Carestream Trophy Panoramic images too bright

All other questions regarding DCMTK

Moderator: Moderator Team

Post Reply
Message
Author
martinrame
Posts: 347
Joined: Mon, 2009-02-23, 19:57

Carestream Trophy Panoramic images too bright

#1 Post by martinrame »

Hi, I found Panoramic images generated by Kodak/Carestream Trophy are displayed too bright (you can see an example here: https://github.com/nroduit/Weasis/discussions/335).

I checked agains dcmtk's dcmj2pnm, Weasis and CornerstoneJs based viewes and all shows the same behavior. The only one that shows those images correctly is Horos.

Do you know which algorithm Horos/Osirix is applying to correctly display the images?. Btw, I asked them (https://github.com/horosproject/horos/issues/716), but so far they didn't answer.

J. Riesmeier
DCMTK Developer
Posts: 2501
Joined: Tue, 2011-05-03, 14:38
Location: Oldenburg, Germany
Contact:

Re: Carestream Trophy Panoramic images too bright

#2 Post by J. Riesmeier »

Could you make a DICOM sample file available for download?

martinrame
Posts: 347
Joined: Mon, 2009-02-23, 19:57

Re: Carestream Trophy Panoramic images too bright

#3 Post by martinrame »

J. Riesmeier wrote: Mon, 2022-10-24, 19:57 Could you make a DICOM sample file available for download?
Yes: http://45.63.8.72/downloads/carestream1.dcm

J. Riesmeier
DCMTK Developer
Posts: 2501
Joined: Tue, 2011-05-03, 14:38
Location: Oldenburg, Germany
Contact:

Re: Carestream Trophy Panoramic images too bright

#4 Post by J. Riesmeier »

Since there are no VOI LUT settings in the DICOM data set, it is up to the viewer (rendering tool) to select appropriate settings. The tool dcmj2pnm provides the following options for this purpose:

Code: Select all

  VOI LUT transformation:
    -W    --no-windowing        no VOI windowing (default)
    +Wi   --use-window          [n]umber: integer
                                use the n-th VOI window from image file
    +Wl   --use-voi-lut         [n]umber: integer
                                use the n-th VOI look up table from image file
    +Wm   --min-max-window      compute VOI window using min-max algorithm
    +Wn   --min-max-window-n    compute VOI window using min-max algorithm,
                                ignoring extreme values
    +Wr   --roi-min-max-window  [l]eft [t]op [w]idth [h]eight: integer
                                compute ROI window using min-max algorithm,
                                region of interest is specified by l,t,w,h
    +Wh   --histogram-window    [n]umber: integer
                                compute VOI window using Histogram algorithm,
                                ignoring n percent
    +Ww   --set-window          [c]enter [w]idth: float
                                compute VOI window using center c and width w
    +Wfl  --linear-function     set VOI LUT function to LINEAR
    +Wfs  --sigmoid-function    set VOI LUT function to SIGMOID
Do you know which algorithm Horos/Osirix is applying to correctly display the images?
Unfortunately not. Did you already check the source code of these tools.

Marco Eichelberg
OFFIS DICOM Team
OFFIS DICOM Team
Posts: 1437
Joined: Tue, 2004-11-02, 17:22
Location: Oldenburg, Germany
Contact:

Re: Carestream Trophy Panoramic images too bright

#5 Post by Marco Eichelberg »

In any case, selecting appropriate values for Window Center and Window Width should "fix" the display, since there are no unusual look-up tables. When using dcmj2pnm, the --min-max-window might be a good starting point.

Post Reply

Who is online

Users browsing this forum: Ahrefs [Bot], Bing [Bot] and 1 guest