[Insight-users] 64-bit and mhd long int output (watershed 'labelled' image)

[Stephen R. Aylward]

Hi Robert,

Thanks for pointing this out.

What pixel type are you using?  What does sizeof return for your pixel type?

Regretfully I don't see an easy solution.   For example, we will 
probably need to define a new itkImageIOBase::ComponentType type and a 
new MetaIO::ValueEnumType to deal with longs on 64 bit machines.   As 
is, GetComponentSize does a sizeof(long) to determine the size of 
itkImageIOBase::ComponenType::LONG.   Since sizeof(long) differs by 
machine/OS, reading/writing images with pixel type LONG won't work 
on/from 64 bit machines - this is true for MetaIO images and any other 
image/pixel format that relies on ITK's report of ComponentSize and 
ComponentType.   There is simply no easy way to support 128bit longs on 
a 32 bit machine.

The easy "non-solution" is to use a different pixel type.   Ideally 
USHORT or maybe even UINT will work...

Did you add this problem to the bug tracker?

Thanks,
Stephen

Atwood, Robert C wrote:
> The good news is that the results on a Intel em64t (SUSE 9.1 gnu/Linux
> distib) for my use of the watershed appear good and somewhat faster than
> on the 32 bit machine. The bad news is that I only get half the output.
> I traced the problem to 'magic numbers' for the data element size
> defined as constants in metaTypes.h shown below. 
> 
> I am not sure how it should be fixed in keeping with overall ITK program
> style, I would use a preprocessor directive for a quick fix assuming
> that CMAKE can set a macro by probing the system information Is there
> already a macro created for this purpose?
> 
> or perhaps it is better in the long run to use a sizeof() -- then I
> don't think it can be const and cannot be set in the header file?
> 
> Also, I could not find the itk::MetaImageIO member object m_MetaImage in
> the Doxygen list of all members, though it appears in the header file as
> displayed by Doxygen.
> 
> ********** CVS status of the file *******************
> 
> ===================================================================
> File: metaTypes.h       Status: Up-to-date
> 
>    Working revision:    1.4
>    Repository revision: 1.4
> /cvsroot/Insight/Insight/Utilities/MetaIO/metaTypes.h,v
> 
> 
> 
> ************* Excerpt from metaTypes.h ****************
> 
>      27 typedef enum
>      28    {
>      29    MET_NONE,
>      30    MET_ASCII_CHAR,
>      31    MET_CHAR,
>      32    MET_UCHAR,
>      33    MET_SHORT,
>      34    MET_USHORT,
>      35    MET_INT,
>      36    MET_UINT,
>      37    MET_LONG,
>      38    MET_ULONG,
>      39    MET_FLOAT,
>      40    MET_DOUBLE,
>      41    MET_STRING,
>      42    MET_CHAR_ARRAY,
>      43    MET_UCHAR_ARRAY,
>      44    MET_SHORT_ARRAY,
>      45    MET_USHORT_ARRAY,
>      46    MET_INT_ARRAY,
>      47    MET_UINT_ARRAY,
>      48    MET_LONG_ARRAY,
>      49    MET_ULONG_ARRAY,
>      50    MET_FLOAT_ARRAY,
>      51    MET_DOUBLE_ARRAY,
>      52    MET_FLOAT_MATRIX,
>      53    MET_OTHER
>      54    } MET_ValueEnumType;
>      55
>      56
>      57 const unsigned char MET_ValueTypeSize[MET_NUM_VALUE_TYPES] = {
>      58    0, 1, 1, 1, 2, 2, 4, 4, 4, 4, 4, 8, 1, 1, 1, 2, 2, 4, 4, 4,
> 4, 4, 8, 4, 0 };
>      59
> 
> *********************copied   from Doxygen web pages
> **********************
> 
> http://www.itk.org/Doxygen/html/classitk_1_1MetaImageIO-members.html
> m_FileName	itk::ImageIOBase	 [protected]
> m_FileType	itk::ImageIOBase	[protected]
> m_Initialized	itk::ImageIOBase	[protected]
> m_IORegion	itk::ImageIOBase	[protected]
> m_NumberOfComponents	itk::ImageIOBase	[protected]
> m_NumberOfDimensions	itk::ImageIOBase	[protected]
> m_Origin	itk::ImageIOBase	[prot
> 
> 
> 
> http://www.itk.org/Doxygen/html/itkMetaImageIO_8h-source.html
> 00097 private:
> 00098   
> 00099   MetaImage m_MetaImage;
> 00100 
> 00101   MetaImageIO(const Self&); //purposely not implemented
> 00102   void operator=(const Self&); //purposely not implemented
> 00103   
> 00104 }; 
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-- 
===========================================================
Dr. Stephen R. Aylward
Associate Professor of Radiology
Adjunct Associate Professor of Computer Science and Surgery
http://caddlab.rad.unc.edu
aylward at unc.edu
(919) 966-9695