Wednesday, February 19, 2014

Watercooler Wednesday #25 - Tracing Historical Maps

A lot of quality GIS data about historical boundaries exists. Here are two examples:
Sadly, both of those data sets have non-commercial clauses in their licenses, which makes their data difficult to use for anything but academic research.

A solution to this problem is tracing historical maps. NYPL has a nice project called Map Warper which allows you to georectify digital scans of old maps. However, that's just one step of the process. After properly aligning the map, we want to trace and extract the historical boundaries.

So we're going to create our own map warper. Though it will be heavily inspired by the NYPL Map Warper, we're going to start from scratch. It will be written in node.js and include the second step of tracing the map after it's been georectified.

Sadly, this requires a small refactor of OPDs infrastructure, but we've already finished the first step.

No comments:

Post a Comment