Vai alla Home Page About me Courseware Federica Living Library Federica Federica Podstudio Virtual Campus 3D Le Miniguide all'orientamento Gli eBook di Federica La Corte in Rete
 
I corsi di Ingegneria
 
Il Corso Le lezioni del Corso La Cattedra
 
Materiali di approfondimento Risorse Web Il Podcast di questa lezione

Luigi Paura » 2.Data Compression


Summary

  • Information source model
  • Measure of the information: entropy of a discrete random variable
  • Entropy of an information source
  • Conditional Entropy
  • Source Coding Theorem (I Shannon Theorem)
  • Huffman Coding
  • Lempel-Ziv Coding

Reference : Proakis Salehi (II ed.) Cap.4

Information Source Model

Examples of information sources:

Audio-broadcasting System : speech signal

Video-broadcasting System : video signal

Fax transmission system: monochromatic image

Communication System among computers : ASCII symbol
Sequence or sequence of binary symbols

Information Source Model


Information Source Model (next)


Information Source Model (next)


Example of source coding


Example of source coding (next)


Example of source coding (next)

How much memory amount can we save at most?
I Shannon Theorem gives us the answer
The lowest number of symbols to represent “without distortion” (say, distortion-less or noiseless) every source symbol is given by the average amount of information carried by any source symbol.

Measure of the information


Measure of the information (next)


Measure of the information of a discrete random variable


Measure of the information of a discrete random variableĀ  (next)


Measure of the information of a discrete random variable (next)


Measure of the information of a discrete random variable (next)


Measure of the information of a discrete random variable (next)


Entropy of a pair of RV


Entropy of a pair of RV (next)


Entropy of a pair of RV (next)


Entropy of a vector of RV’s


Conditional Entropy


Conditional Entropy (next)


Conditional Entropy (next)


Conditional Entropy (next)


Conditional Entropy (next)


Proprieties of the Entropy


Information rate of a discrete source


Information rate of a discrete memoryless source (DMS)


Information rate of a discrete memoryless source (DMS)


Measure of the information of a DMS


Measure of the information of a DMSĀ  (next)


I materiali di supporto della lezione

Proakis Salehi (II ed.) Cap.4

  • Contenuti protetti da Creative Commons
  • Feed RSS
  • Condividi su FriendFeed
  • Condividi su Facebook
  • Segnala su Twitter
  • Condividi su LinkedIn
Progetto "Campus Virtuale" dell'Università degli Studi di Napoli Federico II, realizzato con il cofinanziamento dell'Unione europea. Asse V - Società dell'informazione - Obiettivo Operativo 5.1 e-Government ed e-Inclusion