okok3857

People have georeferenced a lot of SF maps on OIM as well, you can explore them here: https://oldinsurancemaps.net/san-francisco-ca/

Email sent, and thank you!

I should have mentioned this earlier, but folks can make direct tax-deductible donations to OldInsuranceMaps.net, which is now affiliated with OSM US's 501(c)(3) status.

https://openstreetmap.app.neoncrm.com/forms/donate-oim

That's basically what's going on, but it's all a manual process so far. The goal is scoped really just to the actual georeferencing and mosaic creation, no post-processing or OCR is performed on the maps within this platform (people are certainly downloading the final rasters and doing that with them though).

Absolutely, this would be incredibly cool, and if they can do it with burnt ancient scrolls it should be a cakewalk with these... Even just shining very strong light behind the pages you can see all the old layers. However, most of the LoC collection is original copyright deposits, so much of what's on OIM doesn't have pasted-on slips.

This is something we need to add to the FAQ. There is some cross-compatibility already, in that OIM has endpoints to spit out Allmaps-compatible annotations from the database, e.g. https://oldinsurancemaps.net/iiif/resource/88127/. You can paste that right into Allmaps, which will in turn pull tiles from the Library of Congress IIIF server and warp them based on the annotation information. That's just the beginning though, more to come...

I started this project and couldn't be happier about this partnership with OSM US!

Also here's a past HN thread with some more context: https://news.ycombinator.com/item?id=46788588

Rapid Editor is a good web app for editing OSM: https://rapideditor.org/

Thanks for sharing, this is really nice. I've added it to the list of other projects I have on the site [0]. Feel free to get in touch if you want to use OIM for other years of Paris, TX.

[0] https://oldinsurancemaps.net/more-about-sanborn-maps/

Thanks! Frankly the presentation side of the site needs a lot of work, and it's more about doing the georeferencing work, which sounds like you've already done. But you should get in touch I'd love to discuss further! I've done demo projects with old plat maps like you are working with.

Yes, some maps in the site are hidden as they are part of an ongoing research project, just happens that Tampa and Key West are both examples of that. If you follow the blog/newsletter I'll surely announce when those are available.

Yes, at certain points, like when I made that ohmg.dev website, I have looked at this as a re-deployable platform that anyone could self-host. It still technically is, but I've slowed down a lot on that idea (no one really showed up with interest). There are other good places to georeference maps on the web, like mapwarper.net and allmaps.org. That said, I do hope to expand to handle import of other atlases, not only Sanborns, and if you have something particular in mind you can mention it here: https://github.com/ohmg-dev/OldInsuranceMaps/issues/266

No (or, not yet...) and yes, I know the Allmaps team well--it is an excellent project. There are a lot of similarities, but I would say two high-level differences are 1) OIM is built around server-side processing that immediately produces downloadable files and web services (geotiffs) while Allmaps applies a client-side transformation to non-geo IIIF tiles, and 2) OIM is designed around the creation of mosaics from many different pages to a greater extent than Allmaps is. This year I do see bringing more IIIF/Allmaps tooling into OIM though, so stay tuned!

Hi! I added a page about "georeference-a-thons" recently here: https://oldinsurancemaps.net/community-georeferencing/

Yes, there are a number of maps (the FHA ones and also one Sanborn) that are part of a research project that is still in the works, so they are hidden for now.

Great question: no. I've spent a lot more time making the georeferencing side of things work well than improving search and discovery, and even presentation (like the /viewer/ pages), of the maps on the site. It's something I hope to spend a lot more time on in the coming months. I know, dealing with those sliders is pretty cumbersome in big cities with many volumes (like SF).

I developed and maintain this site so I am both very happy to see it get posted here and also watching htop intently...

I wanted to point out it is a crowdsourcing project, so every overlaid page you see has been placed there by a person, often through large institutional efforts at universities, but also individuals just looking to learn about their hometown through these old maps. Thanks for the interest!

Fun fact: QGIS was originally written just to view PostGIS tables.

GRASS v.generalize() has a lot of different methods: https://grass.osgeo.org/grass85/manuals/v.generalize.html. I can't personally speak to the differences but probably worth looking into.

The QGIS Simplify tool also has a Visvalingam method: https://docs.qgis.org/3.40/en/docs/user_manual/processing_al...

It may be interesting to combine a workflow with the QGIS Smooth tool: https://docs.qgis.org/3.40/en/docs/user_manual/processing_al...

I don't see mention of OHM anywhere within TimeMap, is there something I'm missing? Is there a page about where the historical data comes from for the map?

You may be interested in OpenHistoricalMap: https://www.openhistoricalmap.org, which anyone can contribute to (you can read much more about it here: https://wiki.openstreetmap.org/wiki/OpenHistoricalMap). Edit: I didn't realize at first but from other comments it sounds like TimeMap actually pulls data directly from OHM.

This was an incredible aspect of the app to have when in Rome this summer! So many public water sources, and it was so, so hot....

Well, when I registered an LLC in the US, Google mailed me a postcard to confirm my address, and third-party providers begin calling to help "claim my Google listing". So they've really just ecosystem that you immediately become part of rather than something you have to seek out. Edit: I also completely agree that this is what drives the monopoly.

Sure, I just mentioned it in the off-chance it was good enough out of the box. Big jump from making a screenshot (or perhaps stitching a few together) to editing OSM vectors in QGIS/Inkscape, which others have mentioned already.

The tile size doesn't change, but the number of pixels per meter does as you note--distortion being greater the farther you get from the equator (in the Mercator projection).

The protomaps blog has some heady stuff you may enjoy reading: https://protomaps.com/blog/free-tier-maps. Felt apparently uses protomaps.js, which you can learn more about in that blog as well.

Can people add their own layers, like a WMS overlay? and, relatedly, have you considered adding georeferenced historical map layers? It seems like a good platform for story-telling.

Very cool you are using protomaps.js! I recently found their blog and really like the ideas in there: https://protomaps.com/blog

The Stamen toner map may work well for you: http://maps.stamen.com/#toner/14/37.8024/-122.2645 Also checkout their watercolor rendering... probably my favorite basemap that I never get to use.

If you do use QGIS, you can get the Quick Map Services plugin that will connect you with these Stamen basemaps as well (and tons of other basemaps, a must-have plugin).