Re: [HOT] Validating and imagery offset

2016-10-24 Thread Kretzer 

Well, as I said, in most of the tiles I checked, the mapping was surprisingly 
good. I only did a little cleanup in some tiles, and reminded one or two 
mappers of the squaring.
 
But in my example there were cleanly mapped buidlings aligned to the provided 
custom imagery, and a well mapped road aligned to the Bing image which was 
quite offset. So I was wondering if it's the right thing to do to move the road 
as all the other features are aligned to the custom image.
Also most of the other newly mapped structures in the task would be aligned to 
the custom imagery. So I guess it's better to keep those? 
But in the end everything should be in the "right" place, shouldn't it? 

 

Gesendet: Montag, 24. Oktober 2016 um 16:38 Uhr
Von: "john whelan" <jwhelan0...@gmail.com>
An: Kretzer <kret...@gmx.net>
Cc: "HOT Openstreetmap" <hot@openstreetmap.org>
Betreff: Re: [HOT] Validating and imagery offset

This is my personal view after doing more than a fair amount of validation.
 
If you square the buildings you are making an approximation on what the 
original mapper mapped.  It doesn't look as pretty to leave it as it was but 
that is what I would do.  If mappers used the JOSM building tool to start with 
there wouldn't be the problem.  Garbage in garbage out I think is the technical 
computing term.  Politically you aren't supposed to delete the mapper's work 
realistically it can be faster to delete and remap using the JOSB building_tool 
plugin.  If you have the mappers for three hours I can get more buildings 
mapped with the tool than they can do in iD and its a lot more accurate, that 
includes the overhead for installing and configuring JOSM.
 
If the buildings are way out compared to Bing then you could select one 
displaced building and note the name.  Now search for all the buildings, within 
that search for the mapper.  Hopefully all their buildings will be displaced 
the same amount, move one building to alignment and the others will fall into 
place.  Again realistically if a building is six feet or a couple of meters out 
its findable so I don't even bother moving them these days.
 
Why even bother validating you may ask, well its the 10,000+ unlabeled ways in 
Africa, the 2,000+ highway=living_street in Nigeria the groups of buildings 
that should be tagged landuse=residential but are tagged building=house, the 
crossing highways, the highways that almost meet, the highway=motorway between 
two villages 200 meters apart these are the ones I try to catch.
 
Try to provide feedback, "added 97 buildings" if it nudges the mapper to do it 
right next time you've saved some poor validator a lot of work correcting but 
don't bother if it was mapped more than a month earlier.
 
I know I'm cynical.
 
Cheerio John
 
On 24 October 2016 at 08:03, Kretzer <kret...@gmx.net[mailto:kret...@gmx.net]> 
wrote:Hi,
as there seemed to be a need for validating the last Haiti projects, I did some 
tiles, though I am not very comfortable with validating - considering myself 
halfway experienced at best.

I found several tiles that were very neatly mapped, all the buidlings squared, 
although they were all done by new mappers ... probably that was a mapathon or 
something with good instructions and supervisison.

But I don't really know what do do when I hit structures that are mapped to 
different imagery whith quite a lot of offset, like here: 
http://tasks.hotosm.org/project/2229#task/188[http://tasks.hotosm.org/project/2229#task/188]
Should I clean this up while validating the "buildings only" project? How would 
I do this, align everything to Bing? (I remmeber having read that this is 
considered the most accurate). But then I would have to move around a lot of 
polygons, as all the new buildings are mapped to the custom imagery.
Or would you move the road to fit in with the majority of existing structures?

Thanks for your advice!
K

___
HOT mailing list
HOT@openstreetmap.org[mailto:HOT@openstreetmap.org]
https://lists.openstreetmap.org/listinfo/hot

___
HOT mailing list
HOT@openstreetmap.org
https://lists.openstreetmap.org/listinfo/hot

Re: [HOT] Validating and imagery offset

2016-10-24 Thread Mike Thompson 
On Mon, Oct 24, 2016 at 8:38 AM, john whelan  wrote:

>
> If the buildings are way out compared to Bing then you could select one
> displaced building and note the name.  Now search for all the buildings,
> within that search for the mapper.  Hopefully all their buildings will be
> displaced the same amount,
>
Typically the displacement between two imagery sources will vary with
location, thus selecting all of the buildings in a task done by a certain
mapper and moving them will not usually work unfortunately.

>
> On 24 October 2016 at 08:03, Kretzer  wrote:
>
>>
>> Should I clean this up while validating the "buildings only" project? How
>> would I do this, align everything to Bing? (I remmeber having read that
>> this is considered the most accurate). But then I would have to move around
>> a lot of polygons, as all the new buildings are mapped to the custom
>> imagery.
>> Or would you move the road to fit in with the majority of existing
>> structures?
>>
> This is an area where the instructions for the individual tasking manager
projects could be improved.
___
HOT mailing list
HOT@openstreetmap.org
https://lists.openstreetmap.org/listinfo/hot

Re: [HOT] Validating and imagery offset

2016-10-24 Thread john whelan 
This is my personal view after doing more than a fair amount of validation.

If you square the buildings you are making an approximation on what the
original mapper mapped.  It doesn't look as pretty to leave it as it was
but that is what I would do.  If mappers used the JOSM building tool to
start with there wouldn't be the problem.  Garbage in garbage out I think
is the technical computing term.  Politically you aren't supposed to delete
the mapper's work realistically it can be faster to delete and remap using
the JOSB building_tool plugin.  If you have the mappers for three hours I
can get more buildings mapped with the tool than they can do in iD and its
a lot more accurate, that includes the overhead for installing and
configuring JOSM.

If the buildings are way out compared to Bing then you could select one
displaced building and note the name.  Now search for all the buildings,
within that search for the mapper.  Hopefully all their buildings will be
displaced the same amount, move one building to alignment and the others
will fall into place.  Again realistically if a building is six feet or a
couple of meters out its findable so I don't even bother moving them these
days.

Why even bother validating you may ask, well its the 10,000+ unlabeled ways
in Africa, the 2,000+ highway=living_street in Nigeria the groups of
buildings that should be tagged landuse=residential but are tagged
building=house, the crossing highways, the highways that almost meet, the
highway=motorway between two villages 200 meters apart these are the ones I
try to catch.

Try to provide feedback, "added 97 buildings" if it nudges the mapper to do
it right next time you've saved some poor validator a lot of work
correcting but don't bother if it was mapped more than a month earlier.

I know I'm cynical.

Cheerio John

On 24 October 2016 at 08:03, Kretzer  wrote:

> Hi,
> as there seemed to be a need for validating the last Haiti projects, I did
> some tiles, though I am not very comfortable with validating - considering
> myself halfway experienced at best.
>
> I found several tiles that were very neatly mapped, all the buidlings
> squared, although they were all done by new mappers ... probably that was a
> mapathon or something with good instructions and supervisison.
>
> But I don't really know what do do when I hit structures that are mapped
> to different imagery whith quite a lot of offset, like here:
> http://tasks.hotosm.org/project/2229#task/188
> Should I clean this up while validating the "buildings only" project? How
> would I do this, align everything to Bing? (I remmeber having read that
> this is considered the most accurate). But then I would have to move around
> a lot of polygons, as all the new buildings are mapped to the custom
> imagery.
> Or would you move the road to fit in with the majority of existing
> structures?
>
> Thanks for your advice!
> K
>
> ___
> HOT mailing list
> HOT@openstreetmap.org
> https://lists.openstreetmap.org/listinfo/hot
>
___
HOT mailing list
HOT@openstreetmap.org
https://lists.openstreetmap.org/listinfo/hot

[HOT] Validating and imagery offset

2016-10-24 Thread Kretzer 
Hi,
as there seemed to be a need for validating the last Haiti projects, I did some 
tiles, though I am not very comfortable with validating - considering myself 
halfway experienced at best.

I found several tiles that were very neatly mapped, all the buidlings squared, 
although they were all done by new mappers ... probably that was a mapathon or 
something with good instructions and supervisison.

But I don't really know what do do when I hit structures that are mapped to 
different imagery whith quite a lot of offset, like here: 
http://tasks.hotosm.org/project/2229#task/188
Should I clean this up while validating the "buildings only" project? How would 
I do this, align everything to Bing? (I remmeber having read that this is 
considered the most accurate). But then I would have to move around a lot of 
polygons, as all the new buildings are mapped to the custom imagery.
Or would you move the road to fit in with the majority of existing structures?

Thanks for your advice!
K

___
HOT mailing list
HOT@openstreetmap.org
https://lists.openstreetmap.org/listinfo/hot