[ITK Community] Smoothness term in ITK

[Matt McCormick]

Hi,

There is a class implemented that does Gaussian smoothing on a
displacement field transform during a registration iteration update:

 http://itk.org/Doxygen/html/classitk_1_1GaussianSmoothingOnUpdateDisplacementFieldTransform.html#a486d7a5466744497b3793b8161472fdc

Hope this helps,
Matt

On Sun, Jan 19, 2014 at 10:43 PM, David R. Haynor
<haynor at u.washington.edu> wrote:
> hi all,
>
> a smoothing term is easily incorporated into registration, along with its
> gradients.  i don't understand luis's comment.
>
> -dh
>
>
> On Mon, 20 Jan 2014, Andras Lasso wrote:
>
>>
>> It would be great to have a term in the registration metric to penalize
>> non-smoothness of the BSpline (displacement of the control points).
>> Currently, the
>> BSpline registration in ITK cannot be used on many radiation therapy CT
>> scans, because the BSpline control points wander randomly in the soft-tissue
>> regions
>> that look quite homogeneous in CT. For example, the BSpline registration
>> implementation in Plastimatch can penalize the control point displacement
>> and the
>> result is a nice smooth displacement field.
>>
>>
>>
>> Andras
>>
>>
>>
>> From: Community [mailto:community-bounces at itk.org] On Behalf Of Luis
>> Ibanez
>> Sent: January 19, 2014 3:44 PM
>> To: Hana Cherif
>> Cc: community at itk.org
>> Subject: Re: [ITK Community] Smoothness term in ITK
>>
>>
>>
>> Hana,
>>
>>
>>
>> A smoothing term, will probably only make sense for the Deformable
>> transforms:
>>
>>
>>
>> * Kernel Transform
>>
>> * Displacement Field
>>
>> * BSpline Deformations
>>
>>
>>
>> Note that, this would be rather a measure that is computed after the fact,
>>
>> rather than something that is computed during the registration process.
>>
>>
>>
>> Although in the case of the Demons registration, there is indeed the
>> equivalent
>>
>> of a smoothness constraint.
>>
>>
>>
>>    Regards,
>>
>>
>>
>>
>>
>>        Luis
>>
>>
>>
>>
>>
>>
>>
>> On Sun, Jan 19, 2014 at 3:27 PM, Hana Cherif <hanacherif62 at gmail.com>
>> wrote:
>>
>> Hi Mr.  Louis
>>
>> I  refer to transform classes in itk ,, thanks
>>
>>
>>
>> 2014/1/19 Luis Ibanez <luis.ibanez at kitware.com>
>>
>> Hi Hana,
>>
>>
>>
>> Are you referring to the itk::Transform classes ?
>>
>>
>>
>> or to Level Set filters ?
>>
>>
>>
>> Could you please elaborate a bit more ?
>>
>>
>>
>>     Thanks
>>
>>
>>
>>          Luis
>>
>>
>>
>>
>>
>> On Sun, Jan 19, 2014 at 3:21 PM, Hana Cherif <hanacherif62 at gmail.com>
>> wrote:
>>
>>       Hello,, all!!
>>
>> A question please ::  In addition to the similarity term,,  is there a
>> componnent  in itk used to compute the smothness term of that transformation
>> ??
>>
>> Thanks for help in advance!!
>>
>>
>>
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>>
>>
>>
>>
>>
>>
>>
>>
>
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