[ITK] Update()

[Luis Ibanez]

ITK uses a data pipeline architecture.

This means that you select a set of filters that are connected
in a sequence (the pipeline), and data will flow through the
pipeline as it is being process by each filter.


To connect the pipeline you use the methods

     FilterB->SetInput(   FilterA->GetOutput()   )


and so on for

FilterC
FilterD
FilterE
...



This typically starts with a Reader in one end,
and a Writer on the other end.

Connecting the filters in the pipeline, does not
perform yet any computation.

The goal of the Update() method is to trigger the
execution of the Pipeline.  It will execute all the
filters "upstream", that is, from the beginning of
the pipeline, up to the filter in which you call Update().

Typically, you call Update() in the last filter of the pipeline,
because in that way, you execute the full pipeline.

However, you can always call Update() in the intermediate
filter, and therefore execute the pipeline, only up to that
intermediate filter.

In the particular case of the reader that you asked,
the Update() method, triggers the actual reading of
the content of a file (usually an image), into memory,
typically to store it in an itk::Image instance.


    Luis





On Fri, May 9, 2014 at 4:05 PM, Simplicity Peace <
simplicitypeacescm at gmail.com> wrote:

> Hello,
>
> I'm new to `ITK`. I just want to ask, what does `Update()` mean? For
> example, I found that I had to use it with an `ImageFileReader`. Why is
> that?
>
> Thanks.
>
> _______________________________________________
> Community mailing list
> Community at itk.org
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>
>
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