Hi John,
As stated before, I don't consider the Microsoft dataset being close to
the minimum quality requirements I would expect from any automated
building entry into OSM. If you just want to display buildings, you can
download the MS dataset and use it right away - no need to import into
OSM. I think, the MS dataset has value as proof of concept and to count
the number of buildings in a given area (e.g. to estimate market size
for roofers, estimate number of persons living there for desaster
relief, etc.). I also think, when Microsoft feeds its algorithm with
higher resolution data than they did (I don't recall, but I think they
only used the regular Bing data) they will probably end up with building
footprints that will meet our/my quality requirements for import into
OSM one day.
For me, the value of OSM is having accurate information in terms of tags
and geometry. Otherwise, we could join Wikimapia; they don't care too
much about geometry accuracy but emphasize on content/tags of objects.
Pretty interesting project, but different from OSM.
Cheers,
Tim
On 2020-01-17 10:40, john whelan wrote:
>first, to add missing buildings (if it were
just for this purpose we could also use the much bigger Microsoft
dataset)
I can't resist. Does this infer that for parts of the country without
Stat Can data we are happy to import Microsoft dataset buildings as is?
Or would we wish to wait until we have some more imports done before
looking at preprocessing them in some way first.
Thanks John
On Thu, Jan 16, 2020, 10:11 PM Tim Elrick, <o...@elrick.de
<mailto:o...@elrick.de>> wrote:
I would assume in most cases the imported building footprint will be
more precise than existing data. For me, this would be a reason to
replace already existing objects. However, I think this is a case by
case decision. However, I think it is important to keep tags and
history
of buildings already existent in OSM. This is how I would
read/interpret
the import guideline stated by Nate: "If you are importing data where
there is already some data in OSM, then *you need to combine this data*
in an appropriate way or suppress the import of features with overlap
with existing data." (emphasis added by me)
However, that just means, the import, hence, is nothing easy and could
not be achieve quickly, I would assume. One way of making sure that
this
is dealt with diligently, would be setting the tasking manager to
'experienced mappers only'. We would have to ask James, who is in
charge
of the Canada Tasking Manager, how to edit/set up the 'experienced
mapper role' in the TM. It might be possible to feed in a list of
mappers manually or to set a threshold of objects/changesets that they
must have entered in OSM. However, maybe only mappers who feel
experienced enough to handle the import would contribute to the TM
project anyway and we let everyone judge on their own and don't
restrict
access.
If we were to separate the new and overlapping buildings, I am also
leaning towards Daniel's assessment. I would be afraid to cause more
issues than by doing it all at once (with a reasonable tile size, of
course).
In the end, the main point of importing this specific dataset fulfils
two purposes, in my opinion: first, to add missing buildings (if it
were
just for this purpose we could also use the much bigger Microsoft
dataset), second, to get the best geospatial representation possible in
our OSM database. That means, we defer from using the Microsoft dataset
and use the much higher quality data from the ODB. This also means that
we should replace already existing buildings (yet keeping tags and
history) wherever the ODB footprint is more precise than the
existing one.
Just my two cents here,
Tim
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