There’s not a lot of info on the web for transforming the fisheye images you get with the Canon Dual Fisheye lens to rectilinear images.
I finally found this tutorial for Stereo Photo Maker but I was missing the options that I needed in the menu. Finally I realized that these were only available in the Windows version. Thankfully I have an old Windows laptop that I keep for things like this. So following the tutorial I produced this image.