Edge preserving filtering by combining filters for Magnetic Resonance Image

Image filtering is widely used for noise reduction. It´s an important preprocessing step in Magnetic Resonance Imaging (MRI) progressing. However, most noise suppression filters have the undesirable side effect of blurring edges. This paper presents a filtering method in which image pixels are treated differently according to whether they are on edges or not. It´s not only effective in noise reduction, but also in edge preserving. We call it Combining Mean-Median (CMM) filter. Experimental results show that the CMM filtering is effective for noise reduction, and it can preserve edges for possible edge-detection efforts.