[vtkusers] How to render the contours of a binary image?

[Thomas Kilgus]

Hi Dominik,

the documentation of vtkDiscreteMarchingCubes tells me that I should use 
vtkMarchingSquares for 2D image slices (which i have in my case). 
vtkDiscreteMarchingCubes is not applicable for data with dimension != 3. 
If I use vtkMarchingSquares instead the following message occurs: 
"vtkPainterPolyDataMapper: Mapper has no input" and my image is still 
completely rendered in one color.

regards
thomas

On 31.05.2011 13:24, Dominik Szczerba wrote:
> See vtkDiscreteMarchingCubes.
> What I also do at times is to cast the binary image to float, smooth
> it, and then extract 0.5 value.
>
> On Tue, May 31, 2011 at 1:19 PM, Thomas Kilgus
> <t.kilgus at dkfz-heidelberg.de>  wrote:
>> Hi,
>>
>> I am using a vtkPolyDataMapper to render images as a texture on a plane.
>> Some images (in the form of vtkImageData) just consist of the values 1.0 and
>> 0.0. By means of a vtkLookuptable I can easily render those images with a
>> single color (the 1.0 values) and with a transparent background (0.0
>> values). What would be the best way to render just the contours of those
>> images?
>>
>> I already found the vtkContourFilter. But when I use it like this:
>>
>>       vtkSmartPointer<vtkContourFilter>  contourFilter =
>> vtkSmartPointer<vtkContourFilter>::New();
>>       contourFilter->SetInput(image);
>>       contourFilter->GenerateValues(1, 1.0, 1.0);
>>       contourFilter->Update();
>>       texture->SetInputConnection(contourFilter->GetOutputPort());
>>
>> the whole image is just rendered as a single color.
>>
>> Is there anything wrong with my code or is the vtkContourFilter just not the
>> appropriate filter for my task?
>>
>> regards
>> thomas kilgus
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