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<DIV>Karthik&nbsp;Krishnan,您好！</DIV>

<DIV>&nbsp;</DIV>

<DIV>I&nbsp;am&nbsp;a&nbsp;student&nbsp;in&nbsp;SJTU,Shanghai,China.&nbsp;I&nbsp;want&nbsp;to&nbsp;implement&nbsp;registration&nbsp;by&nbsp;myself,&nbsp;and&nbsp;I&nbsp;have&nbsp;gotten&nbsp;</DIV>

<DIV>lots&nbsp;of&nbsp;help&nbsp;from&nbsp;ITK&nbsp;src&nbsp;and&nbsp;users&nbsp;list.&nbsp;However,&nbsp;I 

can understand some special procedures using in GradientDescent and Powell 

optimizer :&nbsp;(</DIV>

<DIV>for example, to calculate the derivative in GradientDescent:</DIV>

<DIV>MutualInformationImageToImageMetric&lt;TFixedImage,TMovingImage&gt;<BR>::CalculateDerivatives( 

--------------------------------------&nbsp;&nbsp;&nbsp;: &lt;<BR>&nbsp; const 

FixedImagePointType&amp; point,<BR>&nbsp; DerivativeType&amp; derivatives ) 

const</DIV>

<DIV>&nbsp;</DIV>

<DIV>Although I had read some paper about Mutual Imformation and Gradient 

Descent</DIV>

<DIV>could you be so kind to tell me more about the principle on which this 

method is based, and any&nbsp;papers about Powell description.</DIV>

<DIV>Thanks a lot :)</DIV>

<DIV>&nbsp;</DIV>

<DIV>=======&nbsp;2005-04-12&nbsp;12:56:00&nbsp;您在来信中写道：=======</DIV>

<DIV>&nbsp;</DIV>

<DIV>&gt;&gt; 庄吓海&nbsp;wrote:</DIV>

<DIV>&gt;&gt; </DIV>

<DIV>&gt;&gt; &gt; &nbsp;insight-users，您好！</DIV>

<DIV>&gt;&gt; &gt; &nbsp;　　　　　　　　致</DIV>

<DIV>&gt;&gt; &gt; &nbsp;礼！</DIV>

<DIV>&gt;&gt; &gt; &nbsp;　　　　　　　　庄吓海</DIV>

<DIV>&gt;&gt; &gt; &nbsp;　　　　　　　　arhye@163.com</DIV>

<DIV>&gt;&gt; &gt; &nbsp;　　　　　　　　　　2005-04-11</DIV>

<DIV>&gt;&gt; &gt; </DIV>

<DIV>&gt;&gt; &gt; 

------------------------------------------------------------------------</DIV>

<DIV>&gt;&gt; &gt; </DIV>

<DIV>&gt;&gt; &gt; _______________________________________________</DIV>

<DIV>&gt;&gt; &gt; Insight-users&nbsp;mailing&nbsp;list</DIV>

<DIV>&gt;&gt; &gt; Insight-users@itk.org</DIV>

<DIV>&gt;&gt; &gt; http://www.itk.org/mailman/listinfo/insight-users</DIV>

<DIV>&gt;&gt; &gt; &nbsp;&nbsp;</DIV>

<DIV>&gt;&gt; &gt; </DIV>

<DIV>&gt;&gt; 

A&nbsp;quick&nbsp;look&nbsp;at&nbsp;the&nbsp;code&nbsp;will&nbsp;probably&nbsp;help.&nbsp;You&nbsp;will&nbsp;also&nbsp;find&nbsp;ample</DIV>

<DIV>&gt;&gt; 

information&nbsp;(about&nbsp;20&nbsp;slides&nbsp;or&nbsp;so&nbsp;on&nbsp;GradientDescent&nbsp;with&nbsp;lots&nbsp;of</DIV>

<DIV>&gt;&gt; 

pictures&nbsp;:)&nbsp;)&nbsp;at&nbsp;the&nbsp;NAMIC&nbsp;Registration&nbsp;presentation&nbsp;that&nbsp;Luis&nbsp;gave.</DIV>

<DIV>&gt;&gt; </DIV>

<DIV>&gt;&gt; Here's&nbsp;the&nbsp;link</DIV>

<DIV>&gt;&gt; </DIV>

<DIV>&gt;&gt; 

http://www.na-mic.org/Wiki/images/b/ba/Insight-Registration.ppt</DIV>

<DIV>&gt;&gt; </DIV>

<DIV>&gt;&gt; Thanks</DIV>

<DIV>&gt;&gt; Regards</DIV>

<DIV>&gt;&gt; Karthik</DIV>

<DIV>&nbsp;</DIV>

<DIV>=&nbsp;=&nbsp;=&nbsp;=&nbsp;=&nbsp;=&nbsp;=&nbsp;=&nbsp;=&nbsp;=&nbsp;=&nbsp;=&nbsp;=&nbsp;=&nbsp;=&nbsp;=&nbsp;=&nbsp;=&nbsp;=&nbsp;=</DIV>

<DIV></DIV>

<DIV>&nbsp;</DIV>

<DIV>　　　　　　　　致</DIV>

<DIV>礼！</DIV>

<DIV>&nbsp;</DIV>

<DIV>&nbsp;</DIV>

<DIV>　　　　　　　　庄吓海</DIV>

<DIV>　　　　　　　　arhye@163.com</DIV>

<DIV>　　　　　　　　　　2005-04-13</DIV>

<DIV>&nbsp;</DIV></BODY></HTML>