[Insight-users] New filter outputs overwrite previous output?

[Zachary Pincus]

Hello,

I was hoping to re-use a particular filter object for multiple 
different image inputs.

My code is something like this:
		// Step 1
		typename ResampleType::Pointer resampler = ResampleType::New();
		resampler->SetTransform(affineReverseTransform);
		
		// Step 2
		resampler->SetInput(mask);
		resampler->Update();		
		newMask = resampler->GetOutput();
		
		// Step 3
		resampler->SetInput(image);
		resampler->Update();		
		newImage = resampler->GetOutput();

However, after this executed, newMask and newImage are identically the 
outputs of the "step 3" code. If I comment out the "step 3" code, 
newMask is as it should be.

So it looks like the filter is overwriting it's outputs after the next 
update. This isn't unreasonable behavior, but is there a way to make 
the filter make a new output image each time it's updated? (So it can 
be easily used in this manner.) Currently, I've fixed this by just 
creating a new filter object for each new image I want to make -- but 
this seems wasteful, since this sort of code is eventually going to go 
in an inner loop and I don't want to constantly be creating and 
destroying filter objects...

The answer doesn't seem to be in the documentation, which probably is 
just a function of me not knowing where to look. Any pointers in the 
right direction would be most helpful.

Thanks,
Zach Pincus

Department of Biochemistry and Program in Biomedical Informatics
Stanford University School of Medicine