Orthanc GDCM Windows, do I need it?

General
1

Hi everyone,

I’m trying to C-STORE a study from Orthanc to another DICOM application.

However I get the error:

DCMTK was unable to transcode from 1.2.840.10008.1.2.4.70 to one of: 1.2.840.10008.1.2.1
Internal error while transcoding to 1.2.840.10008.1.2.1

So I did some googling, and found that 1.2.840.10008.1.2.4.70 = JPEG Lossless, and I also found this wiki.

  1. Is this error hinting that I need GDCM to handle JPEG lossless transcoding instead of DCMTK?

  2. How do I install GDCM on Orthanc in 64-bit Windows?
    Is it already installed by default, since I see OrthancGdcm.dll already appears in the “C:\Program Files\Orthanc Server\Plugins” folder, and I also see it mentioned in the logs.

The wiki seems to suggest otherwise, and seems like it needs to be installed so I followed the wiki and downloaded the 64-bit OrthancGdcm-mainline.dll, and placed it “C:\Program Files\Orthanc Server\Plugins\OrthancGdcm-mainline.dll”

  1. With the Orthanc.json file , I already had:

“Plugins” : [ “C:\Program Files\Orthanc Server\Plugins” ],

Do i need to change it to:

“Plugins” : [ “C:\Program Files\Orthanc Server\Plugins”, “C:\Program Files\Orthanc Server\Plugins\OrthancGdcm-mainline.dll”],

Thanks!

2

Hi,

GDCM is already installed by default on Windows if you used the Windows Installers. You can check it on http://localhost:8042/ui/app/#/settings

By default, GDCM will not handle JPEG Lossless because it only handles JP2K. You can update this by adding 1.2.840.10008.1.2.4.70 in the configuration:

  "Gdcm" : {
    "Enable" : true,
    "RestrictTransferSyntaxes" : [
      "1.2.840.10008.1.2.4.90",   // JPEG 2000 Image Compression (Lossless Only)
      "1.2.840.10008.1.2.4.91",   // JPEG 2000 Image Compression
      "1.2.840.10008.1.2.4.92",   // JPEG 2000 Part 2 Multicomponent Image Compression (Lossless Only)
      "1.2.840.10008.1.2.4.93",   // JPEG 2000 Part 2 Multicomponent Image 
Compression
      "1.2.840.10008.1.2.4.70"   ////// Added ///////
    ]
  }

Note that, DCMTK is supposed to handle JPEG Lossless so, I’m really not sure GDCM will do better.

Best regards,

Alain.

3

Thanks for clarification. GDCM is indeed installed by default in the Windows installer.
Solution was to disable inbound and outbound transcoding in the orthanc.json.