Adaptive DW-MTM Filter

#include "BIFILTER.H"

 

HANDLE CALLBACK FilterAdaptiveDWMTM(              HDIB  hDIB,
int           N,
int           Q,
int           C,
int           iShowProgress,
HWND  hParent)

Description

This function will filter the image by the adaptive DW-MTM filter method. This function works for only monochrome, 8 bit per bixel and 24 bit per pixel images. The adaptive double-window modified mean filter overcomes the difficulties of using MMSE filter in the presence of impulsive noise by using the median estimator to estimate the local mean. The adaptive DW-MTM filter is defined as follows : Given a pixel located at (x, y) coordinates, a median filter is computed within an N x N local region surrounding the location x, y. The median value computed from this filter is used to estimate the mean value of the N x N local area. Next, a larger-sized (Q x Q) matrix is used to calculate the mean value. In computing the mean value, only pixels within the graylevel range of

MED[g(x, y)] - C to MED[g(x, y)] + C

are used, eliminating any outliers from the mean calculation.

Examples

Description: Gauss                                    Description: adwmtm

The original 256 x 256 pixel image corrupted by additive Gauss noise and the adaptive DW-MTM filtered image with N = 2, Q = 7 and C = 30 parameter values.

Parameters

HDIB

hDIB

Handle of the DIB to filter.

int

N

This parameter specifies the size of the inner matrix where the median value is computed from. See the description and examples above for further information and a possible value.

int

Q

This parameter specifies the size of the outer matrix where the mean value is computed from. See the description and examples above for further information and a possible value.

int

C

This parameter specifies the value of parameter C mentioned in the definiton of adaptive DW-MTM filter above. 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:

DISPLAY_NONE (0)      -     The progressbar and the preview dialog will not display before filtering.

DISPLAY_PROGRESS (1) -The progressbar will display during filtering procedure.

DISPLAY_DIALOG (2) -     The preview dialog will display before filtering. This dialog shows the part of the image before and after filtering.

DISPLAY_BOTH (3)      -     The progressbar and the preview dialog will display.

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.