Impulse Detection Adaptive Fuzzy (IDAF) Filter

Abstract

An Impulse Detection Adaptive Fuzzy (IDAF) filter is proposed in this paper, to achieve improved filtering of impulsive noise while preserving image details. It is a spatial filter which operates in 2-stage 3x3 windows where the update value of the central pixel is a function of the median value of the pixels in the window. The proposed IDAF filter operates as follows. First, an impulse detection method classifies each pixel to be noisy pixel or image pixel. Then, if a pixel is assumed to be noisy, it is not used for deciding the new value of other pixels. A scheme is introduced to obtain a good replacement pixel value, which is then stored. The median of the stored values is a considered a good estimate of the image pixel. Finally, the adaptive fuzzy filter will then assign weights to the stored pixel values to produce the central pixel’s new value. Weights are assigned to remove impulse noise or preserve the image details, depending on the pixel’s characteristics. These characteristics are identified from the noisy image beforehand using a compatibility measure. The process detailed above enables the IDAF filter to remove impulse noise while preserving image details. Through testing, our experimental results show that the IDAF filter performs better than other standard median based methods.