date:20211001

Hi,

I agree with going the python road. I would normally go with a geopandas as I 
am not tto good with the QGIS API. 

 I am basically trying  to figure out if I am missing an obvious existing tool. 
I looked at the multiple input.  It  could work with multiple layers that are 
already opened but my initial idea is to do this from the geopackage so layers 
are not yet opened.  

Thanks for the input

Nicolas Cadieux
https://gitlab.com/njacadieux

> Le 1 oct. 2021 à 18:44, Charles Dixon-Paver  a écrit :
> 
> 
> I think this would be rather challenging to achieve with the graphical 
> modeler with the current toolset and would be much more readily developed in 
> a pyqgis script.
> 
> Whilst it may be possible (although I'm not entirely sure how), the model 
> builder tools support for iterators and conditionals can be a bit hit or 
> miss. Using a python script that is integrated into the model might help 
> provide the interface you are looking for.
> 
> If you are intent on trying to dig deeper into the modeler, a couple notes 
> would be to use the "multiple inputs", and check out the "conditional branch" 
> and "filter by geometry" tools.
> 
> Hope that helps.
> 
> Regards
> 
>> On Fri, 1 Oct 2021 at 23:39, Nicolas Cadieux  
>> wrote:
>> Hi,
>> 
>> I must be missing the obvious but how can I load a particular layer (or 
>> all layers) from a Geopackage using the graphical modeler? The idea I 
>> want to implement is :1) load geopackage from file -> 2)filter all 
>> layers by geometry type -> 3)save point, line and polygon layers.  I 
>> can't find how to get a handle on the layers between 1 and 2.
>> 
>> Nicolas
>> 
>> -- 
>> Nicolas Cadieux
>> https://gitlab.com/njacadieux
>> 
>> ___
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[Qgis-user] Join Attributes by Location

2021-10-01 Thread Andrea Giudiceandrea


Hi krishna Ayyala,
what QGIS version are you using?
What you mean with "Exported the joined layer"?
Does the temporary layer "Joined layer" contain any features?

With the options visible in the screenshot, the "Join attributes by 
location" algorithn should create a temporary layer with 100 points, not 98.


Anyway, maybe it might be useful if you shared your layers (if 
necessary, with a subset or your features) so it could be possible to 
investigate the issue.


Best regards.

Andrea


krishna Ayyala Fri, 01 Oct 2021 10:51:18 -0700





I have used "Join  attributes location" tool on the same layers. Exported
the joined layer. I see zero records in the Joined layer. Technically there
should be 98 records. Can someone help me fix this please?


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[Qgis-user] Couldn't load SIP module - Windows 10

2021-10-01 Thread Fred Perloff



 
 
  
   
Hi,

   
   

   
   
After a fresh install of OSGeo4W network installer, I start QGISD Desktop.  A python error box pops up with the error copied below. I close the error window and the program loads. However, if I click on plugins settings, I receive the error: No Python support detected.

   
   

   
   
I suspect I know the source of the problem. I have installed Python from Anaconda. Anaconda uses an older version of Python and of qt. I modified C:\OSGeo4W\etc\ini\python3.bat by prepending %OSGEO4W_ROOT%\apps\Python39;%OSGEO4W_ROOT%\apps\Python39\Lib;%OSGEO4W_ROOT%\apps\Python39\Lib\site-packages; to PYTHONPATH. There's a curious mix of / and escaped \\ in the resulting path.

   
   

   
   
How do I enable loading python __init__.py when the desktop starts?

   
   
Thanks!

   
   

   
   
Error window:

   
   

   
   
Couldn't load SIP module.
Python support will be disabled.
   
   
Traceback (most recent call last):
File "", line 1, in 
File "C:\OSGeo4W/apps/qgis/./python\qgis\__init__.py", line 82, in 
from qgis.PyQt import QtCore
File "C:\OSGeo4W/apps/qgis/./python\qgis\PyQt\QtCore.py", line 24, in 
from PyQt5.QtCore import *
ImportError: DLL load failed while importing QtCore: The specified procedure could not be found.
   
   
Python version:
3.9.5 (tags/v3.9.5:0a7dcbd, May 3 2021, 17:27:52) [MSC v.1928 64 bit (AMD64)]
   
   
QGIS version:
3.20.3-Odense 'Odense', 495fbaec
   
   
Python path:
['C:/OSGeo4W/apps/qgis/./python', 'C:/Users/Fred/AppData/Roaming/QGIS/QGIS3\\profiles\\default/python', 'C:/Users/Fred/AppData/Roaming/QGIS/QGIS3\\profiles\\default/python/plugins', 'C:/OSGeo4W/apps/qgis/./python/plugins', 'C:\\ProgramData\\Anaconda3', 'C:\\ProgramData\\Anaconda3\\DLLs', 'C:\\ProgramData\\Anaconda3\\lib', 'C:\\ProgramData\\Anaconda3\\lib\\site-packages', 'C:\\ProgramData\\Anaconda3\\lib\\site-packages\\win32', 'C:\\ProgramData\\Anaconda3\\lib\\site-packages\\win32\\lib', 'C:\\ProgramData\\Anaconda3\\lib\\site-packages\\Pythonwin', 'C:\\Users\\Fred\\Documents', 'C:\\OSGeo4W\\bin\\python39.zip', 'C:\\OSGeo4W\\apps\\Python39\\DLLs', 'C:\\OSGeo4W\\apps\\Python39\\lib', 'C:\\OSGeo4W\\bin', 'C:\\OSGeo4W\\apps\\Python39', 'C:\\OSGeo4W\\apps\\Python39\\lib\\site-packages', 'C:\\OSGeo4W\\apps\\Python39\\lib\\site-packages\\win32', 'C:\\OSGeo4W\\apps\\Python39\\lib\\site-packages\\win32\\lib', 'C:\\OSGeo4W\\apps\\Python39\\lib\\site-packages\\Pythonwin']
OS version: Windows 10 Version 2009
QGIS version: 3.20.3-Odense 495fbaec
Qt version: 5.15.2
Python version: 3.9.5
   
   
Windows 10 Pro

   
  
  
   

   
   
Fred Perloff
   
   
f...@perloff.us
   
  
 

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Re: [Qgis-user] Loading geopackage layers in a model

I think this would be rather challenging to achieve with the graphical
modeler with the current toolset and would be much more readily developed
in a pyqgis script.

Whilst it may be possible (although I'm not entirely sure how), the model
builder tools support for iterators and conditionals can be a bit hit or
miss. Using a python script that is integrated into the model might help
provide the interface you are looking for.

If you are intent on trying to dig deeper into the modeler, a couple notes
would be to use the "multiple inputs", and check out the "conditional
branch" and "filter by geometry" tools.

Hope that helps.

Regards

On Fri, 1 Oct 2021 at 23:39, Nicolas Cadieux 
wrote:

> Hi,
>
> I must be missing the obvious but how can I load a particular layer (or
> all layers) from a Geopackage using the graphical modeler? The idea I
> want to implement is :1) load geopackage from file -> 2)filter all
> layers by geometry type -> 3)save point, line and polygon layers.  I
> can't find how to get a handle on the layers between 1 and 2.
>
> Nicolas
>
> --
> Nicolas Cadieux
> https://gitlab.com/njacadieux
>
> ___
> Qgis-user mailing list
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> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
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[Qgis-user] Loading geopackage layers in a model


Hi,

I must be missing the obvious but how can I load a particular layer (or 
all layers) from a Geopackage using the graphical modeler? The idea I 
want to implement is :1) load geopackage from file -> 2)filter all 
layers by geometry type -> 3)save point, line and polygon layers.  I 
can't find how to get a handle on the layers between 1 and 2.


Nicolas

--
Nicolas Cadieux
https://gitlab.com/njacadieux

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Re: [Qgis-user] Geo Raster Background


I use PDF as well, there you can not save a background-color or
something like that.

This should be better an option in QGIS to "set the colors of the black
recangles" ;-)

thanks all.


Am 01.10.2021 um 23:19 schrieb Nicolas Cadieux:


Hi,

It's quite simple, you just need to set the nodata value (what you
call the background-color) in the original file and then save it.  The
complication is that this requires that the datatype for the file
accepts the no data value. This part is harder to figure out for your
not used to dealing with datatypes.   Perhaps, what should be asked
for is a check to see if the nodata in the translate tool check in 
compatibility with the datatype format. Another possibility is to
allow for setting the nodata value (other than zero) in the
Georeferencer tool (for both the input file and the output file).

Nicolas

On 2021-10-01 4:04 p.m., L.W. wrote:


sounds like rocketscience ... for a simple task to set the
background-color ...

may be I am searching the web where I have to place my feature
request for this ...


Am 01.10.2021 um 21:39 schrieb Nicolas Cadieux:


Hi,

Start by setting the nodata value in the input raster.
(raster/conversion/translate/Assign a specific nodata value to
output bands).  Make sure you select a data type that allows your
nodata value.  For example, if you select Byte - Eight bit unsigned
integer, and a no data value of *-999*, -999 does not exist in that
data type so the nodata values will be 0 therefore affecting all
black pixels in the image.  Select something like int16 of
float32... and a no data value of -999 for the test.  Load the new
raster and in the layer properties, make sure you have been
successful changing the nodata values.

Then, when georeferencing, make sure you *DO NOT select "Use 0 for
transparency when needed".*  The nodata from the georefrenced file
will be taken from the original file (-999).  Therefore, pixels with
the value 0 in the image will not be affected.

Nicolas


On 2021-10-01 2:33 p.m., L.W. wrote:


Hi,

nope this isn't what I want ... it is the same as setting
transparent color manually.

I am using PDF and TIF for georeferencing.

Regards

Without no-data-0 or transparent-color:

Set transparent-color to 0,0,0 or use no-data-0:


Am 01.10.2021 um 19:26 schrieb Charles Dixon-Paver:

I just loaded an unreferenced png with black content into qgis,
then set the nodata value to 9, then did a fake georeference
with arbitrary coordinates, and the result seemed to be rotated
without any background pixels. Using 3.20 on Windows. The
geoereferencer has a checkbox for setting nodata to 0, so uncheck
that first. Otherwise, if you're still unable to get the
"triangles" to change, my previous messages should still apply.

On Fri, 1 Oct 2021 at 18:27, L.W. mailto:eagl...@gmx.de>> wrote:

yes, maybe to orange, a color that is not in the original
image, so I can do this color transparent.


Am 01.10.2021 um 18:25 schrieb David Strip:

When georeferencing, aren't the areas outside the original
image, eg, the "triangles" resulting from rotation, treated
as no data? Wouldn't this issue be resolved by setting the no
data value to something other than black?
Just guessing here, obviously.


On 10/1/2021 2:36 AM, L.W. wrote:


Thanks for answering, but I think this is not the way I want
to go ...

Or, I do not have written detailed.

I have a raster image e.g. a white rectangle, after setting
the points, QGIS rotats this image, let's say, by 45 degrees.

The corners of the imported image are now black triangles.

I do want to have e.g. red triangles ...

Regards


Am 01.10.2021 um 09:50 schrieb Charles Dixon-Paver:

There's not really any way for a GIS system to
automatically differentiate between black background pixels
and black data pixels. QGIS supports users setting custom
pixel values to render as transparent pixels, but it's left
up to users to ensure that their data and background values
are different.

From my view, there are a couple of options when it comes
to fixing this issue in your data. One is to use an image
processing tool like GIMP or Photoshop effectively, but
that requires retaining the geographic information and
knowing how to reprocess the raster accordingly.

The simplest solution I'm aware of is probably to follow
this workflow in QGIS:

  * Start a new QGIS project
  * Set all black pixels to transparent in the transparency
tab of the raster layer properties
  * Digitize a "bounding area" - you can do this with a
memory layer
  * Move your vector layer to render underneath the raster
  * Give the vector a simple black symbology
  * Use the "Convert map to raster" tool from the
processing toolbox

There are a wide number of variations on that workflow that
are possible of course, but I think that's the easiest to
get

Re: [Qgis-user] Geo Raster Background

2021-10-01 Thread Gabriel De Luca

 Hi, I usually do a brief adjustment on pixel values prior to
georeferencing, to make sure that no pixel has the value I need to assign
to nodata.

Depending on the source dataset, I usually try to replace the zeros with
ones, and reserve the zero for nodata.

El vie, 1 de oct. de 2021 a la(s) 15:34, L.W. (eagl...@gmx.de) escribió:

> Hi,
>
> nope this isn't what I want ... it is the same as setting transparent
> color manually.
>
> I am using PDF and TIF for georeferencing.
>
> Regards
>
> Without no-data-0 or transparent-color:
>
> Set transparent-color to 0,0,0 or use no-data-0:
>
>
> Am 01.10.2021 um 19:26 schrieb Charles Dixon-Paver:
>
> I just loaded an unreferenced png with black content into qgis, then set
> the nodata value to 9, then did a fake georeference with arbitrary
> coordinates, and the result seemed to be rotated without any background
> pixels. Using 3.20 on Windows. The geoereferencer has a checkbox for
> setting nodata to 0, so uncheck that first. Otherwise, if you're still
> unable to get the "triangles" to change, my previous messages should still
> apply.
>
> On Fri, 1 Oct 2021 at 18:27, L.W.  wrote:
>
>> yes, maybe to orange, a color that is not in the original image, so I can
>> do this color transparent.
>>
>>
>> Am 01.10.2021 um 18:25 schrieb David Strip:
>>
>> When georeferencing, aren't the areas outside the original image, eg, the
>> "triangles" resulting from rotation, treated as no data? Wouldn't this
>> issue be resolved by setting the no data value to something other than
>> black?
>> Just guessing here, obviously.
>>
>>
>> On 10/1/2021 2:36 AM, L.W. wrote:
>>
>> Thanks for answering, but I think this is not the way I want to go ...
>>
>> Or, I do not have written detailed.
>>
>> I have a raster image e.g. a white rectangle, after setting the points,
>> QGIS rotats this image, let's say, by 45 degrees.
>>
>> The corners of the imported image are now black triangles.
>>
>> I do want to have e.g. red triangles ...
>>
>> Regards
>>
>>
>> Am 01.10.2021 um 09:50 schrieb Charles Dixon-Paver:
>>
>> There's not really any way for a GIS system to automatically
>> differentiate between black background pixels and black data pixels. QGIS
>> supports users setting custom pixel values to render as transparent pixels,
>> but it's left up to users to ensure that their data and background values
>> are different.
>>
>> From my view, there are a couple of options when it comes to fixing this
>> issue in your data. One is to use an image processing tool like GIMP or
>> Photoshop effectively, but that requires retaining the geographic
>> information and knowing how to reprocess the raster accordingly.
>>
>> The simplest solution I'm aware of is probably to follow this workflow in
>> QGIS:
>>
>>- Start a new QGIS project
>>- Set all black pixels to transparent in the transparency tab of the
>>raster layer properties
>>- Digitize a "bounding area" - you can do this with a memory layer
>>- Move your vector layer to render underneath the raster
>>- Give the vector a simple black symbology
>>- Use the "Convert map to raster" tool from the processing toolbox
>>
>> There are a wide number of variations on that workflow that are possible
>> of course, but I think that's the easiest to get started.
>>
>>
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Re: [Qgis-user] Geo Raster Background


Hi,

It's quite simple, you just need to set the nodata value (what you call 
the background-color) in the original file and then save it.  The 
complication is that this requires that the datatype for the file 
accepts the no data value. This part is harder to figure out for your 
not used to dealing with datatypes.   Perhaps, what should be asked for 
is a check to see if the nodata in the translate tool check in  
compatibility with the datatype format. Another possibility is to allow 
for setting the nodata value (other than zero) in the Georeferencer tool 
(for both the input file and the output file).


Nicolas

On 2021-10-01 4:04 p.m., L.W. wrote:


sounds like rocketscience ... for a simple task to set the 
background-color ...


may be I am searching the web where I have to place my feature request 
for this ...



Am 01.10.2021 um 21:39 schrieb Nicolas Cadieux:


Hi,

Start by setting the nodata value in the input raster. 
(raster/conversion/translate/Assign a specific nodata value to output 
bands).  Make sure you select a data type that allows your nodata 
value.  For example, if you select Byte - Eight bit unsigned integer, 
and a no data value of *-999*, -999 does not exist in that data type 
so the nodata values will be 0 therefore affecting all black pixels 
in the image.  Select something like int16 of float32... and a no 
data value of -999 for the test.  Load the new raster and in the 
layer properties, make sure you have been successful changing the 
nodata values.


Then, when georeferencing, make sure you *DO NOT select "Use 0 for 
transparency when needed".*  The nodata from the georefrenced file 
will be taken from the original file (-999).  Therefore, pixels with 
the value 0 in the image will not be affected.


Nicolas


On 2021-10-01 2:33 p.m., L.W. wrote:


Hi,

nope this isn't what I want ... it is the same as setting 
transparent color manually.


I am using PDF and TIF for georeferencing.

Regards

Without no-data-0 or transparent-color:

Set transparent-color to 0,0,0 or use no-data-0:


Am 01.10.2021 um 19:26 schrieb Charles Dixon-Paver:
I just loaded an unreferenced png with black content into qgis, 
then set the nodata value to 9, then did a fake georeference 
with arbitrary coordinates, and the result seemed to be rotated 
without any background pixels. Using 3.20 on Windows. The 
geoereferencer has a checkbox for setting nodata to 0, so uncheck 
that first. Otherwise, if you're still unable to get the 
"triangles" to change, my previous messages should still apply.


On Fri, 1 Oct 2021 at 18:27, L.W. > wrote:


yes, maybe to orange, a color that is not in the original
image, so I can do this color transparent.


Am 01.10.2021 um 18:25 schrieb David Strip:

When georeferencing, aren't the areas outside the original
image, eg, the "triangles" resulting from rotation, treated as
no data? Wouldn't this issue be resolved by setting the no
data value to something other than black?
Just guessing here, obviously.


On 10/1/2021 2:36 AM, L.W. wrote:


Thanks for answering, but I think this is not the way I want
to go ...

Or, I do not have written detailed.

I have a raster image e.g. a white rectangle, after setting
the points, QGIS rotats this image, let's say, by 45 degrees.

The corners of the imported image are now black triangles.

I do want to have e.g. red triangles ...

Regards


Am 01.10.2021 um 09:50 schrieb Charles Dixon-Paver:

There's not really any way for a GIS system to automatically
differentiate between black background pixels and black data
pixels. QGIS supports users setting custom pixel values to
render as transparent pixels, but it's left up to users to
ensure that their data and background values are different.

From my view, there are a couple of options when it comes to
fixing this issue in your data. One is to use an image
processing tool like GIMP or Photoshop effectively, but that
requires retaining the geographic information and knowing
how to reprocess the raster accordingly.

The simplest solution I'm aware of is probably to follow
this workflow in QGIS:

  * Start a new QGIS project
  * Set all black pixels to transparent in the transparency
tab of the raster layer properties
  * Digitize a "bounding area" - you can do this with a
memory layer
  * Move your vector layer to render underneath the raster
  * Give the vector a simple black symbology
  * Use the "Convert map to raster" tool from the processing
toolbox

There are a wide number of variations on that workflow that
are possible of course, but I think that's the easiest to
get started.




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Re: [Qgis-user] Join Attributes by Location

In that case I think it'll be difficult to troubleshoot without data that
replicates the issue (even if it's fake data). Have you tried the different
cardinality settings available (the "Join Type") to see if something in the
data structure, values, or tool configuration is causing the mismatch
between records?

On Fri, 1 Oct 2021 at 22:00, krishna Ayyala  wrote:

> Yah. It should create temporary layer with 100 points.. The temporary
> layer  "Joined layer" also does not have any features in it. Unfortunately
> I cannot share the data .
>
> Regards.
>
> On Fri, Oct 1, 2021 at 1:40 PM Andrea Giudiceandrea 
> wrote:
>
>> Hi krishna Ayyala,
>> what QGIS version are you using?
>> What you mean with "Exported the joined layer"?
>> Does the temporary layer "Joined layer" contain any features?
>>
>> With the options visible in the screenshot, the "Join attributes by
>> location" algorithn should create a temporary layer with 100 points, not
>> 98.
>>
>> Anyway, maybe it might be useful if you shared your layers (if
>> necessary, with a subset or your features) so it could be possible to
>> investigate the issue.
>>
>> Best regards.
>>
>> Andrea
>>
>>
>> krishna Ayyala Fri, 01 Oct 2021 10:51:18 -0700
>> >
>>
>> > I have used "Join  attributes location" tool on the same layers.
>> Exported
>> > the joined layer. I see zero records in the Joined layer. Technically
>> there
>> > should be 98 records. Can someone help me fix this please?
>>
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Re: [Qgis-user] Geo Raster Background


sounds like rocketscience ... for a simple task to set the
background-color ...

may be I am searching the web where I have to place my feature request
for this ...


Am 01.10.2021 um 21:39 schrieb Nicolas Cadieux:


Hi,

Start by setting the nodata value in the input raster.
(raster/conversion/translate/Assign a specific nodata value to output
bands).  Make sure you select a data type that allows your nodata
value.  For example, if you select Byte - Eight bit unsigned integer,
and a no data value of *-999*, -999 does not exist in that data type
so the nodata values will be 0 therefore affecting all black pixels in
the image. Select something like int16 of float32... and a no data
value of -999 for the test.  Load the new raster and in the layer
properties, make sure you have been successful changing the nodata values.

Then, when georeferencing, make sure you *DO NOT select "Use 0 for
transparency when needed".* The nodata from the georefrenced file will
be taken from the original file (-999).  Therefore, pixels with the
value 0 in the image will not be affected.

Nicolas


On 2021-10-01 2:33 p.m., L.W. wrote:


Hi,

nope this isn't what I want ... it is the same as setting transparent
color manually.

I am using PDF and TIF for georeferencing.

Regards

Without no-data-0 or transparent-color:

Set transparent-color to 0,0,0 or use no-data-0:


Am 01.10.2021 um 19:26 schrieb Charles Dixon-Paver:

I just loaded an unreferenced png with black content into qgis, then
set the nodata value to 9, then did a fake georeference with
arbitrary coordinates, and the result seemed to be rotated without
any background pixels. Using 3.20 on Windows. The geoereferencer has
a checkbox for setting nodata to 0, so uncheck that first.
Otherwise, if you're still unable to get the "triangles" to change,
my previous messages should still apply.

On Fri, 1 Oct 2021 at 18:27, L.W. mailto:eagl...@gmx.de>> wrote:

yes, maybe to orange, a color that is not in the original image,
so I can do this color transparent.


Am 01.10.2021 um 18:25 schrieb David Strip:

When georeferencing, aren't the areas outside the original
image, eg, the "triangles" resulting from rotation, treated as
no data? Wouldn't this issue be resolved by setting the no data
value to something other than black?
Just guessing here, obviously.


On 10/1/2021 2:36 AM, L.W. wrote:


Thanks for answering, but I think this is not the way I want
to go ...

Or, I do not have written detailed.

I have a raster image e.g. a white rectangle, after setting
the points, QGIS rotats this image, let's say, by 45 degrees.

The corners of the imported image are now black triangles.

I do want to have e.g. red triangles ...

Regards


Am 01.10.2021 um 09:50 schrieb Charles Dixon-Paver:

There's not really any way for a GIS system to automatically
differentiate between black background pixels and black data
pixels. QGIS supports users setting custom pixel values to
render as transparent pixels, but it's left up to users to
ensure that their data and background values are different.

From my view, there are a couple of options when it comes to
fixing this issue in your data. One is to use an image
processing tool like GIMP or Photoshop effectively, but that
requires retaining the geographic information and knowing how
to reprocess the raster accordingly.

The simplest solution I'm aware of is probably to follow this
workflow in QGIS:

  * Start a new QGIS project
  * Set all black pixels to transparent in the transparency
tab of the raster layer properties
  * Digitize a "bounding area" - you can do this with a
memory layer
  * Move your vector layer to render underneath the raster
  * Give the vector a simple black symbology
  * Use the "Convert map to raster" tool from the processing
toolbox

There are a wide number of variations on that workflow that
are possible of course, but I think that's the easiest to get
started.




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Re: [Qgis-user] Join Attributes by Location

2021-10-01 Thread krishna Ayyala

Yah. It should create temporary layer with 100 points.. The temporary
layer  "Joined layer" also does not have any features in it. Unfortunately
I cannot share the data .

Regards.

On Fri, Oct 1, 2021 at 1:40 PM Andrea Giudiceandrea 
wrote:

> Hi krishna Ayyala,
> what QGIS version are you using?
> What you mean with "Exported the joined layer"?
> Does the temporary layer "Joined layer" contain any features?
>
> With the options visible in the screenshot, the "Join attributes by
> location" algorithn should create a temporary layer with 100 points, not
> 98.
>
> Anyway, maybe it might be useful if you shared your layers (if
> necessary, with a subset or your features) so it could be possible to
> investigate the issue.
>
> Best regards.
>
> Andrea
>
>
> krishna Ayyala Fri, 01 Oct 2021 10:51:18 -0700
> >
>
> > I have used "Join  attributes location" tool on the same layers. Exported
> > the joined layer. I see zero records in the Joined layer. Technically
> there
> > should be 98 records. Can someone help me fix this please?
>
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Re: [Qgis-user] Geo Raster Background


Hi,

Start by setting the nodata value in the input raster. 
(raster/conversion/translate/Assign a specific nodata value to output 
bands).  Make sure you select a data type that allows your nodata 
value.  For example, if you select Byte - Eight bit unsigned integer, 
and a no data value of *-999*, -999 does not exist in that data type so 
the nodata values will be 0 therefore affecting all black pixels in the 
image.  Select something like int16 of float32... and a no data value of 
-999 for the test.  Load the new raster and in the layer properties, 
make sure you have been successful changing the nodata values.


Then, when georeferencing, make sure you *DO NOT select "Use 0 for 
transparency when needed".*  The nodata from the georefrenced file will 
be taken from the original file (-999). Therefore, pixels with the value 
0 in the image will not be affected.


Nicolas


On 2021-10-01 2:33 p.m., L.W. wrote:


Hi,

nope this isn't what I want ... it is the same as setting transparent 
color manually.


I am using PDF and TIF for georeferencing.

Regards

Without no-data-0 or transparent-color:

Set transparent-color to 0,0,0 or use no-data-0:


Am 01.10.2021 um 19:26 schrieb Charles Dixon-Paver:
I just loaded an unreferenced png with black content into qgis, then 
set the nodata value to 9, then did a fake georeference with 
arbitrary coordinates, and the result seemed to be rotated without 
any background pixels. Using 3.20 on Windows. The geoereferencer has 
a checkbox for setting nodata to 0, so uncheck that first. Otherwise, 
if you're still unable to get the "triangles" to change, my previous 
messages should still apply.


On Fri, 1 Oct 2021 at 18:27, L.W. > wrote:


yes, maybe to orange, a color that is not in the original image,
so I can do this color transparent.


Am 01.10.2021 um 18:25 schrieb David Strip:

When georeferencing, aren't the areas outside the original
image, eg, the "triangles" resulting from rotation, treated as
no data? Wouldn't this issue be resolved by setting the no data
value to something other than black?
Just guessing here, obviously.


On 10/1/2021 2:36 AM, L.W. wrote:


Thanks for answering, but I think this is not the way I want to
go ...

Or, I do not have written detailed.

I have a raster image e.g. a white rectangle, after setting the
points, QGIS rotats this image, let's say, by 45 degrees.

The corners of the imported image are now black triangles.

I do want to have e.g. red triangles ...

Regards


Am 01.10.2021 um 09:50 schrieb Charles Dixon-Paver:

There's not really any way for a GIS system to automatically
differentiate between black background pixels and black data
pixels. QGIS supports users setting custom pixel values to
render as transparent pixels, but it's left up to users to
ensure that their data and background values are different.

From my view, there are a couple of options when it comes to
fixing this issue in your data. One is to use an image
processing tool like GIMP or Photoshop effectively, but that
requires retaining the geographic information and knowing how
to reprocess the raster accordingly.

The simplest solution I'm aware of is probably to follow this
workflow in QGIS:

  * Start a new QGIS project
  * Set all black pixels to transparent in the transparency
tab of the raster layer properties
  * Digitize a "bounding area" - you can do this with a memory
layer
  * Move your vector layer to render underneath the raster
  * Give the vector a simple black symbology
  * Use the "Convert map to raster" tool from the processing
toolbox

There are a wide number of variations on that workflow that
are possible of course, but I think that's the easiest to get
started.




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Re: [QGIS-it-user] ordine elenco plugin

2021-10-01 Thread Andrea Giudiceandrea


Ciao Stefano,
finalmente oggi il problema che impediva di ordinare correttamente nel 
Plugin Manager la lista dei plugin per data dell'ultimo aggiornamento 
(cioè la data di pubblicazione dell'ultima versione disponibile del 
plugin) è stato risolto.


A presto.

Andrea

Andrea Giudiceandrea Mon, 23 Aug 2021 14:12:44 -0700


Il 23/08/2021 11:38, Stefano Campus ha scritto:
come faccio a mettere in ordine di pubblicazione/aggiornamento l'elenco dei
plugin?
cliccando sul pulsante di destra del mouse effettivamente c'è l'opzione
ordina per data di aggiornamento, ma rimangono in ordine alfabetico...


Ciao Stefano,
effettivamente c'è in problema... la funzionalità di ordinamento della lista 
dei plugin per data di aggiornamento, che era stata introdotta l'anno scorso 
[1], attualmente non funziona come dovrebbe.

Ho dato un occhiata e il problema dipende dal fatto che nella lista dei plugin 
scaricata in QGIS da server dei plugin, il campo relativo alla data di 
aggiornamento di ogni plugin è vuoto.

Provo a segnalare il problema affinché venga risolto.


[1] https://github.com/qgis/QGIS/pull/35008



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Re: [Qgis-user] georeferencing and displaying lat long.


Hi Byron,

Start by selecting the CRS for your project that matches your map. 
Project/Properties/CRS.  Then, go to Vector/Research tools/Create Grid.


Voilà!

Nicolas

On 2021-10-01 1:30 p.m., Firstname Lastname wrote:


i have several maps to georeference that have reference grid in 
lat/long.  can someone please tell me how to display the coordinate 
grid in lat long on the map so that i get some nice grid lines for 
reference.  actually, knowing how to post the reference lines in any 
coordinate system would be helpful.

--
Byron Veilleux, MSc. P.Geo
Conjugate Geologic Services Limited
Calgary, Alberta Canada
by...@conjugategeo.com 
Cell:4037108414

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Re: [Qgis-user] georeferencing and displaying lat long.

If you are wanting to use the canvas with a graticule you can configure it
from view>>decorations>>grid. That only supports using the map CRS units
afaik. For producing vector grids in various coordinate systems and
intervals, you can use the create grid tools from the processing toolbox.
As an aside, map layouts support multiple grids in various CRS as well.

On Fri, 1 Oct 2021 at 19:30, Firstname Lastname 
wrote:

>
> i have several maps to georeference that have reference grid in lat/long.
> can someone please tell me how to display the coordinate grid in lat long
> on the map so that i get some nice grid lines for reference.  actually,
> knowing how to post the reference lines in any coordinate system would be
> helpful.
> --
> Byron Veilleux, MSc. P.Geo
> Conjugate Geologic Services Limited
> Calgary, Alberta Canada
> by...@conjugategeo.com
> Cell:4037108414
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Re: [Qgis-user] Geo Raster Background


Hi,

nope this isn't what I want ... it is the same as setting transparent
color manually.

I am using PDF and TIF for georeferencing.

Regards

Without no-data-0 or transparent-color:

Set transparent-color to 0,0,0 or use no-data-0:


Am 01.10.2021 um 19:26 schrieb Charles Dixon-Paver:

I just loaded an unreferenced png with black content into qgis, then
set the nodata value to 9, then did a fake georeference with
arbitrary coordinates, and the result seemed to be rotated without any
background pixels. Using 3.20 on Windows. The geoereferencer has a
checkbox for setting nodata to 0, so uncheck that first. Otherwise, if
you're still unable to get the "triangles" to change, my previous
messages should still apply.

On Fri, 1 Oct 2021 at 18:27, L.W. mailto:eagl...@gmx.de>> wrote:

yes, maybe to orange, a color that is not in the original image,
so I can do this color transparent.


Am 01.10.2021 um 18:25 schrieb David Strip:

When georeferencing, aren't the areas outside the original image,
eg, the "triangles" resulting from rotation, treated as no data?
Wouldn't this issue be resolved by setting the no data value to
something other than black?
Just guessing here, obviously.


On 10/1/2021 2:36 AM, L.W. wrote:


Thanks for answering, but I think this is not the way I want to
go ...

Or, I do not have written detailed.

I have a raster image e.g. a white rectangle, after setting the
points, QGIS rotats this image, let's say, by 45 degrees.

The corners of the imported image are now black triangles.

I do want to have e.g. red triangles ...

Regards


Am 01.10.2021 um 09:50 schrieb Charles Dixon-Paver:

There's not really any way for a GIS system to automatically
differentiate between black background pixels and black data
pixels. QGIS supports users setting custom pixel values to
render as transparent pixels, but it's left up to users to
ensure that their data and background values are different.

From my view, there are a couple of options when it comes to
fixing this issue in your data. One is to use an image
processing tool like GIMP or Photoshop effectively, but that
requires retaining the geographic information and knowing how
to reprocess the raster accordingly.

The simplest solution I'm aware of is probably to follow this
workflow in QGIS:

  * Start a new QGIS project
  * Set all black pixels to transparent in the transparency tab
of the raster layer properties
  * Digitize a "bounding area" - you can do this with a memory
layer
  * Move your vector layer to render underneath the raster
  * Give the vector a simple black symbology
  * Use the "Convert map to raster" tool from the processing
toolbox

There are a wide number of variations on that workflow that are
possible of course, but I think that's the easiest to get started.


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[Qgis-user] Join Attributes by Location

2021-10-01 Thread krishna Ayyala

Hello,
I have Layer 1 -- 100 Points

I have Layer 2--- 100 Polygons

I have used the select by location tool as below 98 Points selected.
[image: image.png]


I have used "Join  attributes location" tool on the same layers. Exported
the joined layer. I see zero records in the Joined layer. Technically there
should be 98 records. Can someone help me fix this please?

[image: image.png]

Regards
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[Qgis-user] georeferencing and displaying lat long.

2021-10-01 Thread Firstname Lastname

i have several maps to georeference that have reference grid in lat/long.
can someone please tell me how to display the coordinate grid in lat long
on the map so that i get some nice grid lines for reference.  actually,
knowing how to post the reference lines in any coordinate system would be
helpful.
-- 
Byron Veilleux, MSc. P.Geo
Conjugate Geologic Services Limited
Calgary, Alberta Canada
by...@conjugategeo.com
Cell:4037108414
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Re: [Qgis-user] Geo Raster Background

I just loaded an unreferenced png with black content into qgis, then set
the nodata value to 9, then did a fake georeference with arbitrary
coordinates, and the result seemed to be rotated without any background
pixels. Using 3.20 on Windows. The geoereferencer has a checkbox for
setting nodata to 0, so uncheck that first. Otherwise, if you're still
unable to get the "triangles" to change, my previous messages should still
apply.

On Fri, 1 Oct 2021 at 18:27, L.W.  wrote:

> yes, maybe to orange, a color that is not in the original image, so I can
> do this color transparent.
>
>
> Am 01.10.2021 um 18:25 schrieb David Strip:
>
> When georeferencing, aren't the areas outside the original image, eg, the
> "triangles" resulting from rotation, treated as no data? Wouldn't this
> issue be resolved by setting the no data value to something other than
> black?
> Just guessing here, obviously.
>
>
> On 10/1/2021 2:36 AM, L.W. wrote:
>
> Thanks for answering, but I think this is not the way I want to go ...
>
> Or, I do not have written detailed.
>
> I have a raster image e.g. a white rectangle, after setting the points,
> QGIS rotats this image, let's say, by 45 degrees.
>
> The corners of the imported image are now black triangles.
>
> I do want to have e.g. red triangles ...
>
> Regards
>
>
> Am 01.10.2021 um 09:50 schrieb Charles Dixon-Paver:
>
> There's not really any way for a GIS system to automatically differentiate
> between black background pixels and black data pixels. QGIS supports users
> setting custom pixel values to render as transparent pixels, but it's left
> up to users to ensure that their data and background values are different.
>
> From my view, there are a couple of options when it comes to fixing this
> issue in your data. One is to use an image processing tool like GIMP or
> Photoshop effectively, but that requires retaining the geographic
> information and knowing how to reprocess the raster accordingly.
>
> The simplest solution I'm aware of is probably to follow this workflow in
> QGIS:
>
>- Start a new QGIS project
>- Set all black pixels to transparent in the transparency tab of the
>raster layer properties
>- Digitize a "bounding area" - you can do this with a memory layer
>- Move your vector layer to render underneath the raster
>- Give the vector a simple black symbology
>- Use the "Convert map to raster" tool from the processing toolbox
>
> There are a wide number of variations on that workflow that are possible
> of course, but I think that's the easiest to get started.
>
>
>
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[Qgis-user] Accessing Google gvfs mounted files from QGIS

2021-10-01 Thread chris hermansen

Good day everyone,

I have some data stored in Google Drive.  In Ubuntu (21.04) I can view this
data from the Nautilus file manager.  If I open a terminal window in one of
those folders and do an "ls" I see files with names like:

102DKMhG5dFOgocGZcExtph8QVZvH8ya9
104L05_H6_SMc-QpdWO4KWe3EN_40S-DS
106jT1GqnE3vCn2AHfB3OwdMOFSBitFRl
10b8HAKH_FqBudNq6nattu5uh1i4Q_vxX
10c-G1EYbFpUkrheTiuUV0ve3W05oSrP7
10d12QQJ_2V6vI1VIw559Eyk_PQy_lGIs
10F6_2M5JTZamwCsHCxkR2ecSXdr0sjx8
10imLzy8wGtHV76N6woH72aotiiKgBYlK
10IsenXQBSzNlohlWpn0zvvvC99DG5_wU
10IZ5hygKLIWvq-ZjEBsyiJ-9XW2HtgxR

if I use gio list -d (to list files with "display names") I see files with
names like

Poblados_INE.cpg
Red_Vial_Vialidad_2019.cpg
America_del_Sur.cpg
Hortalizas_ODEPA_2014.shp
Monumentos_Nacionales_CMN_2019.dbf
Industria_Forestal_INFOR_2016.shp
LT_AYSEN_MIE.prj
SE_SIC_MIE_2017.prj
Ganado_bovino_ODEPA_2014.prj
Prodesal_INDAP_2015.shx

which is more like what I expect (or at least, hope for).

I would like to access these files with QGIS.  Unfortunately, it doesn't
see the "display names", but rather those shown with "ls", which creates a
problem with navigating to the relevant .shp file.

Has anyone been down this particular rabbit hole with any success?

Thanks in advance.

-- 
Chris Hermansen · clhermansen "at" gmail "dot" com

C'est ma façon de parler.
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Re: [Qgis-user] Geo Raster Background

2021-10-01 Thread David Strip


  
  
When georeferencing, aren't the areas
  outside the original image, eg, the "triangles" resulting from
  rotation, treated as no data? Wouldn't this issue be resolved by
  setting the no data value to something other than black?
  Just guessing here, obviously.
  
  
  On 10/1/2021 2:36 AM, L.W. wrote:


  Thanks for answering, but I think this is not the way I want to
go ...
  Or, I do not have written detailed.
  
  I have a raster image e.g. a white rectangle, after setting the
points, QGIS rotats this image, let's say, by 45 degrees.
  The corners of the imported image are now black triangles.
  I do want to have e.g. red triangles ...
  Regards
  
  
  
  Am 01.10.2021 um 09:50 schrieb
Charles Dixon-Paver:
  
  

There's not really any way for a GIS system to
  automatically differentiate between black background pixels
  and black data pixels. QGIS supports users setting custom
  pixel values to render as transparent pixels, but it's left up
  to users to ensure that their data and background values are
  different.
  
  From my view, there are a couple of options when it comes to
  fixing this issue in your data. One is to use an image
  processing tool like GIMP or Photoshop effectively, but that
  requires retaining the geographic information and knowing how
  to reprocess the raster accordingly.
  
  The simplest solution I'm aware of is probably to follow this
  workflow in QGIS:
  
Start a new QGIS project
Set all black pixels to transparent in the transparency
  tab of the raster layer properties
Digitize a "bounding area" - you can do this with a
  memory layer
Move your vector layer to render underneath the raster
Give the vector a simple black symbology
Use the "Convert map to raster" tool from the processing
  toolbox
  
  There are a wide number of variations on that workflow
that are possible of course, but I think that's the easiest
to get started.

  


  

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Re: [Qgis-user] Geo Raster Background


yes, maybe to orange, a color that is not in the original image, so I
can do this color transparent.


Am 01.10.2021 um 18:25 schrieb David Strip:

When georeferencing, aren't the areas outside the original image, eg,
the "triangles" resulting from rotation, treated as no data? Wouldn't
this issue be resolved by setting the no data value to something other
than black?
Just guessing here, obviously.


On 10/1/2021 2:36 AM, L.W. wrote:


Thanks for answering, but I think this is not the way I want to go ...

Or, I do not have written detailed.

I have a raster image e.g. a white rectangle, after setting the
points, QGIS rotats this image, let's say, by 45 degrees.

The corners of the imported image are now black triangles.

I do want to have e.g. red triangles ...

Regards


Am 01.10.2021 um 09:50 schrieb Charles Dixon-Paver:

There's not really any way for a GIS system to automatically
differentiate between black background pixels and black data pixels.
QGIS supports users setting custom pixel values to render as
transparent pixels, but it's left up to users to ensure that their
data and background values are different.

From my view, there are a couple of options when it comes to fixing
this issue in your data. One is to use an image processing tool like
GIMP or Photoshop effectively, but that requires retaining the
geographic information and knowing how to reprocess the raster
accordingly.

The simplest solution I'm aware of is probably to follow this
workflow in QGIS:

  * Start a new QGIS project
  * Set all black pixels to transparent in the transparency tab of
the raster layer properties
  * Digitize a "bounding area" - you can do this with a memory layer
  * Move your vector layer to render underneath the raster
  * Give the vector a simple black symbology
  * Use the "Convert map to raster" tool from the processing toolbox

There are a wide number of variations on that workflow that are
possible of course, but I think that's the easiest to get started.


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[Qgis-user] Introduction to QGIS course with Kartoza, 11-13 October 2021

2021-10-01 Thread Amy Burness

Good day GIS community

Learn how to make beautiful, functional maps and to use QGIS like a
professional. Kartoza's next three-day Introduction to QGIS
 course will be
on the 11-13 October 2021.


Course Agenda:

Day 1 - Introduction to QGIS, adding layers, working with attribute data
and basics of map creation.

Day 2 - Advance map creation, creating data, projections and data analysis.

Day 3 - Plugins, data resources, GRASS, database concepts and PostgreSQL.


For more information and to book, see:
https://kartoza.com/shop/product/introduction-to-qgis


Kind regards
Kartoza Team
-- 

Amy Burness
Junior GIS Specialist / technician
Visit http://kartoza.com to find out about open source:
* Desktop GIS programming services
* Geospatial web development
* GIS Training
* Consulting Services
Office: +27(0)71 225 0039
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Re: [Qgis-user] ordinary kriging parameters

2021-10-01 Thread Kirk Schmidt


Hi Maria:

Just from the cuff, the units are pixels or meters.  Try reprojecting 
your source data to a projected coordinate system (UTM, for example) and 
try kriging again.  Set the raster resolution to a course value that 
makes sense for your data to run a test raster and then run at the final 
resolution you require if you are concerned with processing time.



By using geographic corrdinates, you probably were generating a hugh 
raster which caused your computer to hang.



Kirk Schmidt

On 9/30/2021 3:03 PM, Maria Eugenia Gomez wrote:

Hi,
I am using QGIS 3.16.9 Hannover. I want to create a surface (with 
kriging) from a list of points whose SRC is WGS84. They are in decimal 
degrees covering a surface of 10km x 9km. I can see the points correctly-


My problem comes with the "Ordinary Kriging" setup. I unchecked "block 
kriging" and used the following options:

quality measure: stand. dev.
Logarithmic transf.
variogram model: linear
fit:nodes
search range: local
search directions: all directions
number of points: max. number of points

But when I have to fill "cell size", "maximum search distance, block 
size.. etc", I do not understand the units and I think this is the 
problem. Which type of units should I use? I tried to use decimal 
degrees units but then the number of iterations was so high that my 
computer hangs.


Can somebody help me with this? I searched on the QGIS documentation 
but it does not say anything about units.

Thanks in advance,
Maria


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--
Kirk Schmidt, MScF, BScF, RPF
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Nortek Resource Solutions Inc.
26 Church Road
Sutherlands River, NS
B0K 1W0
Tel (902) 922.3607
Email: k...@nortekresources.com
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[Qgis-user] query for automatic building parcel/footprint extraction from high resolution satellite image

2021-10-01 Thread shrawan tripathi

Hi All,
Would anyone please suggest to me the tool name or plug-in name to
automatically extract building parcels/footprint from high resolution
satellite image in QGIS.
-- 
Warm regards
Shrawan Kumar Tripathi
Senior GIS Engineer
PATAA Navigations Pvt. Ltd.
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Re: [Qgis-user] Geo Raster Background

Hi,

Perhaps you can add a file or a screen shot because what you want to do it not 
clear.  An image would help. In your second email, you talk about triangles?  
Did you mean to write rectangles?

Nicolas Cadieux
https://gitlab.com/njacadieux

> Le 1 oct. 2021 à 05:30, L.W.  a écrit :
> 
> 
> I think one of us is on the wrong track with what is to be achieved.
> 
> I don't want to manipulate the image itself, just the background at the 
> moment when the raster image (or raster pdf) is converted to a TIF and 
> georeferenced.
> 
> if the rectangle contains black text, as described, this would also be 
> manipulated after the described manipulation, that's not what I want.
> 
> Thank you for your efforts.
> 
> 
> 
> Am 01.10.2021 um 10:49 schrieb Charles Dixon-Paver:
>> You can translate pixel values with the raster calculator (available under 
>> the raster menu). Black pixels will have a value of 0,0,0 on RGB bands and 
>> red pixels would have a value of 255,0,0 so it's just a matter of changing 
>> the values accordingly on those bands.
>> 
>> The raster calculator will contain an if expression in the next QGIS 
>> release, but if you're using an existing release you will have to use a bit 
>> of a quirky syntax to achieve that.
>> 
>> So if you select the red band and use an expression similar to ( "Image@1" = 
>>  0 )  *  255 it should work. If you need assistance on raster calculator 
>> syntax gis stack overflow has a large number of Q on the topic.
>> 
>> If you need info on a particular pixel value at each band, just use the 
>> identify features tool (it works on rasters too).
>> 
>> Note that the previous statement about the GIS identifying valid data values 
>> from background pixel values still applies to the calculator.
>> 
>> 
>> On Fri, 1 Oct 2021 at 10:36, L.W.  wrote:
>>> Thanks for answering, but I think this is not the way I want to go ...
>>> 
>>> Or, I do not have written detailed.
>>> 
>>> I have a raster image e.g. a white rectangle, after setting the points, 
>>> QGIS rotats this image, let's say, by 45 degrees.
>>> 
>>> The corners of the imported image are now black triangles.
>>> 
>>> I do want to have e.g. red triangles ...
>>> 
>>> Regards
>>> 
>>> 
>>> 
>>> Am 01.10.2021 um 09:50 schrieb Charles Dixon-Paver:
 There's not really any way for a GIS system to automatically differentiate 
 between black background pixels and black data pixels. QGIS supports users 
 setting custom pixel values to render as transparent pixels, but it's left 
 up to users to ensure that their data and background values are different.
 
 From my view, there are a couple of options when it comes to fixing this 
 issue in your data. One is to use an image processing tool like GIMP or 
 Photoshop effectively, but that requires retaining the geographic 
 information and knowing how to reprocess the raster accordingly.
 
 The simplest solution I'm aware of is probably to follow this workflow in 
 QGIS:
 Start a new QGIS project
 Set all black pixels to transparent in the transparency tab of the raster 
 layer properties
 Digitize a "bounding area" - you can do this with a memory layer
 Move your vector layer to render underneath the raster
 Give the vector a simple black symbology
 Use the "Convert map to raster" tool from the processing toolbox
 There are a wide number of variations on that workflow that are possible 
 of course, but I think that's the easiest to get started.
 
 Regards
 
 
 
 On Fri, 1 Oct 2021 at 09:28, L.W.  wrote:
> Hi,
> 
> how to change the backgroundcolor of a georeferenzed raster image?
> 
> When a raster image is rotated by qgis after setting all points the
> backgroundcolor is black RGB(0,0,0).
> 
> Set black to transparent is difficult when there is black text.
> 
> regards
> 
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Re: [Qgis-user] Geo Raster Background

2021-10-01 Thread Roland Spielhofer

Maybe this has to do with this longstanding issue:

https://github.com/qgis/QGIS/issues/23760

Regards,

Roland

Gesendet: Freitag, 01. Oktober 2021 um 11:30 Uhr
Von: "L.W."
An: "Charles Dixon-Paver"
Cc: "qgis-user@lists.osgeo.org"
Betreff: Re: [Qgis-user] Geo Raster Background

I think one of us is on the wrong track with what is to be achieved.

I don't want to manipulate the image itself, just the background at the moment when the raster image (or raster pdf) is converted to a TIF and georeferenced.

if the rectangle contains black text, as described, this would also be manipulated after the described manipulation, that's not what I want.

Thank you for your efforts.

Am 01.10.2021 um 10:49 schrieb Charles Dixon-Paver:

You can translate pixel values with the raster calculator (available under the raster menu). Black pixels will have a value of 0,0,0 on RGB bands and red pixels would have a value of 255,0,0 so it's just a matter of changing the values accordingly on those bands.

The raster calculator will contain an if _expression_ in the next QGIS release, but if you're using an existing release you will have to use a bit of a quirky syntax to achieve that.

So if you select the red band and use an _expression_ similar to ( "Image@1" = 0 ) * 255 it should work. If you need assistance on raster calculator syntax gis stack overflow has a large number of Q on the topic.

If you need info on a particular pixel value at each band, just use the identify features tool (it works on rasters too).

Note that the previous statement about the GIS identifying valid data values from background pixel values still applies to the calculator.

On Fri, 1 Oct 2021 at 10:36, L.W. wrote:

Thanks for answering, but I think this is not the way I want to go ...

Or, I do not have written detailed.

I have a raster image e.g. a white rectangle, after setting the points, QGIS rotats this image, let's say, by 45 degrees.

The corners of the imported image are now black triangles.

I do want to have e.g. red triangles ...

Regards

Am 01.10.2021 um 09:50 schrieb Charles Dixon-Paver:

There's not really any way for a GIS system to automatically differentiate between black background pixels and black data pixels. QGIS supports users setting custom pixel values to render as transparent pixels, but it's left up to users to ensure that their data and background values are different.

>From my view, there are a couple of options when it comes to fixing this issue in your data. One is to use an image processing tool like GIMP or Photoshop effectively, but that requires retaining the geographic information and knowing how to reprocess the raster accordingly.

The simplest solution I'm aware of is probably to follow this workflow in QGIS:

Start a new QGIS project
Set all black pixels to transparent in the transparency tab of the raster layer properties
Digitize a "bounding area" - you can do this with a memory layer
Move your vector layer to render underneath the raster
Give the vector a simple black symbology
Use the "Convert map to raster" tool from the processing toolbox

There are a wide number of variations on that workflow that are possible of course, but I think that's the easiest to get started.

Regards

On Fri, 1 Oct 2021 at 09:28, L.W. wrote:

Hi,

how to change the backgroundcolor of a georeferenzed raster image?

When a raster image is rotated by qgis after setting all points the
backgroundcolor is black RGB(0,0,0).

Set black to transparent is difficult when there is black text.

regards

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Re: [QGIS-it-user] Assegnare geometria a tabella dati esistenti

2021-10-01 Thread michele . ribecai

Confermo,

la cosa strana e che lo avevo provato e mi aveva funzionato però ora ripetendo 
mi da errore.


Un'altra prova che potresti fare è lato PostGis popolare i punti di scarico 
come le vasche;

update tuatabella

set geom(scarico)=geom(imhof)

(se non sbaglio erano entrambe puntuali).

A questo punto lato QGIS ti trovi gli scarichi sopra le vasche, attivi la 
tabella e li sposti.

Ciao



> Il 1 ottobre 2021 alle 10.17 Alberto Poggi  ha scritto:
> 
> Ciao Michele,
> ho provato la tua soluzione ma non funziona perchè vai a fondere due 
> elementi che hanno il campo geom in una riga, e il campo geom_sca nell'altra 
> riga di tabella vuoti e fondendo le due geometrie ottieni la cancellazione 
> dei due punti.
> Probabilmente il comando non è fatto per considerare due campi geometrici 
> differenti nella stessa tabella.
> La "fusione" riguarda comunque (e giustamente) soltanto un campo 
> geometrico
> 
> Il giorno ven 1 ott 2021 alle ore 09:21 < 
> michele.ribe...@cbtoscananord.it mailto:michele.ribe...@cbtoscananord.it > ha 
> scritto:
> 
> > > 
> > Ciao,
> > 
> > secondo me è da usare il comando di QGIS "Fondi Elementi 
> > Selezionati" e non "fondi attributi degli elementi selezionati",
> > 
> > in questo modo.
> > 
> > Disegni il punto dello scarico quindi nuova geometria, selezioni 
> > questo e la riga relativa alla vasca alla quale lo vuoi collegare.
> > 
> > Digiti "Fondi Elementi Selezionati" e prendi gli attributi dalla 
> > riga già presente relativa alla vasca imhoff.
> > 
> > A questo punto hai un'unica riga con gli attributi presi dalla riga 
> > esistente compresa la geometria della vasca, e la colonna
> > 
> > della geometria dello scarico popolata con il punto appena appena 
> > disegnato.
> > 
> > Ciao
> > 
> > Michele
> > 
> > 
> > 
> > > > > Il 30 settembre 2021 alle 9.59 Alberto Poggi < 
> > albpo...@gmail.com mailto:albpo...@gmail.com > ha scritto:
> > > 
> > > Buongiorno a tutti, ho un problema che non riesco a risolvere 
> > > con una tabella dati in postgis.
> > > La tabella contiene i dati di fosse imhoff esistenti. Ho la 
> > > necessità di registrare anche il punto di scarico di queste imhoff e il 
> > > modo più "semplice" mi è sembrato quello di aggiungere un altro campo 
> > > geometrico nel quale registrare il punto di scarico.
> > > Ho quindi sulla stessa riga due campi geometrici, uno per la 
> > > imhoff e uno per lo scarico.
> > > Ho collegato due volte la stessa tabella in qgis, vestendola 
> > > in modo diverso, utilizzando il primo campo geometrico per rappresentare 
> > > la fossa imhoff  e il secondo per lo scarico.
> > > 
> > > Il problema è: come faccio ad assegnare la geometria dello 
> > > scarico alla singola riga della tabella già esistente?
> > > 
> > > Ho cercato in rete e ho visto che la procedura in qgis 
> > > dovrebbe utilizzare la funzionalità "fondi attributi degli elementi 
> > > selezionati" ma non sono riuscito ad ottenere nulla.
> > > Qualcuno mi può aiutare?
> > > grazie in anticipo
> > > 
> > > ___
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> > > mailto:QGIS-it-user@lists.osgeo.org
> > > https://lists.osgeo.org/mailman/listinfo/qgis-it-user
> > > 
> > > > > 
> > > 
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Re: [Qgis-user] Geo Raster Background


I think one of us is on the wrong track with what is to be achieved.

I don't want to manipulate the image itself, just the background at the
moment when the raster image (or raster pdf) is converted to a TIF and
georeferenced.

if the rectangle contains black text, as described, this would also be
manipulated after the described manipulation, that's not what I want.

Thank you for your efforts.


Am 01.10.2021 um 10:49 schrieb Charles Dixon-Paver:

You can translate pixel values with the raster calculator (available
under the raster menu). Black pixels will have a value of 0,0,0 on RGB
bands and red pixels would have a value of 255,0,0 so it's just a
matter of changing the values accordingly on those bands.

The raster calculator will contain an if expression in the next QGIS
release, but if you're using an existing release you will have to use
a bit of a quirky syntax to achieve that.

So if you select the red band and use an expression similar to (
"Image@1" =  0 )  *  255 it should work. If you need assistance on
raster calculator syntax gis stack overflow has a large number of Q
on the topic.

If you need info on a particular pixel value at each band, just use
the identify features tool (it works on rasters too).

Note that the previous statement about the GIS identifying valid data
values from background pixel values still applies to the calculator.


On Fri, 1 Oct 2021 at 10:36, L.W. mailto:eagl...@gmx.de>> wrote:

Thanks for answering, but I think this is not the way I want to go ...

Or, I do not have written detailed.

I have a raster image e.g. a white rectangle, after setting the
points, QGIS rotats this image, let's say, by 45 degrees.

The corners of the imported image are now black triangles.

I do want to have e.g. red triangles ...

Regards


Am 01.10.2021 um 09:50 schrieb Charles Dixon-Paver:

There's not really any way for a GIS system to automatically
differentiate between black background pixels and black data
pixels. QGIS supports users setting custom pixel values to render
as transparent pixels, but it's left up to users to ensure that
their data and background values are different.

From my view, there are a couple of options when it comes to
fixing this issue in your data. One is to use an image processing
tool like GIMP or Photoshop effectively, but that requires
retaining the geographic information and knowing how to reprocess
the raster accordingly.

The simplest solution I'm aware of is probably to follow this
workflow in QGIS:

  * Start a new QGIS project
  * Set all black pixels to transparent in the transparency tab
of the raster layer properties
  * Digitize a "bounding area" - you can do this with a memory layer
  * Move your vector layer to render underneath the raster
  * Give the vector a simple black symbology
  * Use the "Convert map to raster" tool from the processing toolbox

There are a wide number of variations on that workflow that are
possible of course, but I think that's the easiest to get started.

Regards



On Fri, 1 Oct 2021 at 09:28, L.W. mailto:eagl...@gmx.de>> wrote:

Hi,

how to change the backgroundcolor of a georeferenzed raster
image?

When a raster image is rotated by qgis after setting all
points the
backgroundcolor is black RGB(0,0,0).

Set black to transparent is difficult when there is black text.

regards

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Re: [Qgis-user] Geo Raster Background

You can translate pixel values with the raster calculator (available under
the raster menu). Black pixels will have a value of 0,0,0 on RGB bands and
red pixels would have a value of 255,0,0 so it's just a matter of changing
the values accordingly on those bands.

The raster calculator will contain an if expression in the next QGIS
release, but if you're using an existing release you will have to use a bit
of a quirky syntax to achieve that.

So if you select the red band and use an expression similar to ( "Image@1"
=  0 )  *  255 it should work. If you need assistance on raster calculator
syntax gis stack overflow has a large number of Q on the topic.

If you need info on a particular pixel value at each band, just use the
identify features tool (it works on rasters too).

Note that the previous statement about the GIS identifying valid data
values from background pixel values still applies to the calculator.


On Fri, 1 Oct 2021 at 10:36, L.W.  wrote:

> Thanks for answering, but I think this is not the way I want to go ...
>
> Or, I do not have written detailed.
>
> I have a raster image e.g. a white rectangle, after setting the points,
> QGIS rotats this image, let's say, by 45 degrees.
>
> The corners of the imported image are now black triangles.
>
> I do want to have e.g. red triangles ...
>
> Regards
>
>
> Am 01.10.2021 um 09:50 schrieb Charles Dixon-Paver:
>
> There's not really any way for a GIS system to automatically differentiate
> between black background pixels and black data pixels. QGIS supports users
> setting custom pixel values to render as transparent pixels, but it's left
> up to users to ensure that their data and background values are different.
>
> From my view, there are a couple of options when it comes to fixing this
> issue in your data. One is to use an image processing tool like GIMP or
> Photoshop effectively, but that requires retaining the geographic
> information and knowing how to reprocess the raster accordingly.
>
> The simplest solution I'm aware of is probably to follow this workflow in
> QGIS:
>
>- Start a new QGIS project
>- Set all black pixels to transparent in the transparency tab of the
>raster layer properties
>- Digitize a "bounding area" - you can do this with a memory layer
>- Move your vector layer to render underneath the raster
>- Give the vector a simple black symbology
>- Use the "Convert map to raster" tool from the processing toolbox
>
> There are a wide number of variations on that workflow that are possible
> of course, but I think that's the easiest to get started.
>
> Regards
>
>
>
> On Fri, 1 Oct 2021 at 09:28, L.W.  wrote:
>
>> Hi,
>>
>> how to change the backgroundcolor of a georeferenzed raster image?
>>
>> When a raster image is rotated by qgis after setting all points the
>> backgroundcolor is black RGB(0,0,0).
>>
>> Set black to transparent is difficult when there is black text.
>>
>> regards
>>
>> ___
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>> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
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>>
>
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Re: [Qgis-user] Geo Raster Background


Thanks for answering, but I think this is not the way I want to go ...

Or, I do not have written detailed.

I have a raster image e.g. a white rectangle, after setting the points,
QGIS rotats this image, let's say, by 45 degrees.

The corners of the imported image are now black triangles.

I do want to have e.g. red triangles ...

Regards


Am 01.10.2021 um 09:50 schrieb Charles Dixon-Paver:

There's not really any way for a GIS system to automatically
differentiate between black background pixels and black data pixels.
QGIS supports users setting custom pixel values to render as
transparent pixels, but it's left up to users to ensure that their
data and background values are different.

From my view, there are a couple of options when it comes to fixing
this issue in your data. One is to use an image processing tool like
GIMP or Photoshop effectively, but that requires retaining the
geographic information and knowing how to reprocess the raster
accordingly.

The simplest solution I'm aware of is probably to follow this workflow
in QGIS:

  * Start a new QGIS project
  * Set all black pixels to transparent in the transparency tab of the
raster layer properties
  * Digitize a "bounding area" - you can do this with a memory layer
  * Move your vector layer to render underneath the raster
  * Give the vector a simple black symbology
  * Use the "Convert map to raster" tool from the processing toolbox

There are a wide number of variations on that workflow that are
possible of course, but I think that's the easiest to get started.

Regards



On Fri, 1 Oct 2021 at 09:28, L.W. mailto:eagl...@gmx.de>> wrote:

Hi,

how to change the backgroundcolor of a georeferenzed raster image?

When a raster image is rotated by qgis after setting all points the
backgroundcolor is black RGB(0,0,0).

Set black to transparent is difficult when there is black text.

regards

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Re: [QGIS-it-user] R: Assegnare geometria a tabella dati esistenti

2021-10-01 Thread Alberto Poggi

Ciao Francesco,
hai sicuramente ragione sul fatto che dovendo considerare dati di tipo
diverso le tabelle debbano essere due per la corretta gestione dei dati
Comunque, parlando in generale e non del caso specifico, postgres ti
consente di avere due o più campi geometrici nella stessa tabella

Dal lato Qgis se tu fai due connessioni distinte sulla stessa tabella in
fase di connessione puoi indicare qual è il campo geometrico da considerare
nei due differenti casi.
Ho provato e qgis accetta senza problemi la cosa rappresentando con due
punti ovviamente differenti per posizione sia la imhoff che lo scarico (nel
mio caso) con due campi geometrici differenti (geom per la imhoff e
geom_sca per lo scarico)

Di conseguenza la cosa sembra possibile.

Il problema stà nella gestione dei dati

Se, ad esempio, io inserisco una nuova imhoff, non c'è problema, aggiungo i
dati che mi interessano, ho una nuova riga di dati in tabella e sono a
posto.
Subito dopo aver registrato il punto imhoff devo inserire anche il punto di
scarico.
Apro in editing la seconda connessione (lo scarico che punta al campo
geometrico dedicato) ma in questo caso devo assegnare la geometria ad una
riga già esistente (quella della imhoff creata prima) e non creare una
nuova riga della tabella.
Quindi mi ritrovo a dover assegnare la nuova geometria ad una riga di
tabella già esistente.

So che è possibile assegnare una geometria ad una tabella dati già
esistente con il comando "fondi attributi degli elementi selezionati"

in questo caso però non riesco a farlo perchè qgis considera tabelle
differenti le due connessioni e dalla connessione dello scarico non vede la
riga della imhoff appena creata perchè il campo geom_sca è vuoto.

Forse, visto che in tabella ho due campi float per le coordinate x e y, si
può risolvere il problema con un trigger su postgres che una volta inseriti
i dati delle coordinate nei due campi vada ad aggiornare il campo geom_sca.



> ciao,
> concettualmente io credo che l'unica soluzione sia quella di gestire i
> due oggetti in due layer (tabelle) distinti: nel caso di una geometria
> multipoint non hai la possibilità di caratterizzare il punto (se
> imhoff o scarico), mentre nella soluzione che stai provando in QGIS
> (due campi geometry nella stessa tabella) non è possibile aggiungere
> una geometria (lo scarico) ad un record esistente (imhoff) e comunque
> si tratta di due oggetti distinti e ti troverai sicuramente ad avere
> dei dati riferiti ad uno e dati all'altro, violando quindi la più
> basilare norma dei database (normalizzazione).
> in generale in un GIS l'elemento geografico non è un attributo in più
> di un altro elemento, ma è una primitiva che contiene degli attributi
> (che tu stai rappresentando).

> saluti,
> francesco


> Da: QGIS-it-user  Per conto di
Alberto Poggi
> Inviato: giovedì 30 settembre 2021 10:00
> A: QGIS-it-user@lists.osgeo.org
> Oggetto: [QGIS-it-user] Assegnare geometria a tabella dati esistenti
>
>
>
> Buongiorno a tutti, ho un problema che non riesco a risolvere con una
tabella dati in postgis.
>
> La tabella contiene i dati di fosse imhoff esistenti. Ho la necessità di
registrare anche il punto di scarico di queste imhoff e il modo più
"semplice" mi è sembrato quello di aggiungere un altro campo geometrico nel
quale registrare il punto di scarico.
>
> Ho quindi sulla stessa riga due campi geometrici, uno per la imhoff e uno
per lo scarico.
>
> Ho collegato due volte la stessa tabella in qgis, vestendola in modo
diverso, utilizzando il primo campo geometrico per rappresentare la fossa
imhoff  e il secondo per lo scarico.
>
>
>
> Il problema è: come faccio ad assegnare la geometria dello scarico alla
singola riga della tabella già esistente?
>
>
>
> Ho cercato in rete e ho visto che la procedura in qgis dovrebbe
utilizzare la funzionalità "fondi attributi degli elementi selezionati" ma
non sono riuscito ad ottenere nulla.
>
> Qualcuno mi può aiutare?
>
> grazie in anticipo
>
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Re: [Qgis-user] Configuring QGIS server on Ubuntu 20.4

2021-10-01 Thread Alessandro Pasotti

On Fri, Oct 1, 2021 at 9:46 AM Mats Elfström 
wrote:

> Hi Alessandro!
>

Please keep the conversation on the user list so that others can benefit
from it or jump in and give some advice.


> I'd be glad to help. Just to make sure, which of these three docs is valid?
> You linked to the first, but I used the second, since I am on QGIS 3.20.
>
>
> https://docs.qgis.org/3.16/en/docs/server_manual/getting_started.html#installation-on-debian-based-systems
>
>
They all probably have the same content.

These are probably best suit for 3.20 even if they (theoretically) might
contain features that are not yet available for 3.20 :

https://docs.qgis.org/testing/en/docs/server_manual/getting_started.html#installation-on-debian-based-systems
>
> https://docs.qgis.org/testing/pdf/en/QGIS-testing-ServerUserGuide-en.pdf
>


> I have tried Docker, but my cloud computing provider did not support that
> kind of containerization. Tomcat works fine, though. Would it be possible
> to build a QGIS server *.war file?
>

No, AFAIK war is for java applications.

Best regards.



> I'll be back.
>
> Mats.E
>
> Den tors 30 sep. 2021 kl 21:25 skrev Alessandro Pasotti <
> apaso...@gmail.com>:
>
>>
>> Hi, I'm sorry to hear that: we have even recently spent a considerable
>> amount of time (and money, because it was financed with a grant) to rewrite
>> the QGIS Server documentation with detailed information about deployment
>> [1], we have clearly missed the goal if you couldn't find what you needed
>> in these pages.
>>
>> It would be useful to know what exactly were your problems and what did
>> you try to do.
>>
>> A common problem with server deployments is that there are multiple ways
>> of doing things, it really depends on what you need, for example we are now
>> commonly using docker containers (there are many out there that provide a
>> QGIS Server working installation almost without the need to manually
>> configure anything).
>>
>> Also, I tend to use nginx, but apache is totally fine too.
>>
>> [1]
>> https://docs.qgis.org/3.16/en/docs/server_manual/getting_started.html#installation-on-debian-based-systems
>>
>>
>> On Thu, Sep 30, 2021 at 8:24 PM Mats Elfström 
>> wrote:
>>
>>> Hi!
>>> I am setting up a Geodata stack. I have installed PostgreSQL/Postgis and
>>> Geoserver under Tomcat9 and FME:d a lot of data to PostGIS. All is up and
>>> running.
>>> Then I installed QGIS 3.20. No problems so far. Then I decided to try
>>> QGIS server as an alternative to Geoserver. But I am having trouble
>>> configuring QGIS server, or Apache2 rather.
>>> Over the past 5-6 years, I have spent more time and energy than I care
>>> to mention trying to make QGIS server run on Windows servers. Asking for
>>> advice on those occasions, I have more than once got the advice to use
>>> Linux instead, since no QGIS developers really know Windows servers. And
>>> Linux would be much easier.
>>> Fair enough. So now I am on Ubuntu, sudoing this and that and it works
>>> pretty well.
>>> Apart from QGIS server. I find the same mess of incomplete or
>>> contradictory instructions. No wonder QGIS server is under-used.
>>> If Linux(Ubuntu) is so simple, how come no one has put together a
>>> working script to configure and deploy QGIS server on a standard setup?
>>> I am most disappointed, having spent yet 5 hrs that I will never get
>>> back on QGIS server.
>>>
>>> Regards, Mats.E
>>>
>>> --
>>>
>>>
>>> *GisKraft*, Geodatakonsult
>>>
>>> Mats Elfström, Marsvinsholms stationsväg 80, 271 93 Ystad, Sweden
>>> tel: +46 70 595 39 35 / www.giskraft.se
>>> ___
>>> 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
>>>
>>
>>
>> --
>> Alessandro Pasotti
>> QCooperative:  www.qcooperative.net
>> ItOpen:   www.itopen.it
>>
>
>
> --
>
>
> *GisKraft*, Geodatakonsult
>
> Mats Elfström, Marsvinsholms stationsväg 80, 271 93 Ystad, Sweden
> tel: +46 70 595 39 35 / www.giskraft.se
>


-- 
Alessandro Pasotti
QCooperative:  www.qcooperative.net
ItOpen:   www.itopen.it
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Re: [Qgis-user] Geo Raster Background

There's not really any way for a GIS system to automatically differentiate
between black background pixels and black data pixels. QGIS supports users
setting custom pixel values to render as transparent pixels, but it's left
up to users to ensure that their data and background values are different.

>From my view, there are a couple of options when it comes to fixing this
issue in your data. One is to use an image processing tool like GIMP or
Photoshop effectively, but that requires retaining the geographic
information and knowing how to reprocess the raster accordingly.

The simplest solution I'm aware of is probably to follow this workflow in
QGIS:

   - Start a new QGIS project
   - Set all black pixels to transparent in the transparency tab of the
   raster layer properties
   - Digitize a "bounding area" - you can do this with a memory layer
   - Move your vector layer to render underneath the raster
   - Give the vector a simple black symbology
   - Use the "Convert map to raster" tool from the processing toolbox

There are a wide number of variations on that workflow that are possible of
course, but I think that's the easiest to get started.

Regards



On Fri, 1 Oct 2021 at 09:28, L.W.  wrote:

> Hi,
>
> how to change the backgroundcolor of a georeferenzed raster image?
>
> When a raster image is rotated by qgis after setting all points the
> backgroundcolor is black RGB(0,0,0).
>
> Set black to transparent is difficult when there is black text.
>
> regards
>
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Re: [QGIS-it-user] Assegnare geometria a tabella dati esistenti

2021-10-01 Thread michele . ribecai

Ciao,

secondo me è da usare il comando di QGIS "Fondi Elementi Selezionati" e non 
"fondi attributi degli elementi selezionati",

in questo modo.

Disegni il punto dello scarico quindi nuova geometria, selezioni questo e la 
riga relativa alla vasca alla quale lo vuoi collegare.

Digiti "Fondi Elementi Selezionati" e prendi gli attributi dalla riga già 
presente relativa alla vasca imhoff.

A questo punto hai un'unica riga con gli attributi presi dalla riga esistente 
compresa la geometria della vasca, e la colonna

della geometria dello scarico popolata con il punto appena appena disegnato.

Ciao

Michele



> Il 30 settembre 2021 alle 9.59 Alberto Poggi  ha scritto:
> 
> Buongiorno a tutti, ho un problema che non riesco a risolvere con una 
> tabella dati in postgis.
> La tabella contiene i dati di fosse imhoff esistenti. Ho la necessità di 
> registrare anche il punto di scarico di queste imhoff e il modo più 
> "semplice" mi è sembrato quello di aggiungere un altro campo geometrico nel 
> quale registrare il punto di scarico.
> Ho quindi sulla stessa riga due campi geometrici, uno per la imhoff e uno 
> per lo scarico.
> Ho collegato due volte la stessa tabella in qgis, vestendola in modo 
> diverso, utilizzando il primo campo geometrico per rappresentare la fossa 
> imhoff  e il secondo per lo scarico.
> 
> Il problema è: come faccio ad assegnare la geometria dello scarico alla 
> singola riga della tabella già esistente?
> 
> Ho cercato in rete e ho visto che la procedura in qgis dovrebbe 
> utilizzare la funzionalità "fondi attributi degli elementi selezionati" ma 
> non sono riuscito ad ottenere nulla.
> Qualcuno mi può aiutare?
> grazie in anticipo
> 
> ___
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> QGIS-it-user@lists.osgeo.org
> https://lists.osgeo.org/mailman/listinfo/qgis-it-user
> 
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[Qgis-user] Geo Raster Background