[ITK-users] Float dicom images

[Tim Allman]

I just read Supplement 172 and it certainly addresses what I want which 
is to create parametric maps and not lose information (sign, dynamic 
range etc.) on storage.

My situation is that I am writing a plugin for Osirix, a DICOM (only) 
viewer which runs on OSX (only). I can create the maps I want internally 
as the viewer uses float as its pixel type internally but it saves 
everything as unsigned 16 bit integers. It will read floating point 
images however so perhaps writing them will come soon.

I single stepped through the writing of a float image and discovered 
that GDCM has some code clearly intended to support I/O of these images 
but it is incomplete. It will indeed write float images but they are 
rescaled to have a range of 0 - MAXFLOAT.

Tim

On 14-12-02 05:14 PM, David Clunie wrote:
> We (DICOM) have only recently added support for floating point
> pixel data in DICOM (Sup 172), so I don't know if any of the
> toolkits used by ITK support it yet.
>
> I know dcmtk will, hopefully soon, but I can't speak for GDCM.
>
> I have some samples at:
>
> https://www.dropbox.com/sh/n4iqdjbhmwljx5e/AABllea-Muk0C2oo576nm_Mua?dl=0
>
> if you want to try them; not perfect yet, but they have the float pixel
> data payload.
>
> I am assuming that you actually want to write floating point pixels,
> rather than integer quantized pixels with a floating point scaling
> factor.
>
> David
>
> On 12/2/14 3:40 PM, Matias Montroull wrote:
>> adding insight users..
>>
>> I've never dealt with float dicom images, can you send me a sample 
>> image? I
>> can try to write and see what's the problem. isn's saving the image 
>> or you
>> get a wrong saved image, such as WL WC changed etc?
>>
>> On Tue, Dec 2, 2014 at 4:53 PM, Tim Allman <dr.tim.allman at gmail.com> 
>> wrote:
>>
>>>
>>> On Dec 2, 2014, at 14:44 , Matias Montroull <matimontg at gmail.com> 
>>> wrote:
>>>
>>>> are you trying to write float dicom images?
>>>
>>> Yes. Sorry for noting that only in the subject line. :-(
>>>
>>>>
>>>> On Tue, Dec 2, 2014 at 4:35 PM, Tim Allman <dr.tim.allman at gmail.com>
>>> wrote:
>>>> I have been having a bit of trouble trying to write Dicom images using
>>> itk::GDCMImageIO. The code suggests that this is supported but I 
>>> know that
>>> this is a new feature. Has anyone else had any experience with this?
>>>>
>>>> Thanks,
>>>> Tim
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-- 
Tim Allman, Ph.D.
35 Margaret Street,
Guelph Ontario N1E 5R6
Canada

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