DiPixel::getData() vs. DicomImage::getOutputData()

[sovaldes]

Dear DCMTK team,

I had been able to load a dicom image in a iPad thank for your libraries. The only thing I am wondering is what is the difference between using DiPixel::getData() and DicomImage::getOutputData(). In my code I am loading a MRI with 300 slices and I did'n t have any problem using the both methods mentioned above, but again I can see what is the diference. To give you a hint I am developing an app in which I am interested to get the raw value of the pixel in whatever position for doing some segmentation calculations. So which method Do you will me advise to use?

Thanks

Samuel

[J. Riesmeier]

If you need the raw (not the rendered) pixel data, then getInterData() is what you should probably use.

[sovaldes]

Hi Jörg,

Thanks for the reply. However I Have one more question. I am kind of confuse between the terms raw data and render data. Can you explain me the difference or correct me if I am wrong?

What I am understand from your forums is that the raw data is the internal data stored in the DICOM file, while the rendered data is the data that you want to display in your device after applying some the Modality LUT, VOI LUT and Presentation LUT) transformations? Is it Correct or not?

Thanks

Samuel

[J. Riesmeier]

Almost correct, and the main purpose of the DICOM image class is visualization/display of images, i.e. not accessing raw data. So, the access to the internal representation has been added later because many users asked for it. Btw, the modality LUT transformation is already applied to the internal pixel data (if not disabled in the constructor). This makes sure that you get Hounsfield Units for CT images.

[sovaldes]

Thanks Jörg