Struct QForm 

struct QForm {
    quatern: [f64; 3],
    offset: [f64; 3],
    qfac: f64,
}

NIfTI-1’s quaternion (“qform”) description of a voxel→world transform — method 2 in the spec.

A reader rebuilds the matrix from the quaternion, the voxel sizes in pixdim[1..=3], and qfac. The quaternion’s scalar part is not stored: it is implied by the other three components, which is why only b, c, d appear here.

Fields

quatern: [f64; 3]

quatern_b, quatern_c, quatern_d.

offset: [f64; 3]

qoffset_x, qoffset_y, qoffset_z — the affine’s translation, verbatim.

qfac: f64

pixdim[0]: -1 for a left-handed (negative determinant) transform, +1 otherwise.

A quaternion only ever describes a rotation, so a mirrored acquisition cannot be expressed by one. This is how the spec carries the reflection separately: the reader negates the third column after rotating. 0 is not a legal value, and the spec says to read it as +1.

Trait Implementations

impl Clone for QForm

fn clone(&self) -> QForm

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for QForm

impl Debug for QForm

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for QForm

fn eq(&self, other: &QForm) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for QForm