title: How to intelligently degrade or smooth GIS data (simplifying polygons)?
body: <p>I have detailed US county maps, from the <a href="http://www.census.gov/geo/www/tiger/" rel="noreferrer">TIGER LINE</a> data sets. How might I sample, smooth, or degrade the data so that I get straighter, more boxy, less "noisy" shapes to represent the geographical features -- in this case just county boundaries and state lines, but maybe also in the general case?  </p>
  
  <p>The sampling could happen at rendering time if that can be done efficiently, or a parallel data set could be generated and stored. I am using <a href="http://postgis.refractions.net/" rel="noreferrer">PostGIS</a>, and the lines are multi-polylines generated by <code>shp2pgsql</code> -- but any solution where you take a squiggly line and reduce it to a smoother line of roughly the same significance to a human interpreter would be very useful.</p>