Hello,

I am using GDAL through OTB (the Orfeo Toolbox) to process TSX/TDX products 
with the specific driver: COSAR/COSAR Annotated Binary Matrix (TerraSAR-X).

With TSX products, the driver works fine.
I have also tried to read CoSAR files from TDX products. Data have a huge 
difference with a floating point data format instead of integer values. This 
floating format is a specific format called "Half Precision Floating Point" for 
each of the complex values. Thus, TDX products are not well-interpreted. 
Further information are available in 
TD-GS-PS-3028_TanDEM-X-Experimental-Product-Description_1.2. The annotations 
seem to be the same than TSX products.

I need your help to include this new format in GDAL and so in OTB.

As far as I can understand, the specific driver for CoSAR binaries is 
implemented in 
https://github.com/OSGeo/gdal/blob/master/gdal/frmts/cosar/cosar_dataset.cpp. 
The data type is set to GDT_CInt16. I think that explains why TDX are not 
well-interpreted. In my opinion, in order to include TDX products a conversion 
has to be made before assigning the buffer. I have found an algorithm to 
convert "half float" to single float : 
http://blog.schmorp.de/data/binary16/fasthalffloatconversion.pdf

Do you think, is it possible to implement this feature in GDAL?

Regards,
Gaëlle.

--------------------------------------------------------------------------------------------------------------
Gaëlle Usseglio -Thales Services
Responsable de prestation : Support HPC (Portages, Optimisations, Audits, 
Expertises, etc.)

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