Perfect masking using a highpass
There are several methods to extract/mask objects or persons from the background. But sometimes you need perfect masking that includes for example the hair of a woman. The method i use for this is called highpass. We need to simulate this filter because there is no filter in GIMP that does this for us. The point of the techqnique is that you'll save lots of time for the difficult hair part, because when you do everything right the hair is extracted automatically.