3x3 Median Filter. Linear filters are also know as convolution filters as they can be represented using a matrix multiplication. Some examples of filtering.
Separability fy1 fy2 fy3. The basic algorithm calculates two medians in one step and reuses sorted slices of three vertical neighbouring pixels. Such noise reduction is a typical pre processing step to improve the results of later processing for example edge detection on an image.
An example of median filtering of a single 3x3 window of values is shown below.
The median filter is also a sliding window spatial filter but it replaces the center value in the window with the median of all the pixel values in the window. J medfilt2 i m n performs median filtering where each output pixel contains the median value in the m by n neighborhood around the corresponding pixel in the input image. 2 median filtering median filtering is a nonlinear method used to remove noise. An example of median filtering of a single 3x3 window of values is shown below.
