How to start creating your own online graphics editor?

Question

User interface

How to start creating your own online graphics editor?
What literature can you suggest? What to watch (courses, etc.)?

Answer 1

From the choice of technology.
And in order to advise here, you need to know the level of your skill, what technologies and languages ​​you know, etc.
By the way, it's nice to know the theory of image processing.

Answer 2

CanvasApi (2d)
is quite enough to build ala-paint