Let's say I paint a mask in GIMP and I want to convert that to a selection for applying filters, etc. What are the steps for doing this?
Using this sample image from Pixabay we'll create a mask for the purpose of adding more blur to the background.
Here's the original image:
Next I paint some white around the flowers on a new layer:
Then I add a layer below this one of solid black and merge the layers into a mask:
What is the next step for getting a selection from this mask layer so that I can apply a filter to only this area? Thanks.
[Note: This is a workflow I use regularly in Photoshop, but still have no idea how to do it in GIMP and would like to know how.]