1. image read
2. image show
3. window
4. mouse event
5. image create
6. image write
7. pixel access
8. arithmetic operations
9. bitwise operations
10. drawing
11. video capture
12. contrast
13. color space (object tracking)
14. histogram
15. histogram equalization
16. contour
17. minMaxLoc
18. convolution
19. filter2D
20. track bar
21. smoothing
22. sharpening
23. Canny
24. NonPhotorealistic Rendering
25. oil painting effect
26. erode
27. dilate
28. optical flow
29. face detection
30. object tracking