I found Markus N's 'gdal tips and tricks' web page and tried applying it to warp a DEM so north is up rather than tilted to the right.
The script: ----- #!/usr/bin/bash # set region to the map to be warped g.region rast=45123h5_clatsop # The file format is ENVI or Ehdr, not a GTiff so use r.gdal.out r.out.gdal in=45123h5_clatsop out=45123h5_clatsop.tif for=GTiff --o # raster map reprojection (warping) gdalwarp -rb 45123h5_clatsop.tif test1.tif ----- r.out.gdal appears to work but did not like the 'elev' color scale; r.out.gdal in=45123h5_clatsop out=45123h5_clatsop.tif for=GTiff --o Checking GDAL data type and nodata value... 100% Using GDAL data type <Float32> Input raster map contains cells with NULL-value (no-data). The value -nan will be used to represent no-data values in the input map. You can specify a nodata value with the nodata option. Exporting raster data to GTiff format... ERROR 6: SetColorTable() only supported for Byte or UInt16 bands in TIFF format. 100% r.out.gdal complete. File <45123h5_clatsop.tif> created. The gdalwarp test1.tif output looks the same as the input .tif. It's still slightly skewed clockwise. Since I've not before had a need to use gdalwarp I'm totally inexperienced with the tool. How should the script be modified to produce a northup.tif output that can be imported back to grass with r.in.gdal? TIA, Rich _______________________________________________ grass-user mailing list [email protected] https://lists.osgeo.org/mailman/listinfo/grass-user
