# how to write code for finding KL transform in Matlab

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Ramessh Naiidu on 25 May 2015
Edited: Walter Roberson on 18 Jun 2017
about image compression using KL transform in matlab
##### 2 CommentsShowHide 1 older comment
Walter Roberson on 25 May 2015

B.k Sumedha on 25 May 2015
Well here is the code
clc;
close all;
clear all;
I=im2double(I);
m=1;
for i=1:8:256
for j=1:8:256
for x=0:7
for y=0:7
img(x+1,y+1)=I(i+x,j+y);
end
end
k=0;
for l=1:8
img_expect{k+1}=img(:,l)*img(:,l)';
k=k+1;
end
imgexp=zeros(8:8);
for l=1:8
imgexp=imgexp+(1/8)*img_expect{l};%expectation of E[xx']
end
img_mean=zeros(8,1);
for l=1:8
img_mean=img_mean+(1/8)*img(:,l);
end
img_mean_trans=img_mean*img_mean';
img_covariance=imgexp - img_mean_trans;
[v{m},d{m}]=eig(img_covariance);
temp=v{m};
m=m+1;
for l=1:8
v{m-1}(:,l)=temp(:,8-(l-1));
end
for l=1:8
trans_img1(:,l)=v{m-1}*img(:,l);
end
for x=0:7
for y=0:7
transformed_img(i+x,j+y)=trans_img1(x+1,y+1);
end
end
mask=[1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 ];
for l=1:8
inv_trans_img(:,l)=v{m-1}'*trans_img(:,l);
end
for x=0:7
for y=0:7
inv_transformed_img(i+x,j+y)=inv_trans_img(x+1,y+1);
end
end
end
end
imshow(transformed_img);
figure
imshow(inv_transformed_img);
##### 2 CommentsShowHide 1 older comment
Walter Roberson on 18 Jun 2017
Note that B.k Sumedha and Ramessh Naiidu will not be notified of your posting.
Did you look at the File Exchange link I posted above?