1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Perona-Malik Diffusion Equation

  1. Dec 7, 2011 #1
    1. The problem statement, all variables and given/known data
    Implement the non-linear de-noising algorithm of Perona-Malik. Consider a noisy image, u, with pixel values referenced by u(i,j). Non-linear de-noising can be achieved by solving the following non-linear diffusion equation:

    ∇ · (g(∇u)∇u) = 0

    with g(s) = ((K^2)v) / ((K^2) + |s|)

    where v and K are parameters controlling the amount of diffusion.

    Write down the linear system associated with this discretization.

    My question is how do I do this? How can I take the gradient of a pixel? It isn't a function so how can I do partial derivative with respect to x and y to it?
    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Dec 7, 2011 #2
    I have no idea what to do here. If I could have shown work I would have, but I have no work done. I just need a nudge in the right direction here.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook