[Insight-developers] ITKv4: Features vs Clean up

Thu Jun 30 08:12:24 EDT 2011

Hi Brian,

This looks very interesting.  I hope you dont mind a few questions.
If theres a written document to refer me to, feel free.

I've been reading this:
http://www.itk.org/Wiki/ITK_Release_4/Enhancing_Image_Registration_Framework
but i have trouble mapping it to what i see in the GIT.

I'm having some trouble identifying all the diffs between the
Registration branch and current ITK master, but it seems to me that
most is in Modules/Registration/Refactoring.  Would that be the case?
Is this ImageToObjectRegistration framework intended to replace one or
more of the current Parametric / PDE / FEM registration frameworks, or
to be in parallel with them.   Or, to ask my question another way - I
currently have some feedback / commentary regarding
itkOptimizer.h and its children...
itkCompositeTransform.txx
itkImageToImageMetric.txx
itkNormalizedCorrelationImageToImageMetric.txx
which are in Modules/Registration/Common

Currently in RegistrationRefactoringNew these seem to be the same as
in master.  Will the new refactored framework replace these classes,
so i shouldnt spend any time fiddling with them, or is it more or less
independent.

I've only had about half an hour to look at it, and i havent had time
to compile it yet, so i may be about to embarrass myself with a stupid
question.  I'll ask anyway.  A core fundamental refactoring - looking
at the example you pointed me to - is that the update to the
parameters seems to have been pushed down all the way to the
transform, via the metric in the middle.  This is a very interesting
choice - for transforms such as the versor transform, which must
remain on a manifold that doesnt embed well in Euclidean space, this
removes the constraint issue from the optimizer. However - it did make
me wonder - what if i want to do anything other than gradient descent?
 Also, it seems to force the computation to complete an entire
computation of the gradient, and hold it in memory, even though for a
local transform, it may be possible to perform the same update without
ever actually creating the whole gradient object in memory at once?

I saw tantalizing pieces of GPU registration code commented out.  Is
that in process somewhere?

In any case, i will spend more time on it which should hopefully lead
to more intelligent commentary, over the weekend.

Cheers,
Rupert
--------------------------------------------------------------
Rupert Brooks
rupert.brooks at gmail.com

On Wed, Jun 29, 2011 at 21:13, brian avants <stnava at gmail.com> wrote:
> rupert
>
> help is very welcome.
>
> refactored registration framework is here:
>
> https://github.com/picslITK/ITK4_topics/tree/RegistrationRefactoringNew
>
> take a look at :
>
> ITK4_topics/Modules/Registration/Refactoring/test/itkDemonsImageToImageObjectRegistrationTest.cxx
>
> which gives an example of a demons registration run in the standard
> framework.  the framework is changing, though, so realize what's there
> now is a mid-stream snapshot.
>
> brian
>
>
>
>
> On Wed, Jun 29, 2011 at 8:59 PM, Rupert Brooks <rupert.brooks at gmail.com> wrote:
>> Hi Luis and everyone,
>>
>> As a pretty heavy user of ITK, I'm interested in helping out as well.
>> At the moment im working on some registration problems and im trying
>> to explore the refactored registration framework in ITK 4.
>> As im going through the current master, im noticing various things
>> ranging from typos to classes that seem to have gotten left behind to
>> questionable math.  I'd be happy to give this information as feedback
>> or fixes if its helpful.
>>
>> So question 1 - is the registration refactoring well represented in
>> ITK master, or is there more work elsewhere?  Is this the right time
>> to review it from a user perspective or is it premature?
>>
>> Question 2 - whats the best way to proceed?  Do i need to configure
>> Gerrit access, etc as a developer to contribute to the textual notes
>> you mentioned?
>>
>> Cheers,
>> Rupert
>> --------------------------------------------------------------
>> Rupert Brooks
>> rupert.brooks at gmail.com
>>
>>
>>
>>
>> On Fri, Jun 3, 2011 at 09:46, Luis Ibanez <luis.ibanez at kitware.com> wrote:
>>> Hi Tom,
>>>
>>> Thanks for volunteering.
>>>
>>>
>>> The plans for the global clean up are here:
>>> http://www.itk.org/Wiki/ITK_Release_4/Global_Code_Review
>>>
>>> The procedure is described here
>>> http://www.itk.org/Wiki/ITK_Release_4/Modularization/Code_Reviews/Process#Git-Based
>>>
>>> Essentially:
>>>
>>> We have a duplicate Git repository
>>> https://github.com/InsightSoftwareConsortium/itk-retroactive-review
>>>
>>> that contains a .txt file for every source code file in ITK.
>>>
>>> Instead of making bug entries in MANTIS,
>>> just edit those .txt files, and commit them.
>>>
>>> Of course, if some issues are actual bugs,
>>> please feel free to report them in MANTIS.
>>>
>>>
>>> More comments below...
>>>
>>>
>>> On Fri, Jun 3, 2011 at 5:11 AM, Tom Vercauteren <tom.vercauteren at m4x.org> wrote:
>>>> Hi Luis,
>>>>
>>>> I would like to help in the cleanup process (especially for the code I
>>>> worked on in the past) but have unfortunately very little time for it.
>>>> The least I could do is pinpoint some places that I believe require
>>>> cleanup. The problem is I don't really know if such a task is wanted
>>>> and if so, how it should be done. Should I file bug reports  for each
>>>> cleanup task and mark them as feature requests? But then, who would be
>>>> in charge of triaging these feature requests? Are other more effective
>>>> options available?
>>>>
>>>
>>> http://www.itk.org/Wiki/ITK_Release_4/Modularization/Code_Reviews/Process#Git-Based
>>> https://github.com/InsightSoftwareConsortium/itk-retroactive-review
>>>
>>>> For the time being, there are a least a few places on the top of my
>>>> head that require cleanup (some of which might be considered as
>>>> features depending on how you look at it). Sorted by order of
>>>> importance:
>>>>
>>>> 1) Bad design in ImportImageContainer.
>>>> https://github.com/Kitware/ITK/blob/master/Modules/Core/Common/include/itkImportImageContainer.h
>>>> The memory allocation and deallocation functions have an inconsistent
>>>> signature. One uses a member and the others returns a pointer:
>>>>  virtual TElement * AllocateElements(ElementIdentifier size) const;
>>>>  virtual void DeallocateManagedMemory();
>>>>
>>>> This makes it really difficult to override the class in a correct
>>>> manner. I have actually stumped into a bug in TestImportImageContainer
>>>> coming from this design issue ( that I haven't filed yet :( )
>>>> https://github.com/Kitware/ITK/blob/master/Modules/Core/Common/test/itkFactoryTestLib.cxx
>>>> With this TestImportImageContainer class, reallocating an image will
>>>> fail. This is bad since it will most certainly be the first thing
>>>> people will look at when trying to override the default memory
>>>> handling of ITK.
>>>>
>>>
>>> Fair enough...
>>>
>>>>
>>>> 2) The unicode filename problem on windows.
>>>> Most of the low-level code necessary to deal with unicode filenames
>>>> through utf-8 encoding is already in the repository but it isn't used
>>>> yet. What still need to be done is use this low-level code for all IO
>>>> operations. More detail in:
>>>> http://www.itk.org/Bug/view.php?id=9623
>>>>
>>>>
>>>> 3) There are a lot of useless vector-specific classes that were
>>>> introduced probably for MSVC 6. It might be the right time to merge
>>>> them back into the corresponding "scalar" classes.
>>>> http://itk.org/Bug/view.php?id=2712
>>>> http://www.itk.org/Wiki/ITK_Release_4/Wish_List#Image_Registration
>>>>
>>>
>>> Yes,
>>> Cory, Arnaud, Gaetan and Brad L. have been improving
>>> the support for multiple components...
>>> We need raise the priority of this one,
>>> since it is so fundamental for
>>> Microscopy and for Remote Sensing.
>>>
>>>
>>>>
>>>> 4) Some default options are not the most meaningful ones:
>>>> http://www.itk.org/Wiki/ITK_Release_4/Wish_List#Backward_compatibility_and_cleanup
>>>> For example Gaussian smoothing uses either a sigma defined in terms of
>>>> physical space or pixel space depending on its implementation
>>>> (discrete versus recursive).
>>>>
>>>
>>> Yeap, the API is inconsistent.
>>> Plus some take Sigma, while others take Variance...
>>>
>>>>
>>>> 5) Others inconsistencies
>>>> http://www.itk.org/Bug/view.php?id=7351
>>>> http://www.itk.org/Bug/view.php?id=8944
>>>> http://www.itk.org/Wiki/ITK_Release_4/Wish_List#Make_the_boundary_conditions_usage_consistent_across_the_toolkit
>>>> For example the behavior of the interpolators outside the image domain
>>>> is not practical. This is one of the reason why I implemented
>>>> VectorLinearInterpolateNearestNeighborExtrapolateImageFunction
>>>> https://github.com/Kitware/ITK/blob/master/Modules/Nonunit/Review/include/itkVectorLinearInterpolateNearestNeighborExtrapolateImageFunction.h
>>>> Ideally, the functionnality of this class should be handled by
>>>> LinearInterpolateImageFunction.
>>>>
>>>>
>>>> Hope this helps,
>>>
>>>
>>> It certainly does.
>>>
>>>
>>>   Many Thanks
>>>
>>>
>>>        Luis
>>>
>>>
>>>
>>> -----------------------------
>>>> Tom
>>>>
>>>> On Thu, Jun 2, 2011 at 15:06, Luis Ibanez <luis.ibanez at kitware.com> wrote:
>>>>> I want to second Brad L. comment regarding
>>>>> our current misplaced focus on ITKv4.
>>>>>
>>>>> There is a disproportionate number of changes
>>>>> that are introducing new features in the toolkit,
>>>>> when we are supposed to be focused on cleaning
>>>>> up and restructuring for the next 10 years.
>>>>>
>>>>> I suggest that we prioritize every patch in Gerrit
>>>>> based on whether it is:
>>>>>
>>>>>
>>>>> 1) Bug fix
>>>>> 2) Clean up resulting from code reviews
>>>>> 3) Needed for refactoring (FEM, Regist, LevelSets)
>>>>> ....
>>>>> 99) New features
>>>>>
>>>>>
>>>>> We have limited time and resources to do all
>>>>> the refactoring and revision of ITKv4 and we
>>>>> are being side-tracked dealing with changes
>>>>> that are not part of the ITKv4 charter.
>>>>>
>>>>>
>>>>>       Luis
>>>>> _______________________________________________
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>>>>>
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>>>>>
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>>>>> http://kitware.com/products/protraining.html
>>>>>
>>>>> Please keep messages on-topic and check the ITK FAQ at:
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>>>>>
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>>>>>
>>>>
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>> _______________________________________________
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>>
>> Visit other Kitware open-source projects at
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>>
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>> http://kitware.com/products/protraining.html
>>
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>