Many maps show built-up areas of cities and other settlements in a different color on scales where you can’t show individual buildings. This gives the viewer an immediate idea on where the landscape is more urban and where it is more rural. This is the third problem I wanted to work on described in this blog post.

Most maps need little symbols and labels for settlements like cities and towns. Of course you can’t put all settlements on the map, so you have to select those you want to show. For that you need to “rate” the places in some way, so that you can show only the more important ones. And then you want to show a “reasonable” selection of places, not too many so the map isn’t too crowded, not too few to make the map look empty.

Like any project, the generalization project I am working on has its share of experiments. Not everything you try out will work in the end, or is fast enough, or actually needed, etc. These experiments often don’t end up in the progress reports or final reports, but without them we can’t create something new. I want to talk about three experiments related to raster data in PostgreSQL/PostGIS, one successful, one failed and one where the outcome is still open.