[vtkusers] Writing a JPEG from vtkActor

[Dominik Szczerba]

> 
> I always have to check the source code to see which way it should go.
> Could I suggest adding a simpler API like:
> 
>  SetOutputRange(lowValue, highValue)?


I strongly second the notion.
Dominik

> 
>>
>>
>>>   vtkPNGWriter* writer = vtkPNGWriter::New();
>>>   writer->SetInput(iss->GetOutput());
>>>   writer->SetFileName(argv[2]);
>>>   writer->Write();
>>>
>>> Always the first scalar is taken, regardles of explicit selection with
>>> setActiveScalarrs. The info seems displayed properly (of the first
>>> scalar) whih is in my case -9.11732e-06 1.53533e-05, output is black
>>> image (empty histogram).
>>> I will be grateful if you shed some light on this mystery.
>>> Dominik
>>>
>>> Amy Squillacote wrote:
>>> > Try using vtkImageShiftScale instead.  Do something like the
>>> following.
>>> >
>>> > double range[2];
>>> > grid->GetCellData()->GetScalars("abc")->GetScalarRange(range);
>>> >
>>> > vtkImageShiftScale *iss = vtkImageShiftScale::New();
>>> > iss->SetInput(grid);
>>> > iss->SetOutputScalarTypeToUnsignedChar();
>>> > iss->SetShift(-range[0]);
>>> > iss->SetScale((range[1] - range[0]) / 256.0);
>>> >
>>> > Are you sure that the data in your grid (a vtkImageData, I assume)
>>> is in
>>> > cell data? It's usually in point data.
>>> >
>>> > - Amy
>>> >
>>> > At 09:44 AM 12/20/2005, Dominik Szczerba wrote:
>>> >
>>> >> Thanks a lot, yes, I am trying the vtkImageCast, compiles fine,
>>> but get
>>> >> a black image at the end. Shouldnt I set ranges somewhere?
>>> >> I can do
>>> >>
>>> >> grid->GetCellData()->GetScalars("abc")->GetRange())
>>> >>
>>> >> but where do I plug the output?
>>> >>
>>> >> Dominik
>>> >>
>>> >> Amy Squillacote wrote:
>>> >> > Try using either vtkImageCast or vtkImageShiftScale to change your
>>> >> image
>>> >> > data to contain either unsigned char or unsigned short data.
>>> >> >
>>> >> > - Amy
>>> >> >
>>> >> > At 08:58 AM 12/20/2005, Dominik Szczerba wrote:
>>> >> >
>>> >> >> What is the error? I try to do the same with vtkPNGWriter
>>> ending up
>>> >> with:
>>> >> >>
>>> >> >> vtkPNGWriter (0x8058948): PNGWriter only supports unsigned char
>>> and
>>> >> >> unsigned short inputs
>>> >> >>
>>> >> >> Meanwhile I try to figure out how to do the appropriate
>>> convertion in
>>> >> >> vtk.
>>> >> >> --dsz
>>> >> >>
>>> >> >> Marlos Fabris wrote:
>>> >> >> > Hi,
>>> >> >> >
>>> >> >> > I'm trying to write a jpeg file (using vtkJPEGWriter) from a
>>> >> vtkActor
>>> >> >> > but I can't accomplish this. I have a vtk file with structured
>>> >> points
>>> >> >> > data and I wish to transform to vtkPolyData and color it with my
>>> >> >> > vtkLookupTable.
>>> >> >> >
>>> >> >> > Is there a way to convert only my vtkActor to a vtkImageData,
>>> >> without
>>> >> >> > the frameborders of vtkWindowToImageFilter?
>>> >> >> >
>>> >> >> > Or is there a way to trim my image?
>>> >> >> >
>>> >> >> > Thank you in advance,
>>> >> >> >
>>> >> >> > Marlos Fabris
>>> >> >> > _______________________________________________
>>> >> >> > This is the private VTK discussion list.
>>> >> >> > Please keep messages on-topic. Check the FAQ at:
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>>> >> >>
>>> >> >> --
>>> >> >> Dominik Szczerba, Dr.
>>> >> >> ETZ C110 CO-ME/BIWI CH-8092 Zurich
>>> >> >> http://www.vision.ee.ethz.ch/~domi
>>> >> >> _______________________________________________
>>> >> >> This is the private VTK discussion list.
>>> >> >> Please keep messages on-topic. Check the FAQ at:
>>> >> >> http://www.vtk.org/Wiki/VTK_FAQ
>>> >> >> Follow this link to subscribe/unsubscribe:
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>>> >>
>>> >> --
>>> >> Dominik Szczerba, Dr.
>>> >> ETZ C110 CO-ME/BIWI CH-8092 Zurich
>>> >> http://www.vision.ee.ethz.ch/~domi
>>> >> _______________________________________________
>>> >> This is the private VTK discussion list.
>>> >> Please keep messages on-topic. Check the FAQ at:
>>> >> http://www.vtk.org/Wiki/VTK_FAQ
>>> >> Follow this link to subscribe/unsubscribe:
>>> >> http://www.vtk.org/mailman/listinfo/vtkusers
>>>
>>> -- 
>>> Dominik Szczerba, Dr.
>>> ETZ C110 CO-ME/BIWI CH-8092 Zurich
>>> http://www.vision.ee.ethz.ch/~domi
>>> _______________________________________________
>>> This is the private VTK discussion list.
>>> Please keep messages on-topic. Check the 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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> 
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-- 
Dominik Szczerba, Dr.
ETZ C110 CO-ME/BIWI CH-8092 Zurich
http://www.vision.ee.ethz.ch/~domi