[Insight-users] still unsuccessful in dewarping a fluo image

[Karthik Krishnan]

Strange.

For interpolating TPS, the deformed target landmarks and source
landmarks should perfectly overlap.

Either the computed TPS transform is incorrect or something went wrong
at the warping stage.

Perhaps, you could overlay the input fluoro and the grid on top of the
deformation field in paraview.

Then use the probe Paraview over a few landmarks to ascertain that the
deformation field at the probed locations is indeed a vector of the
right magnitude and direction.

(Be sure to turn off "mask points" on the glyph filter, since it
generates glyphs for a few randomly chosen pixels in the image and not
at every pixel. As a result your probe will yield a value of 0 at a
lot of locations and mislead you. For visual inspection of the field
however, "mask points" is great as it does not clutter your
visualization by glyphing the def field at every single pixel.)

This might help you validate the transform.

HTH
--
karthik

On Mon, Apr 14, 2008 at 5:10 PM, Boettcher, Dr. Peter
<Boettcher at kleintierklinik.uni-leipzig.de> wrote:
>
>
>
>
>
> I am not sure what you mean with "aspect". I try to dewarp a 2D fluoroscopic
> image using KernelBase spline deformation and two sets of landmarks. My code
> is exactly what is shown in the LandmarkWarping2 example.
>
>
>
> I manually defined a set of source and target landmarks. Than I performed
> the deformation along with the computation of a 2D deformation field. The
> dewarped image I get is better than the original but far from what I would
> need.
>
>
>
> What seems strange to me is the fact that the dewarped image looks enlarged
> even thought the deformation field is oriented to the centre of the original
> target image.
>
>
>
> Fluo image: http://www.bilder-upload.eu/show.php?file=lOAULD07LeTb0fZ.jpg
>
> Grid: http://www.bilder-upload.eu/show.php?file=ON5DUNAnbRZaQ9w.jpg
>
> Dewarped fluo image:
> http://www.bilder-upload.eu/show.php?file=F5KaxAcLLwbY1og.JPG
>
> Source landmarks
> http://www.bilder-upload.eu/show.php?file=wcG9VZa0BapBS1k.jpg
>
> Manual deformation field within MeVisLab
> http://www.bilder-upload.eu/show.php?file=iBrGaequ69018Re.jpg
>
> Deformation field within ParaView:
> http://www.bilder-upload.eu/show.php?file=xeMgaegspa3qQpJ.jpg
>
>
>
>
>
> Many thanks – Peter.
>  ________________________________
>  Von: Luis Ibanez [mailto:luis.ibanez at kitware.com]
> Gesendet: Mo 14.04.2008 22:35
> An: Boettcher, Dr. Peter
> Cc: insight-users @ itk. org
> Betreff: Re: [Insight-users] still unsuccessful in dewarping a fluo image
>
>
>
>
>
>
> Hi Peter,
>
> What is the aspect of the deformed image that doesn't
> match to what you were expecting ?
>
>
>    Please give us more details,
>
>
>       Thanks
>
>
>          Luis
>
>
>
> ------------------------------
> Boettcher, Dr. Peter wrote:
> > Thank you Karthik for your help!
> >
> >
> >
> >
> >
> > I managed to get my deformation field into ParaView
> > (http://www.bilder-upload.eu/show.php?file=aq49RZ0Lv1xIMh1.jpg). It
> > looks quite good, but the deformed image is still not what I expected
> > (http://www.bilder-upload.eu/show.php?file=F5KaxAcLLwbY1og.JPG).
> >
> >
> >
> >
> >
> > Is there anything I could try to find out where the problem is?
> >
> >
> >
> > Regards, Peter.
> >
> >
> > ------------------------------------
> > Peter Böttcher, Dr med vet, DipECVS
> > European Veterinary Specialist in Surgery
> > Fachtierarzt für Kleintierchirurgie
> > Klinik für Kleintiere
> > Universität Leipzig
> > An den Tierkliniken 23
> > D-04103 Leipzig (Germany)
> > Tel: +49-341-9738700
> > Fax: +49-341-9738799
> > email: boettcher at kleintierklinik.uni-leipzig.de
> > <mailto:boettcher at kleintierklinik.uni-leipzig.de>
> >
> >
> > ------------------------------------------------------------------------
> >
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> > Insight-users at itk.org
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>
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