[MapProxy] poor WMS-Quality

[Tobias Wendorff]

Am 29.12.2020 um 16:41 schrieb Travis Kirstine:
> The degradation of quality is usually from the srs of the source WMS not 
> matching the srs of the cache as a result mapproxy must warp the image 
> generated from the source WMS which is never optimal.  This can be 
> defined using supported_srs in the source section.
> 
> You can also bypass the cache when defining a layer and use the wms 
> source directly, if this is done all WMS requests will be forwarded to 
> the backend WMS resulting in no quality loss.

Don't forget the different pixel sizes and the "dpi" parameter. I had 
lots of "fun" to find the right values for MapServer and QGIS-server, 
but never had it 100% fitting.

Also, some ESRI WMS has a switch "resample=true", which might make 
quality better when warping is needed.