[Insight-developers] Bug in itkShrinkImageFilter

[Bill Lorensen]

Hans,

Another issue if you make your changes. If the new Shrink is run on a
labeled image, I believe your code will interpolate the new pixels.
This behavior is not desirable for subsampling a labeled image.

Perhaps we should leave this filter alone and change the
multiresolution pyramid code to use ResampleImageFilter with the
proper values set to do subsampling.

Bill

On Wed, Dec 10, 2008 at 12:05 AM, Bill Lorensen <bill.lorensen at gmail.com> wrote:
> Hans,
>
> The documentation for ShrinkImageFilter says that it does simple
> subsampling. So it is not really a bug according to the documentation.
> However, I think your implementation is more useful (I assume it is
> correctly done). You should probably fix the documentation in the .h
> file when you commit these changes.
>
> Also, beware that we have enabled a KWStyle commit check for some
> directories. These directories are Testing/Code/Review, Code/Review,
> Code/IO and Code/BasicFilters. All of these directories are currently
> clear of any style defects.
>
> Bill
>
> On Tue, Dec 9, 2008 at 11:55 PM, Bill Lorensen <bill.lorensen at gmail.com> wrote:
>> Hans,
>>
>> Two of the tests are seg faulting.
>>
>> Bill
>>
>> On Tue, Dec 9, 2008 at 11:38 PM, Hans Johnson <hans-johnson at uiowa.edu> wrote:
>>> Luis and Bill,
>>>
>>> I think I've uncovered a bug in the itkShrinkImageFilter that has
>>> ramifications in any use of the itkMultiResolutionPyramidImageFilterTest.
>>>
>>> I was writing a program that aligns the mid-sagital plane with the center of
>>> an image, and found that as I went from low-resolution estimates to
>>> high-resolution estimates, the center of mass of the object in the different
>>> scale images would change.
>>>
>>> A new test (currently failing) has been added, and the patch that makes that
>>> test pass has been included in the Bug report:
>>> http://public.kitware.com/Bug/view.php?id=8275
>>>
>>> This change, however, will cause any of the tests that depend on the
>>> MultiResolutionPyramidImage (and prehaps others) to start failing.  I'd like
>>> your advice on how to get this bug fix resolved in the least obtrusive way.
>>>
>>> Thanks,
>>> Hans
>>>
>>>
>>
>