% ------------------------------------------------------------------------

function images = prepare_batch(image_files,mean_data,batch_size)

% ------------------------------------------------------------------------

if nargin < 2

% load mean file

d = load('/home/iis/Research/packages/caffe-master/matlab/+caffe/imagenet/ilsvrc_2012_mean.mat');

mean_data = d.mean_data;

end

num_images = length(image_files);

if nargin < 3

batch_size = num_images;

end

IMAGE_DIM = 256;

CROPPED_DIM = 227;

indices = [0 IMAGE_DIM-CROPPED_DIM] + 1;

center = floor(indices(2) / 2)+1;

num_images = length(image_files);

images = zeros(CROPPED_DIM,CROPPED_DIM,3,batch_size,'single');

parfor i=1:num_images

% read file

fprintf('%c Preparing %s\n',13,image_files{i});

try

im = imread(image_files{i});

% resize to fixed input size

im = single(im);

im = imresize(im, [IMAGE_DIM IMAGE_DIM], 'bilinear');

% Transform GRAY to RGB

if size(im,3) == 1

im = cat(3,im,im,im);

end

% permute from RGB to BGR (IMAGE_MEAN is already BGR)

im = im(:,:,[3 2 1]) - mean_data;

% im = im(:,:,[3 2 1]);

% Crop the center of the image

images(:,:,:,i) = permute(im(center:center+CROPPED_DIM-1,...

center:center+CROPPED_DIM-1,:),[2 1 3]);

catch

warning('Problems with file',image_files{i});

end

end