apply_transform3d: Apply a linear RAS transform to resample a 3D volume

In ravetools: Signal and Image Processing Toolbox for Analyzing Intracranial Electroencephalography Data

Apply a linear ⁠RAS⁠ transform to resample a 3D volume

Description

Warps a moving volume onto a reference grid given a 4x4 ⁠RAS⁠-to-⁠RAS⁠ transform (such as the transform returned by register_volume3d). The transform maps reference (fixed) ⁠RAS⁠ coordinates to moving ⁠RAS⁠ coordinates.

Usage

apply_transform3d(
  volume,
  vox2ras,
  transform,
  reference_dim = dim(volume),
  reference_vox2ras = vox2ras,
  interpolation = c("trilinear", "nearest", "bspline"),
  na_fill = 0
)

Arguments

volume	moving 3D array to resample
vox2ras	the moving volume's voxel-to-⁠RAS⁠ 4x4 transform
transform	4x4 ⁠RAS⁠-to-⁠RAS⁠ transform (fixed to moving)
reference_dim	output dimension (the fixed grid); defaults to dim(volume)
reference_vox2ras	the fixed grid's voxel-to-⁠RAS⁠ transform; defaults to vox2ras
interpolation	'trilinear' (default), 'nearest', or 'bspline' (cubic ⁠Catmull-Rom⁠)
na_fill	value for out-of-bounds voxels; default 0

Value

The resampled volume on the reference grid, with a 'vox2ras' attribute equal to reference_vox2ras.

See Also

register_volume3d

ravetools documentation built on Aug. 21, 2026, 5:06 p.m.