[Talk-ca] Buildings in Montreal

Charles Basenga Kiyanda personal at charleskiyanda.com
Tue Jan 30 16:23:52 UTC 2018


Hi all,

I'm one of the local montreal contributors with repeated contacts at the
city of Montreal. To answer the questions:

1) We did get the city to explicitely state authorization for re-use
under odbl as per the guidelines of the LWG for CC-by-4.0. The license
is compatible for montreal opendata

2) Montreal does have building outlines, in autocad DWG format. I
believe cartographie de base is the street outlines, though I haven't
looked at that data in a bit. Montreal has a lot of contiguous buildings
and the biggest problem is that the building outlines aren't necessarily
closed. In fact, when you look at the data, most of the individual
buildings are formed of disjointed lines. When looking at the city data
carefully, you can kind of see how the people who generated the data
worked. They created the dwg data so they could render the building
outlines, but not to keep a database of what are individual buildings.
For example, when tracing a row of adjoining buildings that all share
common walls, the entire block may have been traced at the front with a
single line since the facades are very often aligned. Perpendicular to
this single line are a set of short lines that trace the position of the
shared walls. The back of the row of buildings is unpredictable,
depending on the shape of the different buildings.

Basically, the building data that the city has is not a dabase of
individual buildings, but a "outline probably traced over imagery".
Sampling the data manually, we almost never saw closed polygons
representing buildings.

3) We're not lacking interest. We would very much love to see this data
in the database. What we're missing is manpower. Doing an automated
import would be quite arduous. We're not sure where to start in order to
take the dwg data and automatically reconstruct closed polygons that
correspond to individual buildings.

4) I haven't seen the lidar data. I've seen renderings that really could
only have been done with lidar data, but I hadn't seen the data itself.
If there's an effort to automatically treat lidar data in canda to
generate building footprints and elevation, I'd be happy to help as much
as I can with the Montreal data.


Cheers,


Charles


On 2018-01-30 09:40 AM, john whelan wrote:
> I think its best if they can organise themselves.  We don't have a
> French translation of the wiki which is unfortunate.
>
> If you could bring the matter to their attention that would be
> useful.  I suspect that most of the building outlines are already
> mapped and the real challenge will be tagging more detail on to the
> buildings.
>
> Thanks John
>
> On 30 January 2018 at 09:32, Pierre Béland <pierzenh at yahoo.fr
> <mailto:pierzenh at yahoo.fr>> wrote:
>
>     La série Carte de base contient sans doute les données du
>     cadastre(format Autocad échelle 1/1,000).
>     http://donnees.ville.montreal.qc.ca/dataset/cartographie-de-base
>     <http://donnees.ville.montreal.qc.ca/dataset/cartographie-de-base>
>
>     Les contributeurs de Montréal sont en lien avec la ville de
>     Montréal et peuvent sans doute obtenir des extractions sous
>     d'autres formats. Ils ont leur propre site internet et Liste de
>     discussion. 
>     voir http://www.openstreetmap-montreal.org/
>     <http://www.openstreetmap-montreal.org/>
>     http://listes.osmqc.ca/
>      
>     Pierre
>
>
>     Le mardi 30 janvier 2018 08:39:57 HNE, James <james2432 at gmail.com
>     <mailto:james2432 at gmail.com>> a écrit :
>
>
>     sorry, they do have buildings..... but its combined with a bunch
>     of other things in DWG format called "Cartographie de base"
>
>     On Jan 30, 2018 8:34 AM, "James" <james2432 at gmail.com
>     <mailto:james2432 at gmail.com>> wrote:
>
>         they seem to only have addresses and lidar.
>
>         On Jan 30, 2018 8:30 AM, "john whelan" <jwhelan0112 at gmail.com
>         <mailto:jwhelan0112 at gmail.com>> wrote:
>
>             But do they have a buildings outline file?
>
>             Thanks John
>
>             On 30 Jan 2018 7:52 am, "James" <james2432 at gmail.com
>             <mailto:james2432 at gmail.com>> wrote:
>
>                 I was looking at license on the montreal site and they
>                 even say for OSM to use their data:
>
>                 http://donnees.ville.montreal. qc.ca/portail/license/
>                 <http://donnees.ville.montreal.qc.ca/portail/license/>
>                 (scroll down)
>
>                 On Jan 30, 2018 6:57 AM, "john whelan"
>                 <jwhelan0112 at gmail.com <mailto:jwhelan0112 at gmail.com>>
>                 wrote:
>
>                     Since Montreal would appear to have an acceptable
>                     licence and Open Data does it have a building
>                     outline file that technically could be imported?
>
>                     The second part would be does it have local
>                     mappers who would be willing to support such an
>                     import?
>
>                     On the more technical side I would imagine it
>                     would need to be done in sections and I'm unsure
>                     how many buildings are already mapped.  The more
>                     there are the more complex the import would be.
>
>                     Thanks John
>
>                     ______________________________ _________________
>                     Talk-ca mailing list
>                     Talk-ca at openstreetmap.org
>                     <mailto:Talk-ca at openstreetmap.org>
>                     https://lists.openstreetmap.or g/listinfo/talk-ca
>                     <https://lists.openstreetmap.org/listinfo/talk-ca>
>
>
>     _______________________________________________
>     Talk-ca mailing list
>     Talk-ca at openstreetmap.org <mailto:Talk-ca at openstreetmap.org>
>     https://lists.openstreetmap.org/listinfo/talk-ca
>     <https://lists.openstreetmap.org/listinfo/talk-ca>
>
>
>
>
> _______________________________________________
> Talk-ca mailing list
> Talk-ca at openstreetmap.org
> https://lists.openstreetmap.org/listinfo/talk-ca


-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: OpenPGP digital signature
URL: <http://lists.openstreetmap.org/pipermail/talk-ca/attachments/20180130/d6b5c6c9/attachment-0001.sig>


More information about the Talk-ca mailing list