Is it possible to have 2 separate upload directories? One in which the resized images are created/stored and another to where full size original images are uploaded.
This would let you use the path to the resized images in your templates thus keeping the path to original full size images hidden from public view (but in a location such that they could still be used to regenerate thumbnails/new image sizes etc).
Using a stock WordPress installation, no.
WordPress, by default, stores uploads in the
/wp-content/uploads/yyyy/mm/directory for single sites. For network installations, it stores them elsewhere and maps a similar permalink structure to the new location.I can see what you’re trying to accomplish by keeping things in separate directories, but you’d have to revise a large portion of the WordPress uploader to make it happen. Instead, why not ask a new question about how to protect original full-size images from the public but allow them to view a downsampled smaller version?