Hi, I made some changes in effect.c:ReduceNoiseImage function to support multi threading execution (using OpenMP). For large files the new code achieves improvements in performance around 30%.
Link to the patch:
http://rapidshare.com/files/114037640/effect.patch.html
ReduceNoiseImage parallel patch
Re: ReduceNoiseImage parallel patch
We can't use the patch as is. OpenMP must be enabled with pragma's so ImageMagick can compile if OpenMP is not enabled or available. Refactor your patch and repost and we will get it into the ImageMagick distribution.