fsl.data.constants

This module defines some constant values used throughout fslpy.

The following constants relate to the orientation of an axis, in either voxel or world space:

ORIENT_L2R The axis goes from left to right.
ORIENT_R2L The axis goes from right to left.
ORIENT_P2A The axis goes from posterior to anterior.
ORIENT_A2P The axis goes from anterior to posterior.
ORIENT_I2S The axis goes from inferior to superior.
ORIENT_S2I The axis goes from superior to inferior.
ORIENT_UNKNOWN The axis has an unknown orientation.

These constants relate to the space in which a NIFTI image is assumed to be (i.e. the transformed coordinate space); they are defined in the NIFTI specification:

NIFTI_XFORM_UNKNOWN Arbitrary coordinates.
NIFTI_XFORM_SCANNER_ANAT Scanner-based anatomical coordinates.
NIFTI_XFORM_ALIGNED_ANAT Coordinates aligned to another file’s, or to anatomical “truth”.
NIFTI_XFORM_TALAIRACH Coordinates aligned to Talairach-Tournoux Atlas; (0,0,0)=AC, etc.
NIFTI_XFORM_MNI_152 MNI 152 normalized coordinates.
fsl.data.constants.ORIENT_L2R = 0

The axis goes from left to right.

fsl.data.constants.ORIENT_R2L = 1

The axis goes from right to left.

fsl.data.constants.ORIENT_P2A = 2

The axis goes from posterior to anterior.

fsl.data.constants.ORIENT_A2P = 3

The axis goes from anterior to posterior.

fsl.data.constants.ORIENT_I2S = 4

The axis goes from inferior to superior.

fsl.data.constants.ORIENT_S2I = 5

The axis goes from superior to inferior.

fsl.data.constants.ORIENT_UNKNOWN = -1

The axis has an unknown orientation.

fsl.data.constants.NIFTI_XFORM_UNKNOWN = 0

Arbitrary coordinates.

fsl.data.constants.NIFTI_XFORM_SCANNER_ANAT = 1

Scanner-based anatomical coordinates.

fsl.data.constants.NIFTI_XFORM_ALIGNED_ANAT = 2

Coordinates aligned to another file’s, or to anatomical “truth”.

fsl.data.constants.NIFTI_XFORM_TALAIRACH = 3

Coordinates aligned to Talairach-Tournoux Atlas; (0,0,0)=AC, etc.

fsl.data.constants.NIFTI_XFORM_MNI_152 = 4

MNI 152 normalized coordinates.

fsl.data.constants.NIFTI_XFORM_ANALYZE = 5

Code which indicates that this is an ANALYZE image, not a NIFTI image.