[Insight-developers] itkHDF5ImageIOTest fails on 32 bit systems

[Williams, Norman K]

I figured this out.  The problem was that HDF5 is language-independent;
while C and C++ distinguish between int and long even if sizeof(int) ==
sizeof(long it), HDF5 does not.


So I had to add attributes to long/unsigned long datasets so they can be
distinguished at read time from int/unsigned int (and bool! ;-?)

This will have an effect on pixel data, but I don't think in practice it
will caise the same sort of problems.  If an image is written on a 32 bit
machine, it will read off disk as NATIVE_INT or NATIVE_UINT, and get
converted to whatever voxel type requested by ImageFileReader.

This only would show up if you were reading/writing itk::Image<long,Dim>
or itk::Image<unsigned long,Dim>.

The problem isn't confined to HDF5 files -- other image formats allow for
images of long int types, and you can get into situations where you're
reading a file written on a 32-bit machine on a 64-bit machine. The reader
and the writer have different ideas about how large a long int is.



On 5/30/11 1:55 PM, "Bill Lorensen" <bill.lorensen at gmail.com> wrote:

>Kent,
>
>The subject test is failing on 32 bit systems. After some CSI work, I
>found that HDF5 is not writing long's as long's on the systems. It
>writes them as int's. The test failure logic has two modes of
>failures. It is this test
>!itk::ExposeMetaData<long>(metaDict2,"TestLong",metaDataLong2) that
>fails. I put some print statements in the meta data code and metaDict2
>is returning an int type for long and an unsigned int type for
>unsigned long.
>
>Seems like an HDF5 config problem or bug, but I'm not up to digging into
>HDF5.
>
>Bill



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