DICOM @ OFFIS

Discussion Forum for OFFIS DICOM Tools - For registration, send email with desired user name to the OFFIS DICOM team
It is currently Mon, 2017-12-18, 09:59

All times are UTC + 1 hour




Post new topic Reply to topic  [ 3 posts ] 
Author Message
 Post subject: LUT table in DCMTK
PostPosted: Fri, 2008-09-19, 01:04 
Offline

Joined: Thu, 2008-09-18, 09:20
Posts: 40
Location: Japan
Hi OFFIS team,

I am not sure if the DCMTK reads the Modality LUT or the VOI LUT data in the tags of DICOM data.

We have the DICOM data including Modality LUT and another one including VOI LUT. We investigated the both data using "dataset->findAndGetElement()" as follows;

dataset->findAndGetElement(DCM_ModalityLUTSequence, element, OFFalse);
dataset->findAndGetElement(DCM_VOILUTSequence, element, OFFalse);
dataset->findAndGetElement(DCM_LUTDescriptor, element, OFFalse);
dataset->findAndGetElement(DCM_LUTData, element, OFFalse);

The results are that in the DICOM data including Modality LUT the only "element" of DCM_ModalityLUTSequence has meaningful contents but other "element" has no meaningful contents, in the DICOM data including VOI LUT the only "element" of DCM_VOILUTSequence has meaningful contents but other "element" has no meaningful contents. So far, I have to conclude that DCMTK doesn't read the Modality LUT or the VOI LUT data in the DICOM data.
Is it right?
If so, in order to read and use the Modality LUT or the VOI LUT data, please tell me how should I do?

In addition, is it the same about Presentation LUT?

Thank's for your help,

Best Regards,
Masabumi Ishihara :(

_________________
Maty


Top
 Profile  
 
 Post subject:
PostPosted: Fri, 2008-09-19, 09:33 
Offline
OFFIS DICOM Team
OFFIS DICOM Team

Joined: Tue, 2004-11-02, 17:22
Posts: 1208
Location: Oldenburg, Germany
The Modality LUT Sequence and VOI LUT Sequence are not contained in all DICOM images. When they are present, of course the DCMTK parser reads them and provides access, as to all other elements of the dataset.

Note that both Modality LUT Sequence and VOI LUT Sequence are Sequenceelements, i.e. instances of DcmSequenceOfItems. You will not find a LUT Descriptor or LUT Data in the main dataset, but in the first item of the sequence. See the API documentation for Sequences (class DcmSequenceOfItems and class DcmItem) to see how you navigate through hierarchical data structures.

That said, if you are trying to read the content of the Modality LUT and VOI LUT then you are probably trying to re-implement a functionality that is already present in class DicomImage (module dcmimgle+dcmimage), and highly optimized as well. If you want to display a DICOM image, don't try to re-invent the wheel.


Top
 Profile  
 
 Post subject: Thanks!
PostPosted: Sat, 2008-09-20, 01:03 
Offline

Joined: Thu, 2008-09-18, 09:20
Posts: 40
Location: Japan
Dear, Marco

Thank you for your reply.
Your explanation and advice are very helpful for me to implement the further function of our Viewer.

Yours truely,

_________________
Maty


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 3 posts ] 

All times are UTC + 1 hour


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group