Import Assets from an outside folder


I have a folder on my ubuntu out of pimcore documents root, i would like to save my images in this folder (photoshop,etc). Now i have wrote a symfony Command which should import or copy my images to a pimcore Asset folder (Doc: Assets how to work with PHP API) but it works not realy… The Database Entry exists but the image is not realy there (only string?)

In the documentation I found something “External System Interaction”, I have transformed the examplecode but for Assets

1.How can I import Assets with a symfony cronjob outside of the pimcores documents root?
2. What about the Asset Option “import-from-server” Can i use this with an extern folder?

How can I solve it with pimcore/symfony?