Change No Data Value Geotif File with Qgis or Gdal

Question

I have a little question for Change No Data Value Geotiff File with Qgis or Gdal by another value. Usually one imports or exports a file with no data value -9999, but sometimes we need to change that number for another on raster calculator the expression != but it seems not to work with No data value any idea

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Nice discussion, Carlos but at same Kurt this option is for a range of data. I was user syntax band math of ENVI and I thought to apply something like this on Raster Calculator

( "MCD10A1_2018266@1" != -9999) * -8888 AND  ( "MCD10A1_2018266@1" >=  0 )  * "MCD10A1_2018266@1"

But I do not understand does not work!!

Answer 1

Another possibility

You could to use this tool Menu >> Raster >> Conversion >> Translate (convert format)

And assign the new value to no-data values,

Answer 2

To change No Data values of a raster to something else, like 0 or 1 or whatever, you can use the GRASS tool r.null.

Answer 3

I use this script:

#!/bin/bash

basename=$(echo "$1" | cut -f 1 -d '.')
mask=${basename}_mask.tif
output=${basename}_edt.tif
nodata=$(gdalinfo $1 | grep "NoData" | cut -d "=" -f 2)
gdal_calc.py --NoDataValue=$2 --calc="A!=${nodata}" --outfile="$mask" -A $1
gdal_calc.py --NoDataValue=$2 --calc="A*B" --outfile="$output" -A $1 -B $mask

First it gets the current no data value, then it creates a mask where the data is set as 1 and then multiplies that mask to get new image where no data is set with a parameter.

To run it just write it e.g. as gdal_change_nodata.sh and run it typing:

bash gdal_change_nodata.sh PATH_TO_YOUR_IMAGE.tif NEW_NO_DATA_VAL

or just change the values of $1 param by the path to your original file and $2 by the no data value that you want to set.

Answer 4

when you export the raster, context menu

"Export --> Export Raster Layer As..."

You could to change the no data value, see the picture

From -99999 To -88888 (per example)

Answer 5

I wanted to accomplish this within a Python script using GDAL personally. The following script worked for me

dataset = gdal.Open('path/to/image.tif')
band = dataset.GetRasterBand(1)
band.SetNoDataValue(2**16 - 1) # my No Data value was '65536'.. or 2^16 - 1
dataset.FlushCache()
del dataset