code: def rgb2xyz(r__, g__, b__):
      
  
      r2_ = r__ / 255.0
      g2_ = g__ / 255.0
      b2_ = b__ / 255.0
  
      def f__(arr):
          """Forward
          """
          return np.where(arr > 0.04045,
                          ((arr + 0.055) / 1.055) ** 2.4,
                          arr / 12.92)
  
  
      r2_ = f__(r2_) * 100
      g2_ = f__(g2_) * 100
      b2_ = f__(b2_) * 100
  
      x__ = r2_ * 0.4124 + g2_ * 0.3576 + b2_ * 0.1805
      y__ = r2_ * 0.2126 + g2_ * 0.7152 + b2_ * 0.0722
      z__ = r2_ * 0.0193 + g2_ * 0.1192 + b2_ * 0.9505
  
      return x__, y__, z__
docs: RGB to XYZ