There is strong noise at the margin of mask in local refinement

Hi, all. I met a problem about the mask of local refinement. There is strong noise at the margin of mask in local refinement. And I am sure that there is no density in overall map where the artifact appears. My specific input mask is 6 voxels dilation and has a soft edge of 6 voxels. I also tried the mask looser, for example,dialtion-soft edge are 12-12. It didn’t work, too. I did not know what lead to the artifact. Could someone help me?

Hi Yuqi,

What search parameters are you using, and how big is your mask (what is the mass of the enclosed region). If the mask is very small, you may need to make the mask much softer - e.g. a soft edge of 24 pixels is not uncommon.


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Thanks for your reply! I used prior guassian distribution search parameters. And The parameters are below:

I think that a soft edge of 24 pixels is too large, which resulting in enclosing other regions. I’m afraid that other high quality region may affect the alignment of my focused region.

Hi Yuqi,

Keep in mind that you do not need to dilate by 24 pixels - I would use a tight mask enclosing the region of interest but with a very soft edge.


Thank you very much! I will have a try!