images over 300k pixels wide/high

how does one put an image over 300k pixels wide through the droplets? ive seen images beyond this psb limit in krpano, such as the viena 50GP image, but cant obviously see how to do it myself. The kro format output by autopano seemed the obvious choice but that comes up as unrecognised

Solution: Autopano can render images to psb files over 300k pixels on a side, and krpano will be able to generate tiles, its just photoshop that doesn't support those large images so intermediate editing wont be possible