View Full Version : Shifting miller cylidrical projections

11-29-2009, 01:17 PM
Hey all,

I've got a rasterized miller cylindrical projection. Since,by nature, the projection distorts as it gets closer to the poles, I can't properly do any overlay work on it.

What I want to do is to shift the poles of my image north/south so that I can paint along the lines of the equator with minimal distortion. Then continue to shift -> paint -> shift -> paint, until I end up with a complete globe...

Any ideas how I can go about this?

11-29-2009, 05:48 PM
I am told that Hugin ( http://hugin.sourceforge.net ) will do this sort of reprojection. I have not used Hugin so I won't be able to tell you much about it.

I normally use ReprojectImage ( http://www.fracterra.com/ReprojectImage.zip ) and Wilbur when I need to do this sort of thing ( http://www.ridgenet.net/~jslayton/software.html ). Note that I am well-known as a masochist in certain areas. Using ReprojectImage I would convert the image into an Equirectangular projection that can be more easily ingested into other packages (such as Wilbur). In Wilbur, load the equirectangular image as a Color Image Texture file type. Window>>Map Projection allows projection into your choice of projections. I would recommend something like stereographic for a north and south polar map and Equirectangular for an equatorial aspect. Edit to your heart's content and then use ReprojectImage to convert the polar maps back to Equirectangular. Something like Photoshop or Gimp can be used to put the three images back together into a single map. Lots of effort but better than doing it by hand.

The best solution, of course, is to use a package that allows painting directly in the spherical object space. I don't know a good and inexpensive package that will do this.