'Render trans (only PNG).'

def _render_trans(self, trans, path, info, subject, subjects_dir):

    kwargs = dict(info=info, trans=trans, subject=subject, subjects_dir=subjects_dir)
    try:
        img = _iterate_trans_views(function=plot_alignment, **kwargs)
    except IOError:
        img = _iterate_trans_views(function=plot_alignment, surfaces=['head'], **kwargs)
    if (img is not None):
        global_id = self._get_id()
        html = image_template.substitute(img=img, id=global_id, div_klass='trans', img_klass='trans', caption=('Trans    :    ' + trans), width=75, show=True, image_format='png')
        return html
