Re: [Gdcm-hackers] Write tag with VR::OF, VR::OW

[<jor...@fr...>]

> Works for me:
>
>
http://gdcm.git.sourceforge.net/git/gitweb.cgi?p=gdcm/gdcm;a=commitdiff;h=ac003d4e0f0247f41ebd927729a4960b5ed059fa

It works for me too.

> What error are you getting ?

I have not any error. In fact, I do not get the right result I am looking for.
The Tag (0x0066,0x0016) is made for receive several float coordinates. Its
length value has a maximum of 2^32 - 4 (near of VR::UT, see PS 3.5-2009 Table
6.2-1). But, VR::OF in GDCM has a length value of 4. So, I can not set a float
array (eg: float array[] = { 15.2, -5, 167.3 }) in
gdcm::Attribute<0x0066,0x0016>. After setting, this Attribute has the value
15.2.

And it is the same problem with the Tag (0x0066,0x0023) and string of 16 bits
words.

> On Thu, May 26, 2011 at 1:05 PM,  <jor...@fr...> wrote:
> > Wow! Such a customer service, thank you very much Mathieu!
> >
> > Unfortunately, I still have a problem. It is on a Tag and its VM.
> > Indeed, the Tag (0x0066,0x0016) is defined in the supplement 132 by :
> >
> > Tag : (0x0066,0x0016), VR : OF, VM : 1, Type : 1
> >
> > But, how could I set with GDCM, a float array with a VM = 1 and not 1-n?
> >
> > Thanks again.
> >
> > Selon Mathieu Malaterre <mat...@gm...>:
> >
> >> Hi Jordi,
> >>
> >>   Glad to see you are making progress.
> >>
> >> On Thu, May 26, 2011 at 9:37 AM,  <jor...@fr...> wrote:
> >> > My problem is 1 element of the input string is wrote (eg:
> >> 175.6\25.1\-30\...
> >> > give 175.6).
> >>
> >> ok
> >>
> >> >    template <uint16_t GRP, uint16_t EL>
> >> >    static void setTagValue(const std::string & a_value, ::gdcm::DataSet
> &
> >> a_ds)
> >> >    {
> >> >        if(!a_value.empty())
> >> >        {
> >> >            // Create a data element
> >> >            ::gdcm::Attribute<GRP,EL> gAt;
> >> >
> >> >            ::gdcm::DataElement de( gAt.GetTag() );
> >> >            de.SetByteValue(a_value.c_str(), a_value.size());
> >> >            de.SetVR( gAt.GetVR() );
> >> >
> >> >            gAt.SetFromDataElement(de);
> >> >
> >> >            a_ds.Insert( gAt.GetAsDataElement() );
> >> >        }
> >> >    }
> >>
> >> I am quite lost here. You have two representation in GDCM:
> >> gdcm::Attribute (or gdcm::Element for the more generic approach) and
> >> gdcm::DataElement.
> >>
> >> gdcm::DataElement as the name indicates is the representation of a
> >> DATA ELEMENT as per PS 3.5 specification. Which means that the
> >> ByteValue contained in the DataElement will be *as stored* on the
> >> disk. For instance a VR::US with value 512 will be stored as ByeValue
> >> "0200" (use hexedit to see it).
> >>
> >> What does this means ? This means it is not very convinient to write
> >> DICOM tag that are not ASCII based (eg, US, OF...). In this case you
> >> have two approaches:
> >>
> >> The one derived from GDCM 1.x, where everything is a std::string, in
> >> this case have a look at the gdcm::StringFilter class, you have the
> >> ToString function which converts a DataElement Value into a 'viewable'
> >> string (it will convert "0200" into 512) and the opposite:
> >> StringFilter::FromString
> >>
> >> Now if you are programming in C++, you can take advantage of the
> >> gdcm::Attribute class which will do this hard work for you:
> >>
> >>   DataSet ds;
> >>   const float array[] = { 0, 1, 2, 3, 4 };
> >>   gdcm::Attribute<0x5600,0x0020, gdcm::VR::OF, gdcm::VM::VM1_n> at;
> >>   at.SetValues( array, sizeof( array ) / sizeof( *array ) );
> >>   ds.Insert( at.GetAsDataElement() );
> >>
> >> This will store the array using the binary IEEE notation to disk as
> expected.
> >>
> >>
> >> HTH
> >> --
> >> Mathieu
> >>
> >
> >
> >
>
>
>
> --
> Mathieu
>