[gdal-dev] NODATA value in rasters

[Carl Godkin]

On Fri, Apr 13, 2012 at 12:07 PM, David Strip <gdal at stripfamily.net> wrote:

> What data formats besides geotiff  support a NODATA value? Is there a
> uniform GDAL approach to determining the NODATA value or otherwise
> determining if a pixel is a NODATA pixel? I know that this value is stored
> in a geotiff tag, but that won't work for other formats.
>
>
>
>
I think a lot of formats support the concept of NODATA.  The GDAL API has
functions for checking for this in the GDALRasterBand class, for instance,
as
double GDALRasterBand::GetNoDataValue() in the C++ or in the C API
as GDALGetRasterNoDataValue().

I've found that this sometimes works, but not always.  What I do is to read
the raster data and change everything outside the minimum to maximum range
(returned by two other API functions) to my own software's NODATA value.

Hope that helps,

carl
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