[Insight-users] RecursiveSeparableImageFilter and ReconstructionImageFilter

[Julien Michel]

Tom Vercauteren a écrit :
> Hi Julien,
> 
> As far as I understand it, RecursiveSeparableImageFilter should be
> recursive and separable meaning that (for a 2D image) the filter first
> requires entire lines and then requires entire columns. It can thus
> not easily benefit from streaming (even though it could be
> multithreaded).
> 
> If the filter needs to be run in one direction only, it should however
> be possible to do streaming with regions split in the other direction.
> 
> Regards,
> Tom

Hi Tom, Hi Gaetan,

Thanks a lot for your replies. I understand that streaming is not 
straightforward for these implementations. I think I'll have a look at 
the algorithms and publications used to better understand how it is 
working.

My naive idea is that to compute a gradient, or the opening by 
reconstruction, for a given pixel, you should not need pixels that are 
30 000 pixels away from it. So, given a subregion of the input image, 
there must be a minimal region where values of the gradient on the full 
image and on the subregion are equivalent. The question is how to 
determine this minimal region. If we know how to to do it, with a litle 
overlapping we should be able to turn a lot of filter streamable, which 
would be very useful (especially for us).

Best regards,

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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