Hi Patrick, How many files are we dealing with before it crashes? Nicolas
> Le 27 nov. 2019 à 22:35, Patrick Dunford <[email protected]> a écrit : > > > Hello, > > the issue is not with the performance drawing the raster, it is with the > system only being able to have a certain number of file based rasters loaded > in a project before it will crash. > > On 22/11/19 11:08 AM, Alexandre Neto wrote: >> AFAIK, >> >> WMST creates pyramids in cache as needed, hence it may do a better balance >> between disk usage and performance. You can control the number of pyramid >> layers you create and the compression format of it to save some space. But >> having raster files with 4000x4000 pixels with no pyramids will make a full >> read of the raster file to show even only a bit of it... That will make QGIS >> performance really poor. >> >> Thereºs this blog post from 2010 that does some comparison between several >> formats and their sizes and performances. It's in portuguese, but I think >> you can find ways of translating it. >> >> >> https://blog.viasig.com/2010/01/mosaicos-de-imagens-em-mapserver-com-gdal/ >> >> Hope it helps >> >> Alexandre Neto >> >> On Thu, Nov 21, 2019 at 2:05 PM Patrick Dunford <[email protected]> >> wrote: >>> Building pyramids gobbles up heaps of disk space. I tried pyramids on 157 >>> MB layer, which created an extra file 1.6 GiB. >>> >>> I can't see the WMTS building lots of temporary file pyramids using up disk >>> >>> On 18/11/19 10:50 PM, Alexandre Neto wrote: >>>> Hi Patrick, >>>> >>>> Sorry for asking, did you create pyramids (overlays) for your raster >>>> "tiles"? >>>> >>>> See more information about pyramids on QGIS official documentation: >>>> >>>> https://docs.qgis.org/3.4/en/docs/user_manual/working_with_raster/raster_properties.html#pyramids-properties >>>> >>>> To create pyramids on many files, it's probably better to use GDAL >>>> directly to process all files in a folder: >>>> >>>> https://gdal.org/programs/gdaladdo.html >>>> >>>> My feeling is that the WMS service is doing that for you, and that's the >>>> reason why it works well with a service. >>>> >>>> Alexandre Neto >>>> QGIS Support >>>> www.qcooperative.net >>>> >>> _______________________________________________ >>> Qgis-user mailing list >>> [email protected] >>> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user >>> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user > _______________________________________________ > Qgis-user mailing list > [email protected] > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
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