Nice way to make noise seamless (without tampering with the noise generator) Here's the problem :
I have multiple noise generators in my program I Can't change.
Perlin Noise, Diamond Square, Voronoi, etc.
Unfortunately for me, I want the noise to be tileable, no matter the generator :

The idea is to create a torus-like strategy game with the user choosing a noise and then having it tiled to play on it. 

I'm very well aware it's a rather poor design to make it tileable afterwards, but it's a time saver for the coding part.

Thank you in advance for your help and ideas.
If you can't change the textures, I see 2 possibilities:


Use mirrored repeat on the noise textures so they tile seamlessly.  (taken from here)
Do like Gimp does (or many other alternatives) and create tilable versions of the noise textures. The idea is to blend the left and right, and bottom and top edges together in pairs. Here's how to do it in an image editor: translate the image by 1/2 in both axis so the corners are in the middle. Blur, smudge, etc. to remove the seams. Revert the translation.


 

Keep in mind that the randomness and quality of the noise will of course be affected by either technique.