code: def _convert(matrix, arr):
      """Do the color space conversion.
      Parameters
      ----------
      matrix : array_like
          The 3x3 matrix to use.
      arr : array_like
          The input array.
      Returns
      -------
      out : ndarray, dtype=float
          The converted array.
      """
      arr = _prepare_colorarray(arr)
  
      return arr @ matrix.T.copy()
  
imports: import numpy
  from scipy import linalg
  from warnings import warn
label_desc: Use image node_id 11 for calling a global function with example usage: _convert(matrix, arr) and returns: unknown