[Insight-users] Multi Modality Multi Resolution Doubt

[Arash Jahangir]

Thanks Luis.  Do you happen to know of any public programs/examples that I
could look at to get more familiar with the process?

TIA,
Arash

PS Forget Billy Crystal; they should have gotten you to host the show :-)


----- Original Message ----- 
From: "Luis Ibanez" <luis.ibanez at kitware.com>
To: "Arash Jahangir" <arash at vije.ca>
Cc: "ITK" <insight-users at itk.org>
Sent: Sunday, February 29, 2004 5:04 PM
Subject: Re: [Insight-users] Multi Modality Multi Resolution Doubt


>
> Hi Arash,
>
> The 20 to 30 degrees that a registration method can correct for
> are assumed to be *after* you provide an initialization.
>
> If you have images with a relative rotations that is larger than
> 30 degrees, but you can provide an initialization by for example
> using landmarks, then the actual rotation that the registration
> method has to correct is only the residual rotation error left after
> the initialization.
>
> The problem of reconstructing a panorama is very similar
> to the problem of constructing mosaics in teledetection or
> stitching images in microscopy.  They can be solved with
> the current registration framework in ITK.
>
> You will find usefult to take advantage of the masking
> capabilities that have been added to some metrics.
>
> The extra dificulty in mosaic is that you don't only need
> to register two images but a set of N images in subsets.
> Therefore you may have to iterate among the pairs of
> neighbor images and redistribute the geometric transform
> over the entire set of images.
>
>
> Regards,
>
>
>      Luis
>
>
>
>
> ----------------------------
> Arash Jahangir wrote:
>
> >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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> >>
> >>
> >>
> >>
> >
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