[Insight-developers] question regarding direction cosines

[Leila baghdadi]

Hi Kent

that sounds like a good solution, the only problem with this is what if
the spatial dimensions with meaningful directions are *not* the first 3
dimensions,

The way I envisioned this, the image could have dimensions of any order

i.e, the three spatial dimensions can show up in any order, so that
would make the upper left 3x3 of an NxN not meaningful

will work on your solution plus correct ordering, I am sure once I
commit the code I hear complaints about it


Thanks again

Leila
On Tue, 2005-11-08 at 17:11 -0600, Kent Williams wrote:
> Direction Matrix is NxN where N is the number of dimensions in the 
> image.  In general, only the first 3 directions have any spatial 
> meaning, and 3D images are the most common by far.
> 
> I'd suggest setting the direction matrix to identity, and then filling 
> in the X,Y,Z (0,1,2) columns with the direction cosines representing the 
> 3D orientation -- basically the upper left 3x3 of the matrix.  Anyone 
> else have a suggestion?
> 
> Leila baghdadi wrote:
> 
> >Hi guys
> >
> >I am writing ImageIO classes for our specific file format (minc2) which
> >is like itk N-dimensional,
> >
> >I am a bit confused about how to create a correct matrix for direction
> >cosines,
> >
> >suppose I have an image with the following
> >
> >u,x,r,y,w,z
> >
> >so direction cosines are only for x,y,z
> >
> >the question is what is the correct way to create m_Direction of
> >itkImageIOBase.*
> >
> >do I create a matrix (6x3) where I have (0,0,0) (1,0,0) (0,0,0) 
> >
> >or basically how do you carry the correct index for the spatial
> >dimensions,
> >
> >Hopefully my question is clear if not please let me know
> >
> >Thanks
> >
> >Leila
> >
> >
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> >Insight-developers at itk.org
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> >
> >  
> >
-- 
Leila baghdadi <baghdadi at sickkids.ca>