<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=iso-8859-1">
<META content="MSHTML 6.00.2800.1528" name=GENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=#ffffff>
<DIV><FONT face=Arial size=2>Dear All,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I am very interested in the underlying
registration technique in ITK. I realize that ITK registration is done in
physical coordinates, all the voxels in two datasets should
be transformed to points in physical space before registration.
</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>1. Generally the number of points in two datasets
to be registered are different, are they resampled to the same number of points
in ITK registration framework - is there any interpolated point
involved during registration? If the two point datasets are in
non-uniform grid, how to generate the joint histogram, for example the
element h(i, j) in joint histogram represents the number of point pairs which
have grey value of i in one dataset, and have grey value of j in the
corresponding positions in the other dataset. My question is how to build the
corresponding position if the points are on non-uniform grids.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>2. Since ITK take into account the voxel size, and
use it to compute a scaling factor for transform, is this scaling factor
reflected in the final transform matrix?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Many thanks in advance!</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Regards,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Yan</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV></BODY></HTML>