Image Processing, Bulge Shaping

Question

JavaScript

Actually there is the following task: there is an image. It is necessary to deform the image so that a hemisphere is formed from a square. You will have to implement this on JS + Canvas, so ... I doubt that there is a ready-made solution (although what the hell is not joking) so at least tell me the algorithm for implementing this?

I can't use WebGL... Canvas maximum.

Answer 1

I wanted to explain the algorithm on my fingers, but I came to the conclusion that it is easier to write an example: jsfiddle.net/CDKXm/
Look, if something is not clear - in a personal. The algorithm is clumsy, without anti-aliasing and optimizations.