apply_xfm_ants
======================================

.. py:function:: petpal.preproc.register.apply_xfm_ants(input_image_path: str, ref_image_path: str, out_image_path: str, xfm_paths: list[str], copy_meta: bool = False, **kwargs) -> ants.ANTsImage

   Applies existing transforms in ANTs or ITK format to an input image, onto
   a reference image. This is useful for applying the same transform on
   different images to atlas space, for example.

   :param input_image_path: Path to image on which transform is applied.
   :type input_image_path: str
   :param ref_image_path: Path to image to which transform is applied.
   :type ref_image_path: str
   :param out_image_path: Path to which the transformed image is saved.
   :type out_image_path: str
   :param xfm_paths: List of transforms to apply to image. Must be in
                     ANTs or ITK format, and can be affine matrix or warp coefficients.
   :type xfm_paths: list[str]
   :param copy_meta: If True, copies metadata file read from input_image_path as the metadata
                     for new image out_image_path.
   :type copy_meta: bool

   :returns: *xfm_img (ants.ANTsImage)* -- The input image transformed with an ANTs transform file.