How to import the images into 2D array (one image per row)?

I downloaded the DeepLearnToolbox-master and try to train the CNN. In the test_example_CNN.m,the train images are imported into 2D matrices (one image per row). I would like to train the CNN with my own images, but I don't know how to import the images into 2D array (one image per row). Please, explain me how to do it.

Thanks, May

% Load the MNIST hand-written digit dataset.
load mnist_uint8;

% Reshape the example digits back into 2D images.
%
% 'train_x' and 'test_x' begin as 2D matrices with one image per row.
%   train_x  [60000  x  784]
%   test_x   [10000  x  784]
%
% Also, rescale the pixel values from 0 - 255 to 0 - 1. 
train_x = double(reshape(train_x',28,28,60000))/255;
test_x = double(reshape(test_x',28,28,10000))/255;
train_y = double(train_y');
test_y = double(test_y');

% You can use this command to display an example image. Note that the 
% images need to be transposed in order to be oriented properly.
colormap gray;
imagesc(train_x(:, :, 105)');
axis square;

Answer 1

[Walter Roberson]

http://matlab.wikia.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F

img = imread(TheFileName);
train_x(end+1,:) = reshape(img, 1, []);

[May]

Thank you very much for your answer.