Renaming images random numbers that are located in several subdirectories

I have 1 directory and 63 subdirectory with images in each directory. I need to randomly assign them numbers WITHOUT repeating numbers for all of the images in the 1 directory. The problem I am having is renaming a .tif and a .png with randperm and numbers being reused because of this. I then move all the new images to one folder. See code below.

mainDirectory = '/Users/';
newDir = '/Users/Documents/Pictures/';
subDirectory = dir([mainDirectory '']);
for m = 1 : length(subDirectory)
subFolder1 = dir(fullfile(mainDirectory, subDirectory(m).name,'*.tif'));
subFolder2 = dir(fullfile(mainDirectory, subDirectory(m).name,'*.png'));
fileNames1 = {subFolder1.name};
fileNames2 = {subFolder2.name};
 for iFile = 1 : numel( subFolder1 )
   newName1 = fullfile(mainDirectory, subDirectory(m).name, sprintf( 'image%d.tif', randperm(256,1)));
   movefile( fullfile(mainDirectory, subDirectory(m).name, fileNames1{ iFile }), newName1 ); 
   copyfile(newName1,newDir)
 end
 for iFile = 1 : numel( subFolder2 )
   newName2 = fullfile(mainDirectory, subDirectory(m).name, sprintf( 'image%d.png', randperm(256,1) )); 
   movefile( fullfile(mainDirectory, subDirectory(m).name, fileNames2{ iFile }), newName2 );  
   copyfile(newName2,newDir)
 end
end
end

Thank you in advance.

Answer 1

[Walter Roberson]

Get one of the Recursive Directory tools from the File Exchange, such as http://www.mathworks.com/matlabcentral/fileexchange/40016-recursive-directory-searching-for-multiple-file-specs . Have it find all of the .png and .tif at the same time. You can then calculate how many there are in total, which gives you the range of values to randperm() over. You can use fileparts to pull apart each complete name to find the extension to prepare the destination file, and then you can movefile() or copyfile() from the source to the destination.