Signal Processing Toolbox | ![]() ![]() |
Median Filtering
The function medfilt1
implements one-dimensional median filtering, a nonlinear technique that applies a sliding window to a sequence. The median filter replaces the center value in the window with the median value of all the points within the window [5]. In computing this median, medfilt1
assumes zeros beyond the input points.
When the number of elements n
in the window is even, medfilt1
sorts the numbers, then takes the average of the (n-1)/2
and (n-1)/2
+ 1
elements.
Two simple examples with fourth- and third-order median filters are
medfilt1([4 3 5 2 8 9 1],4) ans = 1.500 3.500 3.500 4.000 6.500 5.000 4.500 medfilt1([4 3 5 2 8 9 1],3) ans = 3 4 3 5 8 8 1
See the medfilt2
function in the Image Processing Toolbox documentation for information on two-dimensional median filtering.
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