17

I am wondering how I can make a band composite from three large bands files from Landsat? I was using option Raster>Miscellaneous>Merge but when I try to do it it crashes.

  • I guess this is for QGIS; if it is the case, please edit your question to mention it. – ArMoraer Mar 15 '16 at 16:23
  • What do you mean it crashes? – HeikkiVesanto Mar 15 '16 at 16:43
  • Just crashes. I assume that this option is for rasters as tiles to be merged in one picture – Dragan Mar 16 '16 at 21:51
25

This is something you can achieve with a Virtual Raster (Catalog). This will create a metadata file (.vrt) that QGIS treats like a merged multi-band raster without having to merge all the bands.

  1. Raster --> Misc. --> Build Virtual Raster
  2. Select the bands you want to use as "Input files"
  3. Check "Separate" to put each input file into a single band (otherwise they will be merged spatially and all put into a single band)
  4. Open the Virtual Raster (.vrt) in QGIS and treat it like a merged composite

Here is an example using a Landsat 8 scene of the Alps to create a band 7,5,2 false color composite. Creation of the Virtual Raster (urban-fcc.vrt) takes seconds and the file is 3KB in size.

enter image description here enter image description here

  • Yes that is exectly what I need. How I can later save it as GeoTiff file? – Dragan Mar 16 '16 at 21:46
  • 3
    You can right click on the layer and use "Save as..GeoTiff" or go to "Raster --> Conversion --> Translate". But this might crash your PC again, since the "merge" tool uses VRTs internally anyway. – Kersten Mar 17 '16 at 8:18

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