unexplored Lands

[selden]

For your amusement, here's what happened when I used MMPS (under Cygwin) to project the south pole in gnomonic (where one could make appropriate changes, but I didn't)



and here it is reprojected to equirectangular. One could then use appropriate tools to merge it with the original artwork, although MMPS could do that for you, too.



Here's the script that I used.

#! /usr/bin/sh -x
#
# project equirectangular to gnomonic
#
convert detail_colored.jpg tmp.ppm
project \
    gnomonic \
    -scale 2 -lat -90 -long 0 -w 2500 -h 2500 \
    -f tmp.ppm >tmp2.ppm
convert tmp2.ppm south_pole.jpg
#
# project gnomonic to equirectangular
#
project \
    -i gnomonic \
    -scale 2 -lat -90 -long 0 -w 5000 -h 2500 \
    -f tmp2.ppm >tmp3.ppm
convert tmp3.ppm eq_south_pole.jpg

"project" is the MMPS re-projection utility and "convert" is the ImageMagick image format conversion utility.

p.s.
Note that .ppm is a lossless, uncompressed image format. Of course, any intermediate editing should be done in a similarly lossless image format like png or bmp, for example, using a lossy format like jpg only for the final image.