mapsnatcher

mapsnatcher

mapsnatcher is a bot to automatically download and splice together tiles from QGIS maps. This simple system uses a URL such as http://mapwebsite.com/z/x/y.png, where z is the zoom level, and x and y are the coordinates of the tile.

You can use a tool such as ChromeCacheView to find these URLs easily.

Installation

You will need ImageMagick and its development headers installed in order to build the dependencies. For Ubuntu these are:

sudo apt-get install imagemagick libmagickwand-dev

Once set up, install through RubyGems:

gem install mapsnatcher

To process larger maps, you may need to comment out or modify the resource policies in /etc/ImageMagick-6/policy.xml.

Usage

Usage is as follows:

mapsnatcher http://mapwebsite.com/0/xxx/yyy.png

Place XXX and YYY (case-insensitive) where the respective coordinate numbers would be in the URL. You will then be prompted to enter the X and Y boundaries that you would like to capture.

mapsnatcher -b http://mapwebsite.com/0/xxx/yyy.png

If you are unsure of the boundaries and would like to capture the entire map, add the -b argument and you will only need to enter one valid coordinate; mapsnatcher will do the rest.

If you would like to save the tiles, add the -s argument.

Coordinates can be passed into mapsnatcher as arguments:

mapsnatcher http://mapwebsite.com/0/xxx/yyy.png -x 200-300 -y 200-250 mapsnatcher http://mapwebsite.com/0/xxx/yyy.png -b -x 200 -y 200

And the output file may be specified with -o:

mapsnatcher http://mapwebsite.com/0/xxx/yyy.png -o map.jpg

If coordinates and output are not specified, you will be prompted for them.