matlab trick

I have a folder which contain thousands of images, how can I load these image into a matrix with the size of (m,n,k), where m and n is the size of the image, k is the kth image. and I do not care the order of the image.

Thanks!

Answer 1

[Image Analyst]

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

Preallocate a 3D image with the known number of files that you will be reading in. Then, inside the loop, insert the 2D image into the volumetric image as a slice (plane):

image3D(:,:,sliceNumber) = image2D;

Answer 2

[Kye Taylor]

I'm assuming the images all have the same extension and that the file format is supported by imread. Also, I'm assuming that the current folder where your images are located is C:\myDir. You can change this in the code below.

folderOfInterest = 'C:\myDir'; % this is the path to your folder
cd(folderOfInterest); % make current folder your folder
ext = '.png'; % here's the extension of the images
files = dir; % get a listing of the current directory

% counts how many images are in current folder
isImageOfInterest = ~cellfun(@isempty,...
  regexp(cellstr(char(files.name)),'.png','ignorecase'));
N = nnz(isImageOfInterest) ;

Images = cell(N,1);
cnt = 0;
for i = 1:length(files)
  if isImageOfInterest(i)
    cnt = cnt+1;
    Images{cnt} = imread(files(i).name);
  end
end

If all the images are the same size, you can create your three-dimensional matrix with the command

 bigArray = cat(3,Images{:});