Some ditherers take REALLY long on larger images. With this limit it's less likely people select a ditherer and then everything freezes for a very long time.
It is not a great solution. In the future I want that users can cancel dithers that take forever. Then, in theory, users can load larger images. If they don't want to wait for dithering their 16k image, then they could just cancel the process.
So yeah, this limitation may not be there in the future.
Recently I use your tool a lot, and it is already annoying that the ditherig actually instantly running when you select a method.
Simply just don't run, start, calculate (or how I can say it) the dithering; just select it. Add a button to actually activate the calculation, so there will be no issue about freezing. I think the best solution would be that adding two buttons; one to actually run the calculation and obviously a cancel button. This eliminate the issues with large images.
