#include "BIFILTER.H"

HANDLE CALLBACK FilterMedian( HDIB hDIB,

int N,

int iShowProgress,

HWND hParent)

**Description**

This function will filter the image by the nonlinear median filter method. This function works for only monochrome, 8 bit per bixel and 24 bit per pixel images. A median filter operation on an image removes long tailed noise such as negative exponential and salt and pepper type noise from the image with a minimum blurring of the image. Median filter is defined as :

Median(A) = median[A(x + i, y + j)]

where the coordinate (x+i, y+j ) is defined over the image A and the coordinate (i, j) is defined over the N x N size square mask.

**Examples**

The original 256 x 256 pixel image corrupted by additive Gauss noise and the median filtered image using a 5 x 5 pixel square mask.

**Parameters**

HDIB |
hDIB |
Handle of the DIB to filter. |

int |
N |
This parameter specifies the size of the square mask. N cannot be less than 1. See the description and examples above for further information and a possible value. |

int |
iShowProgress |
This parameter specifies the displaying of the progressbar and the preview dialog. Available values:
IMPORTANT: The preview dialog will only display, if there is BiDlgs.dll installed. |

HWND |
hParent |
Handler of the parent window. |

**Return values**

The handle of the new filtered DIB or NULL if an error occurred.

**Programming notes**

The function will not free the input DIB.

**Requirements**

Header : Declared in BIFilter.h; include BIFilter.h.

Library : Use BIFilter.lib.

DLLs : BIFilter.dll , BIDlgs32.dl.