code: def deltaE_cie76(lab1, lab2, channel_axis=-1):
      """Euclidean distance between two points in Lab color space
  
      Parameters
      ----------
      lab1 : array_like
          reference color (Lab colorspace)
      lab2 : array_like
          comparison color (Lab colorspace)
      channel_axis : int, optional
          This parameter indicates which axis of the arrays corresponds to
          channels.
  
          .. versionadded:: 0.19
             ``channel_axis`` was added in 0.19.
  
      Returns
      -------
      dE : array_like
          distance between colors `lab1` and `lab2`
  
      References
      ----------
      .. [1] https://en.wikipedia.org/wiki/Color_difference
      .. [2] A. R. Robertson, "The CIE 1976 color-difference formulae,"
             Color Res. Appl. 2, 7-11 (1977).
      """
      lab1, lab2 = _float_inputs(lab1, lab2, allow_float32=True)
      L1, a1, b1 = np.moveaxis(
          lab1, source=channel_axis, destination=0
      )[:3]
      L2, a2, b2 = np.moveaxis(
          lab2, source=channel_axis, destination=0
      )[:3]
      return np.sqrt((L2 - L1) ** 2 + (a2 - a1) ** 2 + (b2 - b1) ** 2)
  
file_path: scikit-image/skimage/color/delta_e.py
imports: import numpy
  from .._shared.utils import _supported_float_type
  from .colorconv import lab2lch, _cart2polar_2pi
label_desc: Use image node_id 2 for calling a global function with example usage: deltaE_cie76(lab1, lab2, channel_axis) and returns: np