[Insight-developers] compose affine with header filter?

[Cory Quammen]

On Fri, Oct 8, 2010 at 1:38 PM, Michael Stauffer (Circular Logic)
<mstauff at verizon.net> wrote:
> We're not interested in shearing (at least at this point, Brian might
> have some ideas about that for down the road). Initially we'd like to be
> able to orient sets of images to a common orientation before batch
> processing, so should need just rotation and/or reflection. The idea, if
> I understand fully, is to account for different orientations between or
> within data sets, possibly due to operator error. Thus, we'll probably
> have to manually set the transforms per image.
>
> The goal with doing this via the image header is to avoid preprocessing
> the image data itself and introducing unnecessary interpolation noise.

I see.

> It seems from what we've looked at so far that the Image::m_Direction
> matrix is expected to be rigid, and if it is not, it is decomposed to
> use only the rigid part? At least, this seems to be how itk snap
> behaves.

Your understanding of the direction matrix matches mine, but I could be wrong.

Perhaps someone more familiar with the assumed properties of the
direction matrix could chime in.

Cory


>
>>-----Original Message-----
>>From: cquammen at gmail.com [mailto:cquammen at gmail.com] On Behalf
>>Of Cory Quammen
>>Sent: Friday, October 08, 2010 1:10 PM
>>To: Michael Stauffer (Circular Logic)
>>Cc: Insight Developers
>>Subject: Re: [Insight-developers] compose affine with header filter?
>>
>>Hi Michael,
>>
>>I don't know of a filter that does what you describe, but it sounds
>>like you want this filter to essentially produce an image on a
>>potentially sheared grid. Does this correctly characterize what you
>>want the filter to produce?
>>
>>An image defined on a sheared grid fits in with a recent discussion on
>>this list about supporting images whose samples do not lie at regular
>>intervals along orthogonal directions, so I'm interested in knowing
>>more about what you are trying to do with this filter.
>>
>>Thanks,
>>Cory
>>
>>
>>On Fri, Oct 8, 2010 at 11:28 AM, Michael Stauffer (Circular Logic)
>><mstauff at verizon.net> wrote:
>>> Hi all,
>>>
>>> I'm new to ITK. I started working with Brian Avants and the
>>reset of the
>>> ANTS team a few weeks ago. I'm about to start on my first
>>ITK filter, a
>>> simple one to learn the ropes. It may or may not end up being useful.
>>> But first we wanted to check if someone else has already
>>implemented the
>>> follow functionality, but not integrated it with itk.
>>>
>>> The filter will accept an image and an affine transform, compose the
>>> input transform with the transform stored in the image's header (via
>>> m_Direction and m_Origin), then output a new image with the composed
>>> transform in its header.
>>>
>>> Cheers,
>>> Michael
>>>
>>> _______________________________________________
>>> Powered by www.kitware.com
>>>
>>> Visit other Kitware open-source projects at
>>> http://www.kitware.com/opensource/opensource.html
>>>
>>> Kitware offers ITK Training Courses, for more information visit:
>>> http://kitware.com/products/protraining.html
>>>
>>> Please keep messages on-topic and check the ITK FAQ at:
>>> http://www.itk.org/Wiki/ITK_FAQ
>>>
>>> Follow this link to subscribe/unsubscribe:
>>> http://www.itk.org/mailman/listinfo/insight-developers
>>>
>>
>>
>>
>>--
>>Cory Quammen
>>Computer Integrated Systems for Microscopy and Manipulation (CISMM)
>>Department of Computer Science
>>University of North Carolina at Chapel Hill
>>http://www.cs.unc.edu/~cquammen
>
>



-- 
Cory Quammen
Computer Integrated Systems for Microscopy and Manipulation (CISMM)
Department of Computer Science
University of North Carolina at Chapel Hill
http://www.cs.unc.edu/~cquammen