[MINC-users] Blurring with noise and/or sharp edges

[John G. Sled]

Dear Gabriel,

Another solution to this problem is to blur the masked image, blur the mask itself, and compute the ratio of the two images.   A third solution is to use spline fitting instead of filtering.

best regards,

John



> On Nov 3, 2016, at 2:29 PM, Christopher Hammill <christopher.hammill at sickkids.ca> wrote:
> 
> I just read about Perona-Malik smoothing which supposedly honours edges.
> 
> https://people.eecs.berkeley.edu/~malik/papers/MP-aniso.pdf
> 
> It's implemented in ANTs using the iMath  PeronaMalik command.
> 
> Chris
> ________________________________________
> From: minc-users-bounces at bic.mni.mcgill.ca [minc-users-bounces at bic.mni.mcgill.ca] on behalf of Gabriel A. Devenyi [gabriel.devenyi at mcgill.ca]
> Sent: Monday, October 24, 2016 1:29 PM
> To: MINC users mailing list
> Subject: [MINC-users] Blurring with noise and/or sharp edges
> 
> Hi all,
> 
> I have some data I'd like to blur which has "nonsense" voxels outside the
> brain (MP2RAGE maps). I want to exclude these voxels from the blur. If I
> zero out these voxels I get an edge effect, the apodizing doesn't help as
> much as I'd like it to.
> 
> Is anyone aware of an alternate blurring method which can avoid these
> issues?
> 
> Thanks.
> 
> --
> Gabriel A. Devenyi B.Eng. Ph.D.
> Research Computing Associate
> Computational Brain Anatomy Laboratory
> Cerebral Imaging Center
> Douglas Mental Health University Institute
> McGill University
> t: 514.761.6131x4781
> e: gabriel.devenyi at mcgill.ca
> _______________________________________________
> MINC-users at bic.mni.mcgill.ca
> http://www.bic.mni.mcgill.ca/mailman/listinfo/minc-users
> 
> ________________________________
> 
> This e-mail may contain confidential, personal and/or health information(information which may be subject to legal restrictions on use, retention and/or disclosure) for the sole use of the intended recipient. Any review or distribution by anyone other than the person for whom it was originally intended is strictly prohibited. If you have received this e-mail in error, please contact the sender and delete all copies.
> _______________________________________________
> MINC-users at bic.mni.mcgill.ca
> http://www.bic.mni.mcgill.ca/mailman/listinfo/minc-users