I'm looking to develop a simple image editor wherein a user can cycle through multiple layers (6-10) of images to develop a unique avatar. For example, the initial image layer will be a 2D character of their choice, mostly void of any accessories. The next image layer would be a shirt, another pants, another jewelry etc. I like the idea of frontend HTML5 so it can be a web app compatible across most platforms, but I'm lost on the backend requirements of such a project. #noob
Any help would be greatly appreciated.