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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'>Dear Sir,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif";color:black'>I have a problem about deformation field. I try to implement Demons Algorithm in Medical Image Processing. I use B-Splines transformation to get Deformation vector field of first transformation image and second transformation image. After that, I will iterate B-Spline transformation step until no significant change in the deformation vector field. So, I must calculate difference (deviation) between previous deformation vector field and pos- deformation vector field to converge. How to compare deviation between deformations vector field</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif";color:#1F497D'> (http://www.ncbi.nlm.nih.gov/pubmed/21692138)</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif";color:black'>. <o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif";color:black'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif";color:black'>Best Regards,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif";color:black'>Bui Toan<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>