Image Processing Pre - Processing

1. Image ProcessingPre-Processing Institute of Medical Engineering University of Lübeck Director: Prof. Dr. T. M. Buzug Lecturer: Mandy Ahlborg

2. Noise - Different Types of Noise Gaussian Rayleigh Gamma Exponential Uniform Impulse

3. Noise - Different Types of Noise Gaussian noise Rayleigh noise

4. Noise - Different Types of Noise Gamma noise Exponential noise

5. Noise - Different Types of Noise Uniform noise Impulse noise

6. Noise - Filter Masks How do we apply a mask?

7. Noise - Filter Masks 9 1 1 1 4 5 1 1 1 9 1 4 5 1 3 1 1 6 0 7 1 1 1 0 1 4 6 7 1 1 3 7 5 1 1 6 2 3 1 7 5 1 6 2 7 0 1 4 5 1 2 7 0 1 4 5 1 2 8 2 1 1 8 2 1 1 1 1 1 1 1 1 1 3 1 9 1 1 3 1 9 7 4 0 7 4 0 2 6 1 1 1 6 1 1 1 5 1 0 5 1 0 Moving average Median filter

8. Noise - Filter Masks 9 1 1 1 4 5 1 5 1 1 6 0 7 1 1 3 7 5 1 1 6 2 7 0 1 4 5 1 2 8 2 1 1 1 1 1 1 3 1 9 7 4 0 4 6 1 1 1 5 1 0 Midpoint filter

9. Noise - Filter Masks 9 1 1 1 4 5 1 1 1 6 0 4 7 1 1 Gaussian/ Binomial filter mask 3 7 5 1 1 6 2 1 2 1 7 0 1 4 5 1 2 2 2 4 8 2 1 1 1 1 1 1 1 2 1 3 1 9 7 4 0 4 6 1 1 1 5 1 0 Gaussian/Binomial filter

10. Noise Reduction with Filtering Gaussian noise Moving average filter

11. Noise Reduction with Filtering Impulse noise Median filter

12. Noise Reduction with Filtering Impulse noise Gaussian filter

13. Noise Reduction with Filtering Uniform noise Moving average filter

14. Noise - Anisotropic Diffusion

15. Noise - Anisotropic Diffusion ; iteration 20 ; iteration 100 ; iteration 1

16. Noise - Anisotropic Diffusion ; iteration 20 ; iteration 100 ; iteration 1

17. Noise - Anisotropic Diffusion ; iteration 20 ; iteration 100 ; iteration 1

18. Noise - Error Measures

19. Spatial-basedMethods-Boundary Treatment zero padding constant extension periodic repetition symmetric extension

20. Spatial-basedMethods - SpatialTransformations Rigid Affine Projection

21. Spatial-basedMethods - Interpolation Nearest neighbor interpolation

22. Spatial-basedMethods - Interpolation Linear interpolation

23. Spatial-basedMethods - Interpolation Cubic interpolation

24. Spatial-based Methods - Interpolation Original Size reduction by 0.25 with nearest neighbor interpolation

25. Spatial-based Methods - Interpolation Original Size reduction by 0.25 with bilinear interpolation

26. Spatial-based Methods - Interpolation Original Size reduction by 0.25 with bicubic interpolation

27. Spatial-basedMethods- Sharpening

28. Spatial-basedMethods- Sharpening detail mask Source: lecture slides Computer Aided Medical Diagnosis, Prof. Navab, TU Munich

29. Intensity-based Methods - Histogram Processing number of bins: 256

30. Intensity-based Methods - Histogram Processing number of bins: 128

31. Intensity-based Methods - Histogram Processing number of bins: 64

32. Intensity-based Methods - Histogram Processing number of bins: 32

33. Intensity-based Methods - Histogram Equalization

34. Intensity-based Methods - Histogram Equalization

35. Intensity-based Methods - Intensity Transformations Identity Negative Thresholding Dark ↔ Light Dark ↔ Light Dark ↔ Light Dark ↔ Light Dark ↔ Light Dark ↔ Light

36. Intensity-based Methods - Intensity Transformations Contrast stretching Contrast stretching Dark ↔ Light Dark ↔ Light Dark ↔ Light Dark ↔ Light

37. Intensity-based Methods - Intensity Transformations -Correction Log transform Dark ↔ Light Dark ↔ Light Dark ↔ Light Dark ↔ Light