[Imports] Facebook's AI-Assisted Road Tracing for OSM

osm osm at fb.com
Wed Mar 15 02:39:36 UTC 2017

Dear OSM Community,

This email is to share the Facebook process and sample data for review by the OSM community. We welcome feedback.

Our goal is to collaborate with the OpenStreetMap community to create quality road data, validated by trained mappers and local OSM communities. Our import documentation on the wiki<https://wiki.openstreetmap.org/wiki/AI-Assisted_Road_Tracing> explains the process in depth, but we're happy to answer any other questions you might have.

To get community feedback we are sharing our sample data (attached) and outlining our process. We understand our process is not a traditional OSM import because we are creating the data ourselves and conflating it with existing OSM. As you will see on the wiki, the process is similar to remote tracing using satellite imagery, where human mappers are assisted with road suggestions generated by machine learning algorithms. Using the tasking manager, multiple people go through each node and way making sure to tag each road appropriately, connect them to current OSM data, fix alignment, when necessary, add sensible changeset comments/notes and resolve conflicts before finally saving where it is merged with the current OSM data.

We are working with just one country at a time and our edits will happen slowly by grouping areas into small regions so we complete one before moving to the next. We plan to spend the next few months in Thailand.

We hope to continue to engage the local community, as we know this is an important part of being an OSM contributor. We are open to feedback and willing to improve processes and learn from feedback. We are happy to share our Tile Service as mentioned here<https://wiki.openstreetmap.org/wiki/AI-Assisted_Road_Tracing>. For now we can also share .osm files for specific areas of interest, while we work on creating a better way to share this through a Tasking Manager or something similar that is public facing. So far we have been chatting with a few members in the community, but as we learnt from the forum discussion we should have also posted publicly and will do that going forward.

Here is an example of how we plan divide the tasks for the country. The colors indicates the current density of roads going from blue to red for high density areas. Of the 77 province boundaries we plan to start in the Southern Region in the province of Yala. Image 1<http://scontent.xx.fbcdn.net/v/t39.10482-6/16686312_1226149567492788_3453256145248976896_n.png?oh=77893d88f0e4a8dffbb8d0427c9ce026&oe=5936917E\>

[cid:image001.png at 01D29CFA.B2341340]

Using DG's Vivid+ imagery and have found we can get a 30% increase in road coverage for Thailand. Because imagery in OSM is much older in most areas we are able to pick newer roads with this imagery. Here are some examples of places we have been able to get road masks for in Thailand compared with OSM's current imagery. (Image 2<http://scontent.xx.fbcdn.net/v/t39.10482-6/16686458_1635190336509160_6301217537245839360_n.png?oh=a47d4813312469aca2068cd113d73693&oe=59304471>, Image 3<http://scontent.xx.fbcdn.net/v/t39.10482-6/16781470_1359746720759904_2477208192824639488_n.png?oh=eca7a3e9c7e5f644532c693865a9d292&oe=596D0EF6> Image 4<http://scontent.xx.fbcdn.net/v/t39.10482-6/16686846_1187920531335558_7954053478257524736_n.png?oh=db31bdd4af9acd3d6d309d1687a5ebc0&oe=5926F69E>, Image 5<http://scontent.xx.fbcdn.net/v/t39.10482-6/16686541_998489256917970_4428448510123180032_n.png?oh=f5e95744de1ab7c20aae37b755353abb&oe=5938D11B>)

[cid:image002.png at 01D29CFA.B2341340]

[cid:image003.png at 01D29CFA.B2341340]

[cid:image004.png at 01D29CFA.B2341340]

[cid:image005.png at 01D29CFA.B2341340]

Please take a look at the attached .osm file for an area in Thailand that contains both our generated and vliadated roads and current OSM data.

Drishtie on behalf of the OSM at Facebook Team

Frequently Asked Questions

What does AI mean?
Artificial Intelligence (AI) is training a computer to do things that require intelligence when done by humans. In this case it involves creating training data for an area by tracing out satellite imagery the same way you would when editing and feeding it to a computer. The output of this is road masks. Here is an example prediction result<http://scontent.xx.fbcdn.net/v/t39.10482-6/16685038_1348901108507836_4612480449938194432_n.png?oh=be39e0c615c0d1dad3e1c55f7b7193ed&oe=59341B65> using deep learning for an area in Thailand.

Are there limitations with AI?
Yes, AI and algorithms still have a long way to go to figure things such as assigning tags according to OSM region specific guidelines, figure out the correct OSM relation, add bridges over waterbodies or figure out connections with crossing railways among many other things. Currently all of this is done by our mappers manually.

Are you adding roads directly to OSM without humans validating?
Every single road from the AI output will be added only after multiple rounds of human validation. After some processing of the road masks shown above we end up with a .osm file. We then treat this like remote tracing. Using iD editor and/or JOSM mappers make sure that merging with the current data has happened smoothly. They tag each road appropriately, connect them to current OSM edits, fix alignment, when necessary, add sensible changeset comments/notes and resolve conflicts before finally saving where it is merged with the current OSM data.

Why are you using iD Editor versus JOSM?
We know JOSM is efficient at what we are trying to do. In fact, we started primarily with JOSM. This said, to make our internal process more efficient, our engineers improved the iD editor so our version has comparable functionality as JOSM. We are working on making this public so we can share it with the community.

What Imagery are you using?
We are using DigitalGlobe's Vivid+ which is high-resolution (50cm / pixel, or zoom 18) color-corrected and cloud-free.

Can we share DG imagery?
While our license does not currently permit this. DG as noted in this forum<https://forum.openstreetmap.org/viewtopic.php?id=57387> is looking at options to publish imagery for OSM editing similar to the imagery that is being used by us.

Who are your editors?
Our team consists of 3 engineers and 14 editors, and usernames can be found on the Import wiki. All editors have also updated their profile to say they map for Facebook.

Why did you choose Thailand?
Facebook has a high number of users in this country and we would like to improve that map for this community. It is also our mission as a company is to make the world more open and connected and one way we can do is by filling in the missing gaps on the map. We also saw a strong OSM community that we could learn from and engage with while we refine our process for mapping. We are hoping for community feedback as we move forward so we can contribute high quality edits.

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