def draw_objects(self, objects, bounds, img):
        '''draw objects on the image'''
        keys = objects.keys()
        keys.sort()
        for k in keys:
            obj = objects[k]
            bounds2 = obj.bounds()
            if bounds2 is None or mp_util.bounds_overlap(bounds, bounds2):
                obj.draw(img, self.pixmapper, bounds)
draw objects on the image