[ITK] reading private tags returns weird strings

[Dženan Zukić]

For posterity: the value Francois was looking for was a float, and the four
bytes 00 80 93 43 indeed encode the float value 295.0

The code to convert to float:
float * fDecoded = (float *)&decoded[0];
std::cout << "float = " << (*fDecoded) << std::endl;

On Wed, Aug 10, 2016 at 10:43 AM, Dženan Zukić <dzenanz at gmail.com> wrote:

> Can you share (either with the list or just me) this DICOM image
> (optionally anonymized) and a runnable example which you use to read it?
>
> On Wed, Aug 10, 2016 at 10:41 AM, <Francois.GIRINON at ensam.eu> wrote:
>
>> Le 10/08/2016 à 16:23, Dženan Zukić a écrit :
>>
>> Does Matlab have special support for those private tags? They may have
>> special encoding besides base64 applied by ITK DICOM dictionary.
>>
>> On Wed, Aug 10, 2016 at 10:13 AM, <Francois.GIRINON at ensam.eu> wrote:
>>
>>> Le 10/08/2016 à 16:05, Dženan Zukić a écrit :
>>>
>>> In fact, this decodes
>>> <http://www.opinionatedgeek.com/dotnet/tools/base64decode/> to 00 80 93
>>> 43 - four bytes given here in hexadecimal notation. The decoder you linked
>>> does not seem to work correctly. I don't know why you expect 295 there.
>>>
>>> On Wed, Aug 10, 2016 at 9:58 AM, <Francois.GIRINON at ensam.eu> wrote:
>>>
>>>> Le 10/08/2016 à 14:35, Dženan Zukić a écrit :
>>>>
>>>> Hi Francois,
>>>>
>>>> is this base64 encoded? You should perhaps do base64 decode on the
>>>> return string to get the binary value.
>>>>
>>>> Regards,
>>>> Dženan
>>>>
>>>> On Wed, Aug 10, 2016 at 7:15 AM, <Francois.GIRINON at ensam.eu> wrote:
>>>>
>>>>> Hi,
>>>>>
>>>>> I'm trying to read private dicom tags using :
>>>>>
>>>>>     ImageIOType::Pointer dicomIO = ImageIOType::New();
>>>>>     ...
>>>>>     dicomIO->SetLoadPrivateTags(true);
>>>>>     std::string offsetFromBottomStr;
>>>>>
>>>>>     std::string offsetFromBottom = "0863|1041";
>>>>>     dicomIO->GetValueFromTag(offsetFromBottom, offsetFromBottomStr);
>>>>>
>>>>> The value *offsetFromBottomStr *returned is *AICTQw==*
>>>>> How does it come and how can I fix this ?
>>>>>
>>>>> Thank you,
>>>>> François.
>>>>>
>>>>> _______________________________________________
>>>>> Community mailing list
>>>>> Community at itk.org
>>>>> http://public.kitware.com/mailman/listinfo/community
>>>>>
>>>>>
>>>> Thanks for your answer. You might be right, they say here
>>>> <http://public.kitware.com/pipermail/community/2016-May/011426.html>
>>>> *private tags and encodes the with Base64 into strings. *Unfortunately,
>>>> *AICTQw== *should correspond to 295 and according to
>>>> https://www.base64decode.org/, *AICTQw==* is a C.
>>>> Besides, I don't understand how does itksysBase64_Decode works (I'm not
>>>> sure I should use this method too).
>>>>
>>>
>>> In fact I have previously red the dicom using matlab and the value of
>>> the private tag 0863 1041 is 295.
>>>
>>
>> I don't know, it doesn't seem really matlab specific, this tool
>> <https://github.com/gerddie/ginkgocadx> also gets a dicom inspector
>> module which displays 295.
>>
>
>
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