[Dcmlib] Trouble with 'Shadow Dictionaries'

[Mathieu Malaterre]

Jean-Pierre Roux wrote:
> Hi !
> 
> Some Shadow Dictionnaries seem to be automatically taken into account ...
> that results in something strange :
> 
> PrintFile on a Siemens image shows :
> 
> D 0011|0010 [LO]                     [Private Creator Identification 
> (GEMS_PATI_01) ] [SPI RELEASE 1 ]
> D 0011|0011 [LO]                                                      
> [gdcm::Unknown] [SIEMENS CM VA0  CMS ]
> D 0011|1110 [  ]                                                      
> [gdcm::Unknown] [19970530]
> D 0011|1111 [  ]                                                      
> [gdcm::Unknown] [081719.000000 ]
> D 0011|1123 [  ]                                                      
> [gdcm::Unknown] [97]

I believe I told you that when visiting France. This has nothing to do 
with the shadow dictionary. This is somewhere in gdcm code. I believe 
this could be side effect of the virtual entry, in the past it created 
entry for me (though this was for public entry).

> Of course, we don't care about shadow elements !
> But some stupid DICOM readers (eg. the MatLab one) cannot process images 
> including groups partially 'ExplicitVR' and partially 'ImplicitVR'...
> 
> Many 'ExplicitVR' images have their Shadow group homogeneous 
> 'ImplicitVR', and they are 'MatLab readable'.
> When we re-write them (Anonymize, for instance), Shadow Group are no 
> longer homogeneous, and MatLab reader fails.

I have no idea what you mean by homogeneous.

> Any suggestion?
> (one easy to implement would be to allow user to ask not to take in 
> account Shadow Dictionnary ?)

Do a grep "0011 0011" you'll see that the siemens shadow dict contains 
another name for the entry. Therefore this is not the shadow dict that 
is taken into account.

Mathieu