IT 327 - Schweber Chap 14 1

Thought of the Day

No pain that we suffer, no trial that we experience is wasted. It ministers to our education, to the development of such qualities as patience, faith, fortitude and humility. All that we suffer and all that we endure, especially when we endure it patiently, builds up our characters, purifies our hearts, expands our souls, and makes us more tender and charitable, more worthy to be called the children of God.

 Elder Orson F. Whitney(1855-1931)

IT 327 - Schweber Chap 14 2

Thought of the Day

Obedience…is a choice between our own limited knowledge and power, and God’s unlimited wisdom and omnipotence.

 Elder L. Tom Perry(Ensign, May 2014, p. 103)

IT 327 - Schweber Chap 14 3

Schweber, Chap 14:TV/Video & Facsimile

TV/Video: A Legacy System Par Excelance

IT 327 - Schweber Chap 14 4

Really OldB&W TV, NTSC (≈1940)Color, NTSC (≈1950)B&W Movies (≈1910)Color Movies (≈1950)

More RecentHDTV (≈2000)MP4 (≈1990)

TV: The Camera

IT 327 - Schweber Chap 14 5

TV: The Screen

IT 327 - Schweber Chap 14 6

525 lines384 pixels/line= 201,600 pixels

30 frames/sec Interleaved from 2 fields per frame

30 f/s * 201,600 pixels/frame = 6,048,000 pixels/sec

TV: Color Standards & Pixels

IT 327 - Schweber Chap 14 7

TV: Color Pixels

IT 327 - Schweber Chap 14 8

TV: The Signal (Time Domain)

IT 327 - Schweber Chap 14 9

Very tight tolerances on timing, frequency

High tolerance for poor signal

TV: The Signal (Frequency Domain)

IT 327 - Schweber Chap 14 10

Video: AM, vestigial sideband Frequency-

multiplexed sub-

carriers

Audio: FM, narrow-band

TV: The Receiver

IT 327 - Schweber Chap 14 11

Just the fax, please

IT 327 - Schweber Chap 14 12

No gray scale: 1 = black, 0 = whiteAt 200 pels/inch and 200 line/inch =

1700 x 2200 = 3.74

Mbits/pageAt 4800 bps =

13 min/pg= impractical

Uses very significant spatial compression

But what if you can’t

compress it?

IT 327 - Schweber Chap 14 13

Andrew Jorgensen; Fall2003 ORR

substitute

Pseudorandom patternCannot be

spatially

compressed12 minutes, then

crashed

Compression

IT 327 - Schweber Chap 14 14

LossyMPEG, MP3, JPG, GIF, MP4, OGGCompression ratios from 2:1 to 1000:1Irreversible loss in quality, data

LosslessZIP, PNG, RAW, BMP, WAV, WMVCompression ratios from 1.1:1 to 2:1Original data not lost and can be completely restored

Methods of compressionMathematicalSpatialTemporal

HDTV@1080 x 1920 p = 2,073,600 pixels/frame; x 3 subpixels = 6,220,800 subpixelsx 60 frames/second x 8 bits/subpixel = 2.986 Gbps (native)The magic of compression

Mathematical Compression

IT 327 - Schweber Chap 14 15

Compression Artifacts

IT 327 - Schweber Chap 14 163.66 MB 27.7 kB = 132x compression

Compression Artifacts

IT 327 - Schweber Chap 14 17

Compression Artifacts

IT 327 - Schweber Chap 14 18

Compression Artifacts

IT 327 - Schweber Chap 14 19

Guy downloads then uploads video to YouTube 1000 times: https://www.youtube.com/watch?v=icruGcSsPp0