Here is an example of what you can do with Toast UI Image Editor.
I recreated a custom interface, because the one proposed by NHN did not suit me. There are many components not present in the toolbar but present in the code that you can activate or not if you wish.
Warning: Some components not implemented may be buggy or simply not finished. I am thinking in particular of the almost impossible to implement crop function from the Toast UI's API Direct.
Happy hacking !