Generating a terrain bigmap with npcs on it

[Cubical]

Is there anyway to generate a bigmap for terrain maps that include npcs? I know I can manually warp myself to each level and use makescreenshot(); then shrink them with drawstrechedimage(); and put them on a drawingpanel and piece them together then save that image. The problem with that is the drawing panel causes Graal to freeze and sometimes my client crashes before it can finish. I'm just looking for an alternative since I know I can do it that way.