1. Concepts of Multimedia Processing and Transmission IT 481, Lecture 3 Dennis McCaughey, Ph.D. 5 February, 2007

2. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 2 Signal properties: (a) time-varying analog signal; (b) sinusoidial frequency components;

3. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 3 Signal properties: (c) signal bandwidth examples; (d) effect of a limited bandwidth transmission channel.

4. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 4 Signal Encoder Design: Circuit Components

5. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 5 Signal Encoder Design: Associated Waveform Set Analog Signal Low Pass Filtered Version Clock Output from Sample & Hold Quantizer Output

6. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 6 Alias Signal Generation Due to Under Sampling

7. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 7 Example 2.1

8. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 8 Quantization Procedure: Source of Errors

9. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 9 Quantization Procedure: Noise Polarity

10. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 10 Example 2.2

11. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 11 Signal Decoder Design: Circuit Components

12. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 12 Signal Decoder Design: Associated Waveform Set

13. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 13 Example character sets to produce unformatted text: the basic ASCII character set m=1101101 M=1001101

14. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 14 Supplementary Set of Mosaic Characters

15. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 15 Example Videotex/ Teletext Characters

16. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 16 Graphics Principles: Example Screen Format

17. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 17 (b) some simple object examples; (c) effect of changing position attribute; (d) solid objects.

18. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 18Attributes Shape: line, circle square, etc. Size Color Shadow Shape can be open or closed 3D through rendering

19. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 19 Facsimile Machine Principles: (a) Schematic; (b) Digitization format

20. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 20 Color Derivation Principles: Additive Color Mixing

21. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 21 Color Derivation Principles: Subtractive Color Mixing

22. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 22 Color principles Gamut: Range of colors produced by combinations of the three primaries Additive Color Mixing –Black is produced when all three primaries are zero –Display applications Subtractive Color Mixing –White is produced when all three primaries are missing –Printing applications

23. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 23 Television/Computer Monitor Principles: Schematic

24. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 24 Television/Computer Monitor Principles: Raster-Scan Principles Progressive Scan

25. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 25 Television/Computer Monitor Principles: Pixel Format on Each Scan Line

26. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 26 Raster-Scan Display Architecture

27. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 27 Some Parameters Phosphor Triad: Primary colors used –Different for NTSC and PAL Typical spot size: 0.025 in Flicker: if the frame rate is too low –NTSC: 60 fields/sec => 30 frames/sec –PAL 50 frames/sec

28. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 28 Example Display Resolutions and Memory StandardResolution Number of Colors Memory Required/Frame (Bytes) VGA640x480x8256307.2kB XGA 640x480x16 1024x768x8 64K 256 614.4kB 786.432kB SVGA 800x600x16 1024x768x8 1024x768x24 64K 256 16M 960kB 786.432kb 2359.296kB

29. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 29 Screen Resolutions: (a) Visible Lines Per Frame; (b) Digitization Spatial Resolution

30. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 30 Example 2.3

31. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 31 Color Image Capture: Schematic

32. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 32 Color Image Capture: RGB Signal Generation Alternatives

33. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 33 Example 2.4

34. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 34 PCM Principles: Signal Encoding and Decoding Schematic

35. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 35 PCM Principles: Companding International Standard: –ITU-T Recommendation G.711 Companding employs a non-linear or un- equal set of quantization steps –Linear quantization produces quantization noise that is independent of signal level –Ear is more sensitive to noise on quiet signals than on –Finer quantization at lower levels provides an increased signal quality, especially 8-Bit PCM

36. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 36 PCM Principles: Compressor Characteristic

37. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 37 PCM Principles: Expander Characteristic

38. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 38 CD-Quality Audio Music Bandwidth = 15Hz-20KHz –Minimum sampling rate=20ksps –Actual sampling rate = 44.1ksps –16bis/sample –Total Bit rate = 44.1x10 3 x16 1.411Mbps –Stereo means that the total bit rate is 2.822Mbps Much greater than the 64kbps of a PCM telephone channel and twice that of a T1 at1.54Mbps

39. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 39 Example 2.5

40. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 40 Audio/Sound Synthesizer Schematic

41. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 41 Interlaced Scanning Principles NTSC employs interlaced scanning Due to bandwidth limitations in the first half of the 20 th century

42. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 42 Color Source Properties Brightness –The amount of energy that hits the eye Hue –The actual Color of the source Saturation –Vividness of the color –Pastels have a lower saturation. e.g. pink has a lower saturation level than red Television transmission does not employ an RGB color space

43. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 43 Luminance and Chrominance To transmit RGB requires three times the bandwidth of a Black & White video Transform the RGB to a Luminance-Chrominance color space as most of the bandwidth is in the Luminance plane –Driven by limited bandwidth available –A B&W TV can receive and display directly on a color composite video signal broadcast –Very Clever Two Analog Luminance-Chrominance color spaces –NTSC (YIQ) –PAL (YUV) –Computer (YCbCr) (digital)

44. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 44 Color Transformations Transformations are different as the PAL & NTSC primaries are not the same

45. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 45 Example 2.6

46. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 46 Baseband Spectrum of Color Television Signals: NTSC System In NTSC, theeye is more sensitive to I than Q, hence more bandwidth I & Q are modulated in quadrature to occupy the same spectrum

47. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 47 Baseband Spectrum of Color Television Signals: PAL System

48. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 48 Sample Positions with 4:2:2 Digitization Format

49. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 49CCIR-601 4:2:2 is the original digitization format used in CCIR-601 RGB bandwidths each up to 6MHz Sampling Rates –Minimum of 12Msps for Y and 6Msps for C b and C r –13.5Msps for Y and 6.75Msps for C b and C r 13.5Msps is the nearest 12Msps resulting in a whole number of samples/line –625 line system 62microsec sweep - 12 microsec blank (62-12)x10 6 x13.5x10 6 =702 samples/line

50. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 50 Example 2.7

51. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 51 Sample Positions in 4:2:0 Digitization Format

52. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 52 HDTV Formats: SIF Source Intermediate Format: SIF Source quality comparable to VCRs Resolutions –525-line system: Y = 360x240 C b =C r = 180x120 –625-Line system: Y = 360x288 C b =C r = 180x114 Worst case bit rate –6.75x10 6 X8+2(1.6875x10 6 x8) = 81Mbps

53. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 53 HDTV Formats: CIF Common Intermediate Format: CIF –Y = 360x288 –Cb = Cr = 180x144 –Progressive Scan –30 Hz 4CIF –Y = 720x576 –Cb = Cr = 360x288 16CIF –Y = 1440x1152 –Cb = Cr = 720x576

54. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 54 HDTV Formats: CIF Quarter CIF: QCIF –Y = 180x144 –Cb = Cr = 90x72 Data Rate –3.375x10 6 X8+2(0.84375x10 6 x8) = 81Mbps

55. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 55 Multimedia Communications Standards and Applications Slide: Courtesy, Hung Nguyen

56. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 56 Sample Positions for SIF and CIF

57. 01/23/2006 Dennis McCaughey, IT 481, Spring 2007 57 Sample Positions for QCIF