new_contents: # $Id$
  #
  # Copyright (C) 2006-2008 Greg Landrum
  #  All Rights Reserved
  #
  
  
  def MolToImageFile(mol,filename,size=(300,300),kekulize=True, wedgeBonds=True):
    import MolDrawing
    try:
      from aggdraw import Draw
      from PIL import Image
      MolDrawing.registerCanvas('agg')
      useAGG=True
    except:
      import traceback
      traceback.print_exc()
      useAGG=False
      from sping.PIL.pidPIL import PILCanvas as Canvas
      canvas = Canvas(size=(300,300),name=filename)
      MolDrawing.registerCanvas('sping')
      drawer = MolDrawing.MolDrawing(canvas)
    if useAGG:
      img = Image.new("RGBA",size,"white")
      canvas = Draw(img)
      canvas.setantialias(True)
      drawer = MolDrawing.MolDrawing(canvas)
  
    if kekulize:
      import Chem
      mol = Chem.Mol(mol.ToBinary())
      Chem.Kekulize(mol)
      
    if not mol.GetNumConformers():
      from Chem import AllChem
      AllChem.Compute2DCoords(mol)
    
    drawer.wedgeDashedBonds=wedgeBonds
    drawer.AddMol(mol)
  
    if useAGG:
      canvas.flush()
      img.save(filename)
    else:
      canvas.save()
      
  
subject: add a convenience function