[gdal-dev] Set/Get Scale and Offset in GDALRasterBand

[Alexander Bobkov]

Hi,

What is the intended usage of methods 
SetScale/GetScale/SetOffset/GetOffset of the GDALRasterBand class?

Documentation says that
>
> This value (in combination with the GetOffset() 
> <http://www.gdal.org/classGDALRasterBand.html#ab62e0761dde3e3b76f83155920275e4f> 
> value) is used to transform raw pixel values into the units returned 
> by GetUnits(). For example this might be used to store elevations in 
> GUInt16 bands with a precision of 0.1, and starting from -100.
>
> Units value = (raw value * scale) + offset
>

Who is responsible for applying the formula: client code before/after 
RasterIO operation, or driver code inside IReadBlock/IWriteBlock methods?

Best regards,
Alexander Bobkov
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