In the past, there was/is a compiled plugin focus blur that comes with lots of options. Old but still working (linux, kubuntu 24.04)
Then, as Ofnuts you can use the Gimp GEGL filter with a mask.
A good alternative these days, as a readily available plugin, is gmic_gimp_qt and the filter blur(depth of field)
I did not do a great job of making a mask, I usually paint in the shape of the foreground to keep it sharp, it is up to the user.
Then, as Ofnuts you can use the Gimp GEGL filter with a mask.
A good alternative these days, as a readily available plugin, is gmic_gimp_qt and the filter blur(depth of field)
I did not do a great job of making a mask, I usually paint in the shape of the foreground to keep it sharp, it is up to the user.