How to parse image for border vertices? Complex object geometry (farseer physics)

How could I create body vertices by scanning image and detecting it's shape (of it's non-transparent pixels)?

I wanna create complex geometry, and I actually have no real idea where to start, so any advice would be highly appreciated. Accepted answer would most likely be the one that explains the topmost idea.

Thanks in advance

FarseerPhysics has functionality for converting textures into polygons (scroll down to Texture to Polygon) suitable to create bodies from.

I think that's what you're looking for?

Be warned though, the nature of texture to polygon conversions is an inherently dangerous and complex thing to carry out, if your image isn't in pristine condition (i.e. it has a lot of half opaque pixels and opacity based blurring) you will get unexpected results.