[Insight-users] Multi Modality Multi Resolution Doubt

Arash Jahangir arash at vije.ca
Sun, 29 Feb 2004 16:10:25 -0500


Hi Luis,
Would this range of 20-30 degrees be still the limiting factor if I had some
user input that could roughly identify matching regions between the images
as a starting point?  To put this question in perspective, let me explain
what I am after.

I have a set of photos that form a "panorama" with some overlap.  Because
the subject was relatively close to the camera, the rotational distortion in
the overlapping region is quite obvious (as compared to say a panorama of
the Rocky Mountains).  I am trying to write a program that would merge all
these photos with each other.  Do you have any suggestions for how I should
go about this?

thanks,
Arash

----- Original Message ----- 
From: "Luis Ibanez" <luis.ibanez at kitware.com>
To: "CSPL" <hyd2_affable at sancharnet.in>
Cc: <insight-users at itk.org>
Sent: Saturday, February 28, 2004 10:55 AM
Subject: Re: [Insight-users] Multi Modality Multi Resolution Doubt


>
> Hi Abdul,
>
> A reasonable registration proces will correct for
> rotations of about 20 to 30 degrees.  Expecting
> it to correct for image orientation (axial, coronal
> saggital) is unrealistic and actually dangerous.
>
> Registration is an optimization problem that is solved
> with a cost function with multiple extrema. There is
> no magic here, if you don't initialize the registration
> close to the optimal region, you can end up anywhere,...
> and don't have to much right to complain.
>
>
> There are filters in ITK for correcting Flipping and
> orienting images:
>
> http://www.itk.org/Insight/Doxygen/html/classitk_1_1OrientImageFilter.html
> http://www.itk.org/Insight/Doxygen/html/classitk_1_1FlipImageFilter.html
>
http://www.itk.org/Insight/Doxygen/html/classitk_1_1ReflectImageFilter.html
>
> This is something that has to be done very carfully since
> you could easily switch left-right on the patient image
> and lead a surgeon to operate on the wrong side.
>
>
> So, to answer your questions explicitly:
>
> 1) Yes, you must set the orientation to be the same
> 2) No,  ITK will not do that for you.
> 3) Yes, you need to supply parameters.
>
>
>
> Regards,
>
>
>     Luis
>
>
> -----------------
> CSPL wrote:
>
> > Hi,
> >
> >  I need to do some registration of SPECT[brain] with MRI[segmented
> > brain]. So i have choosen Multi Modality Multi Resolution Registration
> > and stuck with some problems. I am not getting the final results upto
> > the mark. Later i found that my MRI is in Coronal View and the SPECT is
> > in Transverse View. I want you to clarify in this point that
> >
> > 1. Do we need to set the orientation of both the volumes same? or
> > 2. Does ITK will itself look for this and REGISTER? or
> > 3. Do we need to supply any parameters to get REGISTRATION even in this
> > situation?
> >
> >  Please reply.
> >
> > Thanks in Advance
> > S. Abdul Rahim
>
>
>
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