MapDiff is a utility for visualising OpenStreetMap activity:

Map data © OpenStreetMap and contributors, CC-BY-SA

Each frame represents a daily diff, generated with Osmosis. Changes are displayed as three colours - red for deletion, blue for creation, and green for modification.

Using MapDiff

MapDiff is invoked with a base map, an input change set, and a location to save the output:

mapdiff --map=Map.png --input=2008_01_01.osc --output=2008_01_01.png

The base map must follow the "Google Tile" scheme, i.e., a square mercator projection with a latitude extent of ±85.05112877980659. The Resources directory contains a sample map that fits this size.

Scripts to automate the building of diff images, and to convert them to a movie, can be found in the Resources directory.

Building MapDiff

MapDiff is written in D, and can be built with GDC.