image signal to the current input image signal. A level adjuster adjusts a level of the feedback image signal to a lower level as a level of a luminance or color component of the input image signal is decreased.