[Insight-users] Fwd: Guidelines for speed and memory footprint optimization

[Jerome Maudlin]

---------- Forwarded message ----------
From: Jerome Maudlin <jerome.maudlin at gmail.com>
Date: 2010/11/10
Subject: Re: [Insight-users] Guidelines for speed and memory footprint
optimization
To: Sergio Vera <sergio.vera at alma3d.com>


Hi Sergio,

Thanks for the idea.

We only use streaming with the writers.

Best regards.

JM

2010/11/10 Sergio Vera <sergio.vera at alma3d.com>

A
> We call ReleaseDataFlagOn() on all the filters except the last one and the
> ones that have more than a downstream filter to release intermediate images
> once they are not useful anymore. But if you are activating streaming on the
> writer sink. maybe this will not improve your memory consumption too much.
>
> Also I may ask if you use streaming when there is no writer at the end? and
> if yes, how you enable streaming in this case?
>
> Thanks
>
> Sergio
>
>  On Wed, Nov 10, 2010 at 8:54 AM, Jerome Maudlin <jerome.maudlin at gmail.com
> > wrote:
>
>> Dear all,
>>
>> I am implementing a processing chain which has strong constraints in terms
>> of computational time and memory footprint. We are also forced to use one
>> single thread for whole pipeline.
>>
>> I have identified several ways for optimizing my code, but I was wondering
>> if there are other things I could do. Here is what I have found until now:
>>
>> 1. For multi-channel images, the use of scalar images with FixedArray
>> pixels gives a 1.5 speedup factor with respect to the use of VectorImage
>> with scalar pixel types (I know the number of bands at compilation time).
>>
>> 2. Even though I need to work with real types for the computations
>> (physical magnitudes between 0 and 1), I found that writing intermediate
>> results to files using real types is much slower than multiplying the values
>> by a large constant and writing the result to disk using integer types.
>>
>> I was also wondering if there is a smart way to choose the number of
>> streaming divisions for the writer in order to ensure that the memory
>> footprint of my program does not goes beyond a given size (other than try
>> and error).
>>
>> Thank you very much for your help.
>>
>> JM
>>
>> PS: If there are general guidelines for this kind of optimization, maybe
>> there should be a chapter in the software guide or a wiki page for this
>> topic?
>>
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>
>
> --
> Sergio Vera
>
>  Alma IT Systems
>  C/ Vilana, 4B, 4º 1ª
>  08022 Barcelona
>  T. (+34) 932 380 592
>  www.alma3d.com
>
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