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<DIV><FONT face=Arial size=2>Hi,</FONT></DIV>
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<DIV><FONT face=Arial size=2>I answer your question 2 ,3 and 4</FONT></DIV>
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<DIV><FONT face=Arial size=2>2.origin is the start point of the control grid,
spacing is the actual space between two control points. You need the origin,
spacing and the size to definitely set the control gird.</FONT></DIV>
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<DIV><FONT face=Arial size=2>3.generally, you need 2^(2*D) control points(D
denotes the Dimension), so the number of the parameters are D *
2^(2*D)</FONT></DIV>
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<DIV><FONT face=Arial size=2>4. the size of the grid will impact heavily on the
run time of the Optimizer, so you need trade between the registration precision
and the run time</FONT></DIV>
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<DIV><FONT face=Arial size=2>Hope it help!</FONT></DIV>
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<DIV><FONT face=Arial size=2>Regards,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Yixun liu</FONT></DIV></BODY></HTML>