SIMPLE_WIENER_FILTER_CVIP

simple_wiener_filter_cvip() - Performs simple wiener filter operation.

SYNTAX
DESCRIPTION
REFERENCE
EXAMPLE
CREDITS

SYNTAX

Y = simple_wiener_filter_cvip(d,h,cutoff,limitGain,noiseImage,originalImage,K)

Input Parameters include :

d - The degraded image. A single or multiband image.

h - The degradation function. It can be single band.

cutoff - Cutoff frequency for filtering.

limitGain - Sets the maximum gain using the DC value as a baseline. limitGain=1 --> DC value is the maximum gain. limitGain>1 --> DC_value*limitGain is the maximum gain.

noiseImage - The noise image. It can be single band.

originalImage - The original image. A single or multiband image. The number of bands should match with the input 'd'.

K - constant range from 0.0 to 1.0

Output Parameter includes :

Y - output image after filtering.

DESCRIPTION

This function performs the Simple Wiener Filtering operation on a degraded image to restore it to its original state. The wiener filter response increases as the signal-to-noise ratio increases. As the signal-to-noise ratio starts to decrease, the wiener filter response starts to decrease and hence the noise in the image is attenuated. The function multiplies the wiener filter with the fourier transform of the degraded image and obtains the restored image by taking the inverse transform of the resultant image after filteirng. This is also called as Practical wiener filter.

REFERENCE

1. Scott E Umbaugh. DIGITAL IMAGE PROCESSING AND ANALYSIS: Applications with MATLAB and CVIPtools, 3rd Edition.

EXAMPLE

% Read image

 origImage = imread('butterfly.tif');

 d = imread('Butterfly.gaussian.tif');

 noiseIm = imread('Butterfly.gaussian.tif');

% Degradation function

 h = [ 2.50 4.500 2.250 :4.500 9.001 4.500 : 2.250 4.500 2.250];

% Limit gain

 limitGain = 10;

% Cutoff frequency

 fc = 32;

 k =  0.6;

% Calling function

 Y = simple_wiener_filter_cvip(d,h,fc,limitGain,noiseIm,origImage,k);

% Display input images

 figure;imshow(origImage); title('Original image');

 figure;imshow(noiseIm);title('Noise image');

 figure;imshow(d); title('Degraded image');

% Display output image

 figure;imshow(remap_cvip(Y)); title('Output Image');

SIMPLE_WIENER_FILTER_CVIP

Contents

SYNTAX

DESCRIPTION

REFERENCE

EXAMPLE

CREDITS