pub fn obliquity_from_affine(affine: &[f64; 16]) -> f64Expand description
Scalar obliquity (degrees): the Euclidean norm of obliquity_axes_from_affine.
This is the quantity QSMxT 8.x thresholded on (nibabel obliquity → degrees → np.linalg.norm),
so thresholds carry over unchanged. Note it is a combined measure, not a tilt: a single 23°
oblique acquisition scores ≈32° here because two voxel axes each move. For the physical tilt of
B0 relative to the slice stack, use b0_angle_from_affine.