MATLAB: I am getting an error in disply the eigenvectors the 4 th last line reshape can anyone help me out??

eigenfacesfigure

%%Loading the Images
clear all
input_dir = ‘D:\MATLAB R2012a\work’;
image_dims = [300, 238];
filenames = dir(fullfile(input_dir, ‘*.jpg’));
num_images = numel(filenames);
images = zeros(prod(image_dims),num_images);
for n = 1:num_images
filename = fullfile(input_dir, filenames(n).name);
img = imread(filename);
% img = rgb2gray(img); % I’ve done it manually before using IrfanView
img = im2double(img); % Thanks to this line the best match is shown. Without it it was just a white space.
img = imresize(img,image_dims);
images(:, n) = img(:);
end
%%Training
% steps 1 and 2: find the mean image and the mean-shifted input images
mean_face = mean(images, 2);
shifted_images = images – repmat(mean_face, 1, num_images);
% steps 3 and 4: calculate the ordered eigenvectors and eigenvalues
[evectors, score, evalues] = princomp(images’, ‘econ’);
% step 5: only retain the top ‘num_eigenfaces’ eigenvectors (i.e. the principal components)
num_eigenfaces = 11;
evectors = evectors(:, 1:num_eigenfaces);
% step 6: project the images into the subspace to generate the feature vectors
features = evectors’*shifted_images;
% calculate the similarity of the input to each training image
input_image = imread(‘PC044879_cr.jpg’);
% input_image = rgb2gray(input_image);
input_image = imresize(input_image,image_dims);
input_image = im2double(input_image);
feature_vec = evectors’ * (input_image(:) – mean_face);
similarity_score = arrayfun(@(n) 1 / (1 + norm(features(:,n) – feature_vec)), 1:num_images);
% find the image with the highest similarity
[match_score, match_ix] = min(similarity_score);
% % display the result
% figure, imshow([input_image reshape(images(:,match_ix), image_dims)]);
% colormap(gray);

% title(sprintf(‘matches %s, score %f’, filenames(match_ix).name, match_score));
% display the result
figure, imshow([input_image reshape(images(:,match_ix), image_dims)]);
% colormap(gray);
title(sprintf(‘matches %s, score %f’, filenames(match_ix).name, match_score));
% display the eigenvectors
figure;
for n = 1:num_eigenfaces
subplot(2, ceil(num_eigenfaces/2), n);
evector = reshape(evectors(:,n), image_dims);
imshow(evector);
colormap(gray); % Thanks to this line I’ve got all the eigenfaces instead of getting black rectangles
end

Best Answer

What is the error message you are getting?
My guess is that the total number of elements in evectors(:,n):
numel(evectors(:,n))
is not equal to the product of the dimensions you have specified:
prod(image_dims)
and therefore the reshape cannot be done. If that's the case, you should be able to trace back why that's happening, using debug mode.
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