[Talk-ca] FW: Building Import

Tue Mar 26 20:48:40 UTC 2019

As usual, missed the reply all …

From: jfd553 at hotmail.com
Sent: Tuesday, March 26, 2019 16:26
To: 'John Whelan'
Subject: RE: [Talk-ca] Building Import

It is really kind to consider my background ;-)
You are right regarding the "black box" approach; this is why a large approval from the community is required before I go further.

Daniel

From: John Whelan [mailto:jwhelan0112 at gmail.com]
Sent: Tuesday, March 26, 2019 16:04
To: Begin Daniel
Cc: Jarek Piórkowski; talk-ca at openstreetmap.org; keith hartley; Alessandro (STATCAN)
Subject: Re: [Talk-ca] Building Import

I think my concerns are to do with the "black box" approach.  Knowing your background I trust your work but others might not.

On a technical side I get the impression that cites with buildings that are close to each other are problematical.  I assume that small locations with a population of say under 125,000 this is an insignificant problem?

The other issue is I'd like to either see buy in from Nate or at least some Toronto mappers to get an indication that something will happen at the end of the day as it is a fair chunk of Daniel's time to work out how do the preprocessing.

I think some BC mappers expressed some doubts as well so perhaps they would like to think about if they are happy or would prefer BC to be outside of the import project and express their views.

Out of interest if it does move ahead are we including the Microsoft data for areas where we do not have data from Stats Canada?  If so we will need to amend the project plan.

My personal view is realistically I think having building information even if its a meter or two out is better than not having the building outlines.

What would be nice is if we could have some indication from places such as Manitoba, Alberta, Saskatchewan, Quebec excluding Montreal, Ontario excluding Toronto and the other provinces and territories whether they are happy with importing the buildings either from Stats or Microsoft.

I seem to recall Keith is in Manitoba, so any views other than it wasn't present in the first release from Stats?

Note to Alessandro this is just background stuff.

Thanks

Cheerio John

Begin Daniel wrote on 2019-03-26 3:29 PM:

Jarek,

The area you proposed in quite interesting and will force me to look further at buildings with sharing edges, a concern Pierre also had. I'll be back soon with your area processed.

Daniel

-----Original Message-----

From: Begin Daniel [mailto:jfd553 at hotmail.com]

Sent: Tuesday, March 26, 2019 14:34

To: Jarek Piórkowski; talk-ca at openstreetmap.org<mailto:talk-ca at openstreetmap.org>

Subject: Re: [Talk-ca] Building Import

Jarek,

Since it is a one-time process, I expect to be able to process the files if the community feels comfortable with it. In the meantime, people are welcome to send me the bounding box of an area they would like to examine.

Daniel

-----Original Message-----

From: Jarek Piórkowski [mailto:jarek at piorkowski.ca]

Sent: Tuesday, March 26, 2019 13:46

To: Begin Daniel; talk-ca at openstreetmap.org<mailto:talk-ca at openstreetmap.org>

Subject: Re: [Talk-ca] Building Import

On Tue, 26 Mar 2019 at 13:10, Begin Daniel <jfd553 at hotmail.com><mailto:jfd553 at hotmail.com> wrote:

There is actually no standard “code” available since I use FME (www.safe.com<http://www.safe.com>). It is a proprietary ETL application and all operations are done using “transformers” (https://www.safe.com/transformers/). I can provide you with the workbench I developed (a bunch of linked transformers) but you need a license to run it. This is why I tried to describe the operations I run on the data in the wiki.

As you did, people may send me coordinates (bounding box) of an area they know well. I’ll process the area and send the results back in OSM format. Please, be reasonable on the amount of data to process ;-)

Thanks Daniel. Let me know how it looks then!

Coming from an open-source background, the process is unusual to me,

and I have questions about scalability - will you be able to process

and provide updated data files for all of Canada then? - but if others

are comfortable with it then I won't object.

Some general thoughts regarding tooling as raised upthread:

I was initially excited to see building footprints data as they help

two quite distinct purposes:

1. they provide a mostly-automatic source of geometries for the

millions of single-family houses that wouldn't be mapped in the next

decade otherwise

2. they might provide a corrected and fairly accurate source of

geometries in heavily-built-up areas, where GPS signal is not that

reliable and it can be really difficult to get sufficiently accurate

geometries from imagery, whether because it's not sufficiently

high-resolution, two sets of imagery with conflicting offsets (Bing

and Esri are the two best sets in Toronto, and they're off by about

1-2 m on north-south axis from each other - that's not something I can

check with a consumer-grade GPS so I'm left guessing as to which is

true), or non-vertical imagery (I can count the floors on supposedly

top-down imagery in some cases).

>From what I saw, imports in the GTHA initially focused on the first

case, and I think the Tasking Manager setup was mostly sufficient for

those - where there is nothing currently on the map, or a few simple

2D geometries, a 4 sq km area can feasibly be done in under an hour.

However, as raised by others, I would really want the working squares

in Old Toronto for example to be no more than 500 m x 500 m, or no

more than 1 km x 1 km in St. Catharines. I would _love_ to have the

geometries to manually compare and adjust the 3D buildings already

existing in the area, but it will be much slower.

--Jarek

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