pmedianfiltering

Performs median filtering on image.

Synopsis

pmedianfiltering halfsize [-m mask] [im_in|-] [im_out|-]

Description

pmedianfiltering applies a median filter to the input image im_in. Each pixel of the input image is replaced by the median value of its neighbors. The neighborhood size is defined by the parameter halfsize.

It is an rank filtering which can be used to remove impulse and exponential noise. It remove small details while preserving edge of type "step". However, this filter can affect the image geometry. For example, angle tends to be rounded, and edge of type roof and "peak" tends to be removed.

Parameters

halfsize specifies the size of the neighborhood. It is a positive integer. A halfsize=1 corresponds to a 3x3 neighborhood. This parameter is ignored for graph but must be given. The greater is halfsize, the stronger is the filtering.

Inputs

im_in: a grayscale image.

Outputs

im_out: an image of the same type as the input image.

Result

Returns SUCCESS or FAILURE.

Examples

Applies a 5x5 median filter to tangram.pan:

   pmedianfiltering 2 tangram.pan out.pan

C++ prototype

Errc PMedianFiltering( const Img2duc &im_in, Img2duc &im_out, int halfsize );

Version française

Lissage d'une image par médian standard séparable.

Author: Julien Robiaille