Pyongyang Skyscrapers, a Wikidata-OSM-Commons synergy

Posted by Koreller on 11/1/2023

In May 2023, I discovered the existence of two websites : “The Skyscraper Center” and “Skyscraper Page”, presenting skyscrapers from all over the world and especially… skyscrapers from Pyongyang!

I took this opportunity to enrich several free projects on which I’m active: Wikidata with the creation of the elements in the first instance, combined with images from Wikimedia Commons in the second instance, to place them and link them with the OpenStreetMap data in the final instance!

Creating the skyscrapers in Wikidata

Wikidata is a database that can be very useful for the OSM project. In my case, it was very useful for tracking each skyscraper.

And it’s very well suited to adding all the skyscrapers that existed in The Skyscraper Center and Skyscraper Page for Pyongyang city.

Wikidata has a number of “properties” (PXXX) which can be used to provide a whole range of information:

  • where each building is located (P625)
  • when they were built (P571)
  • their height (P2048)
  • the number of floors (P1101), etc…

Wikidata Element of YokjonApartment 2

This was the longest step and took me two days to complete!

Short extract of SPARQL query on Wikidata for Pyongyang skyscrapers elements

Commons image cropping

Once I’d finished creating all the elements in Wikidata, I wanted to illustrate as many skyscrapers in the city as possible, so I went hunting for free images of those buildings.

I immediately thought of using the Wikimedia Commons images. I identified the areas of Pyongyang offering the best panoramas, hoping to find the city’s skyscrapers, and then I searched in the relevant Commons categories.

I found two categories:

This allowed me to crop a lot of images to illustrate the skyscrapers (with the use of the CropTool tool from Commons !)

Using of CropTool in Wikimedia Commons to extract image of skyscrapers

There are still a lot of buildings without pictures, but Pyongyang isn’t a city that can be photographed everywhere!

Add information to OSM

Once the Wikidata elements had been created and the Commons images had been cropped and linked to their Wikidata elements, the simplest part was left to me: adding the information to OSM.

There’s a lot of useful Wikidata information for OSM, including: the location, the name in English and Korean (name=*, name:en=*, name:ko=*), the height (height=*) and the number of floors (building:levels=*). So I manually added each of these pieces of information and the wikidata=* tag.

I also took the opportunity to link all the Wikidata elements in Pyongyang to the OSM objects using the website Wikishootme on Pyongyang (Wikishootme displays all geolocalised Wikidata elements and geolocalised Commons images, on an OSM map)

Image of Wikishootme on the Pyongyang area

Results

All this work took me 3-4 days, and in the end here are the results for each project:

In short, I’m happy of the work I’ve done and with the result: the map is more accurate, it will be easier for me to estimate the approximate height of Pyongyang’s buildings and I’m getting closer to a good 3D rendering of the city !