6015003 advanced communications lab programs

7/29/2019 6015003 Advanced Communications Lab Programs

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M.Tech-II sem (DECS)

Advanced Communications Lab

List of Experiments:

1. Histogram equalization of an image

2. Fourier Transform & its Inverse Fourier Transform of an image

3. Blurring & Deblurring of an image

4. Dilation & Erosion of an image

5. Edge detection (Sobel, canny edge detector) of an image

6. Sampling of an image

7. Frequency Modulation & Demodulation of a signal.


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MATLAB PROGRAMS

1. Histogram Equalization

Aim: To perform histogram equalization of an image

Equipments:

Operating System: - Windows XP

Software: - Matlab 7.5, Image Processing Toolbox.

Theory:

Program:

clc;

clear all;close all;

f=imread('coins.png');

figure, imshow(f);

title('input image');

h=imhist(f);

h1=h(1:10:256);

horz=1:10:256;

figure, bar(horz,h1);

figure, plot(horz,h1);

title('histogram equalized image');


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Result:-


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2. Fourier Transform & Inverse Fourier Transform

Aim: To perform Fourier Transform & its Inverse Fourier Transform of an image

Equipments:



Theory:

Program:

clc;

clear all;

close all;

A=zeros(30,30);A(5:24,13:17)=1;

subplot(1,2,1);imshow(A);

title('original image');

F=fft2(A);

subplot(1,2,2);imshow(F);

title('fourier transformed image');

S=abs(F)Fc=fftshift(F);

S2=log(1+abs(Fc));

figure,subplot(1,2,1);

imshow(Fc);

title('fourier transformed image');

F=ifftshift(Fc)

f1=(ifft2(F));

subplot(1,2,2);

imshow(f1);

title('inverse transform');


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Result :-


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3. Blurring & Deblurring

Aim: To perform blurring & deblurring of an image

Equipments:



Theory:

Program:

clc;

close all;

clear all;f=imread('cameraman.tif');

subplot(1,2,1);imshow(f);title('original image');

LEN = 31;THETA = 11;

PSF = fspecial('motion',LEN,THETA);

Blurred = imfilter(f,PSF,'circular','conv');

subplot(1,2,2);imshow(Blurred);title('Blurred Image');% deblurring

figure,subplot(1,2,1);imshow(Blurred);title('Blurred image');

wnr1 = deconvwnr(Blurred,PSF);

subplot(1,2,2);imshow(wnr1);title('Deblurred Image');

title('Restored, True PSF');


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Result:-


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4. Dilation & ErosionAim: To perform dilation & erosion of an image

Equipments:

Operating System: - Windows XPSoftware: - Matlab 7.5, Image Processing Toolbox.

Theory:

Program:

close all;

clear all;

clc;

f=imread('cameraman.tif');

level=graythresh(f);f1=im2bw(f,level);

s=[0 1 0; 1 1 1 ; 0 1 0];

f2=imdilate(f1,s);

subplot(1,3,1);imshow(f);title('original image');subplot(1,3,2);imshow(f1);title('binary image');

subplot(1,3,3);imshow(f2);title('dilated image');


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Result:-


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5. Edge Detection

Aim: To perform edge detection of an image

Equipments:



Theory:

Program:

clc;0000

close all;

clear all;

f=imread('trees.tif');subplot(1,2,1);

imshow(f);title('original image');

BW1=edge(f,'sobel');

BW2=edge(f,'canny');

subplot(1,2,2);

imshow(BW1);title('sobel edge detector image');

figure,subplot(1,2,1);imshow(f);title('original image');

subplot(1,2,2);

imshow(BW2);title('canny edge detector image');


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Result:-


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6. Sampling

Aim: To perform sampling of an image

Equipments:

Operating System :- Windows XP

Software:- Matlab 7.5, Image Processing Toolbox.

Theory:

Program:

if (nargin==0)

hFig = figure( 'visible','off' );

hImage = image;

Child = get( hImage,'cdata' );close( hFig );

out = updownsample( Child,300,300,0,1 );

figure;

colormap gray;

subplot( 1,2,1 );

imagesc( Child );

subplot( 1,2,2 );

imagesc( out );

return

elseif (nargin do not change sampling rate

if is_fourier_flag

switch is_real_flag

case 0, out_m = ifft2( in_m );

case 1, out_m = real( ifft2( in_m ) );

case 2, out_m = abs( ifft2( in_m ) );end

else

out_m = in_m;

end

else

% upsample or downsample as needed

% convert to fourier domain, if input is given in the space domain

if ~is_fourier_flag


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in_m = fft2(in_m);

end

% if the input is even & output is odd-> use floor for all

% if the output is even & input is odd -> use ceil for all

% for downsampling -> the oppositeif (~mod( in_x_sz,2 ) & (out_x_sz>in_x_sz)) | (mod( in_x_sz,2 ) & (out_x_szin_y_sz)) | (mod( in_y_sz,2 ) & (out_y_sz


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Result:-


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7. Frequency Modulation & Demodulation

Aim: To perform Frequency Modulation & Demodulation of a signal

Equipments:



Theory:

Program:

Fs = 8000; % Sampling rate of signal

Fc = 3000; % Carrier frequency

t = [0:Fs]/Fs; % Sampling timess1 = sin(2*pi*10*t); % Channel 1

%s2 = sin(2*pi*150*t)+2*sin(2*pi*900*t); % Channel 2

%x = [s1]; % Two-channel signaldev = 50; % Frequency deviation in modulated signal

y = fmmod(s1,Fc,Fs,dev); % Modulate both channels.

z = fmdemod(y,Fc,Fs,dev); % Demodulate both channels.

subplot(2,1,1); plot(t,y); title('frequency modulated image');% Plot x on top.subplot(2,1,2); plot(t,z);title('demodulated image');% Plot y below.


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Result:-


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6015003 advanced communications lab programs

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