1) menu Layer > transparency > Add alpha channel
2) Use the Filters > Distorts > Mosaic with these parameters:
* Tile height : 1.0
* Color averaging : checked
* Tile spacing : 0.0
* Joints color and Light color: full transparent green (0, 255, 0, 0)
* Antialiasing : unchecked
This will set the space between the tiles a bit transparent
3) Use Colors > Curves with these parameters:
* Channel : Alpha
* input : 255, output : 0
This will set the space between the tiles completely transparent
4) Use Filters > Blur > Median Blur :
* Alpha percentile : 100.0
This will merge the colors of the tile in the transparent space
optional) you can add a bit of antialiasing to the result with Filters > Blur > Mean Curvature Blur using a small number of iterations
2) Use the Filters > Distorts > Mosaic with these parameters:
* Tile height : 1.0
* Color averaging : checked
* Tile spacing : 0.0
* Joints color and Light color: full transparent green (0, 255, 0, 0)
* Antialiasing : unchecked
This will set the space between the tiles a bit transparent
3) Use Colors > Curves with these parameters:
* Channel : Alpha
* input : 255, output : 0
This will set the space between the tiles completely transparent
4) Use Filters > Blur > Median Blur :
* Alpha percentile : 100.0
This will merge the colors of the tile in the transparent space
optional) you can add a bit of antialiasing to the result with Filters > Blur > Mean Curvature Blur using a small number of iterations