[eluser]loosetops[/eluser]
It wouldn't help for it to dynamically create folders. You would need the folders to follow a particular naming pattern and be created only when the current upload folder is filled to your requirements.
You can count the image files yourself
Code:
$dir = new DirectoryIterator('/path/to/dir');
foreach($dir as $file ){
$x += (isImage($file)) ? 1 : 0;
}
if you are sure the directory contains only image files
Code:
$dir = new DirectoryIterator('/path/to/dir');
foreach($dir as $file ){
++$x;
}
Then you can use mkdir to create a new directory