LFWProcess.m

function [M, A, B] = LFWProcess()

% preprocess the LFW images. The output of the function is the centered
% images data as matrix M. Centered female images as group A and centered
% male images as group B. 

addpath data/images

% 13232 images starting from img0 to img13231.txt
data_size = 13232;
img_size = 1764;

fileID1 = fopen('sex.txt', 'r');
formatSpec = '%f';
sex= fscanf(fileID1, formatSpec);
fclose(fileID1);

images = zeros(data_size, img_size);

for ell=0 : (data_size -1)
    fileIDtmp = fopen(strcat('img', num2str(ell),'.txt'));
    formatSpec = '%f';
    array = fscanf(fileIDtmp, formatSpec);
    images(ell+1,:) = transpose(array);
    fclose(fileIDtmp);
end

% normalization
images = images/255;
% center the images
mm = mean(images,1);
images_centered= images - repmat(mm, data_size, 1);

images_female = images(find(~sex),:);
female_mean = mean(images_female, 1);
size_female = size(images_female);
images_female_centered = images_female - repmat(female_mean, size_female(1), 1);

images_male = images(find(sex),:);  
male_mean = mean(images_male, 1);
size_male = size(images_male);
images_male_centered = images_male - repmat(male_mean, size_male(1), 1);

M = images_centered;
A = images_female_centered;
B = images_male_centered;


end