<html>
<head>
<meta http-equiv="Content-Type" content="text/html;
charset=windows-1252">
</head>
<body>
<p>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:<br>
<a class="moz-txt-link-freetext" href="http://tasks.osmcanada.ca/project/168">http://tasks.osmcanada.ca/project/168</a><br>
<a class="moz-txt-link-freetext" href="https://tasks.openstreetmap.us/project/107">https://tasks.openstreetmap.us/project/107</a></p>
<p>Best,<br>
</p>
<div class="moz-signature">
<p> Nate Wessel<small>, PhD<br>
Planner, Cartographer, Transport Nerd<br>
<a href="https://www.natewessel.com"
style="text-decoration:none;">NateWessel.com</a></small>
</p>
</div>
<div class="moz-cite-prefix">On 2020-01-04 12:40 p.m., Daniel
@jfd553 wrote:<br>
</div>
<blockquote type="cite"
cite="mid:YQXPR01MB24541B0094942485C4C2CE9D94220@YQXPR01MB2454.CANPRD01.PROD.OUTLOOK.COM">
<meta http-equiv="Content-Type" content="text/html;
charset=windows-1252">
<meta name="Generator" content="Microsoft Word 14 (filtered
medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
@font-face
{font-family:Consolas;
panose-1:2 11 6 9 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";
mso-fareast-language:EN-US;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p
{mso-style-priority:99;
mso-margin-top-alt:auto;
margin-right:0cm;
mso-margin-bottom-alt:auto;
margin-left:0cm;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
pre
{mso-style-priority:99;
mso-style-link:"HTML Preformatted Char";
margin:0cm;
margin-bottom:.0001pt;
font-size:10.0pt;
font-family:"Courier New";}
p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph
{mso-style-priority:34;
margin-top:0cm;
margin-right:0cm;
margin-bottom:0cm;
margin-left:36.0pt;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";
mso-fareast-language:EN-US;}
span.EmailStyle19
{mso-style-type:personal;
font-family:"Calibri","sans-serif";
color:windowtext;}
span.HTMLPreformattedChar
{mso-style-name:"HTML Preformatted Char";
mso-style-priority:99;
mso-style-link:"HTML Preformatted";
font-family:"Consolas","serif";
mso-fareast-language:EN-US;}
span.EmailStyle22
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 72.0pt 72.0pt 72.0pt;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
<div class="WordSection1">
<p class="MsoNormal"><span style="color:#1F497D">Bonjour groupe<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Looks like
we're going in the same direction so far :-)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">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?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D" lang="FR-CA"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Daniel<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<div>
<div style="border:none;border-top:solid #B5C4DF
1.0pt;padding:3.0pt 0cm 0cm 0cm">
<p class="MsoNormal"><b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif";mso-fareast-language:EN-CA"
lang="EN-US">From:</span></b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif";mso-fareast-language:EN-CA"
lang="EN-US"> Nate Wessel [<a class="moz-txt-link-freetext" href="mailto:bike756@gmail.com">mailto:bike756@gmail.com</a>] <br>
<b>Sent:</b> Saturday, January 04, 2020 10:09<br>
<b>To:</b> <a class="moz-txt-link-abbreviated" href="mailto:talk-ca@openstreetmap.org">talk-ca@openstreetmap.org</a><br>
<b>Subject:</b> Re: [Talk-ca] Importing buildings in
Canada<o:p></o:p></span></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p>Hi Daniel, <o:p></o:p></p>
<p>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.
<o:p></o:p></p>
<p>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.
<o:p></o:p></p>
<p>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.
<o:p></o:p></p>
<p>That is, each import needs to be local, and not just in a
superficial sense. <o:p>
</o:p></p>
<p>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. <o:p></o:p></p>
<p>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 (
<a href="http://tasks.osmcanada.ca/project/168"
moz-do-not-send="true">http://tasks.osmcanada.ca/project/168</a>
) but this is only the tip of the iceberg.
<o:p></o:p></p>
<p>Again, I thank everyone for their time and effort on this -
we can get this done if we go slow and do it right :-)<o:p></o:p></p>
<p>Best,<o:p></o:p></p>
<div>
<p>Nate Wessel<span style="font-size:10.0pt">, PhD<br>
Planner, Cartographer, Transport Nerd<br>
<a href="https://www.natewessel.com"
moz-do-not-send="true"><span
style="text-decoration:none">NateWessel.com</span></a></span>
<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">On 2020-01-03 3:40 p.m., Daniel @jfd553
wrote:<o:p></o:p></p>
</div>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoNormal"
style="margin-bottom:10.0pt;line-height:115%"><span
lang="FR-CA">Bonjour groupe, mes excuses pour ce très long
courriel !-)</span><o:p></o:p></p>
<p class="MsoNormal" style="line-height:115%">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.<o:p></o:p></p>
<p class="MsoNormal" style="line-height:115%"> <o:p></o:p></p>
<p class="MsoNormal" style="line-height:115%"><b><span
style="font-size:14.0pt;line-height:115%">1. Issues with
the ODB Data Import</span></b><o:p></o:p></p>
<p class="MsoNormal"
style="margin-bottom:10.0pt;line-height:115%">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.<o:p></o:p></p>
<p class="MsoNormal" style="line-height:115%"><b>1.1. Which
data import project?</b><o:p></o:p></p>
<p class="MsoNormal"
style="margin-bottom:10.0pt;line-height:115%">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.<o:p></o:p></p>
<p class="MsoNormal" style="line-height:115%"><b>1.2. What has
been imported so far?</b><o:p></o:p></p>
<p class="MsoNormal"
style="margin-bottom:10.0pt;line-height:115%">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.
<o:p></o:p></p>
<p class="MsoNormal"
style="margin-bottom:10.0pt;line-height:115%">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.<o:p></o:p></p>
<p class="MsoNormal" style="line-height:115%"><b><span
style="font-size:14.0pt;line-height:115%">2. How should
ODB Data be imported?</span></b><o:p></o:p></p>
<p class="MsoNormal"
style="margin-bottom:10.0pt;line-height:115%">I will copy
the following paragraphs in the “Canada Building Import”
wiki page [3] for a detailed discussion…<o:p></o:p></p>
<p class="MsoNormal"
style="margin-bottom:10.0pt;line-height:115%">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].
<o:p></o:p></p>
<p class="MsoNormal" style="line-height:115%"><b>2.1 Importing
Locally</b><o:p></o:p></p>
<p class="MsoNormal"
style="margin-bottom:10.0pt;line-height:115%">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…<o:p></o:p></p>
<p class="MsoNormal">- We contact them to explain our intents
by referring to appropriate wiki pages.<o:p></o:p></p>
<p class="MsoNormal">- We wait a week or two to let them
respond nothing, that they have concerns, or wish to help.<o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom:6.0pt">- Without
negative answers we could proceed to the import.<o:p></o:p></p>
<p class="MsoNormal"
style="margin-bottom:10.0pt;line-height:115%">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.<o:p></o:p></p>
<p class="MsoNormal"
style="margin-bottom:10.0pt;line-height:115%">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.<o:p></o:p></p>
<p class="MsoNormal" style="line-height:115%"><b>2.2
Pre-processing</b><o:p></o:p></p>
<p class="MsoNormal"
style="margin-bottom:10.0pt;line-height:115%">Once local
mappers have agreed, some pre-processing can be done if
required.
<o:p></o:p></p>
<p class="MsoNormal"
style="margin-bottom:10.0pt;line-height:115%">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.<o:p></o:p></p>
<p class="MsoNormal"
style="margin-bottom:10.0pt;line-height:115%">Proposed
pre-processing [4] includes:
<o:p></o:p></p>
<p class="MsoNormal">- Reading of original ODB data,<o:p></o:p></p>
<p class="MsoNormal">- Removal of near collinear nodes
(simplification), <o:p></o:p></p>
<p class="MsoNormal">- Orthogonalization of buildings (for
corners having near right angles),<o:p></o:p></p>
<p class="MsoNormal">- Tagging of building footprints,<o:p></o:p></p>
<p class="MsoNormal"
style="margin-bottom:10.0pt;line-height:115%">- Providing
files in OSM format.<o:p></o:p></p>
<p class="MsoNormal"
style="margin-bottom:10.0pt;line-height:115%"><i>Proposed
tagging:</i> In addition to the tags produced by the
orthogonalization process [4] and the source tag (<a
href="https://wiki.openstreetmap.org/wiki/Key:source"
moz-do-not-send="true"><span
style="color:windowtext;text-decoration:none">source</span></a>=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.<o:p></o:p></p>
<p class="MsoNormal"
style="margin-bottom:10.0pt;line-height:115%">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.<o:p></o:p></p>
<p class="MsoNormal" style="line-height:115%"><b>2.3. Import
Process</b><o:p></o:p></p>
<p class="MsoNormal"
style="margin-bottom:10.0pt;line-height:115%">After the
local mappers, if any, agreed to the import, the
pre-processing completed when required, we can proceed to
the import.
<o:p></o:p></p>
<p class="MsoNormal"
style="margin-bottom:10.0pt;line-height:115%">1- Do not bulk
import the data! Always use the task manager (<a
href="http://tasks.osmcanada.ca/" moz-do-not-send="true">http://tasks.osmcanada.ca/</a>).
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.<o:p></o:p></p>
<p class="MsoNormal"
style="margin-bottom:10.0pt;line-height:115%">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.<o:p></o:p></p>
<p class="MsoNormal"
style="margin-bottom:10.0pt;line-height:115%">3- Align the
existing OSM content to the image (i.e. after the new offset
is applied) if required.<o:p></o:p></p>
<p class="MsoNormal"
style="margin-bottom:10.0pt;line-height:115%">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.<o:p></o:p></p>
<p class="MsoNormal"
style="margin-bottom:10.0pt;line-height:115%"><b><span
style="font-size:14.0pt;line-height:115%">References</span></b><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt">[1] </span><a
href="https://wiki.openstreetmap.org/wiki/The_Open_Database_of_Buildings"
moz-do-not-send="true"><span style="font-size:9.0pt">https://wiki.openstreetmap.org/wiki/The_Open_Database_of_Buildings</span></a><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt">[2] </span><a
href="https://wiki.openstreetmap.org/wiki/Canada_Building_Import#Import_process"
moz-do-not-send="true"><span style="font-size:9.0pt">https://wiki.openstreetmap.org/wiki/Canada_Building_Import#Import_process</span></a><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt">[3] </span><a
href="http://resultmaps.neis-one.org"
moz-do-not-send="true"><span style="font-size:9.0pt">http://resultmaps.neis-one.org</span></a><span
style="font-size:9.0pt"> (“Overview of OpenStreetMap
Contributors aka who’s around me?”)</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt">[4] </span><a
href="https://github.com/jfd553/OrthogonalizingBuildingFootprint"
moz-do-not-send="true"><span style="font-size:9.0pt">https://github.com/jfd553/OrthogonalizingBuildingFootprint</span></a><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt">[5] </span><span
style="font-size:10.0pt"><a
href="https://www150.statcan.gc.ca/n1/pub/92-195-x/2011001/geo/csd-sdr/csd-sdr-eng.htm"
moz-do-not-send="true"><span style="font-size:9.0pt">https://www150.statcan.gc.ca/n1/pub/92-195-x/2011001/geo/csd-sdr/csd-sdr-eng.htm</span></a></span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt">[6] <a
href="https://wiki.openstreetmap.org/wiki/Canada_Building_Import#Conflation"
moz-do-not-send="true">
https://wiki.openstreetmap.org/wiki/Canada_Building_Import#Conflation</a></span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:9.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"
style="margin-bottom:10.0pt;line-height:115%"> <o:p></o:p></p>
<p class="MsoNormal"
style="margin-bottom:10.0pt;line-height:115%">Let’s move
ahead!<o:p></o:p></p>
<p class="MsoNormal"
style="margin-bottom:10.0pt;line-height:115%">Daniel<o:p></o:p></p>
<p class="MsoNormal"><span
style="font-size:12.0pt;font-family:"Times New
Roman","serif";mso-fareast-language:EN-CA"><br>
<br>
<o:p></o:p></span></p>
<pre>_______________________________________________<o:p></o:p></pre>
<pre>Talk-ca mailing list<o:p></o:p></pre>
<pre><a href="mailto:Talk-ca@openstreetmap.org" moz-do-not-send="true">Talk-ca@openstreetmap.org</a><o:p></o:p></pre>
<pre><a href="https://lists.openstreetmap.org/listinfo/talk-ca" moz-do-not-send="true">https://lists.openstreetmap.org/listinfo/talk-ca</a><o:p></o:p></pre>
</blockquote>
</div>
</blockquote>
</body>
</html>