[Insight-users] Re: MultResMIRegistration using CT and US

[Jon Harald Kaspersen]

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Hi again Luis,

Thanks again, this is good news.

With my limited experience with this registration algorithm I can detect
good registrations in some areas and bad in others.  I have to rewrite 
the code so that the
output is in a form that it can be input in one of our VTK visualization 
apps.

And yes, there was a typo in the URL, it should read 
http://www.us.unimed.sintef.no/

Regards
Jon

On Thursday, May 16, 2002, at 03:45 PM, Luis Ibanez wrote:

> From: Luis Ibanez <luis.ibanez@kitware.com>
> Date: Thu May 16, 2002  03:45:54 PM Europe/Paris
> To: Jon Harald Kaspersen <Jon.H.Kaspersen@unimed.sintef.no>
> Cc: insight-users <insight-users@public.kitware.com>, Lydia Ng 
> <lng@insightful.com>
> Subject: [Insight-users] Re: MultResMIRegistration using CT and US
>
>
>
> Hi Jon,
>
>
> Having a different structure of gray levels in both
> images is not a problem for Mutual Information.
> In fact this is the case in which MI is interesting
> and when it behaves better because MI is not measuring
> how similar the pixel's gray levels are but rather
> how often the gray levels appear together.
> So, MI can match drak structure of one image to bright
> structures of the other.
>
> Having structures that light up in one modality and
> do not differentiate in the other is Ok in general.
> The potential risks however is if each modality has
> two different antomical structures that look similar
> and could lead the registration algorithm to try to
> match them.
>
>
> How is the registration behaving ?
> is it converging to a wrong position ?
>
>
> Thanks
>
>
>   Luis
>
>
>
> BTW, I could not load your URL.
> could there by a typo on it, maybe ?
> ============================================
>
========================================================
Jon Harald Kaspersen			Tel: 		+47 73 59 75 89
Ph.D. Mechanical Engineering		Mob:		+47 93 03 65 90
Senior Scientist				Pager	+47 96 84 29 94
SINTEF Unimed - Ultralyd		Fax: 		+47 73 59 78 73
N-7465 Trondheim
NORWAY			e-mail:	Jon.H.Kaspersen@unimed.sintef.no
				WEB:	http://www.us.unimed.sintef.no/
========================================================

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Hi again Luis,


Thanks again, this is good news.


With my limited experience with this registration algorithm I can
detect

good registrations in some areas and bad in others.  I have to rewrite
the code so that the

output is in a form that it can be input in one of our VTK
visualization apps.


And yes, there was a typo in the URL, it should read
http://www.us.unimed.sintef.no/


Regards

Jon


On Thursday, May 16, 2002, at 03:45 PM, Luis Ibanez wrote:


<excerpt>From: Luis Ibanez <<luis.ibanez@kitware.com>

Date: Thu May 16, 2002  03:45:54 PM Europe/Paris

To: Jon Harald Kaspersen <<Jon.H.Kaspersen@unimed.sintef.no>

Cc: insight-users <<insight-users@public.kitware.com>, Lydia Ng
<<lng@insightful.com>

Subject: [Insight-users] Re: MultResMIRegistration using CT and US




Hi Jon,



Having a different structure of gray levels in both

images is not a problem for Mutual Information.

In fact this is the case in which MI is interesting

and when it behaves better because MI is not measuring

how similar the pixel's gray levels are but rather

how often the gray levels appear together.

So, MI can match drak structure of one image to bright

structures of the other.


Having structures that light up in one modality and

do not differentiate in the other is Ok in general.

The potential risks however is if each modality has

two different antomical structures that look similar

and could lead the registration algorithm to try to

match them.



How is the registration behaving ?

is it converging to a wrong position ?



Thanks



  Luis




BTW, I could not load your URL.

could there by a typo on it, maybe ?

============================================


</excerpt>========================================================

Jon Harald Kaspersen			Tel: 		+47 73 59 75 89

Ph.D. Mechanical Engineering		Mob:		+47 93 03 65 90

Senior Scientist				Pager	+47 96 84 29 94

SINTEF Unimed - Ultralyd		Fax: 		+47 73 59 78 73

N-7465 Trondheim

NORWAY			e-mail:	Jon.H.Kaspersen@unimed.sintef.no

				WEB:	<underline><color><param>1A1A,1A1A,FFFF</param>http://www.us.unimed.sintef.no/</color></underline>

========================================================
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