I am using the following code to compressed an image for different principal component. But I faced the error Matrix dimensions must agree. Error in imgP (line 9) X = fly-repmat(mn,1,n);. Please help

[fly,map] = imread('85E.png'); 
fly=double(fly); 
whos
image(fly) 
colormap(map) 
axis off, axis equal
[m,n]=size(fly); 
mn = mean(fly,2); 
X = fly-repmat(mn,1,n);
Z=1/sqrt(n-1)*X'; 
covZ=Z'*Z;
[U,S,V] = svd(covZ);
variances=diag(S).*diag(S); 
bar(variances,'b') 
xlim([0 20]) 
xlabel('eigenvector number') 
ylabel('eigenvalue')

Answer 1

[Walter Roberson]

Your fly is 3 dimensional but you are only expecting it to be 2 dimensional.

If you want to allow fly to be 3 dimensional then change

[m,n]=size(fly);

to

[m, n, ~] = size(fly);