Ever wonder what the Douglas Peuker algorithm does? Here's some visualization.

Here's the Douglas Peuker algorithm in action. DP simplifies polylines by throwing out points that fall within a certain tolerance of heading change. Each successive track sets the DP tolerance lower, so the track gets curvier. These tracks were taken with my soon to be released iPhone app (not affiliated with EveryTrail.com, but allows uploads to the site). http://www.everytrail.com/view_trip.php?trip_id=329754 http://www.everytrail.com/view_trip.php?trip_id=329775 http://www.everytrail.com/view_trip.php?trip_id=329816 http://www.everytrail.com/view_trip.php?trip_id=329825 http://www.everytrail.com/view_trip.php?trip_id=329837 http://www.everytrail.com/view_trip.php?trip_id=329848