Resize images in subdirectories

I’m aware of the question “Resize Images uploaded by other plugin not media wordpress normal rute”. The plugin we use for customer uploads creates subdirectories under a main directory, and puts one image in each.

Can your software be configured to watch not a single directory, but all subdirectories of a given directory.

For example:

Parent upload directory = /uploads/a_parent_directory

Dynamically built image directories:

/uploads/a_parent_directory/alpha/
/uploads/a_parent_directory/beta/
/uploads/a_parent_directory/gamma/
/uploads/a_parent_directory/delta/

with one image file in each subdirectory