Hi guys,

Maybe somebody has an answer to my question. The SCU requests an
association with 2 presentation contexts, both of the same abstract
syntax but with difference transfersyntaxes. F.e. CT with lossless
JPEG and CT with baseline JPEG. The SCP accepts both and now the SCU
issues a C-Store with 2 files, both CT but 1 file is lossless
compressed and one is baseline compressed.
How does the SCP know which one is lossless and which is lossy? Is it
up to the SCP to detect the compression used in the pixel data?
Thanks,
  Rutger

In the C-STORE operation the SCU transfers data to the SCP via P-DATA
PDUs.
These P-DATA PDUs contain values which are prefixed with one of the
previously accepted presentation context IDs (PS 3.8-2009 9.3.5.1).

So when the SCU transfers the lossless dataset it should use the
presentation context ID with the accepted lossless transfer syntax
and
when it transfers the lossy dataset it should use the presentation
context ID with the accepted lossy transfer syntax.

Therefore the receiving SCP should know which transfer syntax is being
used by looking at the presentation context ID of the incoming P-DATA
PDUs.

Nils

Hi Nils,

Thanks! That's exactly what I overlooked!
Rutger