Re: [Talk-us] hydrology Alaska

[Christoph Hormann]

On Wednesday 18 October 2017, Andy Townsend wrote:
>
> https://www.openstreetmap.org/#map=17/69.94271/-152.49898
>
> isn't the result of simplification, though, is it?  You can see the
> pixels...

Like others here i have no practical experience with scanaerial but it 
seems the vectorization algorithm used is very non-sophisticated 
leading to the geometries shown.  Tracing higher resolution images at 
higher resolution and running Douglas-Peucker over it will likely not 
produce good results either (you will get the typical jagged corners).

Those cases where good results were achieved with scanaerial seem to be 
using relatively low resolution images processed at a much higher 
resolution - like here:

http://www.openstreetmap.org/#map=12/68.8084/160.9188

-- 
Christoph Hormann
http://www.imagico.de/

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Re: [Talk-us] hydrology Alaska

[Andy Townsend]

On 18/10/2017 05:49, ANT Berezhnyi wrote:

+10 to what AlaskaDave said



Simplification creates such a crap, as you led me to an example


https://www.openstreetmap.org/#map=17/69.94271/-152.49898

isn't the result of simplification, though, is it?  You can see the 
pixels...


I'd suggest that, before tracing any more, you revisit the lakes that 
you have added so far (like this one) and make sure that they match the 
best imagery.


Best Regards,

Andy


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Re: [Talk-us] hydrology Alaska

[ANT Berezhnyi]

+10 to what AlaskaDave said

I myself want to be beautiful and accurate,
I make with accuracy 1 point on 1..2 meters, on the exact perimeter of the
lake (accuracy 30 ... 50 centimeters from the coastline)
then I am simplifying (because it requires
https://www.openstreetmap.org/user/bdistsoe
https://www.openstreetmap.org/changeset/52811016#map=14/60.8274/-164.9563)

Simplification creates such a crap, as you led me to an example

if I do not make it easier - I will be blocked again (((


--
2017-10-11 06:56:40 UTC bdiscoe Hi, I ran simplify with a 90cm threshold.
That is very conservative for a remote, wild area of mud and tundra. As for
accuracy, I ran the JOSM validator and fixed many of the issues you left,
with multipolygon ways intersecting each other, overlapping ways, and many
other problems. It is fixed now...
--

Define the trouble please what you want to have quality,
because the simplification script is a standard simplification of JOSM
(unchanged)

*The basis I use is:*
Bing:
bing[22]:http://www.bing.com/maps/

DigitalGlobe Premium:
tms[22]:https://{switch:a,b,c,d}.
tiles.mapbox.com/v4/digitalglobe.316c9a2e/{zoom}/{x}/{y}.png?access_token=pk.eyJ1IjoiZGlnaXRhbGdsb2JlIiwiYSI6ImNqM293YnJ5MTAwajIzMnF0bmV4dnV1MW4ifQ.psvzzOez33BOH8xmRiJZWg


DigitalGlobe Standard:  (if on DG-premium clouds)
tms[22]:https://{switch:a,b,c,d}.
tiles.mapbox.com/v4/digitalglobe.0a8e44ba/{zoom}/{x}/{y}.png?access_token=pk.eyJ1IjoiZGlnaXRhbGdsb2JlIiwiYSI6ImNqM293Y3Y5ZjAwaWgycW55ZXFncHk0a3QifQ.6Kprj_J4oDmXqV97RricwA


*I look forward to the answer to what is the understanding of how exactly
it is necessary for the region of Alaska to carry out the mapping of
hydrology.*

*Until there is a final agreed answer,* I will put roads in the reserves,
and correct the inaccuracies of the coastline (editing existing lines)



thnx

-- 
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Re: [Talk-us] hydrology Alaska

[Ben Discoe]

+1 to what AlaskaDave said.

As far as I can tell in this case, the jaggies are a result of running
ScanAerial on imagery of a low resolution (i.e. zoomed out).  At that
level (LandSat resolution), a smooth lake edge looks like a jagged set
of individual pixels, where each pixel is 28 meters across.  Turning
each LandSat pixel into a vector edge produces these unattractive,
stair-setpped, inefficient polygons.

Please don't do that.

I don't know ScanAerial well, but it seems to me that you could run it
on a higher resolution (the Bing database/API has much better than
LandSat resolution here, if you zoom in).  The resulting polygons
would then need to run through a Simplify, to remove excessive detail,
before they could be uploaded to OSM.  That should result in
appropriate number of nodes, e.g. that smooth top edge of lake.

Anton, I can produce illustrations, if you need more help to understand.

If ScanAerial cannot be configured that way, then it's simply the
wrong tool to use for this situation.

On Tue, Oct 17, 2017 at 2:52 PM, Dave Swarthout  wrote:
> The tracing for that pond ( https://www.openstreetmap.org/way/532622119) is
> horrible IMO. This is the sort of geometry that drives me crazy when I look
> at Alaskan coastlines. The long zig-zag at the top edge could be better done
> with a few points and the adjoining ponds at the SE are very rough
> approximations at best. I don't know what method you used to draw that pond
> but please don't add any more that look like that one.
>
> I have done extensive work in Alaska and I appreciate your intent to add
> more Alaskan water bodies to OSM but please find another way to add them.
> There are thousands of tiny ponds dotting the permafrost in northern Alaska.
> Using your tracing technique will add hundreds of thousands of points, many
> of them useless.
>
> Dave
> (AlaskaDave)
>
> On Tue, Oct 17, 2017 at 8:01 AM, ANT Berezhnyi 
> wrote:
>>
>> (sorry for my english)
>>
>> question:
>>
>> On 2017-10-16 02:33:13 UTC velmyshanovnyi
>>
>> http://www.hdyc.neis-one.org/?velmyshanovnyi
>>
>> wrote:
>>
>> ===
>>
>> so on the question ...
>>
>> Is it possible to vectorize the USGS on the OSM if there is no Landsat,
>> and everything else in the clouds, or in the snow, or the quality is bad ...
>>
>> Hello velmyshanovnyi , There are a number of questions here. One is "is it
>> possible to vectorize the USGS". Another is "is it a good idea to do so".
>>
>> I'd suggest that you discuss what is the best source of imagery in this
>> region with other mappers, such as "imagico" who commented on
>> https://www.openstreetmap.org/changeset/52947504 . It may be that you need
>> to use several sources and combine them manually because none of them are
>> perfect. Also I would suggest asking on the talk-us and talk-ca mailing
>> lists for advice.
>>
>> With regard to "is this a good idea" other mappers think it is not. You
>> need to persuade them that it is. You need to explain what your process is.
>> Your comment on https://www.openstreetmap.org/changeset/52947504 that says
>> "Im fixed my soft" suggests that you might be performing some kind of
>> mechanical edit. If so, you need to follow
>> https://wiki.openstreetmap.org/wiki/Mechanical_Edit_Policy , which requires
>> you to discuss what you are proposing to do with other mappers before
>> actually doing it.
>>
>> Best Regards,
>>
>> Andy Townsend, on behalf of OSM's Data Working Group.
>> https://www.openstreetmap.org/user/SomeoneElse
>>
>> 
>> My sample island/hydrology (JOSM+digitalglobe-premium+bing) not import,
>> not bot :
>>
>> https://mc.bbbike.org/mc/?lon=-164.973165=60.843461=13=2=digitalglobe-premium=mapnik=hike_bike=ol_osm-no-labels=35
>>
>> after simplifacation (v2) :
>>
>> https://www.openstreetmap.org/changeset/52809320#map=16/60.8221/-164.9684=H
>> (before see v1)
>> 
>>
>> IF:
>> if there is a need to correct some hydrology somewhere - welcome 
>>
>>
>> --
>> ++ =
>> ++ ANT (Anton Berezhnyi)
>> ++ =
>> ++ E-mail   : velmyshanov...@gmail.com
>> ++ Hangouts : velmyshanov...@gmail.com
>> ++ Telegram : @velmyshanovnyi
>> ++ Skype: velmyshanovnyi
>> ++ Viber: +380939946993
>> ++ Cell : +380939946993
>> ++ https://plus.google.com/+ANTBerezhnyi
>> ++ https://profiles.google.com/velmyshanovnyi
>> ++ https://linkedin.com/in/velmyshanovnyi
>> ++ https://facebook.com/velmyshanovnyi
>> ++ https://twitter.com/velmyshanovnyi
>> ++ =
>> ++ жNtTя, яК і iTNernЕТ,
>> ++ нAЖалb, ТЕж к0лИСь
>> ++ KіH4аЄтьCя..
>> ++ =
>>
>>
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>> 

Re: [Talk-us] hydrology Alaska

[Dave Swarthout]

The tracing for that pond ( https://www.openstreetmap.org/way/532622119) is
horrible IMO. This is the sort of geometry that drives me crazy when I look
at Alaskan coastlines. The long zig-zag at the top edge could be better
done with a few points and the adjoining ponds at the SE are very rough
approximations at best. I don't know what method you used to draw that pond
but please don't add any more that look like that one.

I have done extensive work in Alaska and I appreciate your intent to add
more Alaskan water bodies to OSM but please find another way to add them.
There are thousands of tiny ponds dotting the permafrost in northern
Alaska. Using your tracing technique will add hundreds of thousands of
points, many of them useless.

Dave
(AlaskaDave)

On Tue, Oct 17, 2017 at 8:01 AM, ANT Berezhnyi 
wrote:

> (sorry for my english)
>
> question:
>
> On 2017-10-16 02:33:13 UTC velmyshanovnyi
>
> http://www.hdyc.neis-one.org/?velmyshanovnyi
>
> wrote:
>
> ===
>
> so on the question ...
>
> Is it possible to vectorize the USGS on the OSM if there is no Landsat,
> and everything else in the clouds, or in the snow, or the quality is bad ...
>
> Hello velmyshanovnyi , There are a number of questions here. One is "is it
> possible to vectorize the USGS". Another is "is it a good idea to do so".
>
> I'd suggest that you discuss what is the best source of imagery in this
> region with other mappers, such as "imagico" who commented on
> https://www.openstreetmap.org/changeset/52947504 . It may be that you
> need to use several sources and combine them manually because none of them
> are perfect. Also I would suggest asking on the talk-us and talk-ca mailing
> lists for advice.
>
> With regard to "is this a good idea" other mappers think it is not. You
> need to persuade them that it is. You need to explain what your process is.
> Your comment on https://www.openstreetmap.org/changeset/52947504 that
> says "Im fixed my soft" suggests that you might be performing some kind of
> mechanical edit. If so, you need to follow https://wiki.
> openstreetmap.org/wiki/Mechanical_Edit_Policy , which requires you to
> discuss what you are proposing to do with other mappers before actually
> doing it.
>
> Best Regards,
>
> Andy Townsend, on behalf of OSM's Data Working Group.
> https://www.openstreetmap.org/user/SomeoneElse
> 
> My sample island/hydrology (JOSM+digitalglobe-premium+bing) not import,
> not bot :
> https://mc.bbbike.org/mc/?lon=-164.973165=60.843461=13=2=
> digitalglobe-premium=mapnik=hike_bike=ol_
> osm-no-labels=35
>
> after simplifacation (v2) :
> https://www.openstreetmap.org/changeset/52809320#map=16/60.
> 8221/-164.9684=H
> (before see v1)
> 
>
> IF:
> if there is a need to correct some hydrology somewhere - welcome 
>
>
> --
> ++ =
> ++ ANT (Anton Berezhnyi)
> ++ =
> ++ E-mail   : velmyshanov...@gmail.com
> ++ Hangouts : velmyshanov...@gmail.com
> ++ Telegram : @velmyshanovnyi
> ++ Skype: velmyshanovnyi
> ++ Viber: +380939946993 <093%20994%206993>
> ++ Cell : +380939946993 <093%20994%206993>
> ++ https://plus.google.com/+ANTBerezhnyi
> ++ https://profiles.google.com/velmyshanovnyi
> 
> ++ https://linkedin.com/in/velmyshanovnyi
> ++ https://facebook.com/velmyshanovnyi
> 
> ++ https://twitter.com/velmyshanovnyi 
> ++ =
> ++ жNtTя, яК і iTNernЕТ,
> ++ нAЖалb, ТЕж к0лИСь
> ++ KіH4аЄтьCя..
> ++ =
>
>
> ___
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>
>


-- 
Dave Swarthout
Homer, Alaska
Chiang Mai, Thailand
Travel Blog at http://dswarthout.blogspot.com
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Re: [Talk-us] hydrology Alaska

[Christoph Hormann]

On Tuesday 17 October 2017, ANT Berezhnyi wrote:
>
> so on the question ...
>
> Is it possible to vectorize the USGS on the OSM if there is no
> Landsat, and everything else in the clouds, or in the snow, or the
> quality is bad ...

There are no parts of the US where there is no better imagery available 
than the 15 year old Landsat Geocover background image in Bing.  Most 
of Alaska is now covered by high resolution images in at least one of 
the available imagery layers (Bing/Mapbox/DG/ESRI).  And where this is 
not the case or images are unsuitable you will be able to find newer 
Landsat or Sentinel-2 images.  If you have troubles finding a suitable 
image for a specific area just ask - someone will likely be able to 
point you to them.  The Russian community has used open data images for 
quite some time in remote areas of the north.

But no image, no matter how suitable it is for the mapping task at hand, 
absolves you from carefully verifying what you map.  Tracing helper 
tools like scanaerial do not do this for you.

Old USGS maps are useful for names and as hints to interpreting imagery 
but should never be used for tracing geometries - they are just too old 
for that in most cases.

And as Ben Discoe pointed out you need to adjust your methods of tracing 
water areas, Something like https://www.openstreetmap.org/way/532622119 
is just not a good geometry representation (lots of nodes but with 
coordinates rounded to an arbitrary pixel grid is just wasteful).

-- 
Christoph Hormann
http://www.imagico.de/

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[Talk-us] hydrology Alaska

[ANT Berezhnyi]

(sorry for my english)

question:

On 2017-10-16 02:33:13 UTC velmyshanovnyi

http://www.hdyc.neis-one.org/?velmyshanovnyi

wrote:

===

so on the question ...

Is it possible to vectorize the USGS on the OSM if there is no Landsat, and
everything else in the clouds, or in the snow, or the quality is bad ...

Hello velmyshanovnyi , There are a number of questions here. One is "is it
possible to vectorize the USGS". Another is "is it a good idea to do so".

I'd suggest that you discuss what is the best source of imagery in this
region with other mappers, such as "imagico" who commented on
https://www.openstreetmap.org/changeset/52947504 . It may be that you need
to use several sources and combine them manually because none of them are
perfect. Also I would suggest asking on the talk-us and talk-ca mailing
lists for advice.

With regard to "is this a good idea" other mappers think it is not. You
need to persuade them that it is. You need to explain what your process is.
Your comment on https://www.openstreetmap.org/changeset/52947504 that says
"Im fixed my soft" suggests that you might be performing some kind of
mechanical edit. If so, you need to follow
https://wiki.openstreetmap.org/wiki/Mechanical_Edit_Policy , which requires
you to discuss what you are proposing to do with other mappers before
actually doing it.

Best Regards,

Andy Townsend, on behalf of OSM's Data Working Group.
https://www.openstreetmap.org/user/SomeoneElse

My sample island/hydrology (JOSM+digitalglobe-premium+bing) not import, not
bot :
https://mc.bbbike.org/mc/?lon=-164.973165=60.843461=13=2=digitalglobe-premium=mapnik=hike_bike=ol_osm-no-labels=35

after simplifacation (v2) :
https://www.openstreetmap.org/changeset/52809320#map=16/60.8221/-164.9684=H
(before see v1)


IF:
if there is a need to correct some hydrology somewhere - welcome 


-- 
++ =
++ ANT (Anton Berezhnyi)
++ =
++ E-mail   : velmyshanov...@gmail.com
++ Hangouts : velmyshanov...@gmail.com
++ Telegram : @velmyshanovnyi
++ Skype: velmyshanovnyi
++ Viber: +380939946993 <093%20994%206993>
++ Cell : +380939946993 <093%20994%206993>
++ https://plus.google.com/+ANTBerezhnyi
++ https://profiles.google.com/velmyshanovnyi

++ https://linkedin.com/in/velmyshanovnyi
++ https://facebook.com/velmyshanovnyi 
++ https://twitter.com/velmyshanovnyi 
++ =
++ жNtTя, яК і iTNernЕТ,
++ нAЖалb, ТЕж к0лИСь
++ KіH4аЄтьCя..
++ =
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