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Adding some empty voxel slices.

Posted: Fri May 16, 2008 3:59 pm
by BigBrain_musician
Hi Experts,

When I do the dilation (closing) of some image I get some Border effect, (an unexpected result) that create some error on my output image. To solve this problem I would have to resized the space where is the volume and translate the volome at the center of this space, but this operation would modify my referential, so it's not better.

I could if possible and there is my question adding extra emptys voxels layers (blacks slices) on each side of the volume x, y, z.

My question: Is there an aims or Vip or any function that can do what i wanted. ?

French : Quand je fais la fermetures d'une image, j'ai des effet de bordure, cela créé une erreur sur l'image de sortie comme une bosse sur la tête par exemple.

Pour corriger se probleme il faudrais redimensionner l'espace dans lequel se trouve le volume et déplacer le volume au centre de cet espace. mais cela changerais le référentiel, donc ce n'est pas mieux.

Je pourrais si c'est possible et la est ma question ajouté des couche de voxel vide (noir) sur tout les coté de mon volume en x y et z.

Ma question est de savoir si une des fonctions aims ou vip ou autre peut me permettre de faire une telle opération.


Re: Adding some empty voxel slices.

Posted: Sat May 17, 2008 12:49 am
by riviere
Well, I thought this border handling was already done in the morphomath commands, but maybe there are still problems when the object actually extends to the border.
To add empty spaces, you can use the resampling command: AimsResample (in nearest neighbour mode: order 0), with larger image dimensions, and a transformation providing a translation: provide a motion file (-m option). The transformation matrix format is very simple: ASCII, 4 lines of 3 columns, as follows:

Code: Select all

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.
Then you may apply the inverse translation + crop the morphomath result to get it in the same referential.