[Insight-developers] itk::ImageBase::TransformIndexToPhysicalPoint/TransformPointToContinuousIndex ignores spacing?

[Tom Vercauteren]

Well, what is the policy for moving a class from review to ITK proper?

It might be a good time to move this interpolator if someone needs it
for a bug fix.

Thoughts anyone?

Tom

On Tue, Mar 17, 2009 at 20:12, kent williams
<norman-k-williams at uiowa.edu> wrote:
> This is actually exactly what I need, but unfortunately, I can't change a
> filter that is part of ITK proper to depend on a class in review ;-)
>
>
> On 3/17/09 1:57 PM, "Tom Vercauteren" <tom.vercauteren at m4x.org> wrote:
>
>> Kent,
>>
>> You might also want to switch the interpolator for an
>> interpolator/extrapolator such as the one I contributed to the Review
>> directory:
>> http://www.itk.org/Doxygen/html/classitk_1_1VectorLinearInterpolateNearestNeig
>> hborExtrapolateImageFunction.html
>>
>> With this function, all points are considered as inside the buffer. I
>> think that this approach makes sense in your case.
>>
>> Hope this helps,
>> Tom
>>
>> On Tue, Mar 17, 2009 at 19:43, Bill Lorensen <bill.lorensen at gmail.com> wrote:
>>> Look at what I did in ShrinkImageFilter recently. At Hans's request
>>> (do we all work for Hans?) I changed the subsampling so that the image
>>> centers aligned.
>>>
>>> Bill
>>>
>>> On Tue, Mar 17, 2009 at 11:33 AM, kent williams
>>> <norman-k-williams at uiowa.edu> wrote:
>>>> I was aware of the issue, just never tripped over it before.
>>>>
>>>> I'm just not sure how to deal with it in this case.  It points out a
>>>> fundamental problem in what I'm trying to do.  The net effect is this:
>>>>
>>>> Image A has dimensions { n, n, n } and spacing { s, s, s }
>>>> Image B has dimensions { n/2, n/2, n/2 } and spacing { s*2, s*2, s*2 }
>>>> Assume origin = { 0, 0, 0 } for both, and both are in the same orientation.
>>>>
>>>> Any physical point on an edge farthest from the origin -- e.g. { n-1, y, z
>>>> }, { x, n-1, z }, { x, y, n-1 } etc -- is INSIDE image A, but NOT INSIDE
>>>> image B.  Even though the two images theoretically have the same volume.
>>>>
>>>> And this is independent of whether the index is center-of-voxel or corner of
>>>> voxel, or whether you're a North-going Zax or a South-going Zax.
>>>>
>>>> The mind reels.
>>>>
>>>> On 3/17/09 1:01 PM, "Tom Vercauteren" <tom.vercauteren at gmail.com> wrote:
>>>>
>>>>> Hi Kent,
>>>>>
>>>>> You might already be aware of that bug:
>>>>> http://www.itk.org/Bug/view.php?id=6558
>>>>>
>>>>> Right now the use of rounding vs. truncation is not consistent within
>>>>> the index <-> world transformations.
>>>>>
>>>>> Tom
>>>>>
>>>>
>>>>
>>>>
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