OpenStreetMap – Matthew Petroff https://mpetroff.net mpetroff.net Sun, 01 Jan 2017 19:12:27 +0000 en-US hourly 1 OpenStreetMap Baltimore City Buildings and Addresses Import https://mpetroff.net/2015/04/openstreetmap-baltimore-city-buildings-and-addresses-import/ https://mpetroff.net/2015/04/openstreetmap-baltimore-city-buildings-and-addresses-import/#respond Thu, 30 Apr 2015 13:31:14 +0000 http://mpetroff.net/?p=1807 Continue reading →]]> Two years ago, I started trying to import building footprints and addresses provided by the City of Baltimore into OpenStreetMap but was held up by red tape and eventually gave up.1 The City provides building footprints and parcel data on their open data portal; the download pages for these two datasets list the data as public domain, but the site’s terms of service is the same as the rest of City’s websites, saying the data is copyrighted. I had worked through the technical aspects of preparing and simplifying the building footprints for import and had started working on how to associate addresses from the parcel data but eventually gave up after I was unable to secure the needed licensing clarifications from the Mayor’s Office of Information Technology (MOIT).

This past fall, Elliot Plack, who then worked for Baltimore County GIS and was appointed to the Maryland Open Data Council by Governor O’Malley, got in touch with me about restarting the import, after finishing an import of similar data for the County. After meeting with Jim Garcia from MOIT, he was able to secure the permissions that we needed to proceed with the import. Additionally, he was able to get address point data, which is much superior to and easier to use than the parcel data I was originally going to extract addresses from.

With the address data in hand, I worked through the remaining technical aspect of the import in January and February with help from Elliot.2 Besides simplifying the building footprints,3 footprints intersecting existing footprints needed to be separated out, and addresses needed to be added in. Where buildings didn’t intersect existing footprints and only contained one address point, the address was merged into the building. Addresses that were contained in intersecting buildings were also separated out. Address data also needed to be translated into OSM tags. We decided to automate the import as much as possible, with non-intersecting buildings and addresses to be uploaded via script. Conflicting data would then be manually conflated and uploaded.

About a month ago, with the preparation done, Elliot sent an email to the OSM Imports and US Imports lists announcing the restarted import. After receiving no objections, I executed the automated portion of the import a week and a half later. A job was then set up on the openstreetmap.us tasking server for the manual portion of the import,4 which is currently underway. Elliot and I as well as a couple other local mappers have been working through this portion of the import and should hopefully be finished in the next month or two, which will conclude the import.

  1. http://wiki.openstreetmap.org/wiki/Baltimore_Buildings_Import ↩

  2. The code used for the import is on GitHub. ↩

  3. This is an interesting problem, since the topology of adjacent row houses needs to be accounted for. ↩

  4. http://tasks.openstreetmap.us/job/59 ↩

]]> https://mpetroff.net/2015/04/openstreetmap-baltimore-city-buildings-and-addresses-import/feed/ 0 Print Maps https://mpetroff.net/2015/02/print-maps/ https://mpetroff.net/2015/02/print-maps/#comments Mon, 09 Feb 2015 00:19:35 +0000 http://mpetroff.net/?p=1760 Continue reading →]]> Web maps, e.g. Google Maps, normally don’t print well, as their resolution is much lower than normal print resolution, not to mention the various other unwanted text and elements that print along with the map. While the unwanted elements can be cropped out, the only fix for the low resolution is to render a higher resolution image (or use vectors). Formerly, this required installing GIS software, which also requires a suitable data source. Print Maps changes that by leveraging Mapbox GL JS and OpenStreetMap data to render print resolution maps in the browser. After the user selects the map size, zoom, location, style, resolution, and output format, PNG or PDF, Mapbox GL JS is configured as if it was being used on a very high pixel density display and used to render the map output. To use Print Maps, visit printmaps.mpetroff.net.

Print MapsThe site’s source code is available on GitHub. Also, slides from my HopHacks presentation on the project.

Edit (2017-01-01): Changed printmaps.org to printmaps.mpetroff.net as I’m going to let the printmaps.org domain registration expire.

]]> https://mpetroff.net/2015/02/print-maps/feed/ 7 Map of Baltimore https://mpetroff.net/2013/03/map-of-baltimore/ https://mpetroff.net/2013/03/map-of-baltimore/#comments Mon, 11 Mar 2013 02:00:51 +0000 http://www.mpetroff.net/?p=893 Continue reading →]]> Since living in Baltimore, I’ve wanted some sort of map of the city to hang on my wall. Unfortunately, I never found anything I liked. Something I did like is Stamen Design’s Toner maps. However, in its most easily available form, online map tiles, it is not well suited for high-resolution printing nor does it show the city limits. Fortunately, the style is open source. After cloning the repository, adding a rule to make an outline of Baltimore, rendering it to SVG, and clipping and editing the map with Inkscape, I was left with something I liked.

Map of Baltimore

A vector-based PDF version suitable for high-resolution printing is available here. The map data is copyright OpenStreetMap contributors under the ODbL. The map itself is CC BY-SA Stamen Design (and me). Here is a photo of the map on my wall. Feel free to get the PDF printed.

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