seg_crop_to_pet_fov
=====================================================

.. py:function:: petpal.preproc.segmentation_tools.seg_crop_to_pet_fov(pet_img: ants.ANTsImage, segmentation_img: ants.ANTsImage, pet_thresh_value: float = np.finfo(float).eps) -> ants.ANTsImage

   Zero out segmentation values that lie outside of the PET FOV.

   Especially applicable to scanners with limited FOV (field of view). PET voxels with values less
   than 1e-36 are considered outside of the FOV.

   :param pet_img: PET image in anatomical space used to crop segmentation
   :type pet_img: ants.ANTsImage
   :param segmentation_img: Segmentation image in anatomical space such as
                            FreeSurfer to which FOV cropping is applied.
   :type segmentation_img: ants.ANTsImage
   :param pet_thresh_value: Lower threshold for the PET image by which the segmentation image
                            is masked. Should be <<1. Default machine epsilon for `float`.
   :type pet_thresh_value: float

   :returns: *segmentation_masked_img (ants.ANTsImage)* -- Segmentation image masked to PET FOV.