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IT 327 - Schweber Chap 141 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)
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IT 327 - Schweber Chap 142 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)
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IT 327 - Schweber Chap 143
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TV/Video: A Legacy System Par Excelance Really Old B&W TV, NTSC (≈1940) Color, NTSC (≈1950) B&W Movies (≈1910) Color Movies (≈1950) More Recent HDTV (≈2000) MP4 (≈1990)
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TV: The Camera
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TV: The Screen 525 lines 384 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
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TV: Color Standards & Pixels
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TV: Color Pixels
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TV: The Signal (Time Domain) Very tight tolerances on timing, frequency High tolerance for poor signal
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TV: The Signal (Frequency Domain) Video: AM, vestigial sideband Frequency- multiplexed sub- carriers Audio: FM, narrow- band
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TV: The Receiver
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Just the fax, please No gray scale: 1 = black, 0 = white At 200 pels/inch and 200 line/inch = 1700 x 2200 = 3.74 Mbits/page At 4800 bps = 13 min/pg = impractical Uses very significant spatial compression
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But what if you can’t compress it? Andrew Jorgensen; Fall 2003 ORR substitute Pseudorandom pattern Cannot be spatially compressed 12 minutes, then crashed
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Compression Lossy MPEG, MP3, JPG, GIF, MP4, OGG Compression ratios from 2:1 to 1000:1 Irreversible loss in quality, data Lossless ZIP, PNG, RAW, BMP, WAV, WMV Compression ratios from 1.1:1 to 2:1 Original data not lost and can be completely restored Methods of compression Mathematical Spatial Temporal HDTV @1080 x 1920 p = 2,073,600 pixels/frame; x 3 subpixels = 6,220,800 subpixels x 60 frames/second x 8 bits/subpixel = 2.986 Gbps (native) The magic of compression
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Mathematical Compression
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Compression Artifacts 3.66 MB27.7 kB = 132x compression
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Compression Artifacts
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Guy downloads then uploads video to YouTube 1000 times: https://www.youtube.com/watch?v=icruGcSsPp0https://www.youtube.com/watch?v=icruGcSsPp0
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