code: def bsnr(vblr, vnsy):
      
  
      blrvar = np.var(vblr)
      nsevar = np.var(vnsy - vblr)
      with np.errstate(divide='ignore'):
          rt = blrvar / nsevar
      return 10.0 * np.log10(rt)
docs: Compute Blurred Signal to Noise Ratio (BSNR) for a blurred and noisy
      image.
  
      Parameters
      ----------
      vblr : array_like
        Blurred noise free image
      vnsy : array_like
        Blurred image with additive noise
  
      Returns
      -------
      x : float
        BSNR of `vnsy` with respect to `vblr` and `vdeg`