title: Converting a cubic bezier curves into a cardinal spline and back
body: <p>I've read many articles that describe how to convert cardinal or canonical splines into cubic bezier curves, such as <a href="http://www.charlespetzold.com/blog/2009/01/Canonical-Splines-in-WPF-and-Silverlight.html" rel="nofollow">this</a> one.</p>
  
  <p>Is there a way to do the reverse, i.e. convert a set of cubic bezier curves into a cardinal spline? We know, for example, that the endpoints of each curve are on the spline.</p>
  
  <p>What I'm looking for is a way to roundtrip through the two representations with minimal loss of information. Also ideally the solution should be stable, so that going from cubic bezier => cardinal spline => cubic bezier => cardinal spline should result in the same (or nearly same) curves after the second operation.</p>