Panchromatic - Fork and Beard
Click, to cater for different image content. Choose between silhouette, multi coloured and multi-toned to get the sharpest outline possible. The size and colour of the outline can be configured as well as the background colour. Boxing gloves, toes, lampshades, whatever you've got a picture of, give it a whirl in Panchromatic. If you've got loads of free time why not stick the image through Whitenoir. I have no doubt this can be achieved in Photoshop, GIMP et al, but I'm just too lazy to find out how.