How to output as Int16?

snap
#1

Hello,

I have been trying to transform backscattering values to int16 after rescaling [0,1] double to [0…10000] int. This for storage issues.

I use two tools : BandMaths (dB*10000) and Convert-Datatype (int16).

However, the BigTiff output is still in double (real 32).

Where can I set the option to have a 16bit integer BigTiff?

Thanking you in advance,

Guillaume

#2

I think you have als other bands in the product you write, right?
And probably one of them is still Float, or double.
In geotiff for all bands a single data type is used. And this is the one which covers the value range of all bands.
So either you need to split your product into single geotiff files or you need to convert als the other bands.

#3

For this one it’s only one band (coherence VV). So the proposed hypothesis doesn’t work. Is Snap supposed to adapt output format automatically?

Here is the corresponding graph : TOPSAR Coreg Interferogram IW All Swaths_test5_withBandMath_int16.xml (13.9 KB)

#5

Mmmh…
What is the data format if you write to BEAM-DIMAP, just for testing?
And have you tried to specify int16 directly in the BandMaths operator as type for the target band?

#6

I tried again, it works with BEAM-DIMAP.

As for changing in BandMaths : it’s outputting 16bit int but the overflow is not handled correctly ! And I cannot choose ‘truncate’.