Just wanna tnx to all developers of paint.net (plugins also).. Its amazing what people can do with this proggy which installation is less than 2 mb.. One more time thanks a lot.
EDIT:
Added original picture (name: Picture 237.jpg ...just resized) for comparasion
At the edited pic (named pwc06.jpg) i've used sharpen and played a while withs some adjustments:
Conditional Hue/Saturation & Curves