(11-14-2021, 08:49 PM)Nico Wrote: I can't remove the background so I don't know how to do this.
Thanks for your help !
You don't have to remove the background (the black part) to put the sparks over a layer
Put each layer of the sparks above EACH layer of your original gif, then the black (all sparks's layers) put them in one of these mode
Then merge each sparkles layer down with the one below from the original to keep your timing
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EDIT
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OK, my bad, I did not downloaded the original gif which has transparencies, so it won't work as expected
Only the background layer is fully opaque, thus you do need to duplicate the BG layer and put it under EACH smoke layer, then merge these layer down to make each smoke layer opaque...
Good news you don't have to do it 120 times manually ➤ download this ➤ http://chiselapp.com/user/saulgoode/repo...combine-bg put it in your script folder
Then restart GIMP (or Filters ➤ Script-fu ➤ Refresh scripts )
Then on your original gif Filters ➤ Animation ➤ Combine background
Now you can put each sparkles layer from the flame sparkle gif above each layer of the original (now opaque) in one of the mode cited above (these mode made 50% (or more) gray to black ➤ transparent)
Then merge each sparkles layer down with the one just below from the original to keep your timing