subject:"Re\: \[OSM\-talk\] All you've ever wanted to know about the french cadastre"

On Thu, Sep 27, 2012 at 2:18 AM, Paul Norman penor...@mac.com wrote:

 Conclusion:

 A significant number of cadastre imported buildings consist of multiple
 ways, such as in the example Frederik gave. The difference from other
 buildings a week old is statistically significant. This is true even if only
 looking at the subset of buildings that are new buildings.

 [1]: If anyone doubts this I could carry out an analysis on this point.

Paul, could you repeat your analysis where you distinguish polygons
tagged building=yes and others tagged building=yes+wall=no
(which is our tags to identify non-closed constructions like roof,
balcony, shed) ?

Pieren

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Re: [OSM-talk] All you've ever wanted to know about the french cadastre


Martin Koppenhoefer wrote:

Personally I would prefer to see
http://www.remote.org/frederik/tmp/funnybuilding.png  as a single closed
outline box.


I think that 6-7 buildings (looking at the bing aerial
http://it.bing.com/maps/?v=2cp=44.277739~0.502686lvl=20dir=0sty=hwhere1=44,277748%200,502839form=LMLTCC
  , maybe there is more but on a first remote approximation I could see
6 or 7) would be much better than a single closed outline box,
especially, if the tag is something like building=yes which is used
for one building, not groups of them.

There is a really huge difference between 1 big building and 7
adjacent small ones. The problem is, that the cadastre version doesn't
seem to make sense when compared to the aerial imagery. It is better
to have detailed outlines, but only if this detail is depicting
reality.


Certainly looking at the bing image there seemed to be a major difference 
between what was drawn and the difference in roof structure. And the overall 
shape. THIS is where being able to access the raw import data would be useful as 
a comparison ... if only to identify where the import process is breaking down?


I'm seeing EXACTLY the same sorts of problem with the UK data which I have 
already indicated. I can pull up OS Streetview, bing, and in some cases historic 
maps and see the differences. It was THIS situation which prompted me originally 
to look into how the French data was handling it, and I think that it's exactly 
the same problem! I have referred to 'trusted' data sources, but I do not think 
any of these sources come into that category, while 'boundaryline', and the 
French 'landuse' (? which that is) could be treated as 'trusted'? What data can 
be imported and updated automatically?


While some government data has been made 'open source', the KEY material is 
still locked down! :( Identifying the number of buildings in a block would be 
easy if we had a list of individual buildings and their location. The UK NLPG 
data has that list, but we can't use it. Also in the same way as the French data 
quality varies from town to town, the data within NLPG has the same vast 
differences in quality, and in many cases relies on the well out of data OS 
streetview data. Can the cadastre data be accessed as a list? I presume not as 
I'm sure you would be using it as a cross-check, but it's this 'building list' 
that is the key to ensuring that each identifiable building is displayed on OSM 
in the future. In the case of NLPG this will only identify a 'property' which 
will not necessarily count detached garages and outbuildings unless they are 
under separate ownership, and I would anticipate the same in the cadastre data?


All the discussions here are very much interrelated ( I don't do politics so I 
ignore that debate ) ... The discussion on 'adding layers' is to a certain 
extent academic. We ARE already using layers in the editors, and using 
http://www.openstreetmap.org/?lat=44.2777468264103lon=0.502683520317078zoom=19 
as our current example, edit gives the potlatch view with bing and there is a 
major discrepancy between the two layers. It would be nice here if the cadastre 
import was also available as the OS Streetview is on UK areas. With such a long 
set of threads I've forgotten and can't find who said that OSM had specific to 
USE the cadastre imagery in the editors :( I can understand why a local group 
MANAGING an import source might not want it generally available, but I think 
there needs to be a good reason not to?


At the end of the day, what we need to decide is what level of accuracy is 
acceptable, and while I don't think we want to be getting to a level where 
measurements of OSM can be used to settle property boundary disputes, the 
information imparted should represent the ground conditions as accurately as 
possible. I decided against importing buildings from streetview because it IS 
too far from reality. Claims are being made that the French data is more up to 
date, but if it is not being properly geo-referenced and is producing poor 
quality data should it be allowed in? returning to the example, in the absence 
of evidence that the building IS split into multiple units it SHOULD be drawn as 
a single entity? And tidying up would mean aligning it with the bing footprint? 
NONE of the buildings in the vicinity are of a quality that I would be happy to 
commit at which point I'd like to see the raw data and work out where the 
problem is. Some buildings are actually quite accurate, so the positioning is 
good, I get the same on streetview where I KNOW the build has been constructed 
in the last 5 years! But then the buildings around can be up to 50% off. I moved 
down to the village below the example building ...


Moving this forward ...
I think we are getting to a point where 'staging' or 'construction' layers do 
make sense. And a few of them would also make sense as separately selectable 
layers in viewers. 'Boundaries', with a complete list of what

Re: [OSM-talk] All you've ever wanted to know about the french cadastre

2012-09-27 Thread Paul Norman

 From: Pieren [mailto:pier...@gmail.com]
 Subject: Re: [OSM-talk] All you've ever wanted to know about the french
 cadastre

 On Thu, Sep 27, 2012 at 2:18 AM, Paul Norman penor...@mac.com wrote:

  Conclusion:

  A significant number of cadastre imported buildings consist of
  multiple ways, such as in the example Frederik gave. The difference
  from other buildings a week old is statistically significant. This is
  true even if only looking at the subset of buildings that are new
 buildings.

  [1]: If anyone doubts this I could carry out an analysis on this
 point.

 Paul, could you repeat your analysis where you distinguish polygons
 tagged building=yes and others tagged building=yes+wall=no
 (which is our tags to identify non-closed constructions like roof,
 balcony, shed) ?

For the changesets identified:

 Joined   Ways
building=* -wall=*:   12695  17594
building=* wall=no:6517   6818

I believe the large difference from sets of ways where some are wall=no and
some -wall=* and when combined they simplify farther than either does
separately.

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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

2012-09-27 Thread Martin Koppenhoefer

2012/9/27 Vincent Pottier vpott...@gmail.com:
 Le 27/09/2012 02:22, Martin Koppenhoefer a écrit :
 actually it is not only the diagonal line (which is an obvious error),
 but it is also all or most of the divisions, which don't seem to
 corrispond at all to real buildings or parts of them (maybe they are
 property divisions, but then the property in this ensemble is divided
 quite weird) when confronted with the aerial imagery.
 Looking at the tags on the polygons, you will find that some of them have a
 wall=no
 that canot be seen from aerial.


Interesting, I have never heard before of building=yes with wall=no
but I found documentation in the wiki:
http://wiki.openstreetmap.org/wiki/Tag:wall%3Dno
It looks as if there is an overlap with building=roof

Frankly I don't find building=yes, wall=no very intuitive, if I get
the wiki right, this is used for a series of distinct features like
balkonies, constructions without foundations (what do you mean by
this? temporary buildings? what does qualify for foundation?)
storage sheds and slight constructions (I also don't understand what
this means. Do you intend light constructions?).

I am particularly opposing the idea to use wall=no for a feature
that might have walls but not a roof (balconies), and I do also
generally oppose this tag wall=no because of the reasons given above
(not intuitive, mixes different classes, sometimes even
contradictory).

To get this right: I am not opposing the division into several
buildings instead of one outline (judging from the bing aerial these
are indeed several buildings), but the divisions between those
buildings should follow reality (which they apparently don't do at all
in the cadastre version). I am aware that this is simply one example,
but the way it looks makes me fear that there are lots of similar
problems. In this particular case it looks as if manual tracing would
be faster than adjusting the vector version.

cheers,
Martin

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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

On Thu, Sep 27, 2012 at 12:01 PM, Martin Koppenhoefer
dieterdre...@gmail.com wrote:
 buildings should follow reality (which they apparently don't do at all
 in the cadastre version).

How can you say that from an aerial imagery ? It is also possible that
the cadastre is outdated. Like any source of contribution, including
local survey.

Pieren

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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

2012-09-27 Thread Martin Koppenhoefer

2012/9/27 Pieren pier...@gmail.com:
 On Thu, Sep 27, 2012 at 12:01 PM, Martin Koppenhoefer
 dieterdre...@gmail.com wrote:
 buildings should follow reality (which they apparently don't do at all
 in the cadastre version).

 How can you say that from an aerial imagery ? It is also possible that
 the cadastre is outdated. Like any source of contribution, including
 local survey.


You are right that I cannot be 100% sure from aerial imagery, but how
probable would you think it is that they tore down the whole building
complex and reconstructed it split into different volumes but inside
the same total volume and shape? Would they have also reconstructed
the sheds and anxilliary building parts (if the cadastre is outdated)?
How probable are building divisions like in the cadastre version,
where there are very narrow buildings without direct access to the
street in building which is not particularly wide? From an architects
point of view the building partitions don't look real, it would be
really strange if they were like this, but you are right that I can't
exclude they are really like this, hence the apparently.

cheers,
Martin

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Re: [OSM-talk] All you've ever wanted to know about the french cadastre


Pieren wrote:

On Thu, Sep 27, 2012 at 12:01 PM, Martin Koppenhoefer
dieterdre...@gmail.com  wrote:

buildings should follow reality (which they apparently don't do at all
in the cadastre version).

How can you say that from an aerial imagery ? It is also possible that
the cadastre is outdated. Like any source of contribution, including
local survey.


Pieren
Many of the buildings moving away from the one identified simply do not even fit 
the footprint on the bing imagery and many of the 'divisions' seem to follow the 
ridge of a building rather than a difference between roof colour. The current 
blocks simply make no sense! It is not possible from the aerial imagery to 
identify divisions so unless those divisions are identified by other means ... 
such as a clear identification in Cadastra ... or better still by local 
knowledge ... then the building should simply be an outline! Now that I have 
scanned some of the French material I must say that it is of very low quality 
and all of the stuff I have reviewed needs at least SOME work to bring it up to 
a better standard. At best all one can say currently is 'there are some 
buildings round about here' ... and stripping unsubstantiated detail would at 
least be a start.


--
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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

2012-09-27 Thread Vladimir Vyskocil


On 27 sept. 2012, at 14:04, Lester Caine les...@lsces.co.uk wrote:

 Now that I have scanned some of the French material I must say that it is of 
 very low quality and all of the stuff I have reviewed needs at least SOME 
 work to bring it up to a better standard. At best all one can say currently 
 is 'there are some buildings round about here' ... and stripping 
 unsubstantiated detail would at least be a start.

At least the quality of the French Cadastre is way better than, say... Tiger 
data that was imported almost straight to the base and that is still in most 
part untouched by OSM contributors !

Vlad.


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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

2012-09-27 Thread Sylvain Maillard

Hi,

I think we should perhaps add a new section in the cadastre documentation:
the purpose of the cadastre, and the way it is made.

In France you need to ask for a permission from the public authority (the
municipalities) before to make a new building. It include a detailed map of
what you want to do. This is the map added to the cadastre (at least the
local copy), each time an authorisation is asked. So the data in the
cadastre is an aggregation of every building map provided by the
architects (not always the case).
But you are also authorized to build some new extension of a house without
to ask permission, if the new build is under a predefined size or kind of
building. So, many people are adding new portion of building just at the
limit size, that's why we can sometime see small part of building on the
cadastre. It can be not visible from the street or aerial imagery, but it
is still the reality of the building !

All the wall=no polygon are build on the same kind of rules: you need to
ask for an authorization if you build a full house with foundation, but
you can do almost what you want if the building as no foundation,
especially in the case of agricultural buildings (which seem to be the case
of our current example). So if you build something without real wall, or
without a roof, it's identified in a different way on the cadastre map.

Sylvain

2012/9/27 Lester Caine les...@lsces.co.uk

Pieren wrote:

On Thu, Sep 27, 2012 at 12:01 PM, Martin Koppenhoefer
dieterdre...@gmail.com wrote:

buildings should follow reality (which they apparently don't do at all
in the cadastre version).

How can you say that from an aerial imagery ? It is also possible that
the cadastre is outdated. Like any source of contribution, including
local survey.

Pieren
Many of the buildings moving away from the one identified simply do not
even fit the footprint on the bing imagery and many of the 'divisions' seem
to follow the ridge of a building rather than a difference between roof
colour. The current blocks simply make no sense! It is not possible from
the aerial imagery to identify divisions so unless those divisions are
identified by other means ... such as a clear identification in Cadastra
... or better still by local knowledge ... then the building should simply
be an outline! Now that I have scanned some of the French material I must
say that it is of very low quality and all of the stuff I have reviewed
needs at least SOME work to bring it up to a better standard. At best all
one can say currently is 'there are some buildings round about here' ...
and stripping unsubstantiated detail would at least be a start.

--
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-
Contact -
http://lsces.co.uk/wiki/?page=**contacthttp://lsces.co.uk/wiki/?page=contact
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EnquirySolve - http://enquirysolve.com/
Model Engineers Digital Workshop - http://medw.co.uk
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http://rainbowdigitalmedia.co.**ukhttp://rainbowdigitalmedia.co.uk

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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

On Thu, Sep 27, 2012 at 2:04 PM, Lester Caine les...@lsces.co.uk wrote:
 Many of the buildings moving away from the one identified simply do not even
 fit the footprint on the bing imagery and many of the 'divisions' seem to
 follow the ridge of a building rather than a difference between roof colour.
 The current blocks simply make no sense! It is not possible from the aerial
 imagery to identify divisions so unless those divisions are identified by
 other means ...

Lester, these building data are coming from permits sent by architects
to the tax administration. It is not based on aerial imagery.

Pieren

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Re: [OSM-talk] All you've ever wanted to know about the french cadastre


 De : Lester Caine les...@lsces.co.uk

 Many of the buildings moving away from the one identified simply do not 
 even fit the footprint on the bing imagery ?
What make you so sure that the thruth is in imagery and not in cadastre ? 
particulary considering that Bing is often several year late and that offical 
french maps (IGN) are also relying on cadastre for building ?
There are a lot of examples of places where there are some buiding referenced 
in cadastre that do not appear in Bing but that you can see IRL.
You will decide to remove them because you they are not on Bing or you will 
trust local contributors that introduce them because they know they are real ?

how do you make the difference between the guy that has the knowledge and the 
one that has not ?


 Now that I have scanned some of the French 
material I must say that it is of very low quality and all of the stuff I have 
reviewed needs at least SOME work to bring it up to a better 
standard.
 At best all one can say currently is 'there are some buildings round about 
 here' ... and stripping unsubstantiated detail would at 
least be a start.
According to the way you say that I assume that you have directly check in IRL 
or perform a comparison with a better quality and reliable source to decide 
that the wole cadastre is of very low quality...
Could you share with us you criteria and methodology to be so affirmative and 
allow us to determine which details are unsubstantiated ?
After all we are just mappers that concentrate on part of world  where we are 
living and that we know, if I remember well this is the base of Openstreetmap 
crowdsourcing ?

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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

2012-09-27 Thread Simon Poole


Am 27.09.2012 14:25, schrieb Vladimir Vyskocil:
 On 27 sept. 2012, at 14:04, Lester Caine les...@lsces.co.uk wrote:

 Now that I have scanned some of the French material I must say that it is of 
 very low quality and all of the stuff I have reviewed needs at least SOME 
 work to bring it up to a better standard. At best all one can say currently 
 is 'there are some buildings round about here' ... and stripping 
 unsubstantiated detail would at least be a start.
 At least the quality of the French Cadastre is way better than, say... Tiger 
 data that was imported almost straight to the base and that is still in most 
 part untouched by OSM contributors !


Well at least the Tiger data included further information outside of
just geometry and I'm saying that as a well known Tiger import hater.
Supposedly the cadastre includes street names and house numbers, however
of the 27 million buildings (plus 6 million wall=no) only a minuscule
number have further information attached, matter of fact there are more
nodes with addresses tagged in France than there are building outlines
with house numbers. Why this is the case, I don't know, but house
numbers etc. would be of far more immediate benefit to our data than
just building outlines.

Simon


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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

2012-09-27 Thread Olivier Croquette

On Sep 27, 2012, at 2:18 AM, Paul Norman wrote:
 This is not an example that you only find after a long search; it is a 
 typical cadastre import building.
 
 Until you can back up your claim with solid numbers, your claim, more
 specifically the wordtypical, is just FUD.
 Furthermore it can hurt many hard working french contributors, who for a
 single city spent dozens of hours integrating the cadaster into OSM.
 
 Time for some numbers then...
 
 Detailed data is available upon request.

Thanks Paul for taking the time to give some numbers. I don't understand also 
the technical details but hopefully well enough to provide some feedback that 
makes sense :)
Looking at your examples, I can see that some buildings have a geometry that 
doesn't seem to be in line with the reality. However, like other persons 
mentioned here already, the only way to find out if this is OK is to check with 
a survey.

The problem is however real. I know that our french OSM gurus have some checks 
for the cadaster import, but I don't know if it catches this kind of potential 
errors.

Still, your analysis still doesn't quantify it well enough to entitle it 
typical. 1 day of data is really not enough to be representative. Also, it's 
impossible to find automatically if adjacent building ways should be joined or 
not (wall issue, adjacent but separate buildings…). I am not saying it's not 
a problem, and I am not saying it's not typical, I am just saying there isn't  
enough proof to say that yet.

 A significant number of cadastre imported buildings consist of multiple
 ways, such as in the example Frederik gave.

Could you summarize it in more simple wording and an exact number ?
For instance:
10% of the new buildings imported between … and … share some ways with other 
buildings that have the same tags.

Also, I didn't understand who you differentiate the cadaster imports from the 
rest.

Cheers

Olivier

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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

 De : Simon Poole si...@poole.ch

 Supposedly the cadastre includes street names and house numbers, however
 of the 27 million buildings (plus 6 million wall=no) only a minuscule
 number have further information attached, matter of fact there are more
 nodes with addresses tagged in France than there are building outlines
 with house numbers. Why this is the case, I don't know, but house
 numbers etc. would be of far more immediate benefit to our data than
 just building outlines.

Some people put the house number on a node located where there is the building 
entrace ( and sometimes forgot to tag the entrance)
Sometimes there are several house number on big buildings so house number is 
place on nodes instead of buildings.
Some people prefer to place the number where it is located physically, near the 
street when an house has a long alley
A lot of buildings outside cities does not have house number appearing in 
cadastre.
This kind of reason can explain what you are observing
Cocerning building outlines it can be usefull for people performing study about 
urbanisation density etc so there is not one benefit related to one cateogry of 
data but benefits related to use.
Since we started to massively draw building outlines we also observe in France 
that people put much more POIs because this is very easier to add them when you 
have the buildings instead of just street because you know nuch more that your 
baker is just after 3rd building than 23meter after street corner...

The main interest of opendata is to allow unexpected usage so IMHO this is an 
error to decide in advance what has benefit or not for everyone

Cheers
Julien
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Re: [OSM-talk] All you've ever wanted to know about the french cadastre


THEVENON Julien wrote:


* *Many of the buildings moving away from the one identified simply do not
even fit the footprint on the bing imagery ?
What make you so sure that the thruth is in imagery and not in cadastre ?
particulary considering that Bing is often several year late and that offical
french maps (IGN) are also relying on cadastre for building ?
There are a lot of examples of places where there are some buiding referenced in
cadastre that do not appear in Bing but that you can see IRL.
You will decide to remove them because you they are not on Bing or you will
trust local contributors that introduce them because they know they are real ?
how do you make the difference between the guy that has the knowledge and the
one that has not ?
Not having access to the cadastre layer I can't comment on the differences 
between what has been traced and the source data, but I can SEE a distinct 
positional difference between the bing layer and the OSM buildings. If there was 
a general offset, then I would accept that there was simply a referencing error, 
but the buildings were offset in different directions across the areas I looked 
at. I also have buildings that do not yet appear on Bing ... no problem with 
that, but the ones that appear on both SHOULD be in the same place? You have 
already said that the cadastre data can't be trusted for detail?



* *Now that I have scanned some of the French material I must say that it is
of very low quality and all of the stuff I have reviewed needs at least SOME
work to bring it up to a better standard.
* *At best all one can say currently is 'there are some buildings round
about here' ... and stripping unsubstantiated detail would at least be a start.
According to the way you say that I assume that you have directly check in IRL
or perform a comparison with a better quality and reliable source to decide that
the wole cadastre is of very low quality...
Could you share with us you criteria and methodology to be so affirmative and
allow us to determine which details are unsubstantiated ?
After all we are just mappers that concentrate on part of world  where we are
living and that we know, if I remember well this is the base of Openstreetmap
crowdsourcing ?


http://www.openstreetmap.org/edit?lat=44.273069lon=0.500865zoom=18
YES local knowledge is needed to clean the data up, but some of the buildings 
line up nicely with the image, while others are well offset so if the 
information was reviewed before importing HOW was it reviewed? Certainly not 
against what I would refer to as the base location reference? If the cadastre 
data is providing the fine detail then OK, but I see a lot of what looks like 
lean-tos and porches identified as separate buildings and strange shapes over 
what look like rectangular buildings.
If this was an area I was working on, then I would have concentrated on the road 
structure first and then checked on what businesses are present. This allows a 
safe way of identifying commercial buildings and if they are listed, local house 
sales help add more detail.


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Re: [OSM-talk] All you've ever wanted to know about the french cadastre


On 27/09/2012 12:01, Martin Koppenhoefer wrote:

Interesting, I have never heard before of building=yes with wall=no


I just had lunch in an Italian restaurant, which I promptly tagged while 
waiting for my dessert... It happened to be located in a 
cadastre-imported building in two parts - one of them with wall=no : the 
part tagged with no wall was an extension of the building, enclosed as a 
veranda.



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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

2012-09-27 Thread Simon Poole


Am 27.09.2012 15:03, schrieb THEVENON Julien:
 * De :* Simon Poole si...@poole.ch
 
 * *Supposedly the cadastre includes street names and house
 numbers, however
 * *of the 27 million buildings (plus 6 million wall=no) only a
 minuscule
 * *number have further information attached, matter of fact there
 are more
 * *nodes with addresses tagged in France than there are building
 outlines
 * *with house numbers. Why this is the case, I don't know, but house
 * *numbers etc. would be of far more immediate benefit to our data
 than
 * *just building outlines.

 Some people put the house number on a node located where there is the
 building entrace ( and sometimes forgot to tag the entrance)
 Sometimes there are several house number on big buildings so house
 number is place on nodes instead of buildings.
 Some people prefer to place the number where it is located physically,
 near the street when an house has a long alley
 A lot of buildings outside cities does not have house number appearing
 in cadastre.
 This kind of reason can explain what you are observing

Just so there is no misunderstanding: even taking address tagged nodes
in to account, the addresses / houses ratio is lower and at best not
different than in other countries without countrywide access to 
cadastre-like sources. 3% with nodes, 0.6% without, comparision CH: 18%
/ 12%. The numbers are from the respective taginfo instances.

So the question remains why the information in not being added to the
outlines.

Simon


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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

2012-09-27 Thread maning sambale

At least in my country, address is tied to lot parcels and not to
individual buildings.

And since we dont have parcel data, we add housenumber as nodes.

Maning Sambale (mobile)
On Sep 27, 2012 9:32 PM, Simon Poole si...@poole.ch wrote:


 Am 27.09.2012 15:03, schrieb THEVENON Julien:

  * De :* Simon Poole si...@poole.ch si...@poole.ch
 
 * *Supposedly the cadastre includes street names and house numbers,
 however
 * *of the 27 million buildings (plus 6 million wall=no) only a
 minuscule
 * *number have further information attached, matter of fact there are
 more
 * *nodes with addresses tagged in France than there are building
 outlines
 * *with house numbers. Why this is the case, I don't know, but house
 * *numbers etc. would be of far more immediate benefit to our data
 than
 * *just building outlines.

  Some people put the house number on a node located where there is the
 building entrace ( and sometimes forgot to tag the entrance)
 Sometimes there are several house number on big buildings so house number
 is place on nodes instead of buildings.
 Some people prefer to place the number where it is located physically,
 near the street when an house has a long alley
 A lot of buildings outside cities does not have house number appearing in
 cadastre.
 This kind of reason can explain what you are observing


 Just so there is no misunderstanding: even taking address tagged nodes in
 to account, the addresses / houses ratio is lower and at best not different
 than in other countries without countrywide access to  cadastre-like
 sources. 3% with nodes, 0.6% without, comparision CH: 18% / 12%. The
 numbers are from the respective taginfo instances.

 So the question remains why the information in not being added to the
 outlines.

 Simon



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Re: [OSM-talk] All you've ever wanted to know about the french cadastre


On 27/09/2012 15:29, Simon Poole wrote:
Just so there is no misunderstanding: even taking address tagged nodes 
in to account, the addresses / houses ratio is lower and at best not 
different than in other countries without countrywide access to  
cadastre-like sources. 3% with nodes, 0.6% without, comparision CH: 
18% / 12%. The numbers are from the respective taginfo instances.


So the question remains why the information in not being added to the 
outlines.
Because the cadastre work is an armchair mapping process whereas the 
address tagging requires local survey. They are often done by two 
different type of contributors.


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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

2012-09-27 Thread Christian Quest

2012/9/27 Simon Poole si...@poole.ch:
 Just so there is no misunderstanding: even taking address tagged nodes in to
 account, the addresses / houses ratio is lower and at best not different
 than in other countries without countrywide access to  cadastre-like
 sources. 3% with nodes, 0.6% without, comparision CH: 18% / 12%. The numbers
 are from the respective taginfo instances.

 So the question remains why the information in not being added to the
 outlines.


Addresses are not extracted (yet) from the vector cadastre data.
Adding them is done 100% manually except when other opendata sets are
available (Nantes metropole has just been finished with 400.000+
addresses added if I'm not wrong).
We have the cadastre JOSM plugin who helps adding addresses manually
using the cadastre WMS layer in the background.
I manually added thousands of addresses that way, on both WMS vector
based cadastre and raster one (more difficult to read).

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Re: [OSM-talk] All you've ever wanted to know about the french cadastre


 De :Jean-Marc Liotier j...@liotier.org
 Because the cadastre work is an armchair mapping process whereas the 
 address tagging requires local survey. They are often done by two 
 different type of contributors.

On top of that as the cadastre distinguish light buildings and buildings, house 
with terrasses and veranda etc are represented by several buildings but there 
is still a single house number ( if it exists )

Cheers
Julien
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Re: [OSM-talk] All you've ever wanted to know about the french cadastre


Joakim Fors wrote:

Not having access to the cadastre layer I can't comment on the differences 
between what has been traced and the source data, but I can SEE a distinct 
positional difference between the bing layer and the OSM buildings. If there 
was a general offset, then I would accept that there was simply a referencing 
error, but the buildings were offset in different directions across the areas I 
looked at. I also have buildings that do not yet appear on Bing ... no problem 
with that, but the ones that appear on both SHOULD be in the same place? You 
have already said that the cadastre data can't be trusted for detail?


A lot of times Bing imagery is distorted in different directions in a small 
area. Quite easy to see in some places where you have access to very precise 
ortho imagery or vector data to compare with. For example in Lund where we get 
ortho imagery from the municpality; Here the Bing layer is distorted in 
different directions just a few blocks apart… not to mention that the Bing 
imagery is quite a few years older. Same with some vector data that 
muncipalities in the region have provided to OSM where it is easy to see that 
Bing imagery is quite inaccurate.


Sorry but I do not see any problem with the bing imagery in the area I 
identified. I moved up to 'Prayssas' being the first identifiable location I 
found, and I find it very strange that someone has imported a lot of buildings 
without any reference to roads to access them. I could understand if these 
buildings were then used to add the missing roads, but I've found no problem 
with the location of imagery against other sources in the UK so you would have 
to provide some pretty good evidence that the imagery around 'Prayssas' is 
distorted! I am used to the way building heights affect the ground plan, but if 
anything, the buildings are offset OVER the missing roads. The church looks 
nice, but google streetview only seems to cover the outer ring road :(


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Re: [OSM-talk] All you've ever wanted to know about the french cadastre


Jean-Marc Liotier wrote:


So the question remains why the information in not being added to the outlines.

Because the cadastre work is an armchair mapping process whereas the address
tagging requires local survey. They are often done by two different type of
contributors.


Armchair mapping via the bing imagery is just as rewarding, you just don't get 
the false 'pleasure' of uploading thousands of entities at a time. But it IS 
much more satisfying seeing OSM update an area you have just worked on with a 
lot of missing roads, footpaths and the like. I accept that this does take a 
little practice, and needs clean images, but France would benefit from a few 
'cadastre' importers filling other details in the areas they are importing :(


Personally I would not be happy if *I* had uploaded some of the areas I'm 
looking at ...


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Re: [OSM-talk] All you've ever wanted to know about the french cadastre


On 27/09/2012 16:07, Lester Caine wrote:
France would benefit from a few 'cadastre' importers filling other 
details in the areas they are importing :(
In that you agree with most of the opinions expressed on the French list 
: contributors using the cadastre generally add other details at the 
same time, which is one of the reasons why they find using two different 
accounts inconvenient.



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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

2012-09-27 Thread Martin Koppenhoefer

2012/9/27 THEVENON Julien julien_theve...@yahoo.fr:
 De : Jean-Marc Liotier j...@liotier.org
 Because the cadastre work is an armchair mapping process whereas the
 address tagging requires local survey. They are often done by two 
 different
 type of contributors.

 On top of that as the cadastre distinguish light buildings and buildings,
 house with terrasses and veranda etc are represented by several buildings
 but there is still a single house number ( if it exists )


+1, usually (at least in some cities I checked) housenumbers are
identifying a whole parcel (exceptions exist), IMHO better then
assigning them to a single house as Simon suggested it would be to add
them to the whole parcel (I guess you have these also available in
France, haven't you? In the end that's what a cadastre is about...)

cheers,
Martin

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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

2012-09-27 Thread SomeoneElse


Jean-Marc Liotier wrote:
In that you agree with most of the opinions expressed on the French 
list : contributors using the cadastre generally add other details at 
the same time, which is one of the reasons why they find using two 
different accounts inconvenient.


Maybe it's a work in progress:
http://www.openstreetmap.org/?lat=43.99103lon=0.33956zoom=15layers=M

Cheers,
Andy


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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

De : SomeoneElse li...@mail.atownsend.org.uk

Maybe it's a work in progress:
http://www.openstreetmap.org/?lat=43.99103lon=0.33956zoom=15layers=M


Or there are some people that think this is a good way to highlight where some 
roads are missing.
Personnaly I prefer to draw roads and building at the same time to have more 
complete maps 


Cheers
Julien
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Re: [OSM-talk] All you've ever wanted to know about the french cadastre


De : Martin Koppenhoefer dieterdre...@gmail.com
 +1, usually (at least in some cities I checked) housenumbers are
 identifying a whole parcel (exceptions exist), IMHO better then
 assigning them to a single house as Simon suggested it would be to add
 them to the whole parcel (I guess you have these also available in
 France, haven't you? In the end that's what a cadastre is about...)

In French cadastre you normally have a number for each parcel ( that we do not 
put in OSM )

House number is something different and only some parcel contains buildings 
associated to house numbers ( 0, 1 or more ).


Cheers
Julien
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Re: [OSM-talk] All you've ever wanted to know about the french cadastre


On 27/09/2012 16:28, SomeoneElse wrote:

Jean-Marc Liotier wrote:
In that you agree with most of the opinions expressed on the French 
list : contributors using the cadastre generally add other details at 
the same time, which is one of the reasons why they find using two 
different accounts inconvenient.

Maybe it's a work in progress:
http://www.openstreetmap.org/?lat=43.99103lon=0.33956zoom=15layers=M
Without the isolated clusters of buildings, how would you know that some 
important roads are missing ?



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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

2012-09-27 Thread SomeoneElse


Jean-Marc Liotier wrote:
Without the isolated clusters of buildings, how would you know that 
some important roads are missing ?

Visiting the village and walking around it?

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Re: [OSM-talk] All you've ever wanted to know about the french cadastre


On 27/09/2012 16:45, SomeoneElse wrote:

Jean-Marc Liotier wrote:
Without the isolated clusters of buildings, how would you know that 
some important

roads are missing ?

Visiting the village and walking around it?
Are we now reaching the crux of this discussion ? Do you believe that 
local survey is a requirement for mapping ? I don't and I back my 
position with all the places I have mapped without having visited them - 
I'm curious about what criticism you'll express about the quality of my 
work.


If the opposition to mapping with the assistance of cadastral data is 
grounded in opposition to the principle of remote mapping, then we have 
a problem - and maybe you should talk to everyone who uses some provider 
of orbital imagery in the source tag.



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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

On Thu, Sep 27, 2012 at 4:45 PM, SomeoneElse
li...@mail.atownsend.org.uk wrote:

 Visiting the village and walking around it?

This village is named Condom. That's probably why you remember it
and forward this example from time to time. Would you come if we
organize a mapping party at Condom ? (I said mapping party). But
hey, the village is mapped. We just miss the access to all isolated
dwellings around.
I'm sure in UK, all accesses to isolated dwellings are already mapped.
Like here : http://osm.org/go/eujKAYlx3-

Pieren

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Re: [OSM-talk] All you've ever wanted to know about the french cadastre


Jean-Marc Liotier wrote:

France would benefit from a few 'cadastre' importers filling other details in
the areas they are importing :(

In that you agree with most of the opinions expressed on the French list :
contributors using the cadastre generally add other details at the same time,
which is one of the reasons why they find using two different accounts
inconvenient.


Now that the rest of the world understand what is going on, then I think I can 
understand the problem now! I would STILL expect someone doing a bulk import of 
raw data from cadastre without adding any 'value' so be identified and to be 
honest most of the data I've looked at falls in that category! I've not found 
ANY additional data on the buildings. If I was involved in managing this, then 
to be honest I'd be considering wiping it again. I've done that in the past 
against OS 'imports' that have not been well done, and I've avoided importing 
stuff myself BECAUSE correcting it against the imagery would take too long. I 
think what we are saying here is that this does need a bit more 'hand holding' 
of the people contributing. The 'two accounts' is a bit of red herring here - in 
my opinion - but similarly JUST uploading buildings is pointless?


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Re: [OSM-talk] All you've ever wanted to know about the french cadastre


Jean-Marc Liotier wrote:

Jean-Marc Liotier wrote:

In that you agree with most of the opinions expressed on the French list :
contributors using the cadastre generally add other details at the same time,
which is one of the reasons why they find using two different accounts
inconvenient.

Maybe it's a work in progress:
http://www.openstreetmap.org/?lat=43.99103lon=0.33956zoom=15layers=M

Without the isolated clusters of buildings, how would you know that some
important roads are missing ?


Looking at the imagery or some other source if you are an arm chair mapper, or 
driving around with the GPS tracker if you want a run in the country. THEN 
adding buildings using the other sources. Even just looking at what is available 
on potlatch for France, there is sufficient 'missing' detail to keep many people 
busy, and raw imports of cadastre to my mind are not helping! They should just 
be used to add a little more detail when appropriate?


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Re: [OSM-talk] All you've ever wanted to know about the french cadastre


Pieren wrote:

Visiting the village and walking around it?

This village is named Condom. That's probably why you remember it
and forward this example from time to time. Would you come if we
organize a mapping party at Condom ? (I said mapping party). But
hey, the village is mapped. We just miss the access to all isolated
dwellings around.
I'm sure in UK, all accesses to isolated dwellings are already mapped.
Like here :http://osm.org/go/eujKAYlx3-


Now that is a cheap dig ;)

The buildings are not traced either, but are present on streetview, however the 
absence of a track on streetview would indicate that this is a private driveway 
and probably gated access. At the present time it is NOT common practice to add 
driveways unless they access more than one property or are open to the public. 
Now if you think that we should add ever driveway then I'd be quite happy to 
include that in my workflow :) In this case it would need a local survey to 
ascertain access rights. We do not assume that where there is no data available. 
Further west you will find that the firing ranges on Salisbury plains have some 
gaps as well :)


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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

2012-09-27 Thread Vincent Privat

2012/9/27 Lester Caine les...@lsces.co.uk

 If I was involved in managing this, then to be honest I'd be considering
 wiping it again.


Then I am glad you are not involved in it, because it would be a serious
case of vandalism. This would be totally unjustified to wipe such a valid
geographic information because it lacks a few tags that can be added later
by other people. OSM is a collaborative and iterative map. If you think
uploading buildings is pointless, then don't upload buildings. But that's
not a reason to prevent other people to do so.
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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

 De : Lester Caine les...@lsces.co.uk

 Looking at the imagery or some other source if you are an arm chair mapper, 
 or 
driving around with the GPS tracker if you want a run in the country.
 THEN adding buildings using the other sources. Even just looking at what is 
 available on potlatch for France, there is sufficient 'missing' 
detail to keep many people busy, and raw imports of cadastre to my mind 
are not helping!
 They should just be used to add a little more detail 
when appropriate?

Every people contribute for their own reason and so have their own 
priorities... some cares about roads some not, some care about the world with 
low detail level, some care about small region micro-mapped

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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

 De : Lester Caine les...@lsces.co.uk

 The 'two accounts' is a bit of red herring here - 
in my opinion - but similarly JUST uploading buildings is pointless?

Not at all. This is the heart of the problem for a lot of french contributors 
!!!
as already mentionned raw building import is the expection but you are focus on 
it.
For major part of French contributors we are adding buildings and other details 
not related to cadastre, so having one account per kind of edit will be really 
painfull.. but it it will not be for people that just perform raw building 
imports !

This is the real problem for us. 

We are also discussing a French Cadastre Task force to avoid raw building 
import withtout needed corrections but this is an other topic

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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

2012-09-27 Thread SomeoneElse


Jean-Marc Liotier wrote:
Are we now reaching the crux of this discussion ? Do you believe that 
local survey is a requirement for mapping ? I don't and I back my 
position with all the places I have mapped without having visited them 
- I'm curious about what criticism you'll express about the quality of 
my work.


If the opposition to mapping with the assistance of cadastral data is 
grounded in opposition to the principle of remote mapping, then we 
have a problem - and maybe you should talk to everyone who uses some 
provider of orbital imagery in the source tag.


Actually, I think that on-the-ground mapping and the use of aerial 
imagery / cadastre data are complementary.  There are many things that 
you'd miss if you used one exclusively at the expense of the other.


Cheers,
Andy


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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

2012-09-27 Thread Vincent Pottier


Le 27/09/2012 16:28, SomeoneElse a écrit :


Maybe it's a work in progress:
http://www.openstreetmap.org/?lat=43.99103lon=0.33956zoom=15layers=M

Cheers,
Andy

OSM is a work in progress.
--
FrViPofm

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Re: [OSM-talk] All you've ever wanted to know about the french cadastre


Jean-Marc Liotier wrote:

Jean-Marc Liotier wrote:

Without the isolated clusters of buildings, how would you know that some
important
roads are missing ?

Visiting the village and walking around it?

Are we now reaching the crux of this discussion ? Do you believe that local
survey is a requirement for mapping ? I don't and I back my position with all
the places I have mapped without having visited them - I'm curious about what
criticism you'll express about the quality of my work.
There is a certain level of accuracy that can be achieved as an armchair mapper 
and there is certainly a lot more detail that can be added world wide using just 
the material currently available. I was very tempted to 'tidy up' one of the 
French areas as an example and I may yet do that, but there is more than enough 
work still to do in my local area. AND only local access allows me to correct 
the mistakes in the 'official' data.



If the opposition to mapping with the assistance of cadastral data is grounded
in opposition to the principle of remote mapping, then we have a problem - and
maybe you should talk to everyone who uses some provider of orbital imagery in
the source tag.
I'd certainly appreciate it if the editors automatically added 
'source:trace=xxx' where I'm using a particular background layer - heck I forget 
to ADD the tag most of the time!
With regards data, one needs to know the limits of it's accuracy. I know that 
some streetview data is 40 years old. I can even identify the map it originally 
came from, so it has to be a judgement if I use it. The positional accuracy of 
the cadastral data is what I am questioning. Either someone says 'this is our 
reference' and we ignore the differences to other imagery, or it gets tidied up 
and the obvious flaws such as extra diagonal lines are removed. I get the 
impression that this is a process that should be happening but not everybody is 
'complying', so something needs to be done to re-educate those mappers to the 
'assistance' element over the 'just copy raw' activity?


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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

SomeoneElse li...@mail.atownsend.org.uk wrote:
 Actually, I think that on-the-ground mapping and the use of aerial 
 imagery / cadastre data are complementary.  There are many things that
 you'd miss if you used one exclusively at the expense of the other.

Yes - and local surveyors being the bottleneck resource, we better do as much 
as we can remotely so that they can focus on adding the critical value that 
comes from their local knowledge. 

Today as I added the Italian restaurant where I was having lunch, I was happy 
to find that buildings were already there - with reference to them it was very 
easy to add the restaurant and the customer's parking... I would have done a 
worse job without. 


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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

2012-09-27 Thread Christian Quest

2012/9/27 Martin Koppenhoefer dieterdre...@gmail.com:
 +1, usually (at least in some cities I checked) housenumbers are
 identifying a whole parcel (exceptions exist), IMHO better then
 assigning them to a single house as Simon suggested it would be to add
 them to the whole parcel (I guess you have these also available in
 France, haven't you? In the end that's what a cadastre is about...)


There is no 1-1 link between parcels and addresses as there is no 1-1
link between buildings and addresses.
Parcels, buildings and addresses are 3 completely different things in France.

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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

2012-09-27 Thread Sarah Hoffmann

On Thu, Sep 27, 2012 at 04:59:27PM +0100, THEVENON Julien wrote:
 For major part of French contributors we are adding buildings and other 
 details not related to cadastre, so having one account per kind of edit will 
 be really painfull.. but it it will not be for people that just perform raw 
 building imports !

I don't know which data you have been looking at, but let's ask
Nominatim, shall we?

For France we have:
  raw buildings indexed27337552
  other objects indexed 3799339
---
Total number of objects indexed31136891

Objects are real word objects here: highways, pois, boundaries etc.
In other words, for 7 imported buildings you manage to map one 
non-cadastre object. So indeed, I would agree that French
contributors do map other details. 
Occasionally. Very. Occasionally.

[referring to separate import accounts]
 This is the real problem for us.

For the sake of completeness: planetwide there are currently
152 million objects. Which means 1/6th of the planet consists of
French buildings. Now, there is a real problem.

Whatever use all those balconies, patios and swimming pools might
have in the future, right now in the present the cadastre import
has become a major nuissance for anybody who wants to use OSM data.
It wastes lots of bandwidth and CPU time. If it wasn't for the
cadastre imports, we'd still be able to keep the 32bit id space
for nodes for another year or two, which would save a lot of hard
disk space for a lot of people.

Just some food for thought. Now please don't let me stop you from
continuing to complain about how all those import rules make your 
life so much harder.

Sarah

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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

2012-09-27 Thread Eric Marsden

 sh == Sarah Hoffmann lon...@denofr.de writes:

  sh Objects are real word objects here: highways, pois, boundaries etc.
  sh In other words, for 7 imported buildings you manage to map one 
  sh non-cadastre object. So indeed, I would agree that French
  sh contributors do map other details. 
  sh Occasionally. Very. Occasionally.

  This is an interesting point of view. How many buildings do you think
  there are on an average street in France? Fewer than for an average
  street in the USA, certainly, but likely more than 7. 
  
  sh Whatever use all those balconies, patios and swimming pools might
  sh have in the future, right now in the present the cadastre import
  sh has become a major nuissance for anybody who wants to use OSM data.
  sh It wastes lots of bandwidth and CPU time. If it wasn't for the
  sh cadastre imports, we'd still be able to keep the 32bit id space
  sh for nodes for another year or two, which would save a lot of hard
  sh disk space for a lot of people.

  Amazingly, bandwidth and hard disk space per euro are increasing
  faster than these lazy French cadastre importers can pollute the
  database ... Which isn't to say that buildingless planet extracts
  might be useful to some people.

-- 
Eric Marsden


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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

2012-09-27 Thread Vincent Pottier


Le 27/09/2012 09:49, Lester Caine a écrit :
Claims are being made that the French data is more up to date, but if 
it is not being properly geo-referenced and is producing poor quality 
data should it be allowed in? returning to the example, in the absence 
of evidence that the building IS split into multiple units it SHOULD 
be drawn as a single entity?
What is the unit ? Something used for 3D drawing ? Something used for 
statistics ? Something used for a purpose I don't even imagine ?

And tidying up would mean aligning it with the bing footprint?

Sometimes the Cadastre is better than Bing, Sometimes Bing is better...

We have the chance to have put in OSM a network of survey points. It is 
our best reference... but hard to use for newbies...

--
FrViPofm


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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

 De : Sarah Hoffmann lon...@denofr.de

Hi Sarah,

Sorry for this late response and hope to make debate less passionate.

 I don't know which data you have been looking at, but let's ask
Nominatim, shall we?

Great idea, this is always good to discuss about facts

Ok, so by example could you extract stats from Grenoble instead of whole France 
? I thinks this quite representative of cities where there are buildings and 
quite a lot of details.

Concerning discussions about separated accounts I`m sure that there is a good 
reason behind that but it was perhaps decided for cases that do not match 
French one. What we are trying to do here is to discuss to understand why this 
rule has been done ( that's why we are asking for a list of issues that import 
Guidelines Rules want to address ) and if it is possible to find a solution 
both  satisfy the goal you have and that do not create problems for good-will 
french mapppers that spend time to perform clean cadastre integration. I`m 
convinced ( or at least I hope )that you don`t create this rule to make French 
mappers crazy.

Concerning the waste of bandwidth and CPU, the nuisance for people who want to 
use OSM data I understand the problem but I guess it will come even without 
cadastre because due to Open Data mouvment there will certainly more and more 
big data sources to integrate.
There is certainly something to do also with tools or database schematic 
perhaps to optimise this kind of issues but agains I think that cadastre is the 
thing that put the light on the problem but is not the direct cause of the 
problem.
We are mapping the world and I think this quite surprising to have only 32 bits 
id ( I face this kind of problems in my professional life with long 
microelectronics simulations ) but this is certainly due to good reasons when 
it has been designed and I understand the issue you mention.
So if cadastre building integration create technical issues like too many disk 
space usage or lack of technical solutions to solve the issue you mention I 
would prefer that you say that clearly and ask to stop cadastre import until 
there is a solution rather than saying use separated accounts or things like 
that won't solve your issue.
I`m really happy that you mention a technical problem and something concrete to 
explain clearly one part of the problem and I thinks that Fench community is 
able to understand this kind of problematic.

Thanks for your food for thought and I hope that we will succeed to reach a 
solution

Cheers
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Re: [OSM-talk] All you've ever wanted to know about the french cadastre

On Thu, Sep 27, 2012 at 8:18 PM, Sarah Hoffmann lon...@denofr.de wrote:

 for 7 imported buildings you manage to map one non-cadastre object.

As Eric said, I find the ratio quite good. I would be interested by
the ratio buldings/non buildings in Germany (your email is German). As
I understood, it is acceptable to have 100 Germans tracing 10
buildings from Bing but not 1 lazy French importing 1000 buildings
from the Cadastre. Even if the quality is questionable in both cases.

 So indeed, I would agree that French contributors do map other details.
 Occasionally. Very. Occasionally.

Indecent for all contributors editing in France (incl. many
foreigners) and not importing buildings. No more comments about so
much ignorance.

 For the sake of completeness: planetwide there are currently
 152 million objects. Which means 1/6th of the planet consists of
 French buildings. Now, there is a real problem.

It was a time where TIGER data took half of the database (if I
remember correctly). Then the ratio declined. It will be the same for
French buildings. Germans are also massively adding buildings but by
hand (is it not also imported sometimes ?). It's just a matter of time
until Germans will exceed the French on this. Will you be happy to
read now the German buildings is a real problem because it takes
1/6th or 1/7th of the planet ?

 It wastes lots of bandwidth and CPU time.
Again the same arguments we have seen years ago from those against
imports in general. Nothing new. And for data consumers, they can
filter by tags or areas if they wish.

 If it wasn't for the cadastre imports, we'd still be able to keep the 32bit 
 id space
 for nodes for another year or two, which would save a lot of hard
 disk space for a lot of people.

The 64 bits transition is done now at the same time as the full
re-import due to the relicensing which, I guess, is a good
coincidence.

 Now please don't let me stop you from continuing to complain about how all 
 those import rules make your life so much harder.
...hmm, not sure about this sentence ... but I don't think the
guidelines have been created with the intention of making our life
much harder.

Pieren

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Re: [OSM-talk] All you've ever wanted to know about the french cadastre