How to intelligently degrade or smooth GIS data (simplifying polygons)?

Question

I have detailed US county maps, from the TIGER LINE data sets. How might I sample, smooth, or degrade the data so that I get straighter, more boxy, less \"noisy\" shapes to

Answer 1

The problem with simply throwing away points is that you can quickly distort the shape of the original polygon. A better approach is to come at it from the other direction; start with a basic approximation of the polygon and then refine it upwards towards your complex shape.

An excellent example of this approach is the Douglas-Puecker algorithm. You start with two vertices drawn from the full polygon. Add a third vertex by selecting the one that lies farthest from an edge drawn between the first two vertices. Continue adding points until you have something that sufficiently resembles your original polygon.