1. LCC, MIERSI SM 14/15 – T4 Special Effects Miguel Tavares Coimbra

2. SM 14/15 – T4 - Special Effects Image Processing

3. SM 14/15 – T4 - Special Effects Computer Graphics

4. SM 14/15 – T4 - Special Effects Ray Harryhausen a.k.a. stop action animation

5. ‘Special Effects’ can mean a lot of things

6. Today We will talk about image processing Computer graphics is in Lecture 8 We will not talk about stop-action animation –But you should go and see “Jason and the Argonauts” anyway –http://www.rayharryhausen.com/ SM 14/15 – T4 - Special Effects

7. (Some) Pieces of the Puzzle Image creators (3D -> 2D) –Camera (Today) –Computer Graphics (T8) Image manipulators (2D -> 2D) –Image Processing (Today) Image displays (2D -> ?) –2D Screen –3D Virtual Reality (T7) SM 14/15 – T4 - Special Effects

8. How do we get 2D images of a real 3D world?

9. SM 14/15 – T4 - Special Effects Camera Obscura, Gemma Frisius, 1544

10. SM 14/15 – T4 - Special Effects Pinhole Photography

11. SM 14/15 – T4 - Special Effects Lenses

12. CCD (charge coupled device) Higher dynamic range High uniformity Lower noise CMOS (complementary metal Oxide semiconductor) Lower voltage Higher speed Lower system complexity Image Sensors Convert light into an electric charge SM 14/15 – T4 - Special Effects

13. What is Colour? SM 14/15 – T4 - Special Effects

14. Sensing Colour beam splitter light 3 CCD Bayer pattern Foveon X3 TM SM 14/15 – T4 - Special Effects

15. Analog to Digital The scene is: –projected on a 2D plane, –sampled on a regular grid, and each sample is –quantized (rounded to the nearest integer)

16. SM 14/15 – T4 - Special Effects Images as Matrices Each point is a pixel with amplitude: –f(x,y) An image is a matrix with size N x M M = [(0,0) (0,1) … [(1,0) (1,1) … … (0,0)(0,N-1) (M-1,0) Pixel

17. Colour Space Colour space –Coordinate system –Subspace: One colour -> One point RGB is very popular SM 14/15 – T4 - Special Effects

18. Manipulating Single Pixels

19. SM 14/15 – T4 - Special Effects Pixel Manipulation Let’s start simple I want to change a single Pixel. Or, I can apply a transformation T to all pixels individually.

20. Negative SM 14/15 – T4 - Special Effects

21. Colour Negative SM 14/15 – T4 - Special Effects

22. Pseudocolour

23. SM 14/15 – T4 - Special Effects Colour Slicing

24. SM 14/15 – T4 - Special Effects Chroma Key

25. Digital Filters

26. SM 14/15 – T4 - Special Effects Convolution with a Filter Matrix Simple way to process an image. Mask defines the processing function. Corresponds to a multiplication in frequency domain. Convolution – Mask ‘slides’ over the image Mask Image

27. SM 14/15 – T4 - Special Effects Depth of Field Blurring

28. SM 14/15 – T4 - Special Effects Anti-Aliasing

29. SM 14/15 – T4 - Special Effects Edge Detectors

30. SM 14/15 – T4 - Special Effects Colour Edge Detectors

31. Advanced Processing

32. SM 14/15 – T4 - Special Effects Optical Flow

33. SM 14/15 – T4 - Special Effects Motion Quantification

34. Structure from Motion SM 14/15 – T4 - Special Effects

35. Mosaicing

36. SM 14/15 – T4 - Special Effects Facial Detection and Recognition

37. Augmented Reality Piotr Karasinski 2013/14 SM 14/15 – T4 - Special Effects

38. Crazy Stuff That didn’t really fit anywhere else…

39. SM 14/15 – T4 - Special Effects Lego Mindstorm with a smartphone camera

40. SM 14/15 – T4 - Special Effects Virtual Joystick

41. How do I do all this?

42. Platforms and Source Code Computer Vision DCC –Lecture notes –JAVA platform –Android platform http://www.dcc.fc.up.pt/~mcoimbra/lectures/vc_1415.html OpenCV –Free to use, lots of algorithms, C http://opencv.org/ Gonzalez & Woods book SM 14/15 – T4 - Special Effects