title: Find recurring patterns in paintings
body: <p>I have a large collection of wall paintings(Murals). For a painting, I want to find all the recurring patterns(all repeating designs and number of time each one occurs). But the problem is the paintings are not exact. There is lot of imperfection and distortion. And I want to develop a generic algorithm for all kind of pattens which gives result with high accuracy. Most of the algorithms I tried (feature extraction in opencv, contour matching) work well for photographic images where there is orientation or scale changes and imperfections are minimum. Could anybody suggest any method or source that cab help me.</p>
  
  <p>Links to some sample paintings-
  (There are recurring patterns like different kind of floral shapes, designs in boundary, some other repeating figures)</p>
  
  <p><a href="https://docs.google.com/file/d/0Bx3-s7he2z7xdmRpMTlWUmEtZ2M/edit" rel="nofollow">https://docs.google.com/file/d/0Bx3-s7he2z7xdmRpMTlWUmEtZ2M/edit</a></p>
  
  <p><a href="https://docs.google.com/file/d/0Bx3-s7he2z7xaF9mYTFOYUFNaTg/edit" rel="nofollow">https://docs.google.com/file/d/0Bx3-s7he2z7xaF9mYTFOYUFNaTg/edit</a></p>
  
  <p><a href="https://docs.google.com/file/d/0Bx3-s7he2z7xQi1qbWo0X05sd0U/edit" rel="nofollow">https://docs.google.com/file/d/0Bx3-s7he2z7xQi1qbWo0X05sd0U/edit</a></p>
  
  <p><a href="https://docs.google.com/file/d/0Bx3-s7he2z7xNnNiNEZmQm1XelU/edit" rel="nofollow">https://docs.google.com/file/d/0Bx3-s7he2z7xNnNiNEZmQm1XelU/edit</a> </p>
  
  <p><a href="https://docs.google.com/file/d/0Bx3-s7he2z7xUnNlMmFial9ERkU/edit" rel="nofollow">https://docs.google.com/file/d/0Bx3-s7he2z7xUnNlMmFial9ERkU/edit</a> </p>
  
  <p><a href="https://docs.google.com/file/d/0Bx3-s7he2z7xY185dzhnZDdfM2c/edit" rel="nofollow">https://docs.google.com/file/d/0Bx3-s7he2z7xY185dzhnZDdfM2c/edit</a></p>