[Dcmlib] Signed Images

[Aris Basic]

applying it to the image in fastes possible way :)
and correspodning formula is why i went towards OpenGL (should allowe me 
to use GPU to do it)
dont get how VTK adn some other libraries do it very fast withouth GPU :(


Mathieu Malaterre wrote:

> For the window/level is is pretty easy:
>
> double range[2];
> my_function(range, image);
> // range now contains the pixel value min and pixel value max.
>
> level = (range[1]+range[0] )/2
> window = range[1]-range[0]
>
> In theory there is a window/level tag in DICOM but I don't trust them :P
>
> HTH
> Mathieu
>
> On Jun 14, 2005, at 11:38 AM, Aris Basic wrote:
>
>> I have some of my images havnot tested it with gdcm provided images 
>> will probably do it and compare with vtkgdcmViewer.
>> IM trying to display them with OpenGL (creating and RECT texture from 
>> pixel data [ opengl supposedly shoudl be able to
>> deal with signed pixel data , but doesnt look like its doing )
>> (i tryed too figgure out how is VTK donig the W/L transfomration and 
>> rest but did not have luck finding that piece of code quickly :)
>>
>>
>> Jean-Pierre Roux wrote:
>>
>>> Aris Basic wrote:
>>>
>>>> is gdcm doing any conversion on pixel data from signed 
>>>> (pixelrepresentation == 1) images ?
>>>> pixelrepresentation == 0 images i can display nicely but 
>>>> representation 1 they come up strange :(
>>>
>>>
>>>
>>>
>>> gdcm doesn't make any transformation for 'signed pixels'.
>>> It's up to the user to deal with the sign.
>>> How do you display the image?
>>> Did you try with vtkgdcmViever? (of course, you need VTK ...)
>>>
>>> In our test data set ( gdcmData), there are a few 'signed pixels' 
>>> images :
>>>
>>> MR-MONO2-16-head.dcm CT-MONO2-16-chest.dcm
>>> CT-MONO2-16-ankle.dcm  CT-MONO2-16-ort.dcm
>>> CT-MONO2-16-brain.dcm
>>> GE_RHAPSODE-16-MONO2-JPEG-Fragments.dcm 
>>> GE_GENESIS-16-MONO2-Uncompressed-UnusualVR.dcm
>>> GE_GENESIS-16-MONO2-WrongLengthItem.dcm 
>>> PICKER-16-MONO2-No_DicomV3_Preamble.dcm
>>> 012345.002.050.dcm
>>>
>>> Did you try to display them?
>>> HTH.
>>>
>>> Jean-Pierre
>>>
>>>>
>>>> jsut trying to find a bug :) not pointing fingers
>>>
>>>
>>>
>>> Thx for reporting it.
>>> Could you send us one of your images, so we can check 'at home' if 
>>> there is any problem.
>>>
>>>>
>>>>
>>>> Aris
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>>>>
>>
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>