[Insight-users] UnaryFunctorImageFilter and MetaDataDictionnary

[Bill Lorensen]

I don't think we need another dictionary. As Jim Miller noted in the
original bug report
http://public.kitware.com/Bug/view.php?id=4625

we could copy the dictionary in the CopyInformation method in ProcessObject.

I just checked all of the itk Code/ directories. For the most part,
only IO classes use or encapsulate meta data dictionary information.

I think we can safely copy the meta data dictionary as Jim suggested.

I'll investigate further.


On Tue, Oct 27, 2009 at 10:32 AM, Julien Michel <julien.michel at c-s.fr> wrote:
> Bill Lorensen a écrit :
>>
>> Another possibility is for the application to observe the EndEvent of
>> the filters and copy the input meta data dictionary to the output of
>> the filter. We might be able to package this into a helper class.
>>
>> I'll look into this one.
>
> Bill,
>
> Sometimes we want to have access to these meta-information even-though the
> filter execution has not yet been triggered (for instance we do not need to
> process the whole image just to access its ground control points). That is
> why this solution seems incomplete to me (but I might be wrong).
>
> If you want to make it clear that the beyond the customization point it is
> the user responsibility to ensure data consistency, why not add a second
> metadata dictionnary (for instance m_UserDefinedDictionnary) along with its
> methods (virtual void GenerateOutputUserDefinedDictionnary()), with a
> default implementation copying from first input to outputs ?
>
> This way it is clear that these members are provided for customization and
> that they are the users responsibility (and it does not modify any of the
> existing ITK functionalities).
>
> Julien
> --
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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> Julien MICHEL - Ingénieur d'études - Traitement d'images
> CS Systèmes d'Information - Division ESPACE
> Département Information Géographique & Image
> Téléphone : +33 561 17 64 27
> Email : julien.michel at c-s.fr
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