1. Digital Image Processing
Tania Stathaki
Location: Room 812
Extension: 46229

2. LOGISTICS OF THE COURSE
Duration
20 lectures
Assessment
100% exam
There isn't any coursework or homework

3. IMAGE PROCESSING
Textbook
– R. C. Gonzalez, R. E. Woods, Digital Image Processing, Addison Wesley, 1993, ISBN

4. DIGITAL IMAGE

5. DIGITAL IMAGE

6. FROM ANALOG TO DIGITAL store object observe digitize process
Digital storage (disk)
object
observe
Imaging systems
digitize
Sample and quantize
process
Digital computer
Refresh/store
On-line buffer
Record
output
Display

7. Sampling
256x256
64x64

8. Quantisation – 8 bits
255

9. Quantisation cont.
256x levels
256x levels

10. Quantisation cont.
256x levels
256x256 2 levels

11. Coloured Image

12. Intensity (Gray-Level) Image

13. Binary Image

14. Image Processing manipulation of multidimensional signals
image (photo)
video
CT, MRI

15. Image Processing Why? – Enhancement, restoration, reconstruction
– Coding/compression
– Enhancement, restoration, reconstruction
– Analysis, detection, recognition, understanding
– Visualization

16. Part I: Image Transforms
Original Image
Fourier Transform
Amplitude Phase

17. Part II: Image Enhancement
Original Image
High Pass Filtering

18. Part III: Image Restoration
Distorted Image
Restored Image

19. Distortion due to Camera Misfocus
Original image
Distorted image

20. Distortion due to Camera Misfocus
Camera lens

21. Distortion due to motion
Camera lens

22. Distortion due to Random Noise
Original image
Distorted image

23. Part IV: Image Compression
Signal-Processing Based:
Encoder
Compressed Representation H
Decoder

24. Images are not directly amenable to computer analysis
Computers work with numerical (rather than pictorial) data.
An image must be converted to numerical form before processing by computer can commence.
Picture elements or pixels
Rectangular sampling grid
Brightness of the image

25. Images are not directly amenable to computer analysis

26. APPLICATIONS
Medical images
Satellite images
Astronomy
Radar images

27. Satellite image Volcano Kamchatka Peninsula, Russia

28. Satellite image Volcano in Alaska

29. Medical Images: MRI of normal brain

30. Medical Images: X-ray knee

31. Medical Images: Ultrasound Five-month Foetus (lungs, liver and bowel)

32. Astronomical images