'interpolation and cmap default to their rc settings
cmap is a colors.Colormap instance
norm is a colors.Normalize instance to map luminance to 0-1
extent is data axes (left, right, bottom, top) for making image plots
registered with data plots.  Default is to label the pixel
centers with the zero-based row and column indices.
Additional kwargs are matplotlib.artist properties'

def __init__(self, ax, cmap=None, norm=None, interpolation=None, origin=None, filternorm=1, filterrad=4.0, resample=False, **kwargs):

    martist.Artist.__init__(self)
    cm.ScalarMappable.__init__(self, norm, cmap)
    self._mouseover = True
    if (origin is None):
        origin = rcParams[u'image.origin']
    self.origin = origin
    self.set_filternorm(filternorm)
    self.set_filterrad(filterrad)
    self.set_interpolation(interpolation)
    self.set_resample(resample)
    self.axes = ax
    self._imcache = None
    self.update(kwargs)
