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I am using QGIS 2.14.9 on windows 10 to view our geospatial data and use the QuickMapServices plugin connected to 'OSM Standard' as a base map. Recently, I had need to use WFS layers, which are not compatible with our organisation's proxy server. If I do not use the proxy server then QuickMapServices will not download the tiles.

To overcome this I am using GDAL TMS driver with this xml:

<GDAL_WMS>
  <Service name="TMS">
    <ServerUrl>http://tile.openstreetmap.org/${z}/${x}/${y}.png</ServerUrl>
  </Service>
  <DataWindow>
    <UpperLeftX>-20037508.34</UpperLeftX>
    <UpperLeftY>20037508.34</UpperLeftY>
    <LowerRightX>20037508.34</LowerRightX>
    <LowerRightY>-20037508.34</LowerRightY>
    <TileLevel>19</TileLevel>
    <TileCountX>1</TileCountX>
    <TileCountY>1</TileCountY>
    <YOrigin>top</YOrigin>
  </DataWindow>
  <Projection>EPSG:3857</Projection>
  <BlockSizeX>256</BlockSizeX>
  <BlockSizeY>256</BlockSizeY>
  <BandsCount>3</BandsCount>
  <Cache />
</GDAL_WMS>

However, the displayed tiles are so 'blocky' that they are very hard to read and looks poor.

I noticed that if I right click on 'OSM Standard' layer in the QGIS Layers Panel, select properties and uncheck 'smoothing' then the QuickMapServices tiles look just as blocky.

Is there a way to 'smooth' the tiles in the GDAL XML or by using QGIS?

Update: CRS is 3857. Example images added:

Less 'blocky' image

'Blocky' image

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  • Could you add a small screen capture about how the map appear? Is you QGIS project also in EPSG:3857?
    – user30184
    Jan 18, 2017 at 6:58
  • I've added example images but I must say that the 'blockiness' is a little better today but still evident. e.g 'Rundle Mall' is alomost unreadable. I can confirm the CRS is 3875.
    – Colin
    Jan 18, 2017 at 22:31
  • Clarification: I mentioned above that the plugins I am using are not compatible with our organisation's proxy server. This is an issue with the proxy server and not QGIS or its plugins. For some reason, the proxy serve will not server TMS tiles.
    – Colin
    Jan 22, 2017 at 23:41

1 Answer 1

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If you want the tiles to look good, you have to use the CRS and scale the tiles are rendered for.

The TileMapScaleLevels plugin helps you with that.

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  • Thanks AndreJ. I really like the TileMapScaleLevels plugin :-). It makes the image beautiful and I will continue to use it however, the 'smoothing' in the Quick Map Services plugin, which also has a 'Set Correct Scale' feature, is making a considerable difference.
    – Colin
    Jan 18, 2017 at 23:56
  • If I use a non-optimal scale (says 1:2500 selected from the QGIS standard 'Scale' drop down list) the text in the Quick Map Services layer is comparatively more readable. If I use the TileMapScaleLevels plugin to set the optimal scale (1:2256) and toggle between the two layers, the 'smoothed' image is slightly more readable. Not much but noticable. I'm not sure how the Quick Map Services plugin does the smoothing but if it can be applied to the xml then this would be ideal.
    – Colin
    Jan 18, 2017 at 23:58
  • I guess there is some coding behind the smoothing option of QuickMapServices which a simple WMS driver can not provide.
    – AndreJ
    Jan 19, 2017 at 3:52
  • I can confirm that there is some code in the Quick Map Services plugin that does the smoothing. The guys at NextGIS referred me to the code: github.com/nextgis/quickmapservices/blob/master/src/…
    – Colin
    Jan 22, 2017 at 23:45

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