'Although postscript itself is dpi independent, we need to
imform the image code about a requested dpi to generate high
res images and them scale them before embeddin them'

def __init__(self, width, height, pswriter, imagedpi=72):

    RendererBase.__init__(self)
    self.width = width
    self.height = height
    self._pswriter = pswriter
    if rcParams[u'text.usetex']:
        self.textcnt = 0
        self.psfrag = []
    self.imagedpi = imagedpi
    self.color = None
    self.linewidth = None
    self.linejoin = None
    self.linecap = None
    self.linedash = None
    self.fontname = None
    self.fontsize = None
    self._hatches = {}
    self.image_magnification = (imagedpi / 72.0)
    self._clip_paths = {}
    self._path_collection_id = 0
    self.used_characters = {}
    self.mathtext_parser = MathTextParser(u'PS')
    self._afm_font_dir = os.path.join(rcParams[u'datapath'], u'fonts', u'afm')
