Multimedia information representationMultimedia...
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Multimedia information representation Multimedia information representation 1
Transcript of Multimedia information representationMultimedia...
Multimedia information representationMultimedia information representation
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Multimedia information representation
2 2Digitization principles2.2Digitization principles2.2.1 Analog signals2.2.2 Encoder design2 2 3 Decoder design2.2.3 Decoder design
2.3Text2.3.1 Unformatted text2.3.2 Formatted text2.3.2 Formatted text2.3.3 Hypertext
2.4Images2.4.1 Graphicsp2.4.2 Digitized documents2.4.3 Digitized pictures
2.5Audio2.5.1 PCM speech2.5.2 CD-quality audio2.5.3 Synthesized audio
2.6Video2.6.1 Broadcast television2.6.2 Digital video2 6 3 PC id
22.6.3 PC video2.6.4 Video content
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Digitization principles
The conversion of an analog signal into a digital formform
i l dsignal encoder.
signal decoder.
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Signal properties: (a) time-varying analog signal; (b) sinusoidal frequency components;(b) sinusoidal frequency components;
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Signal properties: (c) signal bandwidth examples; (d) effect of a limited bandwidth transmission channel.
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Signal Encoder Design: Circuit ComponentsComponents
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Signal Encoder Design: Associated Waveform Set
Analog Signal
Low Pass Filtered Version
Clock
Output from Sample & Hold
Quantizer Output
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Ali Si l G i D U dAlias Signal Generation Due to Under Samplingp g
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Example 2.1
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Quantization Procedure: Source of Errors
bifbh2 intervalon quantizati
Vq
bitsofnumber where2
2 max == nVq n
DecibelsinRangeDynamic D( )dBlog20
Decibelsin RangeDynamic
minmax10 VVDD
=
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Quantization Procedure: Noise PolarityQuantization Procedure: Noise Polarity
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Example 2.2
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Si l D d D iSignal Decoder Design: Circuit Components
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i l d i i d fSignal Decoder Design: Associated Waveform Set
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F i T fFourier Transform
Multiplyin time
Convolutionin Frequencyin Frequency
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Quantization
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HW
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