[Qgis-user] Raster analysis , Proximity (raster distance)

[Richard McDonnell]

Dimitris,
Thanks for the update, great to hear you got sorted.
Regards,

Richard

From: Dimitris sal <jimmaras123 at gmail.com>
Sent: 02 August 2019 12:24
To: Richard McDonnell <richard.mcdonnell at opw.ie>
Cc: qgis-user at lists.osgeo.org
Subject: Re: [Qgis-user] Raster analysis , Proximity (raster distance)

Hello

Thanks for your help, i found a different way. I used the GRASS tool r.grow.distance with the geodesic  metric and I got the desired result.

Regards
Dimitris

Στις Πέμ, 1 Αυγ 2019 στις 4:17 μ.μ., ο/η Richard McDonnell <richard.mcdonnell at opw.ie<mailto:richard.mcdonnell at opw.ie>> έγραψε:
Hi Dimitris,

Best tool available is GDAL. You can use this from within QGIS, by going to, Processing Toolbox and typing in repro select Warp (reproject), select your Input layer, set your Source CRS and then select the Target CRS.
This should be able to do what you want.
Hope it helps,

Regards,

Richard.


From: Dimitris sal <jimmaras123 at gmail.com<mailto:jimmaras123 at gmail.com>>
Sent: 01 August 2019 13:32
To: Richard McDonnell <richard.mcdonnell at opw.ie<mailto:richard.mcdonnell at opw.ie>>
Cc: qgis-user at lists.osgeo.org<mailto:qgis-user at lists.osgeo.org>
Subject: Re: [Qgis-user] Raster analysis , Proximity (raster distance)

I tried to change the CRS to a meter one , i create a new distance analysis with it and when i try to convert it back to EPSG 4326 the data in the raster was destroyed.

Richard my image is at 700x700 at specific coordinates in degrees. Is there any tool i can use to convert the data from my raster from degrees to meters?

Στις Πέμ, 1 Αυγ 2019 στις 2:41 μ.μ., ο/η Richard McDonnell <richard.mcdonnell at opw.ie<mailto:richard.mcdonnell at opw.ie>> έγραψε:
Hi Dimitris,
Welcome!!

To answer your question, use the Georeferenced coordinates and run, the distances will be based on the resolution of your image, so 5m resolution will result in a proximity raster of 5m intervals.
You might want to set the Maximum distance, as this will help to minimise processing and Image size.
Reagrds,

Richard.


From: Qgis-user <qgis-user-bounces at lists.osgeo.org<mailto:qgis-user-bounces at lists.osgeo.org>> On Behalf Of Dimitris sal
Sent: 01 August 2019 12:13
To: qgis-user at lists.osgeo.org<mailto:qgis-user at lists.osgeo.org>
Subject: [Qgis-user] Raster analysis , Proximity (raster distance)

Hello to all ,

This is my first message here. I am trying to create a proximity map with the Raster analysis tool. My problem is that I only get two options for distance units , pixels coordinates and georeferenced coordinates while I want to get them in meters.

I also used the grass tool , r.grow.distance that provides in advanced parameters the option "Output distances in meters instead of map units" If i check this option i get the following error ERROR: Raster map or group not found.

Does any of you know any workaround for this?

I am using QGiS 3.8.1 with GRASS 7.6.1

Kind regards
Dimitris


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