Step 1 : edges detection
Tune the edges detection slider to separate edges from surfaces without including noise in edges. The black and white images below show the result effect, for 3 values on 3 parts of the demo image.
Surfacing 50 : not enough, significant edges do not appear
Edges detection 80 : correct, some unwanted details start to appear
Edges detection 86 : too much, a lot of unwanted details appear
: depending on the kind of noise you have, you can play with the "Chroma modes", to avoid chroma artifact to be considered as images details.