code: def _lab_to_rgb(labs):
      """Convert Nx3 or Nx4 lab to rgb"""
      # adapted from BSD-licensed work in MATLAB by Mark Ruzon
      # Based on ITU-R Recommendation BT.709 using the D65
      labs, n_dim = _check_color_dim(labs)
  
      # Convert Lab->XYZ (silly indexing used to preserve dimensionality)
      y = (labs[:, 0] + 16.0) / 116.0
      x = (labs[:, 1] / 500.0) + y
      z = y - (labs[:, 2] / 200.0)
      xyz = np.concatenate(([x], [y], [z]))  # 3xN
      over = xyz > 0.2068966
      xyz[over] = xyz[over] ** 3.0
      xyz[~over] = (xyz[~over] - 0.13793103448275862) / 7.787
  
      # Convert XYZ->LAB
      rgbs = np.dot(_xyz2rgb_norm, xyz).T
      over = rgbs > 0.0031308
      rgbs[over] = 1.055 * (rgbs[over] ** (1.0 / 2.4)) - 0.055
      rgbs[~over] *= 12.92
      if n_dim == 4:
          rgbs = np.concatenate((rgbs, labs[:, 3]), axis=1)
      rgbs = np.clip(rgbs, 0.0, 1.0)
      return rgbs
  
file_path: vispy/vispy/color/color_space.py
imports: from __future__ import division
  import numpy
label_desc: Use image node_id 7 for calling a global function with example usage: _lab_to_rgb(labs) and returns: rgbs