Content Creator for my backend

I currently have been building a database with a front end for clients and a backend to administrate the clients. However right now I am stuck trying to create a feature. When a client logs in they have the ability already to add information for an RSS feed. What I need to create now is the ability for them to create a custom slide. This is for a digital signage solution. My idea of how this should be done is allowing them to basically edit an image that will be saved in HD format. I want the ability for them to Upload images, add them to the image, resize if they want and the ability to just add text. Once they are done they hit save and it will save what they see as an image with the locations id number.