[vtkusers] Re: vtkImagePlaneWidget problem on vtkImageData (C++)

wyssa1 wyssa1 at hta-bi.bfh.ch
Fri Nov 26 02:25:50 EST 2004


Hi Dean

Thanks for the tip, but the output image is still without colors.

Adrian



On Thu, 25 Nov 2004 13:11:54 -0500, <dean.inglis at camris.ca> wrote:

> Adrian,
>
> I think you have to tell vtkImageMapToWindowLevelColors superclass,
> vtkImageMapToColors, to do
> the following:
>
> pImageMapToWindowLevelColors->SetOutputFormatToRGB()
>
> or, depending on your input:
>
> pImageMapToWindowLevelColors->SetOutputFormatToRGBA
> ();
> pImageMapToWindowLevelColors->PassAlphaToOutputOff();
>
> Dean
>
>
>>
>> From: "Adrian Wyssmann" <wyssa1 at hta-bi.bfh.ch>
>> Date: 2004/11/25 Thu AM 11:03:03 GMT-05:00
>> To: <dean.inglis at camris.ca>,  <vtkusers at vtk.org>
>> Subject: Re:[vtkusers] Re: vtkImagePlaneWidget problem on vtkImageData  
>> (C++)
>>
>> I still have the problem with that window-level stuff. I tried different
>> things, but didn't get rid of it. I really get that thing to work. The
>> problem ist, that if I change the window level to somewhat, the image  
>> get's
>> black and white (see attachement). The same happens with
>> vtkImageViewer2
>>
>> pImageMapToWindowLevelColors->SetLevel(0.5*(range[1] + range[0]));	
>> pImageMapToWindowLevelColors->SetWindow(range[1] - range[0]-2);	
>> pImageMapToWindowLevelColors->SetInput(pImageData);
>> pImageMapToWindowLevelColors->SetLookupTable(pLookupTableOriginal);
>> pImageMapToWindowLevelColors->Update();
>> pImageData = pImageMapToWindowLevelColors->GetOutput();
>>
>> The pLookupTableOriginal is the same lookuptable I use for the
>> ScalarBarActor (see attatchment).
>>
>> On resetting the WindowLevel to 255 and 127.5 the colors are back.
>>
>>
>> -----Original Message-----
>> From: vtkusers-bounces at vtk.org [mailto:vtkusers-bounces at vtk.org] On  
>> Behalf
>> Of dean.inglis at camris.ca
>> Sent: Dienstag, 9. November 2004 14:12
>> To: vtkusers at vtk.org
>> Subject: Re:[vtkusers] Re: vtkImagePlaneWidget problem on vtkImageData  
>> (C++)
>>
>> Adrian,
>>
>> if you have tcl wrapping enabled for your vtk build, (or you could  
>> convert
>> to c++), try the following tcl script for window/level interaction using
>> vtkImageViewer2, and maybe with your particular image data.  Default  
>> window
>> level is usually calculated as:
>>
>> double* range = image->GetScalaRange();
>> double window = range[1] - range[0];
>> double level = 0.5*(range[1] + range[0]);
>>
>> So, depending on how the scalar values of your data are distributed, the
>> window level can be weighted either too high or to low and the image  
>> will
>> appear initially "fogged", too dark (even black) or too light (even  
>> white).
>>
>>
>> Dean
>>
>> #///////////////////////////////////////////////////////////////////////////
>> /////////
>> package require vtk
>>
>> vtkBMPReader reader
>> reader SetFileName $VTK_DATA_ROOT/Data/masonry.bmp
>>
>> # set the window/level
>> vtkImageViewer2 viewer
>> viewer SetInput [reader GetOutput]
>> viewer SetColorWindow 100.0
>> viewer SetColorLevel 127.5
>> vtkRenderWindowInteractor iren
>> [viewer GetRenderWindow] SetInteractor iren viewer SetupInteractor iren
>>
>> viewer Render
>>
>> # here's how to interact:
>> # left mouse button left - right controls window # left mouse button up  
>> -
>> down controls level # press "r" key resets the internal
>> vtkImageMapToWindowLevelColors to its default w/l # right button zooms  
>> image
>> # shift + "r" resets the zoom
>>
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>>
>>



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