title: comparing two vector images
body: <p>I want to compare two vector images (say SVG) and see how close they are.
  Basically, I want to test the correctness of a tracing algorithm which converts raster images to vector format.</p>
  
  <p>The way I am thinking to test this algorithm is:</p>
  
  <p>-Take some vector images.</p>
  
  <p>-Rasterize the vector image to png.</p>
  
  <p>-Feed the above png to tracing algorithm.</p>
  
  <p>-Compare the output of tracing program (which is SVG) with the original one.</p>
  
  <p>While I know there are some metrices for raster images like RMSE (in imagemagick), I am not familiar if there are some standard metrices for vector formats.
  I can think of some simple ones like number of arcs, lines, curves etc. But these can not detect the deviation in geometry and colors. Could someone suggest a good standard metric or some other approach to this problem. </p>