Based on your other post, I think what you want is to go from an image like this (equirectangular):
to this:
I did this using Gimp, with the mathmap plugin, using the following mathmap script I wrote:
Code:
unit filter sinusoidal (unit stretched image in)
divs = 9;
py = 2;
counter = 0;
while (counter <= divs) do
px = if (x>1-(2*counter/divs)-1/divs && x<=1-(2*counter/divs)+1/divs)
then (x-(1-(2*counter/divs)))/cos(y*pi)+1-(2*counter/divs)
end;
py = if (x>1-(2*counter/divs)-1/divs && x<=1-(2*counter/divs)+1/divs &&
px<=1-(2*counter/divs)+1/divs && px>=1-(2*counter/divs)-1/divs)
then y
else py
end;
counter = counter + 1;
end;
in(xy:[px,py])
end
Change the divs=9 to however many "petals" you want.
edit: Another thing tha might make this easier to assemble is what i did in the next one. I offset bottom half of the image by 1/2 the petal width (in this case 60 px), ran the filter, then offset the bottom half back (-60px), with wrap on, of course.:
-Rob A>