I have taken a number of images from a very large rock overhang that contains ancient paintings. I want to piece the images together to create a single image of the entire rockshelter. Through ARCGIS I tried to do this by georeferencing the images, which have no spatial data. It worked quite well. However, I don't know how to save it so that when I move onto the next image, the previous georeferencing remains. How can I save it?