Rotation of a MR volume via AimsResample.

AIMS library and commands usage

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BigBrain_musician
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Rotation of a MR volume via AimsResample.

Postby BigBrain_musician » Thu Jun 19, 2008 2:12 pm

Hi denis and others, not long ago you told me how to translate an image with aimsResample.

You told me about the -m option... That transformation matrix format is very simple: ASCII, 4 lines of 3 columns, as follows:
Tx Ty Tz
R11 R12 R13
R21 R22 R23
R31 R32 R33
T for translation, R for the 3x3 linear matrix part. Here the R part will be identity if I want a translation...

The translation part works...

But now, I want to do a rotation of 180 degree (pi radian) around Z, and I'm trying to do that with this matrix :
0 0 0 } no translation
-1 0 0
0 -1 0
0 0 1

But It doesn't work, do you have a clue what's wrong with my matrix ?

I was pretty sure of myself and I thought it was about to work at the first shot :(
Mathieu Gauvin
LATIS - ETS
Electrical Engineering
Intern in Neuro-science.

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Jean-Francois Mangin
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Re: Rotation of a MR volume via AimsResample.

Postby Jean-Francois Mangin » Thu Jun 19, 2008 4:24 pm

This command just applies RX+T to your image, X being the point coordinates from the first corner
of the image. Therefore, your rotation is just pushing your data out of the field of view.
You need to add a rotation (I know this format for the matrix is painful...).

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riviere
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Re: Rotation of a MR volume via AimsResample.

Postby riviere » Fri Jun 20, 2008 10:20 am

You meant: you need to add a translation ;)
Denis

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Jean-Francois Mangin
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Re: Rotation of a MR volume via AimsResample.

Postby Jean-Francois Mangin » Fri Jun 20, 2008 9:05 pm

Thanks Denis...


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