[Insight-developers] failing itkImageFileReaderDimensionsTest_MHD

[Wes Turner]

The first line should have said "I found one code error that I checked
in a fix for - ..."

- Wes

On Mon, May 18, 2009 at 3:16 PM, Wes Turner <wes.turner at kitware.com> wrote:
> Bradley,
>
> I found one code error that I checked in -- a bad file name in the
> last write -- and I also found that by adding a reader update before
> the 4D->3D conversion code the test both passes and doesn't hang my
> VS9 build.  This is now checked in along with a comment that you are
> continuing to work the issue.  This may be a stop-gap, but at least it
> allows the dashboard to run while you look into it.
>
> If you need a Microsoft (or Linux, or Mac) test platform before you
> check in your change, feel free to send your patch to me before you
> commit it and I can test it out for you.
>
> - Wes
>
> On Mon, May 18, 2009 at 2:38 PM, Bradley Lowekamp
> <blowekamp at mail.nih.gov> wrote:
>> There are bugs in the ImageFileReader related to reading of images where
>> dimensions don't match. It can be broken into the following cases:
>>
>> 1) IO Dimension (from file) == ImageDimension (tempted image type)
>> This works good, it's the normal things to do.
>> 2) IO Dimension < ImageDimension
>> ImageSeriesReader makes use of this. When reading 2D slices into a 3D image
>> it requests ImageFileReader regions with size [x, y, 1]. And
>> ImageFileReader::GenerateOutputInformation pads the size of the output
>> image's LargestPossibleRegion with 1s. This works too, I don't see any
>> problems. (Excluding direction cosine issues)
>> 3) IO Dimension > ImageDimension
>> 3a) If the IORegion's size is padded with 1s after ImageDimension, then
>> currently should work with all file types. For example if a 3D image file
>> has size [x,y,1] then it can be read into a 2D image with size [x,y]
>>
>> 3b) If the IORegions's size ends in non-one values, we can have problems,
>> like segfaults. This is because the size of the buffers don't match, and
>> ImageIO object will over write the image buffer.
>> However the ImageIO classes which support streaming appear to handle this
>> case correctly, by padding the region size with 1s.
>>
>> My proposed solution is to
>> modify ImageIOBase::GenerateStreamableReadRegionFromRequestedRegion to
>> actually return the full dimensionality of the image. This reflects what the
>> ImageIO can actually do. Then in
>> ImageFileReader::EnlargeOutputRequestedRegion and a check to make sure this
>> case is not occurring.
>>
>>
>> On May 16, 2009, at 3:39 PM, Lowekamp, Bradley (NIH/NLM/LHC) [C] wrote:
>>
>> This is my doing, I should be checking the fix in on monday.
>>
>> http://www.cdash.org/CDash/testSummary.php?project=2&name=itkImageFileReaderDimensionsTest_MHD&date=2009-05-16
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>> ========================================================
>>
>> Bradley Lowekamp
>>
>> Lockheed Martin Contractor for
>>
>> Office of High Performance Computing and Communications
>>
>> National Library of Medicine
>>
>> blowekamp at mail.nih.gov
>>
>>
>> _______________________________________________
>> Powered by www.kitware.com
>>
>> Visit other Kitware open-source projects at
>> http://www.kitware.com/opensource/opensource.html
>>
>> Please keep messages on-topic and check the ITK FAQ at:
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>>
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>>
>
>
>
> --
> Wesley D. Turner, Ph.D.
> Kitware, Inc.
> R&D Engineer
> 28 Corporate Drive
> Clifton Park, NY 12065-8662
> Phone: 518-371-3971 x120
>



-- 
Wesley D. Turner, Ph.D.
Kitware, Inc.
R&D Engineer
28 Corporate Drive
Clifton Park, NY 12065-8662
Phone: 518-371-3971 x120