[Insight-users] itkResampleImageFilter Up sample take too long?

[Feng Ma]

I got it. Thanks a lot for pointing out.

For some simply operation, e.g., resample a volume by only changing voxel 
size, we can use some simply operation to make it faster.

Thanks again.

-Feng

>From: "Lydia Ng" <lng at insightful . com>
>To: "Feng Ma" <mafeng at hotmail . com>,<insight-users at itk . org>
>Subject: RE: [Insight-users] itkResampleImageFilter Up sample take too 
>long?
>Date: Fri, 24 Oct 2003 10:25:20 -0700
>
>Hi Feng,
>
>The amount of work done by the ResampleImageFilter is proportional to
>the output size. From your numbers,
>
>"upsample work"/ "downsample work"
>= 512x512x251 / 64x64x50
>= 321 (approx)
>
>"upsample time" / "downsample time"
>= 107.77 / 0.33
>= 326 (approx)
>
>So, the time taken to upsample is about what is expected since the
>algorithm is linear with respect to output size.
>
>- Lydia
>
> > -----Original Message-----
> > From: Feng Ma [mailto:mafeng at hotmail . com]
> > Sent: Thursday, October 23, 2003 1:59 PM
> > To: insight-users at itk . org
> > Subject: [Insight-users] itkResampleImageFilter Up sample take too
>long?
> >
> > Hi,
> >
> >   I am using itkResampleImageFilter to do resampling both down
>sampling
> > and
> > up sampling. I found out that down sampling almost take no time, while
>up
> > sampling takes significantly longer. Attached is my test code, with
> > results
> > as below:
> >
> >
> >        Start down sampling: 0
> >        End down sampling: 0.33
> >        Start up sampling: 0.33
> >        End up sampling: 107.77
> >
> >   The code works as:
> >
> >    First downsample a volume 512x512x251 to 64x64x50. Then up sample
>the
> > small volume to original size.
> >
> >   Any idea about this?
> >
> >   Thanks a lot.
> >
> > -Feng
> >
> > _________________________________________________________________
> > See when your friends are online with MSN Messenger 6.0. Download it
>now
> > FREE! http://msnmessenger-download . com

_________________________________________________________________
Cheer a special someone with a fun Halloween eCard from American Greetings! 
Go to  http://www . msn . americangreetings . com/index_msn . pd?source=msne134