Thumbnail (webpages, mediafiles..)

Question

Hi! i would like to create a thumbnail preeviewon webpages and mediafiles (for example for a sitemap). I would like to have images on each item in a specific catalog or a URL. I have tested WEBPAGESNAPSHOTLib and that works great, but i would like too create i by my self in C#. Any ideas how to get in too this problem? There is a function in explorer (my computer) that are just like this function but would like to create a server side function.