How to take principal component to get eigenvalues for an array of face images

Hello, I'm trying to get started on eigenfaces in Matlab. I read in images 100 x 100 grey level with imread. Turned each one into single column of data 10,000 data points long. Created a matrix A with four columns (four images) of data 10,000 rows long. I then tried to use

[COEFF, SCORE, latent] = princomp(A); but it gives me : _Error using svd Out of memory. Type HELP MEMORY for your options.

Error in princomp (line 86) [U,sigma,coeff] = svd(x0,econFlag); % put in 1/sqrt(n-1) later

Error in face1 (line 37) [COEFF, SCORE, latent] = princomp(A);_

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size(A) = 4 x 10000

I just wanted to try four pictures before moving on to get fussy about the face images but it's already telling me it's out of memory.

Please help. I know people use Matlab to do Eigenfaces. What am I doing wrong ? Help please.

Answer 1

[bym]

I am no expert, but I think it has do with how you are arranging the matrix. See Eigenface , in particular the section about computing the Eigenvalues for reducing the size of the problem

 >> size(princomp(rand(100,4)))

ans =

       4     4

>> size(princomp(rand(4,100)))

ans =

     100   100