Converts nodata value in a GeoTiff using GDAL

gdal-nodata-convert.sh

#!/usr/bin/env bash

cp "${INPUT}.tif" "${INPUT}-removed-nodata.tif"

INPUT="${INPUT}-removed-nodata.tif"
OUTPUT="${OUTPUT}.tif"

# Use gdal_edit.py to unset nodata metadata so we can use them in gdal_calc.py
gdal_edit.py -unsetnodata $INPUT

# Use gdal_calc.py to replace all values below 0 with -999, keep all other values.
rm $OUTPUT
gdal_calc.py -A $INPUT --outfile=$OUTPUT --calc="-999*(A<0)+A*(A>=0)" --NoDataValue=-999 

gdalinfo -stats $OUTPUT