Which is what I imagined was the case but the audience in talk-ca is large and with two languages around it is easy for misunderstandings to occur.
Cheerio John On Sun, Jan 5, 2020, 12:33 PM Nate Wessel, <bike...@gmail.com> wrote: > John, > Those links were just to indicate what can be done with task setup. I > don't think we're close to setting up actual import tasks yet, though we do > seem to be on the road toward getting things sorted out :-) > > Nate Wessel, PhD > Planner, Cartographer, Transport Nerd > NateWessel.com <https://www.natewessel.com> > On 2020-01-05 12:20 p.m., john whelan wrote: > > I'm getting lost as to who is organising what and who is taking > responsibility for defining and setting up the tasks and where they are > being set up. > > Are your two examples of what can be done? Or are they to be used by > mappers to add buildings? > > My understanding was Daniel would identify those areas that looked the > most interesting then these would be set up after the process to see if any > local mappers were available and what their input would be. > > Thanks John > > On Sun, Jan 5, 2020, 11:41 AM Nate Wessel, <bike...@gmail.com> wrote: > >> The task size, and even shape is totally customizable. I've set up a >> couple that are entirely based on the density of the data: >> http://tasks.osmcanada.ca/project/168 >> https://tasks.openstreetmap.us/project/107 >> >> Best, >> >> Nate Wessel, PhD >> Planner, Cartographer, Transport Nerd >> NateWessel.com <https://www.natewessel.com> >> On 2020-01-04 12:40 p.m., Daniel @jfd553 wrote: >> >> Bonjour groupe >> >> >> >> Looks like we're going in the same direction so far :-) >> >> I agree with Nate regarding the implementation of the task manager. In my >> experience, a size of a few blocks would be better in urban areas, but >> boring in rural areas. Is it something that can be adjusted? >> >> >> >> Daniel >> >> >> >> *From:* Nate Wessel [mailto:bike...@gmail.com <bike...@gmail.com>] >> *Sent:* Saturday, January 04, 2020 10:09 >> *To:* talk-ca@openstreetmap.org >> *Subject:* Re: [Talk-ca] Importing buildings in Canada >> >> >> >> Hi Daniel, >> >> Thank you for all the work you've put into this. I'd like to offer a >> couple suggestions and/or clarifications for your proposed import process, >> overview though it is. >> >> First, I think it is very important that a tasking manager is set up on a >> city/by city basis only, and that only AFTER consensus is achieved that the >> import should proceed in that area. I would really like to avoid seeing the >> massive nationwide tasking that was set up the first time around. We should >> be making it hard for people to go rogue in regions where consensus for an >> import doesn't (yet) exist. >> >> Related to this, though important enough to be a second point in it's own >> right, the tasking squares need to be small enough that a single user can >> manage them and inspect every single building in a task. The first round of >> import used task squares that were massive, and which couldn't be divided >> any further past a certain point. Even in rural areas, it is likely >> inappropriate to import areas larger than 1km^2. In central Toronto it >> would be (and was) idiotic. An import that doesn't take local scale into >> account shouldn't proceed. "Too big to load into JOSM" is about 100x too >> big to import in my opinion and is not a good enough benchmark for import >> batch sizing. >> >> That is, each import needs to be local, and not just in a superficial >> sense. >> >> I'll also add that the issue of conflation doesn't seem to have been >> worked out yet except to note that it is an issue. What will we do with the >> millions of buildings which will substantially overlap/duplicate existing >> buildings or imports? This needs to be worked out in detail before anything >> starts up again. >> >> And what needs to be done about already existing low quality imports? >> It's good to acknowledge their existence, but what will be done about them? >> We've set up a task to clean up some of the mess in Toronto ( >> http://tasks.osmcanada.ca/project/168 ) but this is only the tip of the >> iceberg. >> >> Again, I thank everyone for their time and effort on this - we can get >> this done if we go slow and do it right :-) >> >> Best, >> >> Nate Wessel, PhD >> Planner, Cartographer, Transport Nerd >> NateWessel.com <https://www.natewessel.com> >> >> On 2020-01-03 3:40 p.m., Daniel @jfd553 wrote: >> >> Bonjour groupe, mes excuses pour ce très long courriel !-) >> >> I have reviewed everything that has been written on the ODB import (aka >> Canada Building Import) in Talk-ca and the wiki. I proposed changes to some >> wiki pages (via talk tabs) to ease the discussions about this import and >> the following. Now, in order to restart the import, here are some thoughts >> and a proposal on how to proceed to complete the task. >> >> >> >> *1. Issues with the ODB Data Import* >> >> Many concerns were raised about the import. One major concern was to >> obtain local communities’ buy-in in the Canadian context. Another concern >> was to improve the quality of the data prior the import. The following >> paragraphs intend to clear most of these concerns. >> >> *1.1. Which data import project?* >> >> According to the import guidelines (steps 3 & 4), a data import >> explicitly refers to a single data source (ODB in our case). Discussions >> about the availability and quality of Microsoft or ESRI data, while >> interesting, are not relevant as they should be dealt with as other import >> projects. >> >> *1.2. What has been imported so far?* >> >> According to what I found [1], the ODB import is completed for 21 >> municipalities. These imports seem to have kept OSM content’s history, at >> least for the samples checked, but many problems were found. In some case, >> the imports brought swimming pools in OSM because they were included in the >> dataset (e.g. Moncton). In other cases, importing buildings with accurate >> locations (XY) over content mapped from less accurate imagery resulted in >> buildings that now overlap the street network (e.g. Squamish). It means >> that all these 21 imports need to be carefully re-examined and corrected as >> required. >> >> For 12 other municipalities, the import is partial, either suspended as >> requested, or because previous imports had already provided most of the >> buildings (often from the same municipal provider). That said the import >> will definitely improve OSM accuracy and completeness if done properly. >> >> *2. How should ODB Data be imported?* >> >> I will copy the following paragraphs in the “Canada Building Import” wiki >> page [3] for a detailed discussion… >> >> Since the data (ODB, OSM and imagery) differ from one municipality to >> another, there can be no imports at the national or provincial level. We >> have to work on a municipal basis and make sure to identify all the >> problems and the corrective measures to apply when dealing with issues like >> those I identified [1]. >> >> *2.1 Importing Locally* >> >> According to the import guidelines (step 2), we must not import the data >> without local buy-in. However, and contrarily to some European country, >> there is usually no such thing as a local OSM community in each >> municipality. However, we may find a few local mappers from time to time. >> Working on a municipal basis should allow identifying these local mappers >> before doing the import. I often use this tool [2] to identify and contact >> local mappers. Once identified, I suggest that… >> >> - We contact them to explain our intents by referring to appropriate wiki >> pages. >> >> - We wait a week or two to let them respond nothing, that they have >> concerns, or wish to help. >> >> - Without negative answers we could proceed to the import. >> >> I first suggest that when a contributor wishes to import ODB for a given >> municipality, he first identifies himself as responsible for the import (we >> need to create an entry for each municipality somewhere in the wiki). He >> can then contact local mappers, as explain above, and go ahead with the >> import once everything settled. For those who already made the import, I >> suggest that they review their work since many issues were detected with >> some of these imports. >> >> Since there are only a few local OSM communities in Canada, and because >> Canada is large, I suggest not limiting the import of a given municipality >> to the people of the concerned province or region. >> >> *2.2 Pre-processing* >> >> Once local mappers have agreed, some pre-processing can be done if >> required. >> >> A few months ago, I developed a tool that could be used to process the >> data [4]. Concerns were raised because the application was developed using >> proprietary software. So I documented the whole process and algorithms in >> order to see courageous coders converting it in open source software. In >> the meantime, and as long as I have access to an FME licence, I could >> process the data, when necessary, prior to make it available through the >> task manager. >> >> Proposed pre-processing [4] includes: >> >> - Reading of original ODB data, >> >> - Removal of near collinear nodes (simplification), >> >> - Orthogonalization of buildings (for corners having near right angles), >> >> - Tagging of building footprints, >> >> - Providing files in OSM format. >> >> *Proposed tagging:* In addition to the tags produced by the >> orthogonalization process [4] and the source tag (source >> <https://wiki.openstreetmap.org/wiki/Key:source>=Statistics Canada - >> Open Building Database), the name of the Census Subdivision provided in ODB >> data [5] is used to add the addr:city tag to each building. >> >> The pre-processing requires parameters that are specific to the data to >> process. These parameters were estimated on a municipal basis using actual >> ODB data. The processing time increases exponentially according to the >> number of buildings so, it may take a couple of days before the data is >> available for a given municipality. Currently, the proposed pre-processing >> does not convert terrace buildings into individual houses nor it tags >> topological errors. >> >> *2.3. Import Process* >> >> After the local mappers, if any, agreed to the import, the pre-processing >> completed when required, we can proceed to the import. >> >> 1- Do not bulk import the data! Always use the task manager ( >> http://tasks.osmcanada.ca/). Select and open a task square in JOSM. If >> it’s too big (e.g. too much work or request is too big to load in JOSM), go >> back to the task manager and split the task into smaller squares. >> >> 2- Load imagery layer (Bing or ESRI World Imagery) and align the imagery >> with ODB data (i.e. create a new image offset) if necessary because, unless >> proven otherwise, ODB should be more accurate (XY) than most available >> images especially in hilly areas. >> >> 3- Align the existing OSM content to the image (i.e. after the new offset >> is applied) if required. >> >> 4- Currently step 2 and following as described in the wiki [2]. I suggest >> merging the Conflation section [6] here and reviewing everything to take >> into account the current proposal. >> >> *References* >> >> [1] https://wiki.openstreetmap.org/wiki/The_Open_Database_of_Buildings >> >> [2] >> https://wiki.openstreetmap.org/wiki/Canada_Building_Import#Import_process >> >> [3] http://resultmaps.neis-one.org (“Overview of OpenStreetMap >> Contributors aka who’s around me?”) >> >> [4] https://github.com/jfd553/OrthogonalizingBuildingFootprint >> >> [5] >> https://www150.statcan.gc.ca/n1/pub/92-195-x/2011001/geo/csd-sdr/csd-sdr-eng.htm >> >> [6] https://wiki.openstreetmap.org/wiki/Canada_Building_Import#Conflation >> >> >> >> >> >> >> >> Let’s move ahead! >> >> Daniel >> >> >> >> _______________________________________________ >> >> Talk-ca mailing list >> >> Talk-ca@openstreetmap.org >> >> https://lists.openstreetmap.org/listinfo/talk-ca >> >> _______________________________________________ >> Talk-ca mailing list >> Talk-ca@openstreetmap.org >> https://lists.openstreetmap.org/listinfo/talk-ca >> >
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