I am trying to change the null values of a raster from -32768 to -3.40282e+38 in QGIS. I tried using warp tool setting the no data values to my desired number but it did not change it. Then I used the translate tool and didn't change it either... I tried using r.null to in grass and it change it to 2.14748e+09 I don't know another method or what should I try to change?
In this test raster (20x20), with values between 1 and 50, I replaced 19 value by -32768 value.
In the following raster, the -32768 values were replaced by -3.40282e+38 values (see window of Value Tool Plugin):
The used expression is in the window of "Raster calculator expression" (below image and code sample):
These changes were verified with Value Tool Plugin (below image). Blue areas have the original values of test raster.