1. Lecture 15 Figures from Gonzalez and Woods, Digital Image Processing, Second Edition, 2002.

2. Geometric Transformation (1)

3. Geometric Transformation (2)

4. Chapter 5 Image Restoration Chapter 5 Image Restoration

5. Geometric Transformation (3)

6. Geometric Transformation (4) Tiepoints established by application dependent methods Physical artifacts (like metallic points) embedded on the sensor itself. Produces a known set of points (called reseau marks) on the image as acquired. An image distorted by some other process, e.g., display or image reconstruction can be geometrically corrected.

7. Chapter 5 Image Restoration Chapter 5 Image Restoration

8. Gray Level Interpolation Above technique can result in noninteger values of x’ and y’ Inferring gray levels can gray level interpolation Two techniques Nearest neighbor interpolation (zero order interpolation) Bilinear interpolation from four nearest points

9. Chapter 5 Image Restoration Chapter 5 Image Restoration

10. Chapter 5 Image Restoration Chapter 5 Image Restoration

11. Color Image Processing Two general types discussed Full-color –acquired with full color sensor such as a TV camera Psuedo-color– Problem of assigning a color to a particular monochrome intensity or range of intensities Until recently almost all color processing was psuedo- color,but full color sensors and hardware are now available at reasonable prices

12. Description of Light Source Chromatic light spans EM spectrum from 400 to 700 nm. Three qualities used to describe light source Radiance-total amount of energy from source (measured in watts) Luminance- energy an observer perceives from source (measured in lumens) Brightness- Embodies notion of intensity. Hard to measure.

13. Chapter 6 Color Image Processing Chapter 6 Color Image Processing

14. Chapter 6 Color Image Processing Chapter 6 Color Image Processing

15. Chapter 6 Color Image Processing Chapter 6 Color Image Processing

16. Colors ``Primary’’ colors—red,green,blue ``Secondary’’ colors—magenta=red+blue; cyan=green+blue; yellow=red+green. In pigment– a primary color subtracts or absorbs primary color of light and reflects or transmits other two Primary colors of pigment are megenta, cyan, and yellow.

17. Chapter 6 Color Image Processing Chapter 6 Color Image Processing

18. Chapter 6 Color Image Processing Chapter 6 Color Image Processing

19. Chapter 6 Color Image Processing Chapter 6 Color Image Processing

20. Color Models Red, Green, Blue (RGB) –color monitors and a broad class of video cameras CMY (cyan, magenta, yellow) and CMYK (cyan, magenta, yellow, black) – for color printing HIS (hue, saturation, intensity)– corresponds with how humans describe and interpret color

21. Chapter 6 Color Image Processing Chapter 6 Color Image Processing

22. Chapter 6 Color Image Processing Chapter 6 Color Image Processing

23. Chapter 6 Color Image Processing Chapter 6 Color Image Processing

24. Chapter 6 Color Image Processing Chapter 6 Color Image Processing

25. Chapter 6 Color Image Processing Chapter 6 Color Image Processing

26. Chapter 6 Color Image Processing Chapter 6 Color Image Processing

27. Chapter 6 Color Image Processing Chapter 6 Color Image Processing

28. Chapter 6 Color Image Processing Chapter 6 Color Image Processing