Digital Image Processing 0909.452.01/0909.552.01 Fall 2003

1. Digital Image Processing0909.452.01/0909.552.01Fall 2003 Lecture 6October 13, 2003 Shreekanth Mandayam ECE Department Rowan University http://engineering.rowan.edu/~shreek/fall03/dip/

2. Plan • Digital Image Restoration • Recall: Environmental Models • Image Degradation Model • Image Restoration Model • Point Spread Function (PSF) Models • Linear Algebraic Restoration • Unconstrained (Inverse Filter, Pseudoinverse Filter) • Constrained (Wiener Filter, Kalman Filter) • Lab 3: Digital Image Restoration

3. DIP: Details

4. Image Preprocessing Restoration Enhancement • Inverse filtering • Wiener filtering Spectral Domain Spatial Domain • Filtering • >>fft2/ifft2 • >>fftshift • Point Processing • >>imadjust • >>histeq • Spatial filtering • >>filter2

5. S f(x,y) g(x,y) h(x,y) n(x,y) Degradation Model: g = h*f + n Degradation Model • demos/demo5blur_invfilter/ • demos/demo5blur_invfilter/degrade.m

6. Restoration Model Degradation Model Restoration Filter f(x,y) f(x,y) Unconstrained Constrained • Inverse Filter • Pseudo-inverse Filter • Wiener Filter • demos/demo5blur_invfilter/

7. f(x,y) Build degradation model f(x,y) Analyze using algebraic techniques Formulate restoration algorithms Implement using Fourier transforms Approach g = h*f + n g = Hf + n W -1g = DW -1f + W -1n f = H -1g F(u,v) = G(u,v)/H(u,v) • demos/demo5blur_invfilter/

8. Degradation & Restoration Examples: Gonzalez & Woods Atmospheric Turbulence Model

9. Degradation & Restoration Examples: Gonzalez & Woods Example 5.11: Inverse Filtering

10. Degradation & Restoration Examples: Gonzalez & Woods Example 5.12: Wiener Filtering

11. Degradation & Restoration Examples: Gonzalez & Woods Example 5.10: Planar Motion Model

12. Degradation & Restoration Examples: Gonzalez & Woods Example 5.13: Inverse and Wiener Filtering

13. Lab 3: Digital Image Restoration http://engineering.rowan.edu/~shreek/fall03/dip/lab3.html

14. Summary