[Insight-users] Extract Image Filter

[Stephen R. Aylward]

The difficult thing is that viewers need an entire slice per view (at 
least).   I don't think any viewer will work if it is only passed a 
Requested or Buffered region.   FltkImageViewer actually has a built-in 
volume renderer, hence it does a GetLargestPossibleRegion.

We could try to determine which data is currently being viewed, and then 
pass that back as the requested region - in effect, the viewer would end 
up driving the pipeline - calculations are made based on which slice the 
user is currently viewing.

There are commercial viz systems for medicine that work that way: slice 
based.

I could try to check something in really fast on this...just kidding... 
  Perhaps we can talk about it at the meeting on Thursday.

Stephen

Luis Ibanez wrote:

> Jim,
>
> Well, may this is the problem....
>
> fltkImageViewer uses internally the GLSliceViewer
> which in the SetInputImage() method it asks for
>
>       GetLargestPossibleRegion()
>
> Should be change it for "GetRequestedRegion()"
> or "GetBufferedRegion()" ?
>
>
> Luis
>
>
>
> --------------------------------------------
>
>
> Miller, James V (Research) wrote:
>
>> Luis,
>>
>>  
>>
>> Does this mean there is an issue with the FLTK image viewer?  Is it 
>> triggering off the wrong Region?
>>
>>  
>>
>> Jim
>>
>>     -----Original Message-----
>>     *From:* Puja Malik [mailto:puja.malik@MEMcenter.unibe.ch]
>>     *Sent:* Tuesday, February 04, 2003 11:27 AM
>>     *To:* itk newsgroup
>>     *Subject:* [Insight-users] Extract Image Filter
>>
>>     Hi Luis,
>>
>>     I've managed to fix my problem in the ExtractImageFilter.  I do have
>>     one concern though.  I cannot directly use the image object from the
>>     output of the filter, and view it in the fltk image filter.  If I do
>>     this, the images intensity range is altered, and the first slice is
>>     distorted.  I must first write the output of the filter ( image
>>     object ) to a file, read it back into a new image object and then
>>     view it.  This way, I see a correctly extracted image.  This is very
>>     strange.  It would be convenient if the output of the filter could
>>     be used directly.  Please see my code below, including the extra
>>     steps I needed to perform to get the desired results.
>>
>>     void ExtractImageRegion(ImageType::Pointer imIN, ImageType::SizeType
>>     regSize,
>>                                                        
>> ImageType::IndexType
>>     regIndex)
>>     {
>>
>>      typedef itk::ExtractImageFilter< ImageType, ImageType > FilterType;
>>      FilterType::Pointer filter = FilterType::New();
>>      ImageType::Pointer imOUT;
>>
>>      ImageType::RegionType region;
>>      region.SetSize(regSize);
>>      region.SetIndex(regIndex);
>>
>>      filter->SetExtractionRegion(region);
>>      filter->SetInput(imIN);
>>      filter->Update();
>>          // View(filter->GetOutput(), "region");  <-- doing this 
>> directly
>>     shows a distorted image
>>
>>     //the following is the extra steps needed to view a correct image
>>     //View, Read, WriteMetaFile are my own functions written using itk
>>     classes.
>>         imOUT = filter->GetOutput();
>>         imOUT->DisconnectPipeline();
>>              ImageType::Pointer im;
>>         WriteMetaFile("/home/encephalon/puja/testRegion.mhd", imOUT);
>>          im=Read("/home/encephalon/puja/testRegion.mhd");
>>          View(im, "region");
>>
>>     }
>>
>>     Thanks for your help,
>>     Puja
>>
>> -- 
>> ---------------------------------------
>> Puja Malik
>> Surgical Instruments Group
>> MEM Research Center for Orthopaedic Surgery
>> Institute for Surgical Technology and Biomechanics University of Bern
>> Murtenstrasse 35, P.O. Box 8354
>> 3010 Bern, Switzerland
>> Phone: +41-31-632-8730
>> Fax: +41-31-632-4951
>> Email: Puja.Malik@MEMcenter.unibe.ch
>> http://www.MEMcenter.unibe.ch
>> ---------------------------------------
>>
>>      
>
>
>
>
>
>
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