[Insight-users] fast marching algorithm very time consuming?

[Luis Ibanez]

Hi Michael,

FastMarching should take only seconds in that size of data set.

You are requesting a stopping time of 2000 and thresholding at 100,
that means that all the times from 101 to 2000 are going to waste.

If you are going to threshold at 100, you can just set the stopping
time to a value slightly above the threshold. For example, you could
stop at 110.

The heuristic for choosing the stopping time relates to the size of
the object that you want to segment and to the average value of the
speed image in the region that goes from the seed points to the
boundaries of the object that you want to segment.



BTW: What is the profile of your computer ?
      OS, Processor, Memory ?



    Regards,


       Luis



-------------------------
Michal Plotkowiak wrote:
> Hi,
> 
> I'm segmenting 3D data of a heart using FastMarchingImageFilter program. The 
> data size is 256x256x362. Every 5th slice I generate seed points (approximately 
> 300 on a slice). My threshold time is 100 and stoping time 2000. When I ran the 
> simulation only for 6 slices I get good results but after about an hour. When I 
> tried to run the sumulation for all the slices (362) two days wasn't enough...
> 
> Has anyone some experience with FastMarching algorithm? The time needed for the 
> simulation seems to be far too long. Should I somehow change my approach to the 
> problem?
> 
> many thanks
> michal
> 
>