Re: [Qgis-user] Disable anti-aliasing on XYZ layer

2023-03-14 Thread Stephane Goldstein via QGIS-User 
So, after fiddling around a bit more, I can see that when zoomed at native
resolution or further out, the "Zoomed out" option works, with "Nearest
Neighbour" showing the source pixels and "Cubic" and "Bilinear" applying
re-sampling.
The options in the "Zoomed in" however do not seem to produce any changes
when overzooming.

On Wed, 15 Mar 2023 at 12:54, Stephane Goldstein  wrote:

>
> Thanks for the replies.
>
> The imagery I'm working with comes from drone mapping.
> The orthomosaic is generated using OpenDroneMap, in WGS84 UTM CRS
> The resulting GeoTIFF is then re-projected  to Web-mercator 3857, before
> being run through gdal2tiles.
> At this stage I'm loading the tiles as an XYZ layer directly from my hard
> drive, and my canvas is set at 3857 as well.
> So I know that the two screenshots I attached earlier come from the same
> PNG file.
>
> When I set the zoom to 1:1 as suggested, I can see the PNG files are
> displayed without anti-aliasing as expected.
> But as soon as I zoom in further, anti-aliasing takes place to oversample
> the image.
> I have tried changing the parameters of the Resampling section in the
> Layer Styling, but they have no effect at all (Zoomed In, Zoomed Out,
> Oversampling and "Early re-sampling" options).
>
> But the weirder thing is that when I set my XYZ layer source as
> "Interpretation: MapTiler Terrain RGB", pixels are shown as squares when
> over-zooming, like a standard raster would, which is what I want (even
> though the data does not make any sense with the MapTiler Terrain RGB
> styling, obviously).
>
> Antialising does not help the interpretation of my imagery, and so far the
> only solution I found was to create tiles up to zoom level 25, which is a
> massive amount of overprocessing and storage, since level 21 is enough to
> account for my 2cm resolution data source. Any other suggestions are really
> appreciated.
>
>
> On Sat, 11 Mar 2023 at 18:29, Johannes Kröger (WhereGroup) <
> johannes.kroe...@wheregroup.com> wrote:
>
>> That looks like the layer's resampling is not set to nearest neighbor.
>>
>> Also be aware that QGIS will have to resample the tiles whenever the
>> scale of the map does not match one of the pre-rendered zoomlevels of
>> the source (and the same CRS). If you have a matching CRS, select the
>> layer and click the "1:1" zoom icon, the image *should* match the
>> original 100%.
>>
>> Cheers, Hannes
>>
>> Am 09.03.23 um 15:55 schrieb Richard Duivenvoorde via QGIS-User:
>> > ( bringing it back to the list :-) )
>> >
>> > And are you sure the image retrieved from the xyz server is not a jpeg
>> > (compared to your original png)?
>> > You can try to see the actual url's used via F12 (the Debugging
>> > Development Tools panel) in QGIS.
>> >
>> > Another option: QGIS does not respect the xyz-zoomlevels always.. so
>> > it is very easy to go to a zoomlevel in which QGIS has to resize the
>> > original image a little (and 'resample' it, see Rendering/Raster
>> > settings in the Options). So to really compare QGIS image to the
>> > original one, you have to use the 'Zoom to native resolution' in the
>> > legend/layer context menu).
>> >
>> > Last idea: is your project in the same CRS as the xyz service
>> > (probably EPSG:3857?) Because if not, QGIS will also resample your
>> > original image to 'fit' the tile in the right position in that other
>> > crs
>> >
>> > (and again: I know nothing about Qt image rendering )
>> >
>> > Regards,
>> >
>> > Richard Duivenvoorde
>> >
>> > On 3/9/23 15:36, Stephane Goldstein wrote:
>> >> I can see the difference by comparing the .png file in an image
>> >> editor (https://pasteboard.co/YodS7tuhtzSC.png
>> >> ) and how it's rendered in
>> >> QGIS (https://pasteboard.co/tcGLRc7XrsNj.png
>> >> ).
>> >> The examples are at the same zoom level.
>> >>
>> >> On Thu, 9 Mar 2023 at 21:46, Richard Duivenvoorde
>> >> mailto:rdmaili...@duif.net>> wrote:
>> >>
>> >> On 3/9/23 14:05, Stephane Goldstein via QGIS-User wrote:
>> >>  > Hi.
>> >>  > Is there a way to disable anti-aliasing of the png tiles
>> >> loaded on an XYZ layer ?
>> >>
>> >> Hi Stephane,
>> >>
>> >>   From what do you conclude that there is anti-aliasing going on
>> >> with XYZ layers?
>> >> I use xyz layers also but I'm not aware of such behaviour?
>> >>
>> >> FYI: this is the code rendering the images:
>> >>
>> https://github.com/qgis/QGIS/blob/master/src/providers/wms/qgswmsprovider.cpp
>> >> <
>> https://github.com/qgis/QGIS/blob/master/src/providers/wms/qgswmsprovider.cpp>
>>
>> >>
>> >> (tried to search for 'alias' but could not find anything)
>> >>
>> >> Note, I'm not an expert in this field, so just wondering...
>> >>
>> >> Regards,
>> >>
>> >> Richard Duivenvoorde
>> >>
>> >>
>> >
>> > ___
>> > QGIS-User mailing list
>> > QGIS-User@lists.osgeo.org
>> > List info:

Re: [Qgis-user] Disable anti-aliasing on XYZ layer

2023-03-14 Thread Stephane Goldstein via QGIS-User 
Thanks for the replies.

The imagery I'm working with comes from drone mapping.
The orthomosaic is generated using OpenDroneMap, in WGS84 UTM CRS
The resulting GeoTIFF is then re-projected  to Web-mercator 3857, before
being run through gdal2tiles.
At this stage I'm loading the tiles as an XYZ layer directly from my hard
drive, and my canvas is set at 3857 as well.
So I know that the two screenshots I attached earlier come from the same
PNG file.

When I set the zoom to 1:1 as suggested, I can see the PNG files are
displayed without anti-aliasing as expected.
But as soon as I zoom in further, anti-aliasing takes place to oversample
the image.
I have tried changing the parameters of the Resampling section in the Layer
Styling, but they have no effect at all (Zoomed In, Zoomed Out,
Oversampling and "Early re-sampling" options).

But the weirder thing is that when I set my XYZ layer source as
"Interpretation: MapTiler Terrain RGB", pixels are shown as squares when
over-zooming, like a standard raster would, which is what I want (even
though the data does not make any sense with the MapTiler Terrain RGB
styling, obviously).

Antialising does not help the interpretation of my imagery, and so far the
only solution I found was to create tiles up to zoom level 25, which is a
massive amount of overprocessing and storage, since level 21 is enough to
account for my 2cm resolution data source. Any other suggestions are really
appreciated.


On Sat, 11 Mar 2023 at 18:29, Johannes Kröger (WhereGroup) <
johannes.kroe...@wheregroup.com> wrote:

> That looks like the layer's resampling is not set to nearest neighbor.
>
> Also be aware that QGIS will have to resample the tiles whenever the
> scale of the map does not match one of the pre-rendered zoomlevels of
> the source (and the same CRS). If you have a matching CRS, select the
> layer and click the "1:1" zoom icon, the image *should* match the
> original 100%.
>
> Cheers, Hannes
>
> Am 09.03.23 um 15:55 schrieb Richard Duivenvoorde via QGIS-User:
> > ( bringing it back to the list :-) )
> >
> > And are you sure the image retrieved from the xyz server is not a jpeg
> > (compared to your original png)?
> > You can try to see the actual url's used via F12 (the Debugging
> > Development Tools panel) in QGIS.
> >
> > Another option: QGIS does not respect the xyz-zoomlevels always.. so
> > it is very easy to go to a zoomlevel in which QGIS has to resize the
> > original image a little (and 'resample' it, see Rendering/Raster
> > settings in the Options). So to really compare QGIS image to the
> > original one, you have to use the 'Zoom to native resolution' in the
> > legend/layer context menu).
> >
> > Last idea: is your project in the same CRS as the xyz service
> > (probably EPSG:3857?) Because if not, QGIS will also resample your
> > original image to 'fit' the tile in the right position in that other
> > crs
> >
> > (and again: I know nothing about Qt image rendering )
> >
> > Regards,
> >
> > Richard Duivenvoorde
> >
> > On 3/9/23 15:36, Stephane Goldstein wrote:
> >> I can see the difference by comparing the .png file in an image
> >> editor (https://pasteboard.co/YodS7tuhtzSC.png
> >> ) and how it's rendered in
> >> QGIS (https://pasteboard.co/tcGLRc7XrsNj.png
> >> ).
> >> The examples are at the same zoom level.
> >>
> >> On Thu, 9 Mar 2023 at 21:46, Richard Duivenvoorde
> >> mailto:rdmaili...@duif.net>> wrote:
> >>
> >> On 3/9/23 14:05, Stephane Goldstein via QGIS-User wrote:
> >>  > Hi.
> >>  > Is there a way to disable anti-aliasing of the png tiles
> >> loaded on an XYZ layer ?
> >>
> >> Hi Stephane,
> >>
> >>   From what do you conclude that there is anti-aliasing going on
> >> with XYZ layers?
> >> I use xyz layers also but I'm not aware of such behaviour?
> >>
> >> FYI: this is the code rendering the images:
> >>
> https://github.com/qgis/QGIS/blob/master/src/providers/wms/qgswmsprovider.cpp
> >> <
> https://github.com/qgis/QGIS/blob/master/src/providers/wms/qgswmsprovider.cpp>
>
> >>
> >> (tried to search for 'alias' but could not find anything)
> >>
> >> Note, I'm not an expert in this field, so just wondering...
> >>
> >> Regards,
> >>
> >> Richard Duivenvoorde
> >>
> >>
> >
> > ___
> > 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
>
> --
> Johannes Kröger / GIS-Entwickler/-Berater
>
> **
> FOSSGIS Konferenz
> 15.-18. März 2023 in Berlin
> https://fossgis-konferenz.de/2023/
>
> WhereGroup-Beiträge auf der FOSSGIS
> https://wheregroup.com/unternehmen/aktuelles/
> **
>
> WhereGroup GmbH
> c/o KK03 GmbH
> Lange Reihe 29
> 20099 Hamburg
> Germany
>
> Tel: +49

Re: [Qgis-user] Disable anti-aliasing on XYZ layer

2023-03-12 Thread Patrick Dunford via QGIS-User 
There's a lot of questions about the context of use of an XYZ layer that 
you haven't given us detail of.


Are you referring to a layer loaded into the Qgis canvas via a data 
connection or some other context involving XYZ layers?


On 10/03/23 02:05, Stephane Goldstein via QGIS-User wrote:

Hi.
Is there a way to disable anti-aliasing of the png tiles loaded on an 
XYZ layer ?

Thanks
Stephane

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Re: [Qgis-user] Disable anti-aliasing on XYZ layer

2023-03-11 Thread WhereGroup 

That looks like the layer's resampling is not set to nearest neighbor.

Also be aware that QGIS will have to resample the tiles whenever the 
scale of the map does not match one of the pre-rendered zoomlevels of 
the source (and the same CRS). If you have a matching CRS, select the 
layer and click the "1:1" zoom icon, the image *should* match the 
original 100%.


Cheers, Hannes

Am 09.03.23 um 15:55 schrieb Richard Duivenvoorde via QGIS-User:

( bringing it back to the list :-) )

And are you sure the image retrieved from the xyz server is not a jpeg 
(compared to your original png)?
You can try to see the actual url's used via F12 (the Debugging 
Development Tools panel) in QGIS.


Another option: QGIS does not respect the xyz-zoomlevels always.. so 
it is very easy to go to a zoomlevel in which QGIS has to resize the 
original image a little (and 'resample' it, see Rendering/Raster 
settings in the Options). So to really compare QGIS image to the 
original one, you have to use the 'Zoom to native resolution' in the 
legend/layer context menu).


Last idea: is your project in the same CRS as the xyz service 
(probably EPSG:3857?) Because if not, QGIS will also resample your 
original image to 'fit' the tile in the right position in that other 
crs


(and again: I know nothing about Qt image rendering )

Regards,

Richard Duivenvoorde

On 3/9/23 15:36, Stephane Goldstein wrote:
I can see the difference by comparing the .png file in an image 
editor (https://pasteboard.co/YodS7tuhtzSC.png 
) and how it's rendered in 
QGIS (https://pasteboard.co/tcGLRc7XrsNj.png 
).

The examples are at the same zoom level.

On Thu, 9 Mar 2023 at 21:46, Richard Duivenvoorde 
mailto:rdmaili...@duif.net>> wrote:


    On 3/9/23 14:05, Stephane Goldstein via QGIS-User wrote:
 > Hi.
 > Is there a way to disable anti-aliasing of the png tiles 
loaded on an XYZ layer ?


    Hi Stephane,

  From what do you conclude that there is anti-aliasing going on 
with XYZ layers?

    I use xyz layers also but I'm not aware of such behaviour?

    FYI: this is the code rendering the images:
https://github.com/qgis/QGIS/blob/master/src/providers/wms/qgswmsprovider.cpp 
 


    (tried to search for 'alias' but could not find anything)

    Note, I'm not an expert in this field, so just wondering...

    Regards,

    Richard Duivenvoorde




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--
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**
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15.-18. März 2023 in Berlin
https://fossgis-konferenz.de/2023/

WhereGroup-Beiträge auf der FOSSGIS
https://wheregroup.com/unternehmen/aktuelles/
**

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c/o KK03 GmbH
Lange Reihe 29
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Germany

Tel: +49 (0)228 / 90 90 38 - 36
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Re: [Qgis-user] Disable anti-aliasing on XYZ layer

2023-03-09 Thread Richard Duivenvoorde via QGIS-User 

( bringing it back to the list :-) )

And are you sure the image retrieved from the xyz server is not a jpeg 
(compared to your original png)?
You can try to see the actual url's used via F12 (the Debugging Development 
Tools panel) in QGIS.

Another option: QGIS does not respect the xyz-zoomlevels always.. so it is very 
easy to go to a zoomlevel in which QGIS has to resize the original image a 
little (and 'resample' it, see Rendering/Raster settings in the Options). So to 
really compare QGIS image to the original one, you have to use the 'Zoom to 
native resolution' in the legend/layer context menu).

Last idea: is your project in the same CRS as the xyz service (probably 
EPSG:3857?) Because if not, QGIS will also resample your original image to 
'fit' the tile in the right position in that other crs

(and again: I know nothing about Qt image rendering )

Regards,

Richard Duivenvoorde

On 3/9/23 15:36, Stephane Goldstein wrote:

I can see the difference by comparing the .png file in an image editor 
(https://pasteboard.co/YodS7tuhtzSC.png ) and 
how it's rendered in QGIS (https://pasteboard.co/tcGLRc7XrsNj.png 
).
The examples are at the same zoom level.

On Thu, 9 Mar 2023 at 21:46, Richard Duivenvoorde mailto:rdmaili...@duif.net>> wrote:

On 3/9/23 14:05, Stephane Goldstein via QGIS-User wrote:
 > Hi.
 > Is there a way to disable anti-aliasing of the png tiles loaded on an 
XYZ layer ?

Hi Stephane,

  From what do you conclude that there is anti-aliasing going on with XYZ 
layers?
I use xyz layers also but I'm not aware of such behaviour?

FYI: this is the code rendering the images:
https://github.com/qgis/QGIS/blob/master/src/providers/wms/qgswmsprovider.cpp 

(tried to search for 'alias' but could not find anything)

Note, I'm not an expert in this field, so just wondering...

Regards,

Richard Duivenvoorde




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Re: [Qgis-user] Disable anti-aliasing on XYZ layer

2023-03-09 Thread Richard Duivenvoorde via QGIS-User 

On 3/9/23 14:05, Stephane Goldstein via QGIS-User wrote:

Hi.
Is there a way to disable anti-aliasing of the png tiles loaded on an XYZ layer 
?


Hi Stephane,

From what do you conclude that there is anti-aliasing going on with XYZ layers?
I use xyz layers also but I'm not aware of such behaviour?

FYI: this is the code rendering the images:
https://github.com/qgis/QGIS/blob/master/src/providers/wms/qgswmsprovider.cpp
(tried to search for 'alias' but could not find anything)

Note, I'm not an expert in this field, so just wondering...

Regards,

Richard Duivenvoorde


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[Qgis-user] Disable anti-aliasing on XYZ layer

2023-03-09 Thread Stephane Goldstein via QGIS-User 
Hi.
Is there a way to disable anti-aliasing of the png tiles loaded on an XYZ
layer ?
Thanks
Stephane
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