You're not even reading in the images. You're just concatenating filename strings. Try inserting images.
folder = 'C:\Users\sara\Desktop\inodastnazan\azmayeshi';
files = dir(fullfile(folder, '*.tiff'));
array4d = zeros(512, 512,3, numel(files));
% Loop over filenames, inserting the image.
for slice = 1 : length(files)
filename = fullfile(folder, files(slice).name);
thisImage = imread(filename);
[rows, columns, numberOfColorChannels) = size(thisImage);
if numberOfColorChannels < 3
message = 'Error: Image is not RGB Color!';
uiwait(warndlg(message));
continue;
end
if rows ~= 512 || columns ~= 512
message = 'Error: Image is not 512x512!';
uiwait(warndlg(message));
continue; % Skip this image.
end
% Image is okay. Insert it.
array4d(:,:,:,slice) = thisImage;
end
