This command is helpful when you've rotated a large image and it's drawing slowly. This will rotate the image and create a new image, so that it doesn't have to be rotated every time it's drawn. If using 32-bit images and you've also extended or condensed the image, the area that's normally white will be transparent.

This operation will save a copy of the bitmap in the history, so it should be used with care if you have limited memory compared to the size of the bitmap.