Here is an example
The image isn't mine, I just grab the firs appeared to be good as an example of the topic issue.
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The image isn't mine, I just grab the firs appeared to be good as an example of the topic issue.
The solution was pretty straightforward.
Covering the stain would work, but just using curves and applying them with a history brush in two modes, soft light and saturation removed the offending stains.
It's not particularly easy to remove entirely because where there are sweat stains there are also generally a lot of texture. I would probably try masking the area (making a layer that covers the area of the stain) and then use that mask to brighten the image up and make the stain less noticeable. I'd 'also probably feather the edges a bit to help blend it in as the wet spot tapers off.
It's still not going to be 100% perfect, but should make it less noticeable. It's also still a reasonably challenging thing to do a good job at without making either a dark ring or a light ring around the outside of the stain.
What you need is the High Frequency Separation technique. Then you will be able to edit the sweat spot on the low resolution image very easily, basically a color replacement, and keep the textures of the T-shirt. You just have to select the proper filter frequency (or pixel blur, in other words, in the described technique).
Do not forget to increase the color bit depth to 16 bit when you start, otherwise you will quickly see color banding.
The other way is just to paint over. With a bit of skill, you can do it with a mouse (... well, I can do it, so you can, too ;-), although a tablet and pen makes this easier (or harder, depending on your skills...).
You could try a brush with a little exposure compensation which will lighten up the dark patches because the moisture is only darkening those colours.
You won't get it all out without lots of work but it will make a lot of difference.
Will depend on the size and texture of the Stain, either of dodge and burn, exposure brush or layer mask might work, but we'll take efforts and precision.
In case of smaller spots, even spot healing gives decent results.
Healing brush may work very well in this case.
You can use the clone tool and set its hardness at a low level to avoid the editing being obvious, but you will have to be very precise. So yes, but depending on the position of sweatspots you may not always be able to use this method.
maybe the "dodge and burn" technique can help for a quick and dirty solution (especially the dodge part of it :-) ). As you probably wont be able to make the stains disappear entirely, you can save yourself some time and try simple but still (maybe) effective ways.