rendering large sprites

I'm working with large pngs to do the map. each png is like 10MB (2000x200 px).
My problem is that you can actually see the picture loading during run time. I mean, whenever I move the camera, the large PNG's moves with it (like it should) but you can see a wave on the image like it's loading.
Is there anyway to render the PNG's before runtime or something like that?