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<p>Hi Elvin,</p>
<p>would be nice then to read here one day about your findings.</p>
<p>Cheers,</p>
<p>Bernd<br>
</p>
<div class="moz-cite-prefix">Am 20.04.19 um 18:02 schrieb Elvin
Roldan:<br>
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cite="mid:C6E3C386-606D-4D36-8611-00DE3B3AE958@gmail.com">
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Hell again:
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<div>Thanks for the help I followed youre recommendations and use
base layer for openstreet map and edited for my needs. None the
less I will keep trying to develop this in spatial analysis due
that Im working with drone collected data and a lot of areas
(whole municipalities) to develop infrastructure maps. </div>
<div><br>
</div>
<div>I will keep posted on progress. Thanks for the help.</div>
<div><br>
<div id="AppleMailSignature" dir="ltr">
<div style="direction: inherit;">Elvin Roldán</div>
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<div dir="ltr"><br>
On Apr 18, 2019, at 12:04 PM, Kirk Schmidt <<a
href="mailto:kirk@nortekresources.com"
moz-do-not-send="true">kirk@nortekresources.com</a>>
wrote:<br>
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<p>Hallo Elvin:</p>
<p>This would be a bit tricky as roads are not created
equal. A paved road and associate paint is very different
from a cobblestone or gravel road. Add shadows from
trees, buildings and rock cuts and the complexity
increases. If you used a supervised classification you
would end up with clusters of pixel polygons or pixel
points that would not be very consistent. The level of
work required to edit and simplify these would be very
time consuming. It is for these reasons that original
line features such as roads where digitized as simple
vectors. As bernd suggest below, existing vector data is
available for most areas and it is simply a matter of
locating and accessing these sources. <br>
</p>
<p>Kirk <br>
</p>
<div class="moz-cite-prefix">On 4/18/2019 12:10 PM, Bernd
Vogelgesang wrote:<br>
</div>
<blockquote type="cite"
cite="mid:93ed973c-3136-28bf-aa4f-0229284e3c3d@gmx.de">
<p>Hi Elvin,</p>
<p>I do not know of any trick how to extract a road
network from images besides a trained image
classification model. But may the question be allowed
why you can't just use the OpenStreetMap data directly?</p>
<p>Cheers,<br>
Bernd<br>
</p>
<div class="moz-cite-prefix">Am 18.04.19 um 15:12 schrieb
Elvin Roldan:<br>
</div>
<blockquote type="cite"
cite="mid:000e01d4f5e8$563cccf0$02b666d0$@gmail.com">
<meta name="Generator" content="Microsoft Word 15
(filtered medium)">
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<p class="MsoNormal">Hello:</p>
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<p class="MsoNormal"> </p>
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<div>
<p class="MsoNormal">I’m writing because I’ve been a
long time user QGIS and really appreciate all the
work that has been put to it and all the
initiatives to continue to evolve and maintain it
as an important open source GIS system.</p>
<p class="MsoNormal">My question is aim does anybody
know how to extract a road network using spatial
analysis tools within QGIS. I want to extract all
roads from aerial images to convert to vectors
(polylines or polygons) to do various analysis
involving the existing road network.</p>
<p class="MsoNormal">If anybody can point me in the
right direction I would appreciated. </p>
<p class="MsoNormal">Thanks.</p>
<div id="AppleMailSignature">
<div>
<p class="MsoNormal">Elvin Roldán</p>
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<pre class="moz-signature" cols="72">--
Kirk Schmidt, MScF, BScF, RPF
General Manager
Nortek Resource Solutions Inc.
RR # 1
Thorburn, NS
B0K 1W0
Tel (902) 922.3607
Email: <a class="moz-txt-link-abbreviated" href="mailto:kirk@nortekresources.com" moz-do-not-send="true">kirk@nortekresources.com</a>
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