Switching median filter with quadripartition method in noise detection
Yihu Chen · Jisuanji gongcheng yu sheji · 2008
A switching median filter based on quadripartition noise detection is proposed to detect impulse noise precisely and denoise.The filter arranges the pixels in the detecting window which is centered around the considered pixel according to the ascending order,and sorts the pixels into four clusters--lower,higher intensity noise clusters,and lower,higher intensity signal clusters.If the considered pixel falls into the signal clusters,it is viewed as signal pixel without processed further,otherwise,it will be classified as noise or un-determined pixel according to the number of pixels in the signal and noise clusters,the window is expanded and redetection is invoked to the undetermined pixel.As to the noise pixel,the filter window is adaptively determined according to the noise density around the pixel,the noise pixel will be substituted by the median of the signals in the filter window.Experimental results show that the filter is ef-fective to preserve impulse noise.