[Insight-users] filter a requested region

[Anna Vignati]

Hi all,
i'm trying to process only a subregion (B) of an inputImage (A) and then 
having an outputImage being the inputImage A with the subregion B 
filtered.

In 2003, someone propose to solve the same problem doing:
someFilter->SetInput( someReader->GetOutput() );
someFilter->GetOutput()->SetRequestedRegion( bRegion );
someFilter->Update();

to obtain an image with the dimension of the subregion, containing the 
subregion filtered, and then use pasteFilter to obtain as output the 
inputRegion (A) with the subregion B filtered.

In my case, the filter I'm using is the BinaryThresholdingImageFilter. The 
problem is that, when i'm doing:

binaryThresholdFilter->SetInput( someReader->GetOutput() );
binaryThresholdFilter->GetOutput()->SetRequestedRegion( bRegion );
binaryThresholdFilter->Update();

I obtain as output the whole input image filtered!!

I know how to set the requested region, but I don't know how to tell a 
filter to work only on that requested region!

At the moment, I solve the problem using the RegionOfInterestImageFilter 
in combination with PasteImageFilter in the following way:

regionOfInterestFilter->SetInput(reader->GetOutput());
regionOfInterestFilter->SetRegionOfInterest( region );
regionOfInterestFilter ->Update();

binaryThresholdFilter->SetInput( regionOfInterestFilter ->GetOutput() );
binaryThresholdFilter->Update();

pasteFilter->SetInput(reader->GetOutput());
pasteFilter ->SetSourceImage(binaryThresholdFilter->GetOutput());
pasteFilter -> 
SetSourceRegion(binaryThresholdFilter->GetOutput()->GetLargestPossibleRegion());
pasteFilter ->SetDestinationImage(reader->GetOutput());

pasteFilter ->SetDestinationIndex(startIndex) ;
pasteFilter ->Update();

writer->SetInput(paste Filter->GetOutput() );

Thanks in advance.

Anna