Works great Graechan. Just thought of some possible additions. Is it posible to have a way to ask what type of mosaic form (triangles, octagon/squares, etc.) and both size and percent distortion of the mosaic blocks. Not sure if the amount of spacing matters, but why not add that too. Just curious. Not sure how easy it would be to implement these features interactively. Also have a check mark to either have grout or transparency (so I can add some addition tweaks to the cobblestone via other filters). Just some future enhancements maybe.

Unfortunately you cannot do anything interactively in a script but should be easy to leave out the grout via a checkbox. I'm glad you like the result . I have no artistic ability but enjoy writing scripts as it keeps me out of the heat.

Great script Graechan! I made a few tweaks to my layers. Don't know if you want to incorporate or not but here's what I did.

1. Isolated the grout on a transparent layer and gave it a 7E7E7E gray color, duplicated it and blurred the dup at 5, bumped the original at 12 (inverted). Then deleted the blurred layer.
2. Made a new white layer inbetween the grout layer and the image layer. Filled it with RGB noise @ .50 and set the layer to multiply then duped the layer to give it a gritty texture.
3. Duped the image layer and blurred the dup at 15, bumped the original image layerat 7. (deleted blurred layer)
4. Did an alpha to selection to the image layer and applied Glossy Stroke 3D set to Fill at 1 and turned the opacity of the shadow to 0. deleted all the glossy stroke layers except for the one named "glossy layer", then did a simple Blur>Blur on the glossy layer.

I got a very shiny look almost like glass tiles and a little better recessed look to the grout. I got a little bit more than I wanted in the upper right hand corner of the pic but I still liked the results. You can see the grout texture layer really well in the lower right corner.

Another cool script thank !

Now that looks fantastic Drac; might try the glossy-stroke idea later (usually use Inkscape; why not do it all in GIMP. lol). Thanks for the update too Graechen.

Nice script thanks!
I was thinking that using the plastic wrap filter within the script could give that glossy look also.Of course that would mean you would have to include it with the mosaic script.
Keep em coming!

Thanks Lyle.

Rod - That's a great idea. I wish I had saved the xcf file and just made a new layer to compare. Oh well....such is life.