Add Files to wp-content/upload folder

Is there a way to have the media library reflect new files added to the upload folder without using the multiple file uploader in wp? I have thousands of photos which I want to add to the media library but not use the media library to import them. I know where my wp-content/uploads/.. /… is on the server. If I just copy and paste all my photos in the folder, how can I make them appear in the media library in wp?

Just wondering if this is possible.