How to lighten a portrait's background

[gogreen1]

I have a portrait with a background I'd like to lighten a bit. As you can see in the snippet, I'd like to create a bit more contrast between my dark suit jacket and the dark background. In paint.net, what is the best way to do that? Thanks.

[BoltBait]

 

You may need to tinker with the settings as I can not see the entire image.

[gogreen1]

Thanks, Boltbait. I hate to ask a dumb question, but do I need to outline or otherwise indicate the area that I wish to lighten?

[BoltBait]

3 hours ago, gogreen1 said:

do I need to outline or otherwise indicate the area that I wish to lighten?

 

Nope.

 

You specify which pixels you want to modify by using the first 4 sliders (and a check box) in the Hue/Saturation+ plugin.

 

Then you use the bottom 4 sliders to modify the selected pixels.

 

I usually start by moving the bottom slider all the way to the left, then adjusting the first 4 sliders until all of my desired pixels turn transparent.  Once all of the pixels I want to modify are gone (and ONLY those pixels are gone) I reset the bottom slider and I start adjusting the 5-7th sliders to make my adjustments.