My ITK tips

itk.cxx

/*
*  Create a float image the size of a short image
*  This is an example of how to create an image of
*  a different type but same size as a given image  
*/
FloatImageType::Pointer ppRecruitImage = FloatImageType::New();

//define origin and size the same as the input

//get the biggest region (which usually is the whole image)
ImageType::RegionType imageregion=expImage->GetLargestPossibleRegion();
//get the image origin
ImageType::IndexType imageIndex=imageregion.GetIndex();
//get the image size
ImageType::SizeType imagesize= imageregion.GetSize();
//get the image spacing
ImageType::SpacingType spacing=expImage->GetSpacing();

ImageType::PointType imageorigin=expImage->GetOrigin();

//create region size and spacing for the output image type
FloatImageType::IndexType floatIndex;
FloatImageType::SizeType floatSize;
FloatImageType::SpacingType floatSpacing;
FloatImageType::PointType floatorigin;

//this will be the number of voxels in the image 
//we can use it as a stopping condition
int cvoxels=1;

//set the new images' index, size and spacing
for(int i=0; i <dims; i++){
    floatIndex[i]=imageIndex[i];
    floatSize[i]=imagesize[i];
    floatSpacing[i]=spacing[i];
    floatorigin[i]=imageorigin[i];
    cvoxels*=imagesize[i];
}

//create region
FloatImageType::RegionType region;

//set their sizes, index
region.SetSize( floatSize );
region.SetIndex( floatIndex );

//create the image
ppRecruitImage->SetRegions( region );
ppRecruitImage->SetSpacing( floatSpacing );
ppRecruitImage->Allocate();
ppRecruitImage->FillBuffer(0.0);
ppRecruitImage->SetOrigin(floatorigin);


/*
*  How to use image duplicator
*/

typedef itk::ImageDuplicator< ImageType > DuplicatorType;
DuplicatorType::Pointer duplicator = DuplicatorType::New();
duplicator->SetInputImage(expImage);
duplicator->Update();
ImageType::Pointer outImage = duplicator->GetOutput();