[GIS] gdal_merge.py with single band raster

gdalgdal-mergeimagerymosaicraster

I'm trying to mosaic the True Marble world imagery 250M geotiffs using gdal_merge.py though one of them doesn't have RGB bands like the rest and gdal_merge fails (same number of bands is listed as a requirement in it's documentation). This is the error I get:

python.exe : ERROR 5: TrueMarble.250m.21600x21600.B4.tif: GDALDataset::GetRasterBand(2) - Illegal band #

This is the tile causing the issue: TrueMarble.250m. 21600x21600.B4

Should I use a different mosaic tool or should I try to coerce the tile into the format gdal_merge requires somehow?

Best Answer

I ran across this mosaicing the True Marble imagery as well, though I used gdalbuildvrt and then gdal_translate. From memory, the recalcitrant tiffs are stored as a single band with a color table.

Just convert them to 3 band RGB with gdal_translate:

gdal_translate -expand rgb TrueMarble.250m.21600x21600.B4.tif TrueMarble.250m.21600x21600.B4.RGB.tif

Related Solutions

[GIS] mosaic rasters with gdal_merge.py

The problem is you are passing a list to subprocess then specifying shell=True (which expects a string as input) so it is only taking the first item in the list, which is gdal_merge, and running this. Just running gdal_merge.py gives the same error.

The same code but without shell=True should work:

import subprocess
filea = 'C:/Users/claudio/workspace/test/test1/rasa.tif'
fileb = 'C:/Users/claudio/workspace/test/test1/rasb.tif'
output = 'C:/Users/claudio/workspace/test/test1/output.tif'
subprocess.call(['gdal_merge', '-o' , output, filea, fileb])

[GIS] Combine multiple USGS topo quads into a single seamless raster

Rather than using individual US Topo quadrangles (which are designed to be displayed in that format), you can download the underlying vector data from The National Map and customize the extent of your display. (There is also a style sheet available to match the symbology of US Topo maps, although this is an ArcGIS-specific format and I don't know whether it can be converted to use in QGIS.)

Best Answer

Related Solutions

[GIS] mosaic rasters with gdal_merge.py

[GIS] Combine multiple USGS topo quads into a single seamless raster

Related Question