Retrieves header metadata from neuroimaging objects or files. Returns a structured list with commonly needed fields like sform/qform matrices, TR, intent codes, and data scaling parameters.
For low-level access to all raw NIfTI header fields, use the
$raw element of the returned list.
Usage
header(x)
# S4 method for class 'FileMetaInfo'
header(x)
# S4 method for class 'character'
header(x)Arguments
- x
A
NeuroVol,NeuroVec,FileMetaInfo, or a character file path.
Value
A list of class "NeuroHeader" with elements:
- dim
Integer dimensions.
- pixdim
Voxel sizes including TR.
- spacing
Spatial voxel sizes (first 3 pixdim values).
- origin
Coordinate origin.
- trans
4x4 affine transform.
- qform
List with
matrix(4x4) andcode(integer).- sform
List with
matrix(4x4) andcode(integer).- intent_code
NIfTI intent code.
- intent_name
NIfTI intent name string.
- descrip
Description string.
- data_type
Storage data type label.
- bitpix
Bits per pixel.
- scl_slope
Data scaling slope.
- scl_inter
Data scaling intercept.
- cal_min
Display intensity minimum.
- cal_max
Display intensity maximum.
- TR
Repetition time (4th pixdim), or
NAif not 4D.- raw
The complete raw header list (all NIfTI fields).
Examples
# \donttest{
f <- system.file("extdata", "global_mask_v4.nii", package = "neuroim2")
h <- header(f)
h$dim
#> [1] 64 64 25 4
h$TR
#> [1] 0
h$sform
#> $matrix
#> [,1] [,2] [,3] [,4]
#> [1,] -3.5 0.0 0.0 112.0
#> [2,] 0.0 3.5 0.0 -108.0
#> [3,] 0.0 0.0 3.7 -46.2
#> [4,] 0.0 0.0 0.0 1.0
#>
#> $code
#> [1] 1
#>
h$descrip
#> [1] NA
# }