[Insight-users] Gradient Vector Field and Level Set

[Luca Antiga]

Hey Diana,
  sorry for the late reply.
Yes, this is what I meant. What is the exact problem you're getting  
when you do the thing below?
SetAdvectionImage takes a Image< FixedArray<... as pixel type, and  
CovariantVector is derived
from FixedArray, so it should work, if I'm not missing anything.
But I believe you when you say it doesn't: can you post a dump of the  
errors?

Luca


On Nov 17, 2008, at 11:13 AM, droettger at uni-koblenz.de wrote:

> Hey Luca,
>
> thaks for your help so far. I see how the different terms work.
> I've tried th SetAdvectionImage method, but I didn't succeed.
>
> Here are parts out of my code:
>
> typedef itk::CovariantVector< double, 3 >  GradientPixelType;
> typedef itk::Image< GradientPixelType, 3> GradientImageType;
>
> typedef itk::GradientVectorFlowImageFilter<GradientImageType,
> 	GradientImageType> GVFFilterType;
>
> GradientImageType::Pointer m_GVFField;
>
> m_GVFField = gradientVectorFlow->GetOutput();
>
> geodesicActiveContour->SetAdvectionImage(m_GVFField);
>
> This is what you meant, right?
>
> Thanks,
> Diana
>
>> Hey Diana,
>>   you should set the vector image using the SetAdvectionImage method.
>> The template parameter for the FeatureImageType has to be a scalar
>> image of the same type of your gradient (take a look at the source
>> code for the filter).
>> I'm in a bit of a rush now, please get back to me if you don't
>> succeed and I'll give you step by step instructions.
>> Regards
>>
>> Luca
>>
>>
>>
>> On Nov 13, 2008, at 5:31 PM, droettger at uni-koblenz.de wrote:
>>
>>> Hey,
>>>
>>> do you mean that I should declare the feature image, the input of
>>> GeodesicActiveContourLevelSetImageFilter, as the output of the
>>> GradientVectorFlowImageFilter?
>>>
>>> I defined a GradientImageType:
>>> typedef itk::CovariantVector< double, 3 >  GradientPixelType;
>>> typedef itk::Image< GradientPixelType, 3> GradientImageType;
>>>
>>> Hence, the definition of GeodesicActiveContourLevelSetImageFilter  
>>> is:
>>>
>>> typedef itk::GeodesicActiveContourLevelSetImageFilter<
>>> InternalImageType,
>>> 	GradientImageType > GeodesicActiveContourFilterType;
>>>
>>> Am I right? That doesn't work in my case.
>>> How should I integrate the vector field?
>>>
>>> Thanks,
>>> Diana
>>>
>>>
>>>
>>>> Hi Diana,
>>>>  you should use it as the advection field in the
>>>> GeodesicActiveContourLevelSetImageFilter, rather than speed.
>>>> Best regards
>>>>
>>>> Luca
>>>>
>>>> 2008/11/13, droettger at uni-koblenz.de <droettger at uni-koblenz.de>:
>>>>> Hi,
>>>>>
>>>>> I want to include the itkGradientVectorFlowImageFilter into a
>>>>> level set
>>>>> approach, using the ShapeDetectionLevelSetImageFilter.
>>>>> The gradient diffusion, resulting out of GVF should perform an
>>>>> external
>>>>> force, in terms of the level set speed function.
>>>>>
>>>>> My question is, if I can simply use the output of
>>>>> itkGradientVectorFlowImageFilter as the speed image, since it is a
>>>>> vector
>>>>> field, and needs a diffrent approximation than a scalar image.
>>>>>
>>>>>
>>>>> Thanks in advance,
>>>>> Diana
>>>>>
>>>>> _______________________________________________
>>>>> Insight-users mailing list
>>>>> Insight-users at itk.org
>>>>> http://www.itk.org/mailman/listinfo/insight-users
>>>>>
>>>>
>>>> --
>>>> Inviato dal mio dispositivo mobile
>>>>
>>>> Luca Antiga, PhD
>>>>  Biomedical Technologies Laboratory
>>>>  Biomedical Engineering Department,
>>>>  Mario Negri Institute
>>>> mail: Villa Camozzi, 24020, Ranica (BG), Italy
>>>> phone: +39 035 4535-381
>>>> email: antiga at marionegri.it
>>>> web: http://villacamozzi.marionegri.it/~luca
>>>>
>>>
>>>
>>> _______________________________________________
>>> Insight-users mailing list
>>> Insight-users at itk.org
>>> http://www.itk.org/mailman/listinfo/insight-users
>>
>>
>
>