IDEAL_HIGH_CVIP

ideal_high_cvip()- Performs ideal highpass filtering.

SYNTAX
DESCRIPTION
REFERENCE
EXAMPLE
CREDITS

SYNTAX

H = ideal_high_cvip( spectrum, block_size, transform_type, fc )

Input Parameters include:

spectrum - An image of size [m n d] which is the spectrum of an image. It can be created by any of the 6 possible transforms availabe in cviptools matlab toolbox: DCT, FFT, Haar, Walsh,Hadamard, Wavelet.

block_size - The same parameter block_size used in the transforms.

transform_type - The user should specify which spectrum is being given to this function.FFT has the origin at the center while the other transforms have their origin located at upper left corner of the image. transform_type is a string. If given spectrum is FFT, then set transform_type = 'fft' or 'center'. Else, the origin would be located at the upper left corner.

fc - The cutoff frequency for high pass filter.

output parameters include:

H - The resultant high pass filtered image.

DESCRIPTION

This function performs a 2D highpass filtering on the spectrum of an image. It applies ideal high pass filter of transform type specified by the user and allows the frequencies that are above the specified cutoff frequency.

REFERENCE

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

EXAMPLE

% Create an spectrum by available transforms

 spectrum = ones(128,256,3);

% Block size

 block_size1  = [];
 block_size2 = [64 128];

% Transform type

 transform_type1 =' fft';
 transform_type2 ='non-fft';
 transform_type3 ='center';

% cutoff frequency

 fc1 = 32;
 fc2 = 23;
 fc3 = 16;


% Call function

 out_s1 = ideal_high_cvip( spectrum,block_size1,transform_type1,fc1);
 out_s2 = ideal_high_cvip( spectrum,block_size2, transform_type2,fc2);
 out_s3 = ideal_high_cvip( spectrum,block_size2 , transform_type3,fc3);

% Display output

 figure; imshow(out_s1,[]);title(' Output with FFT Transform');
 figure; imshow(out_s2,[]);title(' Output with Non FFT Transform')
 figure; imshow(out_s3,[]);title('with center');

IDEAL_HIGH_CVIP

Contents

SYNTAX

DESCRIPTION

REFERENCE

EXAMPLE

CREDITS