Re: [Qgis-user] Road Network Extraction out of Raster Images

2019-04-20 Thread Bernd Vogelgesang 

Hi Elvin,

would be nice then to read here one day about your findings.

Cheers,

Bernd

Am 20.04.19 um 18:02 schrieb Elvin Roldan:

Hell again:

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.

I will keep posted on progress. Thanks for the help.

Elvin Roldán

On Apr 18, 2019, at 12:04 PM, Kirk Schmidt mailto:k...@nortekresources.com>> wrote:


Hallo Elvin:

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.

Kirk

On 4/18/2019 12:10 PM, Bernd Vogelgesang wrote:


Hi Elvin,

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?

Cheers,
Bernd

Am 18.04.19 um 15:12 schrieb Elvin Roldan:


Hello:

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.

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.

If anybody can point me in the right direction  I would appreciated.

Thanks.

Elvin Roldán


___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info:https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe:https://lists.osgeo.org/mailman/listinfo/qgis-user


___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info:https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe:https://lists.osgeo.org/mailman/listinfo/qgis-user

--
Kirk Schmidt, MScF, BScF, RPF
General Manager
Nortek Resource Solutions Inc.
RR # 1
Thorburn, NS
B0K 1W0
Tel (902) 922.3607
Email:k...@nortekresources.com
Web:www.nortekresources.com
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org 
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user


___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

Re: [Qgis-user] Road Network Extraction out of Raster Images

2019-04-20 Thread Elvin Roldan 
Hell again:

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. 

I will keep posted on progress. Thanks for the help.

Elvin Roldán

> On Apr 18, 2019, at 12:04 PM, Kirk Schmidt  wrote:
> 
> Hallo Elvin:
> 
> 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.  
> 
> Kirk  
> 
>> On 4/18/2019 12:10 PM, Bernd Vogelgesang wrote:
>> Hi Elvin,
>> 
>> 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?
>> 
>> Cheers,
>> Bernd
>> 
>>> Am 18.04.19 um 15:12 schrieb Elvin Roldan:
>>> Hello:
>>> 
>>>  
>>> 
>>> 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.
>>> 
>>> 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.
>>> 
>>> If anybody can point me in the right direction  I would appreciated.
>>> 
>>> Thanks.
>>> 
>>> Elvin Roldán
>>> 
>>> 
>>> 
>>> ___
>>> Qgis-user mailing list
>>> Qgis-user@lists.osgeo.org
>>> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
>>> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
>> 
>> 
>> ___
>> Qgis-user mailing list
>> Qgis-user@lists.osgeo.org
>> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
>> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
> -- 
> Kirk Schmidt, MScF, BScF, RPF
> General Manager
> Nortek Resource Solutions Inc.
> RR # 1
> Thorburn, NS
> B0K 1W0
> Tel (902) 922.3607
> Email: k...@nortekresources.com
> Web: www.nortekresources.com
> ___
> Qgis-user mailing list
> Qgis-user@lists.osgeo.org
> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

Re: [Qgis-user] Road Network Extraction out of Raster Images

2019-04-18 Thread Kirk Schmidt 

Hallo Elvin:

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.


Kirk

On 4/18/2019 12:10 PM, Bernd Vogelgesang wrote:


Hi Elvin,

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?


Cheers,
Bernd

Am 18.04.19 um 15:12 schrieb Elvin Roldan:


Hello:

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.


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.


If anybody can point me in the right direction  I would appreciated.

Thanks.

Elvin Roldán


___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info:https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe:https://lists.osgeo.org/mailman/listinfo/qgis-user


___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user


--
Kirk Schmidt, MScF, BScF, RPF
General Manager
Nortek Resource Solutions Inc.
RR # 1
Thorburn, NS
B0K 1W0
Tel (902) 922.3607
Email: k...@nortekresources.com
Web: www.nortekresources.com

___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

Re: [Qgis-user] Road Network Extraction out of Raster Images

2019-04-18 Thread Bernd Vogelgesang 

Hi Elvin,

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?

Cheers,
Bernd

Am 18.04.19 um 15:12 schrieb Elvin Roldan:


Hello:

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.

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.

If anybody can point me in the right direction  I would appreciated.

Thanks.

Elvin Roldán


___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

[Qgis-user] Road Network Extraction out of Raster Images

2019-04-18 Thread Elvin Roldan 
Hello:

 

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.

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.

If anybody can point me in the right direction  I would appreciated. 

Thanks.

Elvin Roldán

___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user