underexposed clothing - a small workaround

[thetraveler]

Every once in a while I come across a situation where a person's clothing or some object is so dark that it merges into the background and the general selection tools don't work very well because the margin between object and background is so ambiguous.

So I take advantage of the fact that, in PS, a selection with marching ants stays live even if I select another layer.

I make a new duplicate layer (CRTL J or CMD J) and then working on this layer I use Image>Adjustments>Brighten or Levels or contrast - anything that defines the margin better.
(Ignore the ugly noise)
Hit Q to go into Quick Mask mode
Be certain that Black is the foreground color (D for default)

Select a brush, make it fairly large large and lower the hardness to about 30 and paint on the less ambiguous edge edited layer.
Try to get a fuzzy edge that somehow matches the fuzziness of the ambiguous edge.
When the edge looks as good as it will get in fizziness, raise the hardness of the brush and paint in the rest of the clothing/object.
Now you have a red 'thing' with a fuzze\y red edge where the ambiguous edge is.
Press Q and you'll end up with marching ants on this edited layer. (the fuzziness doesn't show)
(Remember that what we painted on, the red, is unselected and we only used it because is nice and visible)
So press Ctrl I to invert the selection.

Now we have a selection with marching ants but a fuzzy edge of the part that is too dark.
Press Select>Save Selection>New and give it a name.

Now select the original too-dark layer (and make the edited layer on which you did all the work invisible.)
Now the selection is live on the real working layer, you can copy the selection to a new layer and lighten it, denoise it and do what you like.

You may have to go back to make the edge fuzzier or change is but, because you saved teh selection, you can load it, press Q to see it and much of the work is done already.

[DanK]

Interesting technique. Thanks for posting. Seems to me that the key is how well you do this step:

Try to get a fuzzy edge that somehow matches the fuzziness of the ambiguous edge.

[thetraveler]

Interesting technique. Thanks for posting. Seems to me that the key is how well you do this step:

Yes, but it's easy enough to redo it several times until one gets the best possible look