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RadiAnt DICOM Viewer - Discussion Forum
Calculation Full Dynamic Window values

Mar 31, 2014 03:24 PM
by Kamlesh

Radiant is really nice dicom viewer. I want to know how full dynamic windowing works. When window center and window width missing this full dynamic windowing works well. Can you please let me know how you calculates these values and which entities you use to calculate it.
Mar 31, 2014 07:09 PM
by RadiAnt

You have to find the maximum (vmax) and minimum (vmin) pixel values in your DICOM file.
Now you can calculate the WL and WW values for "full dynamic" window:

WW = vmax - vmin
WL = vmin + WW / 2

and that's it...
Apr 1, 2014 03:11 PM
by Kamlesh

Thanks for your last reply. But I have few more question on this.

How maximum (vmax) and minimum (vmin) pixel values calculated/find from dicom file?
for monochromatic image vmin = 0 and vmax = 255 usually. Can you please clarify on this?
Apr 1, 2014 03:31 PM
by RadiAnt
This subject is too broad to be covered here. I suggest reading a good book on DICOM standard, e.g. and of course the official PDFs from NEMA:
Apr 1, 2014 03:33 PM
by Guest
Basically you have to loop through all the pixels of the image and find minimum and maximum values.
Apr 7, 2014 02:10 PM
by Kamlesh

I tried applying above formula but I am not getting WL value in negative. Also those links are not helpful.

I want to calculate this value because I don't want user to see image black at first look then he need to change windowing.

Can you please help me out for calculate min and max pixel values with applying above formulas to calculate WW and WL.


Apr 8, 2014 12:07 AM
by aaaaa
Klamesh: How is looping through pixel values unclear?
Most DICOM files contain "monochromatic" images, although I have never seen a byte type image you describe.

If you don't know what looping through pixel values to find min and max means, no one will be able to answer your question as you wouldn't understand anyway. Also, describing someone's input as "not helpful" just because you don't understand the subject matter is impolite.
Apr 12, 2019 10:53 AM
by Abrong
I meet the same question as you. Some DICOM files display all dark, and only "full dynamic" can show the images clearly. But I want to measure the CT value(HU) of the ROI, and they are all less than 0HU, even to the -800. Have you solve the problem? Can we a talk about it?
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