[vtkusers] Set ImageData to zero

[speedy]

I see. Do I have to check for every pixel type or is there a way to use the
string directly?
Something like:
    
/const char* PixelType = Image->GetScalarTypeAsString();
(PixelType)* PixelArray;
PixelArray = ((PixelType)*)m_UserLabels->GetScalarPointer();
/

which obviously doesn't work. 


Dominique Töpfer wrote:
> 
> There are macros like VTK_DOUBLE defined in vtkTypes.h ( 
> http://www.vtk.org/doc/nightly/html/vtkType_8h_source.html ). So you can 
> check the scalar type using
> 
> if(Image->GetScalarType() == VTK_DOUBLE)
>      // cast to double
> 
> Of course, you can also GetScalarTypeAsString() as suggested by Jothy.
> 
> HTH
> Dominique
> 
> 
> On 28.09.2011 15:21, speedy wrote:
>> Thanks a lot for your reply Dominique!
>> It is much faster indeed to use GetScalarPointer() instead of iterating
>> through the pixels. I still have a problem though: My class doesn't know
>> the
>> pixeltype of the image beforehand, but I have to cast the pointer to it.
>> How
>> can I achieve this? I know there's the method
>>
>> Image->GetScalarType(),
>>
>> but it returns an integer value and I don't know how to proceed with it..
>>
>>
>> Dominique Töpfer wrote:
>>> Hi,
>>>
>>> a similar question was discussed here:
>>> http://vtk.1045678.n5.nabble.com/Fast-element-access-of-vtkImageData-td4640137.html#none
>>>
>>> HTH
>>> Dominique
>>>
>>> On 27.09.2011 15:47, speedy wrote:
>>>> Sorry if this question actually has a simple answer, but what is the
>>>> fastest
>>>> way to set every pixel of a vtkImageData to zero (or any other value
>>>> fitting
>>>> in its pixeltype)?
>>>> I've tried vtkImageThreshold, but it doesn't seem to do anything or
>>>> maybe
>>>> I
>>>> am using it wrong:
>>>>
>>>>     threshold = vtkSmartPointer<vtkImageThreshold>::New();
>>>>     threshold->SetInput(Image);
>>>>     threshold->ReplaceOutOn();
>>>>     threshold->SetOutValue(Value);
>>>>     threshold->ThresholdByLower(maximum_image_value);
>>>>     threshold->Update();
>>>>
>>>> --
>>>> View this message in context:
>>>> http://vtk.1045678.n5.nabble.com/Set-ImageData-to-zero-tp4845442p4845442.html
>>>> Sent from the VTK - Users mailing list archive at Nabble.com.
>>>> _______________________________________________
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>>>
>>> -- 
>>> Thus spake the master programmer:
>>>       "After three days without programming, life becomes meaningless."
>>>
>>> -- The Tao of Programming by Geoffry James
>>>
>>> Dominique Töpfer, Dipl.-Inform.
>>> Institute of Medical Physics
>>> University of Erlangen
>>>
>>> _______________________________________________
>>> Powered by www.kitware.com
>>>
>>> Visit other Kitware open-source projects at
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>>>
>>> Please keep messages on-topic and check the VTK FAQ at:
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>>
>> --
>> View this message in context:
>> http://vtk.1045678.n5.nabble.com/Set-ImageData-to-zero-tp4845442p4849109.html
>> Sent from the VTK - Users mailing list archive at Nabble.com.
>> _______________________________________________
>> Powered by www.kitware.com
>>
>> Visit other Kitware open-source projects at
>> http://www.kitware.com/opensource/opensource.html
>>
>> Please keep messages on-topic and check the VTK FAQ at:
>> http://www.vtk.org/Wiki/VTK_FAQ
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> 
> 
> -- 
> Thus spake the master programmer:
>      "After three days without programming, life becomes meaningless."
> 
> -- The Tao of Programming by Geoffry James
> 
> Dominique Töpfer, Dipl.-Inform.
> Institute of Medical Physics
> University of Erlangen
> 
> _______________________________________________
> Powered by www.kitware.com
> 
> Visit other Kitware open-source projects at
> http://www.kitware.com/opensource/opensource.html
> 
> Please keep messages on-topic and check the VTK FAQ at:
> http://www.vtk.org/Wiki/VTK_FAQ
> 
> Follow this link to subscribe/unsubscribe:
> http://www.vtk.org/mailman/listinfo/vtkusers
> 


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