title: Robustly estimate Polynomial geometric transformation with scikit-image and RANSAC
body: <p>I would like to robustly estimate a polynomial geometric transform with scikit-image skimage.transform and skimage.measure.ransac</p>
  
  <p>The ransack documentation gives a very nice example of how to do exactly that but with a Similarity Transform. Here is how it goes:</p>
  
  <pre><code>from skimage.transform import SimilarityTransform
  from skimage.measure import ransac
  model, inliers = ransac((src, dst), SimilarityTransform, 2, 10)
  </code></pre>
  
  <p>I need to use <a href="http://scikit-image.org/docs/dev/api/skimage.transform.html#polynomialtransform" rel="nofollow">skimage.transform.PolynomialTransform</a> instead of SimilarityTransform, and I need to be able to specify the polynomial order.</p>
  
  <p>But the RANSAC call takes as input the PolynomialTransform(), which does not take any input parameters. The desired polynomial order is indeed specified in the estimate attribute of PolynomialTransform()... So the RANSAC call uses the default value for the polynomial order, which is 2, while I would need a 3rd or 4th order polynomial.</p>
  
  <p>I suspect it's a basic python problem? 
  Thanks in advance!</p>