Unable to perform assignment because the size of the left side is 1-by-7 and the size of the right side is 1-by-5.

I want replace the 5 LSB of the 'c' image by the 5 MSB of the 's' image but i have this error..

c = imread('lena.tif');
s = imread('boat.png');

[LL1,LH1,HL1,HH1]=dwt2(c,'db1');
[LL2,LH2,HL2,HH2]=dwt2(HH1,'db1');
n= size(LL2)
s = imresize(s,n);

for i=1:n
   LL2(i,(n-6):end) = s(i,1:(i+4));
end

HH1_changed = idwt2(LL2,LH2,HL2,HH2,'db1');
c_changed = idwt2(LL1,LH1,HL1,HH1_changed,'db1');
imshow(mat2gray(c_changed))

error in " LL2(i,(n-6):end) = s(i,1:(i+4)); "

Answer 1

[Nick]

The error message is pretty much the answer, you are trying to assign 5 elements into 7 elements.

% Has 7 elements | Has 5 elements 
LL2(i,(n-6):end) = s(i,1:(i+4));

assigning into 5 elements would mean you replace the index of your LL2

% correct assignment
LL2(i,(n-4):end) = s(i,1:5);

This is assuming you always want to use 5 If you assign using 1:(i+4), your vector size will increase each iteration:

because u are basically calling: 1:5, 1:6, etc. An other alternative is to have the first part transform along: i:(i+5). But i don't know the problem well enough to answer that

(edited - misread the 1:i+4 part)

[Maha Oueghlani]

Thank you for your reply.. in this exemple i will take the first 5 MSB so form 1 to 5 like what you mentionned