[Insight-users] Possible bug reading DICOM MONOCHROME1 images with Pixel Padding Value != 2^bits stored-1

[Mathieu Malaterre]

'lo

On Tue, Feb 17, 2009 at 12:00 PM, Iván Macía <imacia at vicomtech.org> wrote:
> Hi,
>
> If ConvertFixGreyLevels() is removed, all MONOCHROME1 images will fail to
> display correctly.

Presentation is one thing, pixel data is another. I really do believe
what was done in GDCM 1.x is simply a bug, and instead the Pixel Data
should be loaded as is: untouched. In which case it make the Pixel
Padding valid again, as well as Largest Pixel Value (and any other
pixel data associated attribute).
I have not touched GDCM 1.x in years but I do believe that Rescale
Slope/Intercept cannot be applied after this 'ConvertFixGreyLevels'
operation, (which AFAIK is what is happening).
So I am deeply convinced the right thing to do is simply remove this
function completely from the pipeline and have *Presentation*
application handle the Photometric Interpretation as expected. But
again ITK is not a Presentation software.

>On the other hand, right now we cannot use gdcm 2.x.
> since we use gdcm 1.x via ITK and directly in our DICOM/PACS viewer.

Well there is always a solution :)
Set ITK_USE_SYSTEM_GDCM to your gdcm 2.x installation and have another
gdcm 1.x installation where the namespace would be mangled to
something like 'gdcm_legacy'. Then in your code it is just a matter of
recompiling with 'using gdcm_legacy;'.

2cts
-- 
Mathieu