> % V.mat - a 4x4 affine transformation matrix mapping from
> % voxel coordinates to real world coordinates.
> This question may sound really stupid but does the matrix computed and
> stored in the .mat has special properties, for example is it a symmetric
> matrix or anything else?
There are no real constraints on the matrix - other than the bottom row always
contains [0,0,0,1], so I guess they belong to some mathematical Lie Group.
All that is required is that the matrix maps from voxel indices to some real
world space, where voxel indices start at [1,1,1]. i.e.
xcoordinate = M(1,1)*xindex + M(1,2)*yindex + M(1,3)*yindex + M(1,4)
ycoordinate = M(2,1)*xindex + M(2,2)*yindex + M(2,3)*yindex + M(2,4)
zcoordinate = M(3,1)*xindex + M(3,2)*yindex + M(3,3)*yindex + M(3,4)
Best regards,
-John
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