nrrd.vox2ras

NRRD stores the geometry of a volume as one direction vector per space axis
('space directions'), the world position of the center of voxel (0,0,0) ('space origin') and
the world space these refer to ('space'). Voxel indices are 0-based. The matrix returned here
always maps to RAS+ coordinates (x = right, y = anterior, z = superior), which is the space
used by FreeSurfer, by the NIfTI standard and by the rest of this package: a file that states
the LPS space therefore has the sign of its first two axes flipped.

internal

Provides functions to read and write neuroimaging data in various file formats, with a focus on 'FreeSurfer' formats. This includes, but is not limited to, the following file formats: 1) MGH/MGZ/NIFTI format files, which can contain multi-dimensional images or other data. Typically they contain time-series of three-dimensional brain scans acquired by magnetic resonance imaging (MRI). They can also contain vertex-wise measures of surface morphometry data. The MGH format is named after the Massachusetts General Hospital, and the MGZ format is a compressed version of the same format. 2) 'FreeSurfer' morphometry data files in binary 'curv' format. These contain vertex-wise surface measures, i.e., one scalar value for each vertex of a brain surface mesh. These are typically values like the cortical thickness or brain surface area at each vertex. 3) Annotation file format. This contains a brain surface parcellation derived from a cortical atlas. 4) Surface file format. Contains a brain surface mesh, given by a list of vertices and a list of faces.

Tim Schc3<a4>fer

freesurferformats

Read and Write 'FreeSurfer' Neuroimaging File Formats

Tim Schäfer

Van Essen Lab 

Montreal Neurological Institute (MNI) 

nrrd.vox2ras function

<dl><dt>fields</dt>
<dd>named list, the parsed header fields.</dd>
<dt>dimension</dt>
<dd>integer, the number of dimensions of the volume.</dd>
<dt>filepath</dt>
<dd>character string, path to the file, used in warnings.</dd></dl>

Arguments

Compute the voxel-to-RAS matrix of a NRRD volume. — nrrd.vox2ras

<dl>

<dt>fields</dt>
<dd>named list, the parsed header fields.</dd>


<dt>dimension</dt>
<dd>integer, the number of dimensions of the volume.</dd>


<dt>filepath</dt>
<dd>character string, path to the file, used in warnings.</dd>

</dl>

nrrd.vox2ras: Compute the voxel-to-RAS matrix of a NRRD volume.

Description

Usage

Value

Arguments