docs: def corrpix_deform_delta(area_um, px_um=0.34):
      """Deformation correction term for pixelation effects
  
      The contour in RT-DC measurements is computed on a
      pixelated grid. Due to sampling problems, the measured
      deformation is overestimated and must be corrected.
  
      The correction formula is described in :cite:`Herold2017`.
  
      Parameters
      ----------
      area_um: float or ndarray
          Apparent (2D image) area in µm² of the event(s)
      px_um: float
          The detector pixel size in µm.
      inplace: bool
          Change the deformation values in-place
  
      Returns
      -------
      deform_delta: float or ndarray
          Error of the deformation of the event(s) that must be
          subtracted from `deform`.
          deform_corr = deform -  deform_delta
      """
      # A triple-exponential decay can be used to correct for pixelation
      # for apparent cell areas between 10 and 1250µm².
      # For 99 different radii between 0.4 μm and 20 μm circular objects were
      # simulated on a pixel grid with the pixel resolution of 340 nm/pix. At
      # each radius 1000 random starting points were created and the
      # obtained contours were analyzed in the same fashion as RT-DC data.
      # A convex hull on the contour was used to calculate the size (as area)
      # and the deformation.
      # The pixel size correction `pxcorr` takes into account the pixel size
      # in the pixelation correction formula.
      pxcorr = (.34 / px_um)**2
      offs = 0.0012
      exp1 = 0.020 * np.exp(-area_um * pxcorr / 7.1)
      exp2 = 0.010 * np.exp(-area_um * pxcorr / 38.6)
      exp3 = 0.005 * np.exp(-area_um * pxcorr / 296)
      delta = offs + exp1 + exp2 + exp3
  
      return delta