[Insight-users] Deformable Registration

[Miller, James V (Research)]

Kathrin,

You should be able to take a position on your ellipse
and transform it by the calculated transformation to 
identify the corresponding point on the deformed structure.

Note the corresponding point predicted may not fall exactly
on the deformed ellipse.  How close it is will depend on the 
registration metric and transformation.

Jim



-----Original Message-----
From: kathrin [mailto:ktingelh at igd.fhg.de]
Sent: Friday, December 17, 2004 5:24 AM
To: Luis Ibanez
Cc: insight-users at itk.org
Subject: Re: [Insight-users] Deformable Registration


Hello,

thanks for your information!
I've already read the description of the registration algorithms in the 
itk-Software Guide. But the Deformable
Registration in ITK just computes a deformation component for each 
dimension. So the registration tells me,
how the ellipse is deformed in each dimension.
For my problem that is not enough!
I'd like to compute the motion of one point between the two images, the 
point is situated on the ellipse contour.
I dont want to compute a general deformation between two contours. It is 
possible that the ellipse contour
rotates around the centroid and I'd like to get an individual rotation 
angle for each point on the contour. Can I get this
detailed information for several points with an registration algorithm??
To recognize the ellipse is no problem.

Thanks,
Kathrin

Luis Ibanez schrieb:

>
> Hi Kathrin,
>
>
> From your description, it seems to be reasonable to
> solve this problem by using Deformable Registration.
>
> However, depending on the characteristics of your images,
> this may end up being a trivial process for less than
> an hour or...  a Ph.D. dissertation
>
> Note that deformable registration is a computationally
> intensive task. It may be an overkill for the problem
> that you are trying to solve. In particular in 3D.
>
> You may want to consider fitting a geometrical model to
> the ellipse in one image, and then fitting a similar model
> to the other image.  This can be done with the
>
>         SpatialObjectToImageRegistration
>
> You will find a description of this concept on the
> ITK Software Guide
>
>
>     http://www.itk.org/ItkSoftwareGuide.pdf
>
>
> Section 8.14 "Model based registration", pdf-page 328.
>
>
> If you want to give it a try to the DeformableRegistration
> algorithms, probably BSplines is the one that will give
> you a good balance between flexibility and computational
> time. You will find examples for all the Deformable Registration
> algorithms in ITK under the directory:
>
>
>            Insight/Examples/Registration
>
>
>
>
> Are the ellipses in the 3D images easily recognizable ?
>
> or are they immersed in a strong level of noise ?
>
>
>
>
> Please let us know,
>
>
>    Thanks
>
>
>       Luis
>
>
>
> ----------------
> kathrin wrote:
>
>> Hello,
>>
>> I wonder if the following problem can be solved with deformable 
>> registration:
>> I'd like to choose a point in a 3D image and I want the registration 
>> algorithm to find the position of the
>> same point in an other 3D image. The point is part of an ellipse, so 
>> it's no vertex.
>> The two images illustrate the same object at two different points of 
>> time. During the period of time, the
>> shape of the objects warps.
>> Is it possible to solve this point corresponding problem with 
>> deformable registration? If so, can you
>> tell me, which registration algorithm to use?
>>
>> Thanks,
>> Kathrin
>> _______________________________________________
>> Insight-users mailing list
>> Insight-users at itk.org
>> http://www.itk.org/mailman/listinfo/insight-users
>>
>>
>
>
>
>
>

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