title: What is an inverse mapping function in image processing?
body: <p>Does anyone know what an inverse mapping function is in image processing? The <a href="http://www.karlsims.com/papers/siggraph91.html" rel="noreferrer">paper</a> I am reading describes image processing functions that "take input coordinates as arguments instead of pixel coordinates, allowing the result to be distorted by an arbitrary inverse mapping function."</p>