[ITK-users] [ITK] Filter working on both itk::Image and itk::VectorImage

[Lowekamp, Bradley (NIH/NLM/LHC) [C]]

Hello,

Sorry I didn’t see this sooner.

You want to look at the itk::Image::Rebind class. I created it for this exact purpose. [1] 

You can look at itkSmoothingRecursiveGaussianImageFilter.h for an example usage.

HTH,
Brad

[1] https://itk.org/Doxygen/html/structitk_1_1Image_1_1Rebind.html

> On Feb 27, 2017, at 6:09 AM, Cyril Mory <cyril.mory at creatis.insa-lyon.fr> wrote:
> 
> Hi,
> 
> Still the same topic, but a different issue:
> 
> I have a filter that is templated over its image input type, usually itk::Image<T, dim>. I want to modify it so that it also works when that type is itk::VectorImage<T, dim>.
> 
> This filter internally defines SliceType = itk::Image<InputImageType::InternalPixelType, dim - 1>. But when processing an itk::VectorImage, I would like this SliceType to be itk::VectorImage<InputImageType::InternalPixelType, dim - 1>.
> 
> I don't think there is a way in C++ to recover the itk::Image<> or the itk::VectorImage<> "un-templated", and define a type with whole new template arguments. But is there an ITK mechanism that would solve my problem ?
> 
> Best regards,
> 
> Cyril
> 
> On 22/02/2017 17:39, Matt McCormick wrote:
>> Hi Cyril,
>> 
>> Yes, this is a good approach.  Thanks for sharing your investigation.
>> 
>> Matt
>> 
>> On Wed, Feb 22, 2017 at 5:52 AM, Cyril Mory
>> <cyril.mory at creatis.insa-lyon.fr> wrote:
>>> Answering my own question:
>>> 
>>> I found a way to do what I needed using itk::NumericTraits<T> :
>>> 
>>>   OutputImagePixelType pix;
>>>   itk::NumericTraits<OutputImagePixelType>::SetLength(pix,
>>> this->GetVectorLength());
>>>   pix = itk::NumericTraits<OutputImagePixelType>::OneValue(pix) * value;
>>> 
>>> It works for both cases with the same code. However, if there is a better
>>> way (cleaner, safer, more compact, ... whatever the wayin which it is
>>> better), I'd be happy to learn about it.
>>> 
>>> Best regards,
>>> Cyril
>>> 
>>> 
>>> On 22/02/2017 10:38, Cyril Mory wrote:
>>>> Hi ITK users,
>>>> 
>>>> I am writing an itk::ImageToImageFilter<T>, and I want the filter to work
>>>> with T=itk::Image as well as with T=itk::VectorImage.
>>>> 
>>>> To set/get the vectorLength of an image (which is 1 for an itk::Image, and
>>>> varies for an itk::VectorImage), I have successfully used the functions
>>>> Set/GetNumberOfComponentsPerPixel from the itk::ImageBase class, which work
>>>> for both itk::Image and itk::VectorImage.
>>>> 
>>>> But I cannot find a way to initialize one of the pixels to a given value,
>>>> that would work for both cases, i.e. whether that pixel is a scalar or a
>>>> variableLengthVector. For now, the best I could do is define a function
>>>> FillPixel in my filter, like this:
>>>> 
>>>> OutputImagePixelType FillPixel(OutputImageInternalPixelType value) {return
>>>> value;}
>>>> 
>>>> and write a template specialization when my filter is instantiated with
>>>> itk::VectorImage<float, 3>, like this:
>>>> 
>>>> template <>
>>>> itk::VariableLengthVector<float>
>>>> rtk::ConstantImageSource<itk::VectorImage<float, 3> >
>>>> ::FillPixel(float value)
>>>> {
>>>>   itk::VariableLengthVector<float> vect;
>>>>   vect.SetSize(this->GetVectorLength());
>>>>   vect.Fill(value);
>>>>   return (vect);
>>>> }
>>>> 
>>>> Did I miss something ? Is there a better way of doing this in ITK ?
>>>> 
>>>> Looking forward to reading you,
>>>> Cyril
>>>> 
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> _____________________________________
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> 
> Kitware offers ITK Training Courses, for more information visit:
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