     if image_obj?
       @_draw_image(extent.join(':'))
     else
+      @_draw_image(@lastImage.cache_key)
       @render_timer = setTimeout((=> @_create_image(extent)), 65)
 
   _draw_image: (image_key) ->

      bounds : bounds
      cache_key : bounds.join(':')

    image.src = @mget('image_source').get_image_url(bounds[0], bounds[1], bounds[2], bounds[3], Math.floor(@map_frame.get('height')), Math.floor(@map_frame.get('width')))
    return image

  render: (ctx, indices, args) ->

    @x_mapper = this.map_frame.get('x_mappers')['default']
    @y_range = @map_plot.get('y_range')
    @y_mapper = this.map_frame.get('y_mappers')['default']
    @lastImage = undefined
    @extent = @get_extent()

  _map_data: () ->
