One image as a source for different-sized objects

Hello! Is there any possibility to use one image as a source for set of tiles/objects? It’s quite comfortable to work on gfx using one image containing all graphics, but the problem these objects are not same sized (not “tiles”). I mean this, for example:

I know there is possibility to use a set of images (stored as different image files), but I am looking for a way to keep them in one file and use for maps in Tiled.