...Paper.js is easy to learn for beginners and has lots to master for intermediate and advanced users. Paper.js is developed by Jürg Lehni & Jonathan Puckey, and distributed under the permissive MIT License. Paper.js is not simply a wrapper around the Canvas, it offers much more.
A powerful C++ class library for image manipulation
...Its features include load, save, display, transformation, and nearly 100 special image effects. It can be used cross platform (includes Windows, Linux, Mac), and especially under windows it can be used as a DIB wrapper class.