Website with editor and a preview

i'd like to create a website with some kind of editor. The editor gives options to manipulate a picture which is then send to the server on which a python programm does the work.

I'd like to add a preview of the picture in that editor which updates automaitcally when the users does changes or if that's the better way triggers an update.

I've already saw such editors but i'm too new in web development to know what i should use for that.

Could someone give me a hint what i should look for or which framesworks i could use?

I'd really appreciate some hints which push me into the right direction.