[OSM-talk] Visually detect missing roads

[Dave F.]

Stephan

Apart from being confusing to understand & use, you're making the false 
assumption that it's the Google data which is correct. In my area the 
only red lines are either where Google maps are inaccurate or there's an 
error in your algorithm as there's no difference between OSM & Google.

Can't get the Bing overlay to work.

David Fox


On 09/09/2014 08:11, Stephan Knauss wrote:
> I did announce this on the German list last week. As the load did not 
> cause the server to catch fire I'm now announcing it to a wider audience.
>
> I have created a map which visually diffs our data against Google Maps.
> Currently it compares major highways (unclassified and higher) and 
> water features.
>
> The data is styled to show up in bright colors. If there is "matching" 
> data in OSM it would hide the Google data.
>
> So in a "perfect" area the map would be grey. Differences stay visible.
>
> You can try it here: http://compare.osm-tools.org/
>
> It has the possibility to directly load the visible area into the 
> editors.
>
> More details can be found here: http://www.osm-tools.org/compare.html
>
> or if you're able to read German in my blog post at 
> http://www.technologyblog.de/2014/08/wo-fehlen-bei-openstreetmap-noch-daten/
>
> In well-mapped areas the differences are usually caused by OSM data 
> not being tagged as a major highway. If you're looking for areas where 
> roads are actually missing and can be drawn from aerials head over to 
> Asia.
>
> Hope this helps all people interested in arm-chair mapping to focus on 
> the major missing parts of OSM-data.
>
> If you pan the map fast you'll see the original Google data. This is 
> caused by the way technical way the images are layered. When using 
> Google API instead of OpenLayers it would not do this but caching of 
> tiles is worse with Google. That's why I decided to use OL.
>
> Enjoy mapping!
>
> Stephan
>
>
> _______________________________________________
> talk mailing list
> talk at openstreetmap.org
> https://lists.openstreetmap.org/listinfo/talk


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