2. Introduction Tsung-Yi Wu

3. Introduction  What is a multimedia system? –A multimedia system supports the integrated storage, transmission and representation of the discrete media types text, graphics and image and the continuous media types audio and video on a digital computer.

4. A Hybrid (analog/digital) Multimedia System  Early multimedia system, around 1985

5. Digital Multimedia System  The media streams are digital. They can be processed (e.g., compressed/ decompressed,analyzed) in the computer.

6. Time-Independent Media  Information is not related to timing of the data stream  All „ classic “ media in the computer, such as: –text –graphics (line drawings, vector graphic) –image (photo, pixel graphics).

7. Time-Independent Media  Example [Kitaoka 2003]

8. Time-Independent Media Ming-Te Chi et al.)  Illusory Motion (Ming-Te Chi et al.)

9. Time-Independent Media  Example (Image)

10. Time-Independent Media  Example (Image)

11. Time-Independent Media  Example (Image)

12. Time-Independent Media  Hybrid Image –http://cvcl.mit.edu/publications/publication s.htmlhttp://cvcl.mit.edu/publications/publication s.html

13. Time-Independent Media  Example (Graph)

14. Time-Independent Media  Example (3D Stereogram)

15. Time-Independent Media  Example (How to see, 14 cyclic stones)

16. Time-Independent Media  3D Stereogram –DIY  http://www.flash-gear.com/stereo/ http://www.flash-gear.com/stereo/  Why do they look 3D? –http://www.kondo3d.com/stereo/why- 3d/why-3d-e.htmlhttp://www.kondo3d.com/stereo/why- 3d/why-3d-e.html  Paper

17. Time-Independent Media  Why do they look 3D?

18. Time-Independent Media  Example (3D ASCII Stereogram)

19. Time-Independent Media  Example (3D ASCII Stereogram)

20. Time-Independent Media  Optical Illusion –http://www.johnsadowski.com/big_spanis h_castle.phphttp://www.johnsadowski.com/big_spanis h_castle.php

21. Time-Dependent Media  Information is time-related, must be shown to the user at specific points in time  Continuous data streams –Data appears in regular intervals  Examples: –Video (continuous)

22. Time-Dependent Media  Examples: –An animation (not a continuous stream, but time-dependent) –An interactive game on the Internet (not a continuous stream, but has real-time requirements) –Audio (continuous)

23. Time-Dependent Media  Image Morphing –Morphing is a special effect in motion pictures and animations that changes (or morphs) one image into another through a seamless transition.special effectmotion pictures animationsimage  Morph Tools –FantaMorph –Fun Morph

24. Time-Dependent Media  3D Stereogram Movie in Ascii http://www.kammerl.de/ascii/AsciiStere oMovie.php http://www.kammerl.de/ascii/AsciiStere oMovie.php  3D Animated Stereograms –http://www.hidden- 3d.com/stereogram_theory.phphttp://www.hidden- 3d.com/stereogram_theory.php

25. Multimedia System  Integrated  production,  processing,  storage,  representation,  Transmission, etc. of several time-dependent and time- independent media streams

26. History of Bandwidth in Computer Networks

27. Network Requirements of Different Types of Data Streams

28. Multimedia Processing  Compression/Decompression  Encryption/Decryption  Enhancement  Transformation  Recognition  Etc.

29. Compression  Goal –The compression of multimedia data streams saves  storage space  transmission bandwidth

30. Compression  Lossless –If the recovered data are assured to be identical to the source –Lossless compression techniques are requisite for applications involving textual data  e.g. ZIP  Lossy –Other applications, such as those involving voice and image data, may be sufficiently flexible to allow controlled degradation in the data

31. Compression  Lossy –Example (DCT)  Although there is some loss of quality in the reconstructed image, it is clearly recognizable, even though almost 85% of the DCT coefficients were discarded.

32. Encryption  Example 3 1 0 2

33. Encryption  Example

34. Encryption  Example

35. Encryption  Example (Decryption)

36. Encryption  Text/String plaintext ciphertext K A-B encryption algorithm decryption algorithm K A-B plaintext message, m K (m) A-B K (m) A-B m = K ( ) A-B

37. Enhancement  Examples

38. Transformation  Example

39. Transformation  Example –Original –Changed

40. Recognition  Example

41. Tools  Matlab I = imread('cameraman.tif'); I = im2double(I); T = dctmtx(8); B = blkproc(I,[8 8],'P1*x*P2',T,T'); mask = [1 1 1 1 0 0 0 0 1 1 1 0 0 0 0 0 1 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]; B2 = blkproc(B,[8 8],'P1.*x',mask); I2 = blkproc(B2,[8 8],'P1*x*P2',T',T); imshow(I), figure, imshow(I2)

42. Tools  Matlab

43. Tools  PhotoImpact

44. Tools  Audacity

45. FrontPage  HTML  Javascript function encode() { if(document.form2.R1[0].checked){ Result="0 分 "; } if(document.form2.R1[1].checked){ Result="30 分 "; } document.form1.S1.value=Result; }  Java

46. Anfy  Anfy (Java ™ ) includes 52 applets, top effects and menu for web sites and blogs. Plus screensaver. Anfy (Java ™ )

47. Flash MX

48. PowerPoint  Example

49. PowerPoint  Example

50. PowerPoint 49

51. App  http://processing.org/tutorials/android/