DicomExtensionExample2.cpp

#include <ImFusion/Base/SharedImageSet.h>
#include <ImFusion/Dicom/DicomElement.h>
#include <ImFusion/Dicom/DicomIOD.h>
#include <ImFusion/Dicom/Extension.h>
 
#include <dcmtk/dcmdata/dctk.h>
 
using namespace ImFusion;
 
class ExtensionExample2 : public Dicom::Extension
{
public:
    std::unique_ptr<Dicom::Extension> clone() const override { return std::make_unique<ExtensionExample2>(*this); };
    std::string name() const override { return "Extension Example2"; }
 
    std::vector<std::unique_ptr<Data>> load(const Dicom::FrameDescriptor& frame, SharedImageSet& sis) const override
    {
        if (auto enhanced = dynamic_cast<Dicom::EnhancedMultiFrameImageIOD*>(frame.iod))
        {
            // In enhanced DICOM tags can be either shared for a frames in the
            // sharedSequence or individual for each frame in the perFrameSequence
            bool hasShared = false;
            if (enhanced->sharedSequence.count() >= 1)
            {
                auto& shared = enhanced->sharedSequence.item(0);
                Windowing windowing(shared.dataset());
                if (windowing.exists())
                {
                    windowing.load(sis);
                    hasShared = true;
                }
            }
 
            if (!hasShared && frame.index < enhanced->perFrameSequence.count())
            {
                auto& perFrame = enhanced->perFrameSequence.item(frame.index);
                Windowing windowing(perFrame.dataset());
                if (windowing.exists())
                    windowing.load(sis);
            }
        }
        else
        {
            Windowing windowing(frame.iod->dataset());
            if (windowing.exists())
                windowing.load(sis);
        }
 
        return {};    // If you loaded some additional data e.g. from private tags, you can return it here.
    }
 
    void save(const Dicom::FrameDescriptor& frame, const SharedImageSet& sis) const override {}
 
private:
    // Helper class for using the same code for enhanced- and classic DICOMs
    class Windowing
    {
    public:
        Dicom::Element<double> center;
        Dicom::Element<double> width;
 
        Windowing(DcmItem& parent)
            : center(parent, DCM_WindowCenter, Dicom::ElementBase::Conditional, true)
            , width(parent, DCM_WindowWidth, Dicom::ElementBase::Conditional, true)
        {
        }
 
        bool exists() { return center.exists() && width.exists(); }
 
        void load(SharedImageSet& sis)
        {
            // ... e.g. set window/center in DisplayOptions2d
        }
    };
};