Segmenting the nerve like structures in a low resolution image

I have an image like the one attached,

It has low quality and the edges are not very clear. Any idea how to segment the nerve-like structures? I've tried the coherence filter, Frangi filter, and Gabor filter and still, I don't have a satisfying result.

Any help is appreciated.

Answer 1

[Image Analyst]

Well you could try anisotropic diffusion (demo attached) or a tophat filter or a Kuwahara filter (demo attached), though I don't hold out great hope for those either. But they're worth a try.

Then there are more sophisticated noise reduction routines like BM3D, non-local means, non-local means 2, UINTA, K-LLD, K-SVD, etc. See the bible of image denoising overviews: https://users.soe.ucsc.edu/~milanfar/publications/journal/ModernTour.pdf by one of the leaders in the field.

[Image Analyst]

You should be able to find plenty of vessel tracking papers here: http://www.visionbib.com/bibliography/contentsmedical.html#Medical%20Applications,%20CAT,%20MRI,%20Ultrasound,%20Heart%20Models,%20Brain%20Models

[zohreh hosseinaee]

Thank you very much, I have tried several denoising and coherence filters and still, I don't have the results I'm looking for. I tried to remove the BG after despeckling and attached are my images. The final image is after despeckling, BG removal and coherence filter. and the diffuse image is the image after diffusion. I'm looking for a method for just segmenting the nerves (The line structures). The is supposed to be automatic so I don't want to do any manual segmentation. I'd really appreciate your help.

[Image Analyst]

I suggest you look at the papers, or hire someone to develop an algorithm for you. This is not simple and would take way too much time - way more than I can donate to you. Plus, it seems like there are judgment calls involved as to whether a little, disconnected bright blob should be considered as part of a nearby nerve trace or not. Good luck though.