Historical Map Plugin for QGIS Helps You Unlock Historical Data

Occasionally, I like to go through the QGIS plugins and see what’s new. There are all sorts of handy tools in there, but one in particular caught my eye this time. The Historical Map plugin, by Nicolas Karasiak & Antoine Lomellini, takes on a specific challenge: extracting data from old maps. Of course, you can always digitize this data, but it can be quite time consuming. The plugin leverages image classification techniques to speed up the process. The nice thing about historical maps (such as USGS topos) is that there are usually fairly discrete color codings. Discrete colors takes a lot of the guesswork out of the image classification process, but the techniques can be pretty intimidating if you haven’t done them before.

1956 USGS topo map for Manhattan, KS

Continue reading “Historical Map Plugin for QGIS Helps You Unlock Historical Data”

ArcGIS 10.2 Released with Spatialite Support

So, ArcGIS 10.2 was released last week, with a bunch of exciting new features. Among other things, they turned on multi-core support in a few spatial analyst tools, made it easy to create Python add-ins for the GUI, and have posted code templates on GitHub. All of these features are very exciting, but what I’m most excited about is support for Spatialite databases.

by Massimo Zedda
Continue reading “ArcGIS 10.2 Released with Spatialite Support”