[gdal-dev] Writing raster - 0 in every even column

[Goo Creations]

Ah, thanks. This solved the problem.
I however face the problem that I don't know which data type the image has.
So I can't hardcode the array to unsigned short, since it might sometimes be
a int32 or even a float. So is there a way to do this in a generic way?

Chris

On Fri, Jun 3, 2011 at 12:21 PM, Even Rouault
<even.rouault at mines-paris.org>wrote:

> Le vendredi 03 juin 2011 12:13:41, Goo Creations a écrit :
> > Hi all
> >
> > I have a strange problem when writing to a GDAL dataset. I'm currently
> > doing the following:
> >
> > *GDALDataset *mInputDataset = (GDALDataset*) GDALOpen("in.tif",
> > GA_ReadOnly);
> > GDALDataType type = mInputDataset->GetRasterBand(1)->GetRasterDataType();
> > int mWidth = mInputDataset->GetRasterXSize();
> > int mHeight = mInputDataset->GetRasterYSize();
> >
> > GDALDataset *mOutputDataset =
> mInputDataset->GetDriver()->Create("out.tif",
> > mWidth, mHeight, mBands, type, 0);
> >
> > int *data = <<get data for entire band>>
> > mOutputDataset->GetRasterBand(1)->RasterIO(GF_Write, 0, 0,
> aligner.width(),
> > aligner.height(), data, aligner.width(), aligner.height(), type, 0, 0);
> > mOutputDataset->FlushCache();
> > *
> >
> > The input image provided has a datatype of UINT16. When I hardcode all
> > "type" variables in the above example to GDT_Int32, then the image is
> > correctly created, but when I leave the example as is (hence with
> > GDT_UInt16 assigned to "type"), then I get a strange problem that every
> > second column has a value of 0. So every odd column has the correct
> values
> > in, but every even column has values of 0. I've checked the data array,
> > and all the values in there are correct.
> >
> > Does anyone know why this is happening?
>
> Yes, the type parameter must be consistent with the C type of the data
> array,
> otherwise weird things can happen, including crashes.
>
> In your exemple data is of type int*, so type must be set to GDT_Int32.
> If you want to write GDT_UInt16, then data must be declared as being of
> type
> unsigned short*
>
>
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