[Insight-users] itkGDCMImageIO

[Mathieu Malaterre]

Martin Urschler wrote:
> hi all,
> 
> i'd like to discuss something that i found in itkGDCMImageIO:
> 
> the write method decides depending on the image data type how the dicom 
> tags bitsAllocated, bitsStored and HighBit are defined
> 
> e.g. if an unsigned short image is written, these values are filled with 
> 16, 16 and 15 respectively
> 
> in my case i'm working on 12 bit ct input data that has the dicom 
> representation 16, 12, 11
> 
> if i write my unsigned short result volume again as a dicom, these 
> values are modified to become 16, 16, 15
> 
> now i'm not a dicom expert (who is btw.?) and have no idea on the exact 
> outcome of this modification for dicom viewers but imho this is an 
> inconsistent behaviour, i'd like to keep my representation the same as 
> it is in my input file...

Well the short answer is: could you provide a PixelType for ITK that 
would allow you to read/manipulate this '12' bits images ?

The long answer is: gdcm has no intention of rewritting extremely 
optimized libraries that allow you to store image on 12bits pixels. 
Until someone demonstrate that this is indeed an easy task, gdcm will 
keep loading 12bits image into 16bits.

Mathieu