I dunno about free, but Photoshop is the best. You can Limewire it, I think. That'd be for free but illegal and ye..you decide.
The first pic: On photoshop. You play with the levels and contrast. This one has had a color filter added to it (orangish) and the highlight has been stressed (not the hair highlight, the pic's highlights in general). Playing with the curves also works. (these can be found under the tab "image" > "adjustmnents").
The second pic: On photoshop. It's the same thing as the first one. Except this one has more contrast and brightness and has been played with the levels.
The third pic: On photoshop. After playing with curves, levels and brightness/contrast, this pic has its mode changed to "TRITONE", and that is basically when you only have three colors in the pic. You can choose what colors: red, white, green - black, white, purple - or in this case, nude, white and dark brown.
Photoshop works miracles. If you have any more questions, let me know! I know everything about Photoshop since that's what I use every day for my homework (studying graphic design). So...if you want more, ask!
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