medfilt

Apply a median filter to an image. More...

Modules
	medfilt
	The C++ interface for medfilt.
	af_medfilt
	The C interface for medfilt.

Detailed Description

Apply a median filter to an image.

Apply a median filter of a given size to an image. A median filter is similar to the arbitrary filter except that instead of a weighted sum, the median value of the pixels covered by the kernel is returned.

For instance, if we apply a median filter to an simple sequential image:

array = array(seq(1,16), 4, 4);
print(a);
//a = 1.0000        5.0000        9.0000       13.0000
//    2.0000        6.0000       10.0000       14.0000
//    3.0000        7.0000       11.0000       15.0000
//    4.0000        8.0000       12.0000       16.0000

print(medfilt(a, 3, 3));
//    0.0000        2.0000        6.0000        0.0000
//    2.0000        6.0000       10.0000       10.0000
//    3.0000        7.0000       11.0000       11.0000
//    0.0000        4.0000        8.0000        0.0000

This example highlights that pixels outside the image are treated as zeros. So, for the first pixel, the neighborhood looks like:

0 0 0
0 1 5
0 2 6

the median of which is zero.