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Is there a way to add multiple layers to QGIS at once from a list of paths?

I have about 150 rasters to investigate that intersect an area of interest. Their full path is collected in a text file, one image per line. I know I can open layers on the command line with qgis path\to\imageone.tif path\for\imagetwo.tif but there's too many to add that way.

I've tried redirecting qgis < in-tiff-list.txt but that doesn't work.

I can open each image in it's own session with something like for /f %a in (in-tiff-list.txt) do qgis %a but that's a lot of memory overhead and you can't compare layers to each other.

Perhaps there's a way to inject into a running instance of Qgis instead of starting a new session? e.g. for {list of paths} do run "qgis --single-instance %file-path%" (pseudo code).

I'm running QGIS 3.16 on Windows.

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  • If the files are in the same folder, use Data Source Manager to select multiple files/the whole content of the folder at once.
    – Babel
    Commented Jul 8, 2021 at 19:30
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    Have you used the Load Them All plugin before? Depending on the file-folder structure you could configure it to load all your rasters.
    – Germán Carrillo
    Commented Jul 8, 2021 at 19:43
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    Depending on what you want to do afterwards, you could run an algorithm that expects raster layers as input: run it in batch mode, where you have sophisticated possibilities to load filenames, defining certain patterns for paths and/or using QGIS expressions to defained detailed instructions what files to use. Documentation does not mention it all, it is outdated: docs.qgis.org/3.16/en/docs/training_manual/processing/…
    – Babel
    Commented Jul 8, 2021 at 20:01
  • @Babel unfortunately the files are spread all over the place and not in one or even a handful of folders.
    – matt wilkie
    Commented Jul 8, 2021 at 20:05
  • @GermánCarrillo oh that looks interesting! ...but not for this scenario as the filenames don't have common fragments to apply search patterns to. Bookmarked for later though, thanks.
    – matt wilkie
    Commented Jul 8, 2021 at 20:07

2 Answers 2

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The crude I solution I went with is:

  • in a single folder build for each raster in the list file
  • drag and drop all the .vrt onto QGIS

I built the vrt files with (CMD Shell):

for /f %a in (in-tiff-list.txt) do ^
  (gdalbuildvrt staging-folder\%~na.vrt %a)

I'll have some more as yet unidentified legwork later to locate the home folder for each of the rasters but this solves the immediate visual need.

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I'm not sure about Windows but with a POSIX subshell you could do

qgis (cat in-tiff-list.txt)

which is equivalent to qgis path\to\imageone.tif path\for\imagetwo.tif. maybe there is something similar in PowerShell

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