decimation_interpolation.m

digital image decimation-interpolation

clc
clear all
close all


x=imread('rose.tif');
[r c] = size(x);

dif=2; %decimation and interpolation factor

figure(1)
subplot(231),imshow(x),title([' original image [', num2str(size(x)), ']'])

figure(2)
subplot(231),imshow(x),title([' original image [', num2str(size(x)), ']'])

l=2;
for n=1:5

dec=x(1:dif:r,1:dif:c);

[r1 c1] = size(dec);
intr=zeros([dif*r1 c1],'uint8'); %interpolate rows

 k=1;
 for i=1:r1
       intr(k:k+dif-1,1:c1)=repmat(dec(i,1:c1),dif,1);
       k=k+dif;
 end

[r2 c2] = size(intr);
intc=zeros([r2 dif*c2 ],'uint8');%interpolate columns

k=1;
 for i=1:c2
       intc(1:r2,k:k+dif-1)=repmat(intr(1:r2,i),1,dif);
       k=k+dif;
 end

figure(1)
subplot(2,3,l),imshow(dec)
title(['decimated to [',num2str(size(dec)),']'])

figure(2)
subplot(2,3,l),imshow(intc)
title(['intrp2org from [',num2str(size(dec)),']']),xlabel(['new size [',num2str(size(intc)),']'])

l=l+1;

dif=dif*2;
end

% 
% whos x,whos dec, whos intc