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Bug 1295 - ensure consistent handling of the handedness of the volumetric data with respect to the real-world coordinate system

Reported 2012-01-30 12:08:00 +0100
Modified 2012-07-07 20:25:21 +0200
Product: FieldTrip
Component: core
Version: unspecified
Hardware: PC
Operating System: Mac OS
Importance: P3 normal
Assigned to: Jan-Mathijs Schoffelen
Depends on:
Blocks: 1325
See also:

Jan-Mathijs Schoffelen - 2012-01-30 12:08:58 +0100

Now it seems that ft_volumerealign cannot deal correctly with a left-handed volume (so probably needs a flipdim in one of the dimensions to work correctly in this case). first create a test script that implements a sphere in a volume with well defined 'landmarks'. then see what happens when the transformation matrix / orientation of volume are manipulated. determine whether robust detection of volume handedness can be achieved (possibly using ft_determine_coordsys) investigate the suitability of a general purpose flipping function to enforce right-handed volumes, or the suitability of working with left-handed volumes in a correct way. also check the functionality in ft_volumesegment, because some flipping is done there too.

Jan-Mathijs Schoffelen - 2012-07-04 14:58:35 +0200

it has been decided that a particular handedness will not be imposed onto the data. Rather, ft_volumerealign now supports an additional control point to be specified that allows for a consistent transformation matrix, even if there is a mismatch between the handedness of the input and output coordinate system axes.