as_nifti_header: Construct a Minimal NIfTI-1 Header from a NeuroVol

In bbuchsbaum/neuroim2: Data Structures for Brain Imaging Data

Construct a Minimal NIfTI-1 Header from a NeuroVol

Description

Given a NeuroVol object (or similar), this function builds a basic NIfTI-1 header structure, populating essential fields such as dim, pixdim, datatype, the affine transform, and the quaternion parameters.

Usage

as_nifti_header(vol, file_name, oneFile = TRUE, data_type = "FLOAT")

Arguments

vol	A NeuroVol (or 3D array-like) specifying dimensions, spacing, and affine transform.
file_name	A character string for the file name (used within the header but not necessarily to write data).
oneFile	Logical; if TRUE, sets the NIfTI magic to "n+1", implying a single-file format (.nii). If FALSE, uses "ni1" (header+image).
data_type	Character specifying the data representation, e.g. "FLOAT", "DOUBLE". The internal code picks an integer NIfTI code.

Details

This is a convenience function that calls createNIfTIHeader first, then updates the fields (dimensions, pixdim, orientation, etc.) based on the vol argument. The voxel offset is set to 352 bytes, and the quaternion is derived from the transform matrix via matrixToQuatern.

Note: This function primarily sets up a minimal header suitable for writing standard single-file NIfTI-1. If you need a more comprehensive or advanced usage, consider manually editing the returned list.

Value

A list representing the NIfTI-1 header fields, containing elements like dimensions, pixdim, datatype, qform, quaternion, qfac, etc. This can be passed to other functions that write or manipulate the header.

See Also

createNIfTIHeader for the base constructor of an empty NIfTI header.

bbuchsbaum/neuroim2 documentation built on Feb. 26, 2025, 3:49 p.m.