I saw this series of images:
(Click on an image thumbnail to see it larger)
So I want to get the same from my image:
I got as far as reducing the colors to 2 (binary):
But I'm having trouble with the next steps.
Based on the sample set of images with the baby and the cat, here is what I believe has been done:
Filters of any editing software will have similar effects. There is also a lot of websites that can do that. A free app for windows that I always recommend is Paint.net, give its filters a try.
Fir this particular effect you just need to use one filter only, on the menu Effects, select container Artistic and then Ink Sketch, Play with the sliders to get the desired effect. You can change the amount of color and the thickness of the line to achieve this effet: