Chapter 5 Image Restoration

Chapter 5 Image Restoration

^ x(m,n) Deblurring: Pseudo-Inverse Filtering h(m,n) x(m,n) y(m,n) g(m,n) blurring filter deblur filter 1 What if at some(u,v), H(u,v) is 0 (or very close to 0) ? Inverse filter: G(u,v) = H(u,v) small threshold Pseudo-inverse filter:

Inverse and Pseudo-Inverse Filtering blurred image  = 0.1

Chapter 5 Image Restoration

Wiener (Least Square) Filtering Wiener filter: noise power signal power • Optimal in the least MSE sense, i.e. • G(u, v) is the best possible linear filter that minimizes • Have to estimate signal and noise power

Inverse filtering Blurred image Radially limited inverse filtering R = 70 Weiner filtering From [Gonzalez & Woods]

Inverse vs. Weiner Filtering distorted inverse filtering Wiener filtering motion blur + noise less noise less noise From [Gonzalez & Woods]

Chapter 5 Image Restoration