I hope this functionality in 15 days.
Lot of work, because it will include a nice upload security engine, and functions for :
- indirect file access
- Mime type check
- modal preview
- resizing
- cropping
- fitting
Also huge work on the sandboxes to manage your files. Quotas, restoring processes, etc...
The Joomla default modal image picker will be integrated (com_media), but to my opinion is not secure. So to test it in sandbox, I have a lots of hacks to implement in com_media to secure it.
Then, you will have the choice to use it or not this Joomla media manager for production, but in sandbox it will be hacked for security.
I will furnish you a securisated uploader with an indirect file access integrated in your component.

Images, but not only. All types of files could be handled and previewable if possible.
So...
This functionality is comming late, but fully protected for your uses.