GeoScribble

GeoScribble is a website and an online service to collaboratively draw on the map. It is used for free-hand notes when surveying: Every Door editor uploads drawings to the website, while JOSM and other editors can show them with a WMS layer or a dedicated plugin.

All the data uploaded is available under PDDL license, making it public domain (like CC0).

How it is used

While in the field, mapping things right away might not be an option: editing with a phone is not easy, fingers might be cold, data connection unstable. There are alternative ways of storing the surveyed information quickly: e.g. photos, 360° panoramas, voice recordings. Or OSM Notes. Just type some words, and somebody will read them later and update the map.

GeoScribble improves upon the geometric aspect of the notes. Instead of explaining "this road goes from there to there", you just submit a crudely drawn line. Just like with walking papers, you make a rough map of roads, paths, barriers, and back home you launch an OSM editor and turn all these scribbles into a proper map. You annotate the drawings with labels: kind of notes, but without associated workflows, and requiring the context of drawings (e.g. "asphalt").

It looks like this on a phone:

See how the service is being used in Tallinn, for example. You can easily find other scribbles on the website.

Using the layer in editors

• JOSM: open preferences (F12), "Imagery", find "GeoScribble Map Notes" and activate it. Then, having downloaded some data, add the layer on top of a satellite imagery layer from "Imagery" menu.
• iD: no easy way for now, but you can add WMS replacing an imagery layer: open the backgrounds menu ("B", the layers button), click on "..." near "Custom" and paste this URL template: https://geoscribble.osmz.ru/wms?service=WMS&request=GetMap&width={width}&height={height}&srs={proj}&bbox={bbox}&format=image/png&layers=latest
• Rapid: since version 2.3 (currently not live, try the canary build), open the "Map Data" panel (key F) and enable "GeoScribble Annotations".
• Every Door: click on the fourth mode button (for notes), it's already there.

API and data models

GeoScribble accepts objects of two kinds, Scribble and Label, and returns three, including a Box.

• Scribbles are line drawings. They have a style, basically a one-word tag: "road", "footway", "stream", "power". For visualizing, they also have properties like color, thickness, and dashes. Most renderers and editors rely on the latter, ignoring style labels.

• Labels are like OSM notes, but short (40 characters max), no comments and no workflows. They have a point location, color (ignored by all), and text.

These objects have no versions, they can only be added and deleted, but not updated. Identifiers are unique across all types. Also stored are an editor name, user id and name, and creation date.

• For low zooms (currently level 12 and less) instead of those objects, API returns Boxes: rectangular geohash representations with a single value: minimal age for objects inside the box. This make it easier to find fresh scribbles at a regional scale.

See OpenAPI documentation for exact definitions. Note that while it provides GeoJSON and raster WMS endpoints, the /scribbles one is the fastest, since there is virtually no overhead to it.

See Also

• Source code: https://github.com/Zverik/geoscribble