code: def threshold(x, th):
      return np.maximum(np.minimum(x, th), -th)
  
imports: import numpy
  import scipy.linalg
  from nibabel.affines import apply_affine
  from transforms3d.quaternions import mat2quat, quat2axangle
  from .transform import Transform
label_desc: Use image node_id 1 for calling a global function with example usage: threshold(x, th) and returns: np