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FSL Apply Warp Field (applywarp)

Library: FSL | Docker Image: brainlife/fsl

Function

Applies linear and/or non-linear warp fields to transform images between coordinate spaces.

Modality: 3D or 4D NIfTI volume plus warp field and/or affine matrix.

Typical Use: Applying normalization warps to functional data or atlas labels.

Key Parameters

-i (input), -r (reference), -o (output), -w (warp field), --premat (pre-warp affine), --postmat (post-warp affine), --interp (interpolation)

Key Points

Can chain affine + nonlinear transforms in one step. Use --interp=nn for label images, --interp=spline for continuous images. Reference defines output grid.

Inputs

Name Type Required Label Flag
input File Yes Input image to be warped --in=
reference File Yes Reference image --ref=
output string Yes Output filename --out=
warp File No Warp field file --warp=
premat File No Pre-transform affine matrix (applied first) --premat=
postmat File No Post-transform affine matrix (applied last) --postmat=
relwarp boolean No Treat warp as relative (x' = x + w(x)) --rel
abswarp boolean No Treat warp as absolute (x' = w(x)) --abs
interp enum No Interpolation method --interp=
supersample boolean No Enable supersampling --super
superlevel string No Supersampling level (integer or 'a' for auto) --superlevel=
mask File No Mask in reference space --mask=
datatype enum No Output data type --datatype=
padding_size int No Padding size --paddingsize=
verbose boolean No Verbose output -v

Accepted Input Extensions

  • input: .nii, .nii.gz
  • reference: .nii, .nii.gz
  • warp: .nii, .nii.gz
  • premat: .mat
  • postmat: .mat
  • mask: .nii, .nii.gz

Outputs

Name Type Glob Pattern
warped_image File $(inputs.output).nii.gz, $(inputs.output).nii
log File applywarp.log

Output Extensions

  • warped_image: .nii, .nii.gz

Enum Options

interp: nn, trilinear, sinc, spline

Docker Tags

Available versions: latest, 6.0.4-patched2, 6.0.4-patched, 6.0.4, 6.0.4-xenial, 5.0.11, 6.0.0, 6.0.1, 5.0.9

Categories

  • Utilities > FSL > Warp Utilities

Documentation

Official Documentation