NOTCH_FILTER_CVIP

notch_filter_cvip() - performs the notch frequency domain filter.

SYNTAX
DESCRIPTION
REFERENCE
EXAMPLE
CREDITS

SYNTAX

newImage = notch_filter_cvip(Input_spect,zone,number,interactive)

Input Parameters include :

Input_spect - The input spectrum. It can be obtained by fft_cvip().

zone - It must be a struct array containing the the fields X,Y,R which represent the location and the radius.

number - The number of points that should be removed on the spectrum. This number decides how many of the locations in the variable zone is used.

interactive - Instead of the variables zone and number, you can pass the value 1 to this variable and then input the information about the locations and radius using a dialog box.

Output Parameter includes :

newImage - The output spectrum after notch filtering.

DESCRIPTION

Notch is a function to perform selective filtering on a user-defined area of an image or spectrum. It is often applied to frequency domain images to eliminate regular sinusoidal interference.

REFERENCE

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

EXAMPLE

% Read image

 Input_spect = imread('cam.bmp');

% block size

 block = [];

% Calling fft  function

 outImage = fft_cvip( Input_spect,block);

% Zone

 x =  [100  125];

 y =   [112  112];

 r =   [10  10];

 zone = struct('X',{x},'Y',{y},'R',{r});

% number

 number = length(x);

% Display input image

 figure;imshow(Input_spect);title('Input Image');

% Display output image

 filterIm = notch_filter_cvip(outImage,zone,number,0);

 figure;imshow(remap_cvip(log(1+abs(filterIm))));

 inverseIm = ifft_cvip(filterIm,[]);

 figure;imshow(remap_cvip(inverseIm));

NOTCH_FILTER_CVIP

Contents

SYNTAX

DESCRIPTION

REFERENCE

EXAMPLE

CREDITS