Noise adaptive soft-switching median filter for image denoising

We observed that certain fundamental concerns commonly exist in some state-of-the-art switching-based median filters: (i) fixed thresholding for the pre-assumed noise density, (ii) the noise decision accuracy at high density impulse noise, and (iii) the filtering scheme adopted in response to pixel characteristic type identified. In this paper, we propose a novel noise adaptive soft-switching median (NASM) filter to effectively address the above-mentioned issues and achieve much improved filtering performance in terms of efficiency in removing impulse noise and robustness against noise density variations. Experimental results also reveal that the performance of our NASM filter is fairly close to that of ideal-switching median filter.