Applying changes to lots of files

[Ofnuts]

If the images aren't too big, and are all the same size, you can load them as tiles in a single layer, apply the changes to that layer, and then chop the layer into tiles that are individually saved, using my ofn-tiles script(*). If the images have some logical numbering, you can have their name regenerated when exported back to files.

(*) Not to be confused with its cousin ofn-layer-tiles.