Various filters applied to image with Gaussian noise

Lenna.gif corrupted with Gaussian noise of standard deviation 21

Corrupted image

3x3 Mean filter	5x5 Mean filter	7x7 Mean filter

3x3 Median filter	5x5 Median filter	7x7 Median filter

3x3 Gaussian filter	5x5 Gaussian filter	7x7 Gaussian filter

3x3 k-Nearest filter	5x5 k-Nearest filter	7x7 k-Nearest filter