Make seamless edges for maps (not textures)

[Lap]

There are a few good threads on creating seamless textures, however I'm more looking in how I would create seamless edges without really touching too much of the rest of the image.

Let's say I have a map like:



To get it to horizontally and vertically wrap I shouldn't need to touch the middle land mass. However, all the tools I've seen seem to take into account the center far too much.

Things like:
Gimp's seamless filter
Resynthesize filter,
and RR seamless filter

all take into account the middle of an image, making the output a radically different map. instead of just affecting the edge regions.

1. Is there any way to make just the edges seamless?
2. Are there any good links to places where I can learn specifically how to draw seamless map?

[Redrobes]

Well, my normal seamless method would work. If you paste this image 4 times as a 2x2 array of them (as per usual method) and then fix up the middle crossover bits (as normal) you can then chop out the middle of it (which admittedly would look real bad for the mo...) but then paste that down in a 2x2 tile array again and the center should be the original tile with all the edges fixed up. So just chop the middle out again and that's a seamless map. Its all down to how much your prepared to fix up the edges by using wider and wider blends. If you keep it tight like for this map where you have a little space around it as border then you will be fine.

You ok with that or need the mini piccy tut ?

Oh, also, there is my Redrobes Gimp filter plug in (courtesy of RobA) to do the high pass filtering. With this particular map, since the grid is pretty square and so one edge will likely as not line up with the opposite then all you need to do is get the background lightness blended whilst keeping the grid intact. Nightmare of a job without that filter but no problem with it.

[Ascension]

If you have Photoshop just use the Offset filter and make the numbers exactly half of your image size. That filter cuts the image up into 4 squares and repositions them so then you can touch up the edges and redo the offset.

[Redrobes]

Ohh thats a neat time saver option in Photoshop then.

[Nerik]

Ohh thats a neat time saver option in Photoshop then.

Actually in GIMP also;

Layer > Transform > Offset...

Then just press "Offset by x/2, y/2", then press "Offset",

Done.

Charles