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I have around 4GB of tif raster layers (roughly 2000 individuals tifs) which I want to load into QGIS. Loading them without visualisation is not a problem but once QGIS starts rendering my PC locks down. Since I need this data for my atlas creation I believe it is indispensable to render them once. For a future project my data amount would even double.

What solutions are there?

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    Have you tried putting them into a GeoPackage or JP2 (JPG2000) format for example ? – gisnside Aug 10 '17 at 13:24
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    How much RAM do you have? – HeikkiVesanto Aug 10 '17 at 13:26
  • @Vesanto I have 8GB – Carlos Aug 10 '17 at 13:27
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    Same rules apply than for servers. Read slideshare.net/geosolutions/gs-steroids-sgiannecfoss4g20130103 and make sure that tiffs are tiled and that they have overviews. For QGIS you can collect them together into a virtual mosaic with gdalbuildvrt. Still avoid situation when hundreds of image files must be opened at the same time. Use another raster dataset with much bigger pixel size and less individual files for small scales. – user30184 Aug 10 '17 at 13:53
  • @user30184 gdalbuildvrt works! – Carlos Aug 11 '17 at 8:15
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A good start would be to make sure that individual tiff files are tiled and that they have overviews and combine all the tiffs into a single virtual mosaic with gdalbuildvrt.

  • If you do not have tiled tiffs rewrite them with gdal_translate by using creation option :

    -co TILED=YES

  • If overviews are missing, create them with gdaladdo

For optimising raster mosaic for QGIS, the same principles apply as when optimising rasters for an image server. Therefore this GeoServer presentation is good reading.

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If you have Mapinfo (v15 and beyond 64 bit), you can do this very easily. So Mapinfo has come up with a new Raster module which gives excellent performance in handling large datasets.

It's built to handle large datasets. And that too in a very efficient manner.

Just to give you an example, I recently downloaded 5m resolution DEM data of Australia. The data is derived from some 236 individual LiDAR surveys collected between 2001 and 2015. This data covers an area in excess of 245,000 square kilometres. Total data was >3 TB.

Mapinfo Advanced very easily handled this much data and merged it into a single file. For my purpose I used new Mapinfo Raster format (mrr), but you can create output in other supported formats too.

Panning and zooming was very smooth and i had no issue visualizing the data.

Let me know if you need more information regarding the same.

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